| a novel protein binds a key origin sequence to block replication of an e. coli minichromosome. | a sequence of three tandem repeats of a 13-mer in the replication origin (oric) of e. coli is the highly conserved site of opening of the duplex for initiation of dna synthesis. a protein that binds this sequence has been discovered in e. coli and purified to homogeneity. this novel 33 kd polypeptide behaves as a dimer. binding to the 13-mers is specific and limited to this region. at a ratio of 10-20 monomers per oric plasmid, the binding blocks initiation by preventing the opening of the 13-me ... | 1990 | 2208289 |
| hla-a*0201 complexes with two 10-mer peptides differing at the p2 anchor residue have distinct refolding kinetics. | the immune response to viruses partially depends on the biochemical interaction between viral peptides and histocompatibility molecules. in this study, the refolding of recombinant hla-a*0201 heavy chain and beta 2-microglobulin (beta 2-m) in the presence of peptides from influenza b nucleoprotein (bnp), influenza a matrix protein, and hiv gp120 and their analogues was examined. the plateau value for the amount of refolded complex with three peptides, a 10-mer bnp 85-94 (a86) with alanine substi ... | 1995 | 7529284 |
| amplification of a long sequence that includes a processed pseudogene for elongation factor 2 in the mouse. | quantitative southern blotting analysis has demonstrated that mouse cells contain about 70 copies per haploid genome of a dna sequence related to the gene for elongation factor 2. the restriction maps of seven cosmids that each carry one copy of the ef2-related sequence (mer) and nucleotide sequences of mers were highly conserved among the cosmids. data obtained by such analyses suggest that mers were produced by the integration of one copy of mer derived from poly(a)+ mrna for ef2 into a specif ... | 1990 | 2303263 |
| dynamics of dna polymerase iii holoenzyme of escherichia coli in replication of a multiprimed template. | movements of dna polymerase iii holoenzyme (holoenzyme) in replicating a template multiprimed with synthetic pentadecadeoxynucleotides (15-mers) annealed at known positions on a single-stranded circular or linear dna have been analyzed. after extension of one 15-mer on a multiprimed template, holoenzyme moves downstream in the direction of chain elongation to the next primer. holoenzyme readily traverses a duplex, even 400 base pairs long, to exploit its 3'-hydroxyl end as the next available pri ... | 1985 | 2413035 |
| genetic variability in gibberella fujikuroi and some related species of the genus fusarium based on random amplification of polymorphic dna (rapd). | one of the most important rice pathogens is fusarium moniliforme (perfect stage: gibberella fujikuroi), the causal agent of the super-elongation ("bakanae") disease. thirty-seven strains of this species from different geographical regions were analyzed for their ability to produce gibberellins (ga) and for genetic relatedness by random amplified polymorphic dna (rapd). all ga-producing isolates showed nearly identical rapd patterns using 51 oligonucleotide nona- and deca-mers as arbitrary primer ... | 1995 | 7553937 |
| inactive groel monomers can be isolated and reassembled to functional tetradecamers that contain few bound peptides. | for the first time, it has been shown that groel can be converted from tetradecamers (14-mers) to monomers under conditions commonly used for the preparation of this chaperonin. the essential requirements are the simultaneous presence of nucleotides such as mgatp or mgadp and a solid-phase anion-exchange medium. the monomers that are formed are metastable in that they only reassemble to a small degree in the absence of additives. these results are in keeping with previous studies on high pressur ... | 1995 | 7559433 |
| antisense oligodeoxynucleotides provide insight into mechanism of translation initiation of two sendai virus mrnas. | translation of sendai virus nucleocapsid protein (np) and phosphoprotein (p/c) mrnas in rabbit reticulocyte lysates in the presence of antisense oligodeoxynucleotides (15-20-mers) showed that oligonucleotides having complementarity within the 5' noncoding region of the mrnas blocked translation, oligonucleotides having complementarity within 20 nucleotides upstream from the initiator codon blocked translation only partially, and oligonucleotides complementary to the coding region of mrna had no ... | 1987 | 2438279 |
| cdr molecular localization of possible anti-idiotypic anti-dna antibodies in normal subjects, patients with sle, and sle first-degree relatives. | patients with active systemic lupus erythematosus (sle) with disease worsening or severe flares frequently show very low levels of serum immunoglobulin g (igg) anti-f(ab')2 antibody. anti-f(ab')2 antibody probably represents a polyclonal collection of generic anti-idiotypic antibodies involved in immune homeostasis. we synthesized the entire variable regions of the heavy and light chains (vh and vl) of two monoclonal anti-dna antibodies, v88 and 2a4, as overlapping 7-mers on small polypropylene ... | 1995 | 7602233 |
| evaluation of n-ras oncogene anti-sense, sense and nonsense sequence methylphosphonate oligonucleotide analogues. | we have investigated the potential for using anti-sense non-ionic methylphosphonate oligonucleotide analogues to study the relationship between oncogene expression and maintenance of the transformed phenotype in malignant cells. our results confirmed that the methylphosphonates are resistant to biochemical degradation and are devoid of non-specific toxicity towards cultured human ht29 cells. at low temperature (less than 5 degrees c) both n-ras anti-sense and nonsense analogue 9-mers formed 1:1 ... | 1988 | 2457379 |
| sequence-specific cleavage of rna using chimeric dna splints and rnase h. | to cleave rna molecules using e. coli rnase h in a site-specific manner, a short oligodeoxyribonucleotide (3-5 mer) linked with oligo(2'-o-methyl)ribonucleotide(s) was designed to be used as a dna splint. our model experiments with ribooligomer the splint duplexes (9 mers) and rnase h demonstrated that a tetradeoxynucleotide cluster seems to be sufficient for the enzyme recognition and the short dna-containing splint directs a unique cleavage of rna by rnase h. the method could be applied to lon ... | 1988 | 2465538 |
| transcriptional enhancer activity of hr5 requires dual-palindrome half sites that mediate binding of a dimeric form of the baculovirus transregulator ie1. | the hr5 enhancer element stimulates early viral transcription and may function as an origin of dna replication for autographa californica nuclear polyhedrosis virus (acmnpv). the smallest functional unit of hr5 is a 28-bp repeat consisting of an imperfect palindrome (28-mer). to identify essential sequences and examine the molecular basis of hr5 activity, the effects of site-directed mutations on transcriptional enhancement by the 28-mer and binding of the acmnpv transregulator ie1 were investig ... | 1995 | 7636981 |
| isolation of a cdna clone for the human lysosomal proteinase cathepsin b. | the cysteine proteinase cathepsin b is one member of the lysosomal acid hydrolases. based on the peptide sequence of rat liver cathepsin b, an oligonucleotide mixture containing 128 different 17-mers was synthesized and used as a probe to screen adult and fetal human liver cdna libraries. a recombinant clone with a 1540-nucleotide insert was identified from the fetal library, and dna sequence analysis confirmed that this clone encodes human cathepsin b. the clone, designated pcb-1, has sequences ... | 1986 | 3010323 |
| multiple hla a11-restricted cytotoxic t-lymphocyte epitopes of different immunogenicities in the epstein-barr virus-encoded nuclear antigen 4. | epstein-barr virus (ebv), a ubiquitous herpesvirus, induces potent hla class i-restricted cytotoxic t-lymphocyte (ctl) responses. analyses of target antigen choice have shown that the very strong ctl responses which are often observed through the hla a11 allele map are due almost entirely to a single transformation-associated ebv protein, the nuclear antigen ebna4. here, we sought to determine the number and relative immunogenicities of hla a11-restricted epitopes within this 938-amino-acid prot ... | 1993 | 7679748 |
| comparison of serum antibody reactivities to a conformational and to linear antigenic sites in the external envelope glycoprotein of simian immunodeficiency virus (sivmac) induced by infection and vaccination. | forty-six overlapping peptides (20-mers) representing the amino acid sequence of the external envelope glycoprotein of simian immunodeficiency virus (sivmac; 32h isolate) were used to investigate linear antigenic sites recognized by antibodies in sera from siv-infected rhesus macaques and in animals vaccinated with formalin-inactivated siv. the reactivity to a discontinuous antigenic site as defined by a neutralizing monoclonal antibody was measured by competition assay. the majority of infected ... | 1993 | 7685372 |
| rheumatoid factors from patients with rheumatoid arthritis react with tryptophan 60 and 95, lysine 58, and arginine 97, on human beta 2-microglobulin. | to define precise epitopes on human beta 2-microglobulin (beta 2m) reacting with polyclonal igm rheumatoid factors (rf) from patients with rheumatoid arthritis (ra). | 1993 | 7686371 |
| peptidyl transferase inhibition by the nascent leader peptide of an inducible cat gene. | the site of ribosome stalling in the leader of cat transcripts is critical to induction of downstream translation. site-specific stalling requires translation of the first five leader codons and the presence of chloramphenicol, a sequence-independent inhibitor of ribosome elongation. we demonstrate in this report that a synthetic peptide (the 5-mer) corresponding to the n-terminal five codons of the cat-86 leader inhibits peptidyl transferase in vitro. the n-terminal 2-, 3-, and 4-mers and the r ... | 1993 | 7690023 |
| comparative inhibition of ras p21 protein synthesis with phosphorus-modified antisense oligonucleotides. | a rabbit reticulocyte lysate translation assay was used to quantitatively compare a series of antisense oligodeoxyribonucleotides (11-mers) having different internucleoside linkages and various degrees of complementarity (100-80%) with the start codon and downstream 8 bases of balb-ras p21 mrna. the oligomers had either contiguous phosphodiester, or alternating methylphosphonate-phosphodiester, or contiguous methylphosphonate, or contiguous phosphorothioate linkages. under the conditions used fo ... | 1989 | 2679622 |
| optimal conditions for hybridization with oligonucleotides: a study with myc-oncogene dna probes. | we present a study on the refinement of filter-hybridization conditions for a series of synthetic oligonucleotides in the range from 17 to 50 base residues in length. experimental conditions for hybridization and the subsequent washing steps of the filter were optimized for different lengths of the synthetic oligonucleotides by varying the formamide concentration and washing conditions (temperature and monovalent cation concentration). target dna was immobilized to the nitrocellulose filter with ... | 1988 | 3291638 |
| [an improved chemico-enzymatic method of synthesizing long dna segments]. | a simple and economy method of the biochemical assembling of long double-stranded dna segments is described. a single-stranded polydeoxynucleotide 122 bases long representing a fragment of synthetic gene of human beta-interferon was assembled from three synthetic fragments 36 (two) and 50 bases long on four complementary 12-mers as templates. this single-stranded polynucleotide was converted, in the presence of dna polymerase 1 and a 12-meric primer, in to the full-length double-stranded dna (th ... | 1988 | 3382431 |
| processivity and kinetics of the reaction of exonuclease i from escherichia coli with polydeoxyribonucleotides. | the enzyme exonuclease i from escherichia coli hydrolyzes successive nucleotides from the 3'-termini of single-stranded deoxyribonucleotide homopolymers. when the reaction is stopped after partial hydrolysis, only intact starting material and small oligomers can be isolated. the distribution of oligomeric products varies with the base composition of the polymer but the largest oligomer that can be isolated from the reaction of exonuclease i with homopolymers of deoxyadenylate, deoxythymidylate, ... | 1986 | 3519606 |
| a study of side reactions occurring during synthesis of oligodeoxynucleotides containing o6-alkyldeoxyguanosine residues at preselected sites. | as part of our studies on the molecular mechanisms of mutation by carcinogens we have synthesized 12 oligonucleotides (15-mers) containing an o6-alkylguanine residue at a preselected position for use as primers in the enzymatic synthesis of biologically active dna. ten of these oligonucleotides are derived from a minus strand sequence carrying the modified nucleotide in the third codon of gene g of bacteriophage phi x174 dna. two others are derived from plus strand sequences carrying the modific ... | 1987 | 3607028 |
| group-specific differentiation between high- and low-risk human papillomavirus genotypes by general primer-mediated pcr and two cocktails of oligonucleotide probes. | in recent years, general primer-mediated pcr assays have been developed to detect a broad spectrum of human papillomavirus (hpv) genotypes. in this study, a procedure enabling a simple group-specific differentiation of high-risk (hpv-16, -18, -31, -33, -35, -39, -45, -51, -52, -54, -56, and -58) and low risk (hpv-6, -11, -34, -40, -42, -43, and 44) hpvs following an hpv general primer-mediated (gp5+/gp6+) pcr is presented. by computer-assisted sequence analysis, oligonucleotides (30-mers) specif ... | 1995 | 7790457 |
| dna sequencing: modular primers for automated walking. | here we describe our progress in the development of the technology of dna sequencing by primer walking based on the modular primer approach, which eliminates the primer synthesis bottleneck. modular primers are assembled from 5-mers, 6-mers, or 7-mers selected from a presynthesized library of as few as 1000 oligonucleotides. this technology is expected to reduce the time per walk by a factor of 20 to 50, and the cost of dna sequencing by a factor of 5 to 15. both time and expense will be saved n ... | 1994 | 7818910 |
| peptide mapping of bovine t-cell epitopes for the 38 kda tuberculosis antigen. | mycobacterium bovis infection in cattle continues to be a problem in several regions, partly due to inadequate diagnostic tests. the aim of this study was to use an experimental model of the natural disease to identify t-cell epitopes from the mycobacterial 38 kda antigen as potentially specific diagnostic reagents. a panel of overlapping synthetic peptides (16-mers with a five-residue overlap) were produced from the published amino acid sequence. it was found that peripheral blood lymphocytes f ... | 1995 | 7824893 |
| phosphorothioate oligonucleotides inhibit the replication of lentiviruses and type d retroviruses, but not that of type c retroviruses. | phosphorothioate analogs of oligodeoxynucleotides at a concentration of 2 microm protected himalayan tahr cells from infection by caprine arthritis encephalitis virus (caev) and equine dermis cells from infection by equine infectious anemia virus (eiav). the characteristics of this inhibition against these lentiviruses are similar to those previously described for the inhibition of hiv-1 in ath8 cells [17]. thus, the 28-mer homo-oligomer of cytidine [s-(dc)28] was at least as effective as three ... | 1994 | 7826217 |
| site-specifically modified oligodeoxyribonucleotides as templates for escherichia coli dna polymerase i. | oligodeoxyribonucleotides with site-specific modifications have been used as substrates for escherichia coli dna polymerase i holoenzyme and klenow fragment. modifications included the bulky guanine-8-aminofluorene adduct and a guanine oxidation product resembling the product of photosensitized dna oxidation. by a combination of primers and "nick-mers", conditions of single-strand-directed dna synthesis and nick-translation could be created. our results show that the polymerase can bypass both t ... | 1985 | 3887400 |
| oligonucleotide probes for bacterial acylcarrier protein genes. | using a recently-introduced rapid manual method, we have synthesized a family of thirty six individual oligonucleotides of unique sequence (18-mers), which correspond to the conserved amino acid sequence, gadsld, found at the 4'-phosphopantetheine-binding site of the acylcarrier component of bacterial and plant fatty acid synthases. hybridisation of each of these oligonucleotides to southern blots of restricted streptomyces erythreus dna under stringent conditions showed that (i) only two probes ... | 1985 | 4084606 |
| isolation and characterization of a cdna clone for the amino-terminal portion of the pro-alpha 1(ii) chain of cartilage collagen. | we have isolated a cdna clone (prcol 2) which is complementary to the 5'-terminal portion of the rat pro-alpha 1(ii) chain mrna. a synthetic oligonucleotide was used both as a primer for cdna synthesis and as a probe for screening a cdna library. the probe was a mixture of sixteen 14-mers deduced from an amino acid sequence present in the amino-terminal telopeptide of the rat cartilage alpha 1(ii) chain. this primer was chosen so that the resulting cdna would contain the sequence of the 5' end o ... | 1984 | 6094525 |
| use of complementary dna oligomers to probe trp leader transcript secondary structures involved in transcription pausing and termination. | dna oligomers were synthesized that are perfectly complementary to different segments of the tryptophan (trp) operon leader transcript. these 15 nucleotide long oligomers were used as probes of the involvement of transcript secondary structures in two processes: transcription pausing at the pause site located near base pair 90 in the leader region, and transcription termination at the attenuator. the 15-mers were complementary to the four segments of the trp leader transcript which have been sho ... | 1984 | 6201827 |
| immunological correspondence between arthropod hemocyanin subunits. i. scorpion (leiurus, androctonus) and spider (eurypelma, cupiennius) hemocyanin. | the hemocyanins of the scorpions leiurus quinquestriatus and androctonus australis, the tarantula eurypelma californicum (all 24-mers), and the lycosid spider cupiennius salei (dodecamer) were dissociated into subunits, the subunits isolated and studied by two-dimensional immunoelectrophoresis for interspecific cross-reactivities. androctonus hemocyanin yielded a pattern of 8 subunit types in agreement with data from lamy et al. (1979, arch. biochem. biophys. 193, 140-149). leiurus hemocyanin is ... | 1984 | 6479892 |
| isolation of intact polysomes from mechanically dehulled developing grain. | a rapid method for obtaining large quantities of developing groats suitable for the isolation of highly intact polysomes has been developed. developing spikelets were harvested directly from oat panicles into liquid nitrogen and then quickly passed through a dehuller. chaff was removed by air aspiration and the resultant groats were collected directly back into liquid nitrogen. approximately 250 g of groats could be isolated each man-hour by the above method. in comparison, only 10 g of endosper ... | 1983 | 6650835 |
| size fractionation of thermal aggregates of immunoglobulin g. | purified pooled human immunoglobulin g (igg) in solution, when extensively heated at high temperatures or for long periods, irreversibly aggregates and insoluble precipitates result. however, when igg solutions are heated in the temperature range 55-65 degrees c for more limited time periods, soluble turbid polydispersed aggregate mixtures are obtained. gel filtration of such aggregate mixtures on calibrated bio-rad a-150m columns demonstrates a continuous size distribution from dimers to aggreg ... | 1983 | 6660490 |
| identification of antibody epitopes in the cb-11 peptide of bovine type ii collagen recognized by sera from arthritis-susceptible and -resistant rhesus monkeys. | sera from eight rhesus monkeys that had been immunized with native bovine type ii collagen were tested for antibodies to cyanogen bromide peptides (cb peptides) of type ii collagen by western blotting. the monkeys produced igg antibodies to a number of different cb peptides, with five out of eight animals producing antibodies to the cb-11 peptide (four arthritic, one non-arthritic). antibody epitopes on the cb-11 peptide of bovine type ii collagen recognized by these sera were investigated by ep ... | 1994 | 7514515 |
| sphingosine inhibits the synthesis of rna primers by primase in vitro. | we have previously shown the presence of sphingomyelin and sphingomyelinase in cell nuclei, suggesting that they may play a role in the intranuclear production of sphingosine, a potent bioactive molecule modulating diverse cellular functions. in the present study, the direct effects of sphingosine (c18:1) on the activity of dna replication/repair polymerases were studied in vitro. sphingosine had no effect on dna polymerases alpha and beta and slightly inhibited dna polymerases gamma, delta, and ... | 1994 | 7519054 |
| inducible nitric oxide synthase in human lymphomononuclear cells activated by synthetic peptides derived from extracellular matrix proteins. | synthetic peptides with sequences present in extracellular matrix proteins are capable of causing the expression of the inducible form of nitric oxide synthase (inos), detected by immunocytochemistry, and the release of no by human lymphomononuclear cells incubated in their presence. active peptides are 15-mers containing a characteristic 2-6-11 motif in which the amino acid residue at position 2 is leu, ile, val, gly, ala or lys; the residue at position 6 is always pro; and residue 11 is glu or ... | 1995 | 7528687 |
| src-homology 2 (sh2) domain ligation as an allosteric regulator: modulation of phosphoinositide-specific phospholipase c gamma 1 structure and activity. | phosphoinositide-specific phospholipase c gamma 1 (pi-plc gamma 1) catalyses the hydrolysis of ptdins(4,5)p2 to generate the second messengers diacylglycerol and ins(1,4,5)p3. pi-plc gamma 1, an src-homology 2/3 (sh2/sh3)-domain-containing enzyme, is activated in response to growth-factor-induced tyrosine phosphorylation, and, in vivo, is translocated from the cytosol to the particulate cell fraction. here we report the bacterial expression of rat brain pi-plc gamma 1 under the control of the t7 ... | 1995 | 7531435 |
| molecular weight and kinetic parameters of dna undergoing pulsed field gel electrophoresis. | functions relating dna size to reorientation time (tr) should improve the theoretical basis to design pulsed field gel electrophoresis experiments. we initially developed a quantitative approach to calculate tr based on kinetic data: dna migration per pulse (d), and pulse time duration. using this procedure with some modifications and a computer controlled pulsed field electrophoresis switching unit, we obtained the trs of several dna molecules of known molecular weight and analyzed the function ... | 1994 | 7919812 |
| subunit composition of hemocyanins of callinectes sapidus: phenotypes from naturally hypoxic waters and isolated oligomers. | the electrophoretic banding pattern of hemocyanin monomers in blue crabs caught in natural waters indicate that the phenotypes associated with normoxia or hypoxia in the laboratory can also be found in those conditions in nature. page of pure fractions of 1 x 6-mers isolated by hplc revealed only the two invariant plus one slightly variable band. in contrast, the 2 x 6-mer fraction contained those three plus the three highly variable bands. these results support the hypothesis formulated by earl ... | 1994 | 7953073 |
| localization of hla-a2.1-restricted t cell epitopes in the circumsporozoite protein of plasmodium falciparum. | localization of human mhc class i-restricted t cell epitopes in the circumsporozoite (cs) protein of the human parasite plasmodium falciparum is an important objective in the development of antimalarial vaccines. to this purpose, we synthesized a series of overlapping synthetic 20-mer peptides, spanning the entire sequence of the 7g8 cs molecule except for the central repeat b cell domain. the p.f.cs peptides were first tested for their ability to bind to the human mhc class i hla-a2.1 molecule ... | 1995 | 7535817 |
| thromboembolic disease due to thermolabile conformational changes of antithrombin rouen-vi (187 asn-->asp) | a new variant of antithrombin (rouen-vi, 187 asn-->asp) with increased heparin affinity was shown to have normal inhibitory activity which decreased slowly at 4 degrees c and rapidly at 41 degrees c. on electrophoresis the freshly isolated variant had an anodal shift relative to native antithrombin due to the mutation. a further anodal transition occurred after either prolonged storage at 4 degrees c or incubation at 41 degrees c due to the formation of a new inactive uncleaved component with pr ... | 1994 | 7989582 |
| irradiated sporozoite vaccine induces hla-b8-restricted cytotoxic t lymphocyte responses against two overlapping epitopes of the plasmodium falciparum sporozoite surface protein 2. | vaccines designed to protect against malaria by inducing cd8+ cytotoxic t lymphocytes (ctl) in individuals of diverse hla backgrounds must contain multiple conserved epitopes from various preerythrocytic-stage antigens. plasmodium falciparum sporozoite surface protein 2 (pfssp2) is considered an important antigen for inclusion in such vaccines, because cd8+ ctl against the p. yoelii ssp2 protect mice against malaria by eliminating infected hepatocytes. to develop pfssp2 as a component of malaria ... | 1995 | 7595214 |
| open complex formation by dnaa initiation protein at the escherichia coli chromosomal origin requires the 13-mers precisely spaced relative to the 9-mers. | the 245 bp chromosomal origin, oric, of escherichia coli contains two iterated motifs. three 13-mers tandemly repeated at one end of the origin and four 9-mers in a nearby segment of oric are highly conserved in enteric bacteria, as is the distance separating these two sequence clusters. mutant origins were constructed with altered spacing of the 9-mers relative to the 13-mers. loss or addition of even a single base drastically reduced replication, both in vivo and in vitro. spacing mutant origi ... | 1994 | 8022267 |
| identification of a band-3 binding site near the n-terminus of erythrocyte membrane protein 4.2. | protein 4.2 (p4.2) is a major component of the erythrocyte plasma membrane accounting for approx. 5% of total membrane protein. the major membrane binding site for p4.2 is contained within the cytoplasmic domain of band 3 (cdb3), although the precise location of the cdb3 binding site is not known. to identify the cdb3 binding site, we used synthetic p4.2 peptides (15-mers) that spanned the entire 721-amino-acid large isoform of p4.2, and determined the binding of these peptides to cdb3 in an in ... | 1995 | 7626035 |
| o6-methylguanine-induced replication blocks. | the ability of klenow polymerase i, phage t7 polymerase (sequenase), human polymerase alpha, and human polymerase beta to synthesize past (bypass) o6-methylguanine (o6-meg) lesions was studied in the presence of mgcl2 and mncl2. an end-labeled 16-mer primer was annealed to the 3' end of gel-purified oligodeoxyribonucleotide templates (45-mers), each containing a single o6-meg in place of one g in the sequence -g1g2cg3g4t-. extension products were analyzed by denaturing polyacrylamide gel electro ... | 1995 | 7634403 |
| cloning and characterization of an autonomous replication sequence from coxiella burnetii. | a coxiella burnetii chromosomal fragment capable of functioning as an origin for the replication of a kanamycin resistance (kanr) plasmid was isolated by use of origin search methods utilizing an escherichia coli host. the 5.8-kb fragment was subcloned into phagemid vectors and was deleted progressively by an exonuclease iii-s1 technique. plasmids containing progressively shorter dna fragments were then tested for their capability to support replication by transformation of an e. coli pola strai ... | 1994 | 8071197 |
| transport of phosphorothioate oligonucleotides in kidney: implications for molecular therapy. | the systemic administration of phosphorothioated antisense oligonucleotides has been demonstrated to be an effective strategy for the control of gene expression. because previous studies have suggested both hepatic and renal accumulation of systemically administered oligonucleotides, we explored whether the kidney might be a site of free dna transport. [32p]-phosphorothioate oligonucleotides (20 mers) were excreted in urine but cleared at only 30% of glomerular filtration rate. plasma clearance ... | 1995 | 7637275 |
| xrep, a plasmid-stimulating x chromosomal sequence bearing similarities to the bk virus replication origin and viral enhancers. | the human x chromosome-linked fragment, "xrep," was sequenced because it exerts a positive effect on plasmid growth in both e. coli and saccharomyces cerevisiae. the sequence revealed three features similar to the human bk virus replication origin: xrep has a true palindrome, cctcc(t)3cctcc, which is similar to "true" palindrome-like sequences found at the replication origins of polyoma [cctc(t/c)10ctcc], bk [cctc(a/g)8cctcc] and sv40 [cctcc(a)6gcctcc] viruses. twenty nucleotides away from the t ... | 1986 | 3025813 |
| the effects of pregnancy on the mouse thymic epithelium. | changes in the murine thymus during pregnancy were studied using immunocytochemistry with monoclonal antibodies against thymic epithelial, neuroendocrine, and thymulin-producing cells, fibroblasts, blood vessels and connective tissue components. extensive alterations occur in mid-pregnancy. the medulla was greatly enlarged in the involuted thymus, and there were greater numbers of epithelial cells. these epithelial cells had an altered distribution forming large structures surrounding spherical ... | 1994 | 8111839 |
| cationic liposomes mediated delivery of antisense oligonucleotides targeted to hpv 16 e7 mrna in caski cells. | the "high risk" types 16 and 18 of human papillomavirus (hpv) are involved in the etiology of genital squamous cell carcinoma. the early genes 6 and 7 (e6-e7) of these viruses code for the major transforming proteins, capable of inducing cell transformation alone or acting synergistically with other oncogenes. antisense oligonucleotides, recently applied to inhibit the functions of a number of cellular and viral proteins, might provide the basis for a new therapeutic strategy against hpv-induced ... | 1994 | 8147581 |
| cloning of macromomycin apoprotein gene from streptomyces macromomyceticus by use of 50-mer deoxynucleotide probes. | a mixed probe consisting of two synthetic deoxynucleotides (52 and 54 mers referred to as 50-mer) with arbitrarily chosen c or g for the third letters was prepared based on the amino acid sequences no. 31-48 and no. 72-90 of macromomycin (mcm) apoprotein and successfully used to clone the mcm apoprotein gene. digestion with sph i of total dna of mcm-producing streptomyces macromomyceticus m480-m1 yielded a 2.6-kb fragment that hybridized strongly to the probes. the hybridized probe was stable to ... | 1988 | 3056895 |
| cytosine methylation does not affect binding of transcription factor sp1. | dna methylation may be a component of a multilevel control mechanism that regulates eukaryotic gene expression. we used synthetic oligonucleotides to investigate the effect of cytosine methylation on the binding of the transcription factor sp1 to its target sequence (a g + c-rich sequence known as a "gc box"). concatemers of double-stranded 14-mers containing a gc box successfully competed with the human metallothionein iia promoter for binding to sp1 in dnase i protection experiments. the prese ... | 1988 | 3281160 |
| the use of arbitrary primers and the rades method for the rapid identification of developmentally regulated genes in trypanosomes. | biological processes, such as the cell-division cycle, differentiation and development, are driven by changes in gene expression. short oligodeoxyribonucleotide primers (10-mers) of arbitrary sequence are currently used in the polymerase chain reaction (pcr) to generate genomic fingerprints (rapds) for the characterisation and differentiation of organisms and for mapping loci of interest. since the products of such reactions are generally less than 1 kb in size, the use of arbitrary primers on c ... | 1994 | 8163175 |
| interactions of psoralen-derivatized oligodeoxyribonucleoside methylphosphonates with vesicular stomatitis virus messenger rna. | the ability of oligonucleotides to interact selectively with their targets is an important consideration in the design of antisense oligonucleotides. this is especially important in the case of antisense oligomers, such as psoralen-derivatized oligomers, which can irreversibly bind to their targets. we have studied the interactions of a series of psoralen-derivatized antisense oligonucleoside methylphosphonates with the mrnas of vesicular stomatitis virus (vsv), mrnas that have a high degree of ... | 1994 | 7734937 |
| non-sequence-specific antimalarial activity of oligodeoxynucleotides. | the effects of exogenously applied oligodeoxynucleotides on plasmodium falciparum proliferation was investigated. a fluorescence-activated cell sorter assay was employed to measure parasitemia after administration of either phosphodiester or phosphorothioate oligodeoxynucleotides. we report sequence-independent antimalarial activity preferentially with phosphorothioate congeners with ic50 values in the 1-2 microm range. phosphorothioate oligodeoxynucleotides which were antisense, sense or nonsen ... | 1994 | 8183311 |
| recombinant pulmonary surfactant protein d. post-translational modification and molecular assembly. | pulmonary surfactant protein d (sp-d) is a member of a family of collagenous c-type lectins that includes the serum mannose binding proteins and surfactant protein a. recent studies have shown that rat sp-d (rsp-d) molecules are assembled as tetramers of trimeric subunits (12 mers) and that dodecamers can participate in higher orders of molecular assembly involving interactions of the amino-terminal peptide domains. in order to further study the assembly of sp-d in vitro, chinese hamster ovary k ... | 1994 | 8195236 |
| heteroduplex molecules formed between allelic sequences cause nonparental rapd bands. | primers (10-mers) of random sequence were used to amplify rapd bands from genomic dna of an f1 strain of flax rust (melampsora lini) and its two parent strains. one primer out of 160 tested was unusual in that it amplified a product from f1 dna that was not amplified from either parental dnas. the same primer also generated two rapd bands that segregated as codominant alleles amongst f2 progeny. the nonparental band was only generated from dnas of f2 individuals that were heterozygous for these ... | 1994 | 8202363 |
| inhibition of hepatitis b virus surface gene expression by antisense oligodeoxynucleotides in a human hepatoma cell line. | we have studied the inhibitory effect of antisense oligodeoxynucleotides on the expression of hepatitis b virus surface antigens. human hepatoma cell line plc/prf/5 harbors several integrated copies of the hbv genome and produces and secretes hepatitis b virus surface antigen (hbsag) to the medium. synthetic antisense oligodeoxynucleotides complementary to various regions of the surface antigen gene were synthesized and their ability to block its expression was tested. oligodeoxynucleotides (17- ... | 1993 | 8206172 |
| iontophoretic delivery of oligonucleotide derivatives into mouse tumor. | oligodeoxyribonucleotides (22-mers) were delivered through the skin of c3h mice in the region of a mammary gland tumor by means of iontophoresis. it was shown that the oligonucleotides enter the tumor, cross it, and reach all mouse organs. electrophoretic analysis of the oligonucleotide extracted from tumor showed that the compounds were delivered in the tissue in the intact state. | 1994 | 7734944 |
| identification of a binding site on retinal transducin alpha for the phosphodiesterase inhibitory gamma subunit. | transducin alpha (t alpha) activates retinal rod cyclic gmp phosphodiesterase (pde) by interacting with and removing the inhibitory pde gamma subunit. a t alpha-pde gamma complex can be isolated in vitro, and our previous work [morrison, rider and takemoto (1987) febs lett. 222, 266-270; morrison, cunnick, oppert and takemoto (1989) j. biol. chem. 264, 11671-11681] has identified a region of pde gamma, residues 24-45, that binds to t alpha. the c-terminal region of pde gamma is the site that int ... | 1994 | 8280114 |
| escherichia coli fis and dnaa proteins bind specifically to the nrd promoter region and affect expression of an nrd-lac fusion. | the escherichia coli nrd operon contains the genes encoding the two subunits of ribonucleoside diphosphate reductase. the regulation of the nrd operon has been observed to be very complex. the specific binding of two proteins to the nrd regulatory region and expression of mutant nrd-lac fusions that do not bind these proteins are described. a partially purified protein from an e. coli cell extract was previously shown to bind to the promoter region and to regulate transcription of the nrd operon ... | 1994 | 8288532 |
| inhibition of human interferon-gamma expression by antisense oligodeoxynucleotides. | we investigated 12 antisense oligodeoxynucleotides, complementary to different regions of the human interferon-gamma (huifn-gamma) gene, for their ability to inhibit huifn-gamma production in cultures of single donor total leukocytes or lymphocytes (95% purity). out of seven oligomers, specific for a sequence including the translation initiation codon, 15 to 21 nucleotides long, the one resulting in the greatest inhibition was the 16-mer. an inhibitory effect of 90% could be achieved when the ol ... | 1994 | 8301213 |
| immunospecific reduction of antioligonucleotide antibody-forming cells with a tetrakis-oligonucleotide conjugate (ljp 394), a therapeutic candidate for the treatment of lupus nephritis. | a discrete tetravalent conjugate, 7a (ljp 394), consisting of four oligonucleotides attached to a common carrier or platform was prepared. single-stranded oligonucleotide 20-mers consisting of alternating deoxycytidine-deoxyadenosine nucleotides, (ca)10, were attached to a tetrabromoacetylated platform by displacement with sulfhydryl-terminated linkers. the tetrabromoacetylated platform 3a was synthesized in three steps using triethylene glycol bis-(chloroformate). the single-stranded conjugate ... | 1995 | 7783145 |
| purification and characterization of recombinant pea-seed ferritins expressed in escherichia coli: influence of n-terminus deletions on protein solubility and core formation in vitro. | plant ferritin subunits are synthesized as precursor molecules; the transit peptide (tp) in their nh2 extremity, responsible for plastid targeting, is cleaved during translocation to this compartment. in addition, the n-terminus of the mature subunit contains a plant-specific sequence named extension peptide (ep) [ragland, briat, gagnon, laulhère, massenet, and theil, e.c. (1990) j. biol. chem. 265, 18339-18344], the function of which is unknown. a novel pea-seed ferritin cdna, with a consensus ... | 1995 | 7826338 |
| conformational changes and in vitro core-formation modifications induced by site-directed mutagenesis of the specific n-terminus of pea seed ferritin. | plant ferritin has a three-dimensional structure predicted to be very similar to that of animal ferritin. it has, however, an additional specific sequence of 24 amino acids at its n-terminus named extension peptide (ep). in order to determine precisely the interactions between ep and other domains of the pea seed ferritin subunit, three point mutations were performed. the mutated residues were chosen by three-dimensional computer modelling of the pea seed ferritin subunit structure [lobréaux, ye ... | 1995 | 7848297 |
| endonuclease iii interactions with dna substrates. 1. binding and footprinting studies with oligonucleotides containing a reduced apyrimidinic site. | the binding of endonuclease iii from escherichia coli to damaged dna has been studied using gel shift and footprinting assays. oligonucleotides containing a reduced apyrimidinic (ap) site were used since reduction of the ap site blocks the beta-elimination reaction catalyzed by the enzyme and yields a noncleavable substrate. the kobs for a 13-mer carrying a centrally located reduced ap site is (2 x 10(6)-(2 x 10(7) m-1, while the kobs for a 13-mer with no damage is (4.5 x 10(3)-(3.2 x 10(4) m-1 ... | 1995 | 7873533 |
| phosphorothioate-phosphodiester oligonucleotide co-polymers: assessment for antisense application. | efforts have been made to reduce the disadvantages associated with the natural oligonucleotides (all-po) for antisense application by introducing phosphorothioate (ps) linkages into the molecule. a series of such oligodeoxynucleotide copolymers (17-mers) complementary to the coding region of the rabbit beta-globin mrna, and containing different proportions and arrangements of po and ps bonds, were synthesized and tested for their protein-binding properties, nuclease stability in vitro, hybridizi ... | 1993 | 8386513 |
| ancestral, mammalian-wide subfamilies of line-1 repetitive sequences. | analysis of the 3'-ends of approximately 900 separate human line-1 (l1) elements from primates revealed 47 contiguous but distinct subfamilies with the l1 family. eight previously described medium reiteration frequency sequences (mers) were found to be parts of ancient l1 untranslated 3'-regions which show little or no sequence similarity to the presently active l1 3'-end. some of the major changes in 3'-end sequence can be explained by recombination events between different l1 repeats as well a ... | 1995 | 7877164 |
| in vitro dissociation of self-assembly of three chaperonin 60s: the role of atp. | a comparative study has investigated the in vitro dissociation and self-assembly of chaperonin 60 14-mers isolated from e. coli (groel), yeast mitochondria and pea chloroplasts. in all cases mg2+ inhibits, and low temperature stimulates, the urea-induced dissociation. atp or adp in the presence of mg2+ enhance the dissociation of the chaperonins. re-assembly of the 14-mers from their monomers shows different efficiencies between the three proteins. in all cases, however, self-assembly is stimula ... | 1995 | 7890040 |
| in vivo and in vitro replication consequences of stereoisomeric benzo[a]pyrene-7,8-dihydrodiol 9,10-epoxide adducts on adenine n6 at the second position of n-ras codon 61. | benzo[a]pyrene-7,8-dihydrodiol 9,10-epoxide (bpde), a metabolite of the widespread environmental pollutant benzo[a]pyrene, is a mutagenic in both bacterial and mammalian systems. toward understanding the mutagenic effects of different stereoisomers of bpde at specific sites in dna, six stereochemically defined bpde adducts were constructed on adenine n6 at position 2 of the human n-ras 61 codon within an 11-base oligonucleotide fragment. both the nonadducted and bpde-adducted n-ras 61 11-mers we ... | 1995 | 7890605 |
| in vitro reconstitution of the 24-meric e2 inner core of bovine mitochondrial branched-chain alpha-keto acid dehydrogenase complex: requirement for chaperonins groel and groes. | we have investigated the in vitro reconstitution of the 24-meric inner core domain (e2c) of the transacylase (e2) component of bovine branched-chain alpha-keto acid dehydrogenase complex. the yield of recombinant e2c (amino acid residues 161-421 of bovine e2) expressed in escherichia coli was markedly increased by fusing the bacterial maltose-binding protein (mbp) to the amino terminus of bovine e2c. following factor xa digestion to remove the mbp moiety, e2c was completely unfolded in 4.5 m gua ... | 1994 | 7913832 |
| modulation of lysyl oxidase activity toward peptidyl lysine by vicinal dicarboxylic amino acid residues. implications for collagen cross-linking. | the substrate specificity of lysyl oxidase has been explored with synthetic oligopeptides. kcat/km increased with increasing peptide length in ac-(gly)n-lys-(gly)n-conh2 (n = 1-5). using 11-mers as the standard peptide length, glu immediately n-terminal to lys increased kcat/km 8.8-fold over that for the -lys-glu- sequence and 4.9-fold over the glutamate-free control. kinetic constants were significantly less perturbed when glu was 2 or more residues distant from lys. replacement of glu in -glu- ... | 1994 | 7915281 |
| 2-chloro-2'-deoxyadenosine monophosphate residues in dna enhance susceptibility to 3'-->5' exonucleases. | 2-chloro-2'-deoxyadenosine triphosphate, a purine nucleotide analogue and potent antileukaemic agent, was incorporated into double-stranded 36-mers in place of datp to investigate the effects of 2-chloroadenine (clade) on dna polymerase-associated 3'-->5' exonuclease activity. clade residues within one strand of duplex dna did not inhibit exonuclease activity; on the contrary, clade-containing minus strands were digested to a greater extent than was control dna in the absence of deoxyribonucleos ... | 1994 | 7916566 |
| synthesis, cloning and expression of a synthetic gene for high potential iron protein from chromatium vinosum. | a synthetic gene encoding the peptide sequence for the low molecular weight (m(r) approximately 9600 da) high-potential iron protein (hipip) from the photosynthetic bacterium chromatium vinosum has been constructed by shotgun ligation of twelve complimentary oligonucleotides varying in size from 42-mers to 48-mers. after cloning the gene into a pet-21d(+) vector, expression of holoprotein in yields of 35 mg/liter of culture was obtained following induction with isopropyl-beta-d-thiogalactoside ( ... | 1993 | 7916611 |
| identification of the horse epidermal growth factor (egf) coding sequence and its use in monitoring egf gene expression in the endometrium of the pregnant mare. | the pcr technique and highly degenerate oligonucleotide primers were used to amplify a 282 bp fragment of the horse (equus caballus) epidermal growth factor (egf) cdna. the clone corresponded to 94 amino acids of the egf precursor molecule. the deduced amino acid sequence of the 53 residue egf mitogenic peptide within the precursor sequence showed 60-70% identity with five other published egf sequences. the pcr cdna fragment hybridized to a 4.9 kb transcript in horse kidney and endometrial rna w ... | 1994 | 7916972 |
| site-specific mutagenesis by a propanodeoxyguanosine adduct carried on an m13 genome. | the spectrum of mutations induced upon in vivo replication of an m13 genome containing a site-specifically located propanodeoxyguanosine (pdg) adduct was determined. pdg was used as a model for the major deoxyguanosine adduct produced on reaction of dna with the endogenous genotoxin malondialdehyde. pdg was introduced at position 6256 of m13mb102 by ligating the oligodeoxynucleotide 5'-ggt(pdg)tccg-3' into an 8-base gap in the (-)-strand of duplex m13mb102. replication of the adducted strand was ... | 1994 | 7961843 |
| in vitro evaluation of dna-dna hybridization as a two-step approach in radioimmunotherapy of cancer. | the specific delivery of radioisotopes to a tumor at minimal radiation of normal tissue is the ultimate aim of radioimmunotherapy. in this respect a two-step pretargeting regimen generally leads to an improved tumor to normal tissue uptake ratio compared to direct administration of radioimmunoconjugates. in this paper, in vitro studies are described in which the specific hybridization of complementary dna fragments is the recognition mechanism in a pretargeting regimen comprising tumor cell satu ... | 1994 | 8012970 |
| only the two end helixes of eight tandem amphipathic helical domains of human apo a-i have significant lipid affinity. implications for hdl assembly. | human apolipoprotein a-i (apo a-i) possesses multiple tandem repeating 22-mer amphipathic alpha-helixes. computer analysis and studies of model synthetic peptides and recombinant protein-lipid complexes of phospholipids have suggested that apo a-i interacts with hdl surface lipids through cooperation among its individual amphipathic helical domains. to delineate the overall lipid-associating properties of apo a-i, the first step is to understand the lipid-associating properties of individual amp ... | 1996 | 8620350 |
| proliferative t cell responses to human papillomavirus type 16 l1 peptides in patients with cervical dysplasia. | human papillomavirus type 16 (hpv-16) can cause genital warts, cervical dysplasias and carcinoma of the cervix. cell-mediated immunity is thought to be important in protection against the virus and in its elimination, but little is known about the mechanisms involved. in a cross-sectional study we have demonstrated proliferative t cell responses to peptides representing the hpv-16 l1 capsid protein (aa 199-409) in the peripheral blood of 63% of patients (n = 41) with histological evidence of cer ... | 1996 | 8627247 |
| a capillary electrophoresis method for studying apo, holo, recombinant, and subunit dissociated ferritins. | a capillary electrophoresis (ce) method is described for detecting and quantitating apo and holo ferritins from horse spleen (hosf), rat liver (rlf), recombinant human light chain (rlf), recombinant human heavy chain (rhf), site-directed variants of human light chain, and azotobacter vinelandii bacterial ferritin (avbf). this procedure is carried out at ph 8.2, where the ferritin molecules are associated into their 24-mers. protein mobilities as expressed as elution times were clearly resolved a ... | 1994 | 8053567 |
| kinetic and thermodynamic analysis of the interaction between trap (trp rna-binding attenuation protein) of bacillus subtilis and trp leader rna. | in bacillus subtilis, expression of the tryptophan biosynthetic genes is regulated in response to tryptophan by an rna-binding protein called trap (trp rna-binding attenuation protein). trap has been shown to contain 11 identical subunits arranged in a symmetrical ring. kinetic and thermodynamic parameters of the interaction between tryptophan-activated trap and trp leader rna were studied. results from glycerol gradients and mobility shift gels indicate that two trap 11-mers bind to each trp le ... | 1996 | 8647825 |
| changes in rheumatoid factor and monoclonal igg antibody specificity after site-specific mutations in antigenic region of beta 2-microglobulin. | antigenic epitopes on the skdwsfy region (positions 57-63) of human beta 2-microglobulin (beta 2m) reacting in elisa with polyclonal and monoclonal human igm rheumatoid factors (rf) as well as with monoclonal mouse igg anti-beta 2m antibodies were studied after site-specific mutation of single or double beta 2m amino acid residues. single site-specific mutations at lysine 58 and serine 61 produced a major decrease (50-100%) in reactivity of polyclonal igm rf with beta 2m. mutations at serine 57, ... | 1994 | 8062449 |
| long-range sequence analysis in xq28: thirteen known and six candidate genes in 219.4 kb of high gc dna between the rcp/gcp and g6pd loci. | dna comprising 219 447 bp was sequenced in nine cosmids and verified at > 99.9% precision. of the standard repetitive elements, 187 alus make up 20.6% of the sequence, but there were only 27 mers (2.9%) and 17 l1 fragments (1.6%). this may be characteristic of such high gc (57%) regions. the sequence also includes an 11.3 kb tract duplicated with 99.2% identity at a distance of 38 kb. the region is 80-90% transcribed and 12.5% translated. thirteen known genes and their exon-intron borders are al ... | 1996 | 8733135 |
| overcoming multidrug resistance in human tumor cells using free and liposomally encapsulated antisense oligodeoxynucleotides. | antisense oligonucleotides offer a molecular targeting tool for overcoming cellular multidrug resistance. in order to improve the in vitro and the in vivo transport of oligodeoxynucleotides, we developed a new liposomal delivery system, using the minimal volume entrapment (mve) technique. we have demonstrated that cellular uptake and intracellular release of oligodeoxynucleotides were facilitated by delivery in liposomes. 15 mers cap phosphorothioate oligodeoxynucleotides complementary to the 5' ... | 1993 | 8094959 |
| mixed hybridization and conventional strategies for dna sequencing. | oligonucleotide hybridization can be used to sequence short regions of dna. in this report, i examine the extent to which this method can be used to sequence genomic dna, using simulation experiments performed on known human genomic dna sequences, and show that segments of sequence of up to 800-bp length may be unambiguously sequenced using 65,536 mixed 11-mers. conventional sequencing or hybridization to specific, longer oligonucleotides can extend this limit in a mixed strategy that can sequen ... | 1993 | 8110482 |
| de novo antimicrobial peptides with low mammalian cell toxicity. | de novo antimicrobial peptides with the sequences: (klakkla)n, (klaklak)n (where n = 1,2,3), (kalkalk)3, (klgkklg)n, and (kaakkaa)n (where n = 2,3), were prepared as the c-terminus amides. these peptides were designed to be perfectly amphipathic in helical conformations. peptide antibacterial activity was tested against escherichia coli, pseudomonas aeruginosa, and staphylococcus aureus. peptide cytotoxicity was tested against human erythrocytes and 3t3 mouse fibroblasts. the 3t3 cell testing wa ... | 1996 | 8759631 |
| uptake of antisense oligonucleotides and functional block of acetylcholine receptor subunit gene expression in primary embryonic neurons. | several recent studies have used antisense oligonucleotides in the nervous system to probe the functional role of particular gene products. since antisense oligonucleotide-mediated block of gene expression typically involves uptake of the oligonucleotides, we have characterized the mechanism of this uptake into developing neurons from embryonic chickens. antisense oligonucleotides (15 mers) added to the bathing media are taken up into the embryonic chicken sympathetic neurons maintained in vitro ... | 1993 | 7693387 |
| [functional value of 980-1061 sequences of human 18s ribosomal rna using complementary dna probes]. | region 980-1061 in human 18s rrna was chosen on the basis of our previous results indicating, that the cross-linking sites of alkylating mrna analogs are located within this region. in the present study, we have used 10 dna 15-mers complementary to various overlapping sequences within the 18s rrna positions 980-1061. their ability to bind selectively at the desired rrna sequences was proved by hydrolysis of 18s rrna within heteroduplexes with the corresponding probes by rnase h. only four of the ... | 1995 | 7723752 |
| optimization of the rate of dna hybridization and rapid detection of methicillin resistant staphylococcus aureus dna using fluorescence polarization. | the hybridization rate of two complementary single-stranded dna 24-mers was determined at various nacl concentrations using a fluorescence polarization method. the rate was taken as the rate constant of the second order reaction, obtained by mathematical fitting of the time course curves of hybridization. the rate increased with the nacl concentration, plateauing in the concentration range of about 1-2 m. over the temperature range of 46 degrees c to 56 degrees c, it was found that in 0.8 m nacl ... | 1996 | 8861999 |
| internal autocrine regulation by erythropoietin of erythroleukemic cell proliferation. | antisense oligomers (18 mers) corresponding to the erythropoietin and erythropoietin receptor 5' coding sequences cause marked suppression of proliferation of several lines of erythroleukemic cells. in these systems, phosphorothioate protected sense oligomers are inhibitory, while the unmodified sense oligomers have no significant effect on cell growth. these data indicate that proliferation of some erythroleukemic cells is under internal autocrine regulation by erythropoietin and its receptor. | 1996 | 8862443 |
| [pcr amplification of nerve growth factor (beta-ngf) gene in human brain]. | nerve growth factor, an important nutrition factor for neuronal survival, growth, development and maintenance of neuronal functions, consists of three kinds of subunit (alpha 2, beta and gamma 2), but only the subunit beta-ngf has the biological activity. beta-ngf coding sequence is located in a single exon of ngf gene. in our study, a pair of specific primers (29 mers) has been designed and synthesized with abi 318 a dna synthesizer. the upstream primer includes an initiation codon and the 1st ... | 1993 | 8150431 |
| protection against measles virus encephalitis by monoclonal antibodies binding to a cystine loop domain of the h protein mimicked by peptides which are not recognized by maternal antibodies. | after immunization with measles virus (mv) several monoclonal antibodies (mabs) were obtained, which reacted with peptides corresponding to the amino acids 361-410 of the haemagglutinin protein (mv-h). three of these mabs (bh6, bh21 and bh216) inhibited haemagglutination, neutralized mv in vitro and protected animals from a lethal challenge of rodent-adapted neurotropic mv. these mabs reacted with the 15-mer peptides h381 and h386 defining their overlapping region 386-395 as a sequential neutral ... | 1996 | 8887481 |
| a comparison of the sensitivity of epidural and myogenic transcranial motor-evoked responses in the detection of acute spinal cord ischemia in the rabbit. | monitoring motor-evoked responses to transcranial stimulation (tc-mers) provides information about the functional status of the spinal cord during operations that pose the risk of spinal cord ischemia. responses can be recorded from the epidural space (epidural tc-mers) or from muscle (myogenic tc-mers). in this study the relative sensitivity of epidural and myogenic tc-mers to acute spinal cord ischemia was compared. spinal cord ischemia was produced by infrarenal aortic balloon occlusion in ni ... | 1996 | 8895279 |
| chlamydia trachomatis major outer membrane protein (momp) epitopes that activate hla class ii-restricted t cells from infected humans. | we localized peptide epitopes within the chlamydia trachomatis (ct) major outer membrane protein (momp) that activate human t cells. t-momp' cells were prepared by culturing pbl from 38 humans who had ct infections in the presence of ct serovar e momp. some epitopes were first localized by quantifying proliferative responses of t-momp' cells to overlapping momp segments (sixths) that were produced in escherichia coli. further localization was achieved by using overlapping synthetic 16-22 mers th ... | 1996 | 8906834 |
| epitopes on proteinase-3 recognized by antibodies from patients with wegener's granulomatosis. | the 228 amino acid primary sequence of proteinase-3 (pr3) was studied for antigenic epitopes, which react with igg ab in sera of patients with wegener's granulomatosis, by synthesizing overlapping 7 mers of pr3 linear sequence on pins. main regions of linear sequence reactivity included gheaqph (at residues 4-10), qphsrpy (8-14), tqeptqq (65-71), atvqlpq (108-114), qlpqqdq (111-117), pvphgtq (118-124), rvgahdp (132-138), fcrphni (154-160), prrkagi (165-171), fgdsggp (173-179), and idsfviw (189-1 ... | 1994 | 8157982 |
| characterization of pcr products from bacilli using electrospray ionization fticr mass spectrometry. | a procedure for rapid purification of polymerase chain reaction (pcr) products allowing precise molecular weight determination using electrospray ionization-fourier transform ion cyclotron resonance (esi-fticr) mass spectrometry is described. pcr amplification utilized the dna polymerase from pyrococcus furiosus (pfu) which, unlike taq, does not incorporate a nontemplated terminal deoxyadenosine phosphate. an 89-base pair nucleotide portion of the spacer region between the 16s and 23s ribosomal ... | 1996 | 8914480 |
| structural analyses of synthetic immobile holliday junction. | in order to study the structural properties of holliday junctions, we designed and synthesized oligodeoxyribonucleotides to construct the models of the holliday junctions with no sequence symmetry at the sites of branching called immobile junctions. electrophoretic and spectroscopic analyses of the immobile junctions indicated that the holliday junctions constructed from four deoxy 24-mers and four 18-mers were stable in 0.1 m nacl at approximately 5 x 10(-6) m strand concentration at room tempe ... | 1993 | 8247760 |
| effect of acidic ribosomal phosphoprotein mrna 5'-untranslated region on gene expression and protein accumulation. | constructions were made from genes encoding ribosomal acidic phosphoproteins yp1 beta (l44') and yp2 beta (l45) from saccharomyces cerevisiae in which different parts of the 5'-untranslated regions were included. the constructs were inserted into centromeric plasmids under the control of the gal1 promoter and expressed in yeast strains in which the genes coding for each acidic protein family, p1 and p2, had been disrupted. deletions in the 5' region of the two genes have been found to oppositely ... | 1994 | 8307952 |
| genome mapping by arbitrary amplification of yeast artificial chromosomes. | several methods have been described for using the polymerase chain reaction (pcr) to isolate fragments of dna for genome mapping. we have developed an approach for isolating discrete fragments by amplifying dna with single oligonucleotides (10-mers) with arbitrarily selected sequences. the method is rapid and technically simple. we isolated fragments from a contig of three yeast artificial chromosomes (yacs) from the human xq28 chromosomal region. we purified yacs ywxd37, ywxd348, and ywxd705 fr ... | 1993 | 8358170 |
| cleavage of full-length beta app mrna by hammerhead ribozymes. | the sequences surrounding the first 5'guc3' in the mrna encoding the alzheimer amyloid peptide precursor (beta app) were used to construct a pair of transacting hammerhead ribozymes. each ribozyme contained the conserved core bases of the hammerhead motif found in the positive strand of satellite rna of tobacco ringspot virus [(+)strsv] and two stems, 7 and 8 bases long, complementary to the target, beta app mrna. however, one of the ribozyme cleaving strands was lengthened at its 3' end to incl ... | 1993 | 8371986 |
| replicatively active complexes of dnaa protein and the escherichia coli chromosomal origin observed in the electron microscope. | dnaa protein and the escherichia coli chromosomal origin (oric) form an initial complex at an early stage in the initiation of dna replication. we have used electron microscopy to determine which structure among the several formed in the reconstitution of this multicomponent system is the replicatively active complex. one distinctive structure could be correlated with activity and localized to oric, whilst several others could not. formation of an open complex in the next stage of initiation was ... | 1993 | 8377183 |