| comparison of rapid methods for detection of heat-labile (lt) and heat-stable (st) enterotoxin in escherichia coli. | oxoid vet-rpla, st-eia and pharmacia phadebact etec-lt enterotoxin tests were compared to find a simple but reliable method for detecting enterotoxigenic escherichia coli (etec) in hungary. in the oxoid tests, all six reference lt- or st-producing strains, except one st-producer, gave positive results. of 11 reference porcine enterotoxigenic strains, all four lt-producers gave positive reactions for lt but three of 10 st-producers gave negative reactions for st. thirteen of 50 strains from cultu ... | 1992 | 1613778 |
| shigella flexneri induces apoptosis in infected macrophages. | the gram-negative bacterial pathogen shigella flexneri causes dysentery by invading the human colonic mucosa. bacteria are phagocytosed by enterocytes, escape from the phagosome into the cytoplasm and spread to adjacent cells. after crossing the epithelium, shigella reaches the lamina propria of intestinal villi, the first line of defence. this tissue is densely populated with phagocytes that are killed in great numbers, resulting in abscesses. the genes required for cell invasion and macrophage ... | 1992 | 1614548 |
| four conserved cysteine residues are required for the dna binding activity of nuclear factor i. | the role of cys residues in the site-specific dna binding activity of the nuclear factor i (nfi) family of proteins was assessed by chemical modification and site-specific mutagenesis. treatment with the thio-specific reagent n-ethylmaleimide abolished site-specific dna binding of all forms of nfi present in hela nuclear extracts. preincubation of cell extracts with an oligonucleotide containing an nfi-binding site provided partial protection of nfi from n-ethylmaleimide inactivation. mutations ... | 1992 | 1618796 |
| rna polymerase ii initiation factor alpha from rat liver is almost identical to human tfiib. | | 1992 | 1620622 |
| the y-box factors: a family of nucleic acid binding proteins conserved from escherichia coli to man. | the y-box factors interact specifically with both dna and rna. biologically they have roles in both transcriptional and translational regulation. conserved through evolution from prokaryotic to eukaryotic organisms they represent a new family of nucleic acid binding proteins. | 1992 | 1622927 |
| [significance of antimicrobial activities testing of antimicrobial agents in human urine]. | in order to clarify the in vivo effect of the new quinolones in the urinary tract, we investigated the antimicrobial activities against escherichia coli in the human urine. human urine was prepared from a normal volunteer. after cations were removed by chelating resin, human urine was supplemented with 50, 100, or 500 micrograms of mg2+ per ml using mgcl2 or 10, 50, or 150 micrograms of ca2+ per ml using cacl2. the ph of human urine was adjusted to 5.5, 7.0, or 8.0 with hcl or naoh. four clinica ... | 1992 | 1624847 |
| rat tumor necrosis factor-alpha. transcription in rat kupffer cells and in vitro posttranslational processing based on a pcr-derived cdna. | a dna fragment with a reading frame of 708 basepairs coding for tnf-alpha from rat liver was cloned by the polymerase chain reaction. using this species-specific cdna a biotin-labelled antisense (-)rna was transcribed. this probe was used for northern blot analysis of tnf-alpha gene activation. exposure of rat kupffer cells to lps led to a time-dependent change of tnf-alpha-mrna expression with a maximum between one and two hours after stimulation. in vitro translation was carried out with sense ... | 1992 | 1627266 |
| effect of pine seed shell extract on microbial and viral infection. | pretreatment of mice with ammonia extract of seed shell of pinus koraicenis, via the intraperitoneal or intravenous route, effectively protected them from lethal infection of escherichia coli, klebsiella pneumoniae and staphylococcus aureus. the pine seed shell extract also moderately inhibited syncytium formation and cytopathogenic effect induced by human immunodeficiency virus (hiv) infection in cultured human lymphotropic virus type i (htlv-1) positive mt-4 cells. these data suggest a medicin ... | 1992 | 1627738 |
| mutations of ha-ras p21 that define important regions for the molecular mechanism of the sdc25 c-domain, a guanine nucleotide dissociation stimulator. | the sdc25 c-domain is a very active guanine nucleotide dissociation stimulator (gds) isolated from saccharomyces cerevisiae which acts equally well on ha-ras p21 and yeast ras2. these properties make the sdc25 c-domain a suitable tool to study the basic mechanism of a gds. the action of the sdc25 c-domain was analysed by mutation of structurally important regions of p21. substitutions that influence the coordination of mg2+.gdp or the interaction of the guanine ring were found to stimulate the i ... | 1992 | 1628612 |
| generation of specific antibodies against the rap1a, rap1b and rap2 small gtp-binding proteins. analysis of rap and ras proteins in membranes from mammalian cells. | specific antibodies against rap1a and rap1b small gtp-binding proteins were generated by immunization of rabbits with peptides derived from the c-terminus of the processed proteins. immunoblot analysis of membranes from several mammalian cell lines and human thrombocytes with affinity-purified antibodies against rap1a or rap1b demonstrated the presence of multiple immunoreactive proteins in the 22-23 kda range, although at strongly varying levels. whereas both proteins were present in substantia ... | 1992 | 1628649 |
| biochemical and biophysical characterization of human recombinant ige-binding protein, an s-type animal lectin. | ige-binding protein (epsilon bp) was originally identified by virtue of its affinity for ige. it is now known to be a beta-galactoside-binding lectin with the characteristic of an s-type carbohydrate recognition domain. the protein is composed of two domains: the amino-terminal domain consisting of tandem repeats and the carboxyl-terminal domain containing sequences shared by other s-type carbohydrate recognition domains. the amino-terminal domain also contains a number of potential recognition ... | 1992 | 1629216 |
| the signal for golgi retention of bovine beta 1,4-galactosyltransferase is in the transmembrane domain. | the expression and localization of bovine beta 1,4-galactosyltransferase (gal t) has been studied in mammalian cells transfected with gal t cdna constructs, and the role of the amino-terminal domains of gal t in golgi localization examined. here we demonstrate that the transmembrane (signal/anchor) domain of bovine gal t contains a positive golgi retention signal. bovine gal t was characterized in transfected cells with anti-bovine gal t antibodies, affinity-purified from a rabbit antiserum usin ... | 1992 | 1637374 |
| [studies of bacterial indicators for water pollution--growth of escherichia coli and enterococci in limited nutrient conditions]. | bacteria, that would be an ideal indicator for fecal contamination in environmental water, should not proliferate but at the same time should survive a little longer than enteropathogenic bacteria in the environmental water. while conventional methods have recommended escherichia coli as an indicator, enterococci is recommended as a preferable indicator for the estimation of fecal contamination based on the following observation. the relationship between the specific growth rate of organism and ... | 1992 | 1638040 |
| activation of mammalian dna ligase i through phosphorylation by casein kinase ii. | mammalian dna ligase i has been shown to be a phosphoprotein. dephosphorylation of purified dna ligase i causes inactivation, an effect dependent on the presence of the n-terminal region of the protein. expression of full-length human dna ligase i in escherichia coli yielded soluble but catalytically inactive enzyme whereas an n-terminally truncated form expressed activity. incubation of the full-length preparation from e. coli with purified casein kinase ii (ckii) resulted in phosphorylation of ... | 1992 | 1639065 |
| production of human serum transferrin in escherichia coli. | transferrin (tf) crystals diffract to only medium resolution. the mediocre quality of the crystals may be due to two factors: (1) the genetic variations naturally present in the primary sequence of tf, and (2) the glycosylation of the protein. to control genetic variations and glycosylation of samples of tf, it would be desirable to express the tf gene from a recombinant clone. additionally, expression of tf from a clone would allow for manipulation of the structure of tf. the cdna encoding tf h ... | 1992 | 1639274 |
| identification of enap-1, an antimicrobial peptide from equine neutrophils. | endogenous, cysteine-rich antimicrobial peptides known as defensins are prominent components of human, rabbit, and rat neutrophils, yet little is known about their occurrence in other mammalian species. although we did not detect mature (i.e., processed) defensins in equine neutrophil granules, we found that these granules contained small amounts of other cysteine-rich peptides with antimicrobial activity. one of these, enap-1, was purified by a combination of gel permeation and reversed-phase h ... | 1992 | 1639474 |
| biological activity of synthetic phosphonooxyethyl analogs of lipid a and lipid a partial structures. | we investigated the biological activity of four new synthetic analogs of lipid a, termed pe-1, pe-2, pe-3, and pe-4. all compounds contain an alpha-oxyethyl-linked (-o-ch2-ch2-) phosphoryl group in position 1 of the reducing glucosaminyl residue (glcn i) of lipid a. pe-1 is a hexaacylated analog of escherichia coli lipid a (compound 506). pe-2 differs from pe-1 in carrying two myristic acid residues at glcn i. pe-3 has the same acylation pattern as pe-2, but glcn i is present in the beta anomeri ... | 1992 | 1639498 |
| a signature element distinguishes sibling and independent mutations in a shuttle vector plasmid. | we have developed a new shuttle vector plasmid for studying mutagenesis in mammalian cells that permits proof of independence of identical mutations. mutations occur more frequently at some sites in a gene than in others, and in a collection of mutant plasmids from a single transfection of mammalian cells the same mutation may appear several times. however, those arising from independent events cannot be distinguished from siblings of an initial event. the new vector system (psp189) is a populat ... | 1992 | 1644298 |
| a t7 expression vector optimized for site-directed mutagenesis using oligodeoxyribonucleotide cassettes. | site-directed mutagenesis is widely used to examine structure/function relationships in proteins. we have designed a bacterial expression vector series which is optimized for efficient site-directed mutagenesis and subsequent protein synthesis without intervening subcloning steps. the vectors, derived from the t7 expression vectors of studier and his collaborators [studier et al., methods enzymol. 185 (1990) 60-89], are small and have a bacteriophage f1 origin of replication for production of si ... | 1992 | 1644301 |
| production and functional analysis of normal and variant recombinant human transthyretin proteins. | the most common form of hereditary systemic amyloidosis is familial amyloidotic polyneuropathy associated with single amino acid changes in the plasma protein, transthyretin. in addition, there are two variants of transthyretin (ser6 and thr109) not associated with familial amyloidotic polyneuropathy but with familial euthyroid hyperthyroxinemia, also an autosomal dominant disorder. in these autosomal dominant diseases, most affected individuals are heterozygous and therefore have hybrid forms o ... | 1992 | 1644839 |
| activity of recombinant mitogillin and mitogillin immunoconjugates. | a synthetic gene for the aspergillus protein toxin mitogillin has been synthesized and expressed in escherichia coli. the recombinant mitogillin is a potent inhibitor of protein synthesis in vitro with an ic50 of 9.7 pm. immunoconjugates of recombinant mitogillin derivatized with s-acetylmercaptosuccinic anhydride and 5-methyl-2-iminothiolane modified h65 antibody kill t cell lines and peripheral blood mononuclear cells expressing the human cd5 surface antigen. native mitogillin contains 4 cyste ... | 1992 | 1644844 |
| isolation and characterization of temperature-sensitive and thermostable mutants of the human receptor-like protein tyrosine phosphatase lar. | human lar is a transmembrane receptor-like protein whose cytoplasmic region contains two tandemly duplicated domains homologous to protein tyrosine phosphatases (ptpases). whereas the membrane-proximal domain i has enzymatic activity, the membrane-distal domain ii has no apparent catalytic activity but seems to have a regulatory function. in order to study structure-function relationships of the lar ptpase, lar domain i was expressed in escherichia coli, and mutants that have reduced catalytic a ... | 1991 | 1645351 |
| characterization of an extended form of recombinant human insulin-like growth factor ii. | to investigate the biological role of variants of human insulin-like growth factor ii (igf-ii), an extended form designated igf-iie21, with a molecular mass of 9.8 kda, was produced in escherichia coli as a stable and soluble secreted fusion protein. after site-specific cleavage of the affinity purified fusion protein, followed by purification using ion exchange and reversed phase chromatography, it could be demonstrated that igf-iie21 and igf-ii have similar or identical activities according to ... | 1991 | 1645723 |
| inhibition of epstein-barr virus infection in vitro and in vivo by soluble cr2 (cd21) containing two short consensus repeats. | the extracellular domain of cr2, the epstein-barr virus (ebv)/c3d receptor of b lymphocytes, contains 15 or 16 tandemly arranged short consensus repeat elements (scr). recombinant cr2 proteins containing scr 1 and 2 fused to staphylococcus aureus protein a (pa-cr2) and to murine complement factor h scr 20 (cr2fh) were expressed in escherichia coli and in insect cells, respectively. these recombinant cr2 molecules retained functional activity as indicated by their ability to bind to c3dg in an en ... | 1991 | 1645784 |
| human fibroblast stromelysin catalytic domain: expression, purification, and characterization of a c-terminally truncated form. | stromelysin-1 is a member of a tissue metalloproteinase family whose members are all capable of degrading extracellular matrix components. a truncated form of human fibroblast prostromelysin 1 lacking the c-terminal, hemopexin-like domain has been expressed in escherichia coli and purified to homogeneity. treatment of this short form of prostromelysin with (aminophenyl)mercuric acetate resulted in activation and loss of the propeptide in a manner identical with the wild-type, full-length protein ... | 1991 | 1647201 |
| differential degradation of a recombinant albumin-binding receptor in escherichia coli. | the degradation in escherichia coli of the recombinant serum-albumin-binding receptor derived from streptococcal protein g was investigated using a dual-affinity fusion approach. the proteolytic degradation of the receptor was characterized when fused to human proinsulin and human secretin. several cleavages occurred at sequences not normally regarded as proteolytically sensitive, such as the dipeptide sequences ile-gly, val-ser and ser-ala. depending on the fusion partner, large differences in ... | 1991 | 1648486 |
| altering the conserved nucleotide binding motif in the salmonella typhimurium muts mismatch repair protein affects both its atpase and mismatch binding activities. | the salmonella typhimurium and escherichia coli muts protein is one of several methyl-directed mismatch repair proteins that act together to correct replication errors. muts is homologous to the streptococcus pneumoniae hexa mismatch repair protein and to the duc1 and rep1 proteins of human and mouse. homology between the deduced amino acid sequence of both muts and hexa, and the type a nucleotide binding site consensus sequence, suggested that atp binding and hydrolysis play a role in their mis ... | 1991 | 1651234 |
| cooperation of ebv dna polymerase and ea-d(bmrf1) in vitro and colocalization in nuclei of infected cells. | expression of the epstein-barr virus (ebv) dna polymerase (ebvpol) open reading frame (balf5) by in vitro transcription-translation yielded a 116-kda primary translation product. enzymatic dna polymerase activity of the in vitro translated polypeptide required the presence of the 47-kda bmrf1 (ea-d) gene product. antiserum raised to the balf5 gene product expressed in escherichia coli specifically precipitated a 116-kda polypeptide in extracts of latently infected lymphoblastoid cells induced fo ... | 1991 | 1651595 |
| related rna polymerase-binding regions in human rap30/74 and escherichia coli sigma 70. | rap30/74 is a heteromeric general transcription initiation factor that binds to mammalian rna polymerase ii. the rap30 subunit contains a region that is similar in amino acid sequence to the rna polymerase-binding domain of the escherichia coli transcription initiation factor sigma 70 (sigma 70). mammalian rna polymerase ii specifically protected a serine residue in the sigma 70-related region of rap30 from phosphorylation in vitro. in addition, human rap30/74 bound to escherichia coli rna polym ... | 1991 | 1652156 |
| cloning, nucleotide sequence, and regulation of met14, the gene encoding the aps kinase of saccharomyces cerevisiae. | the met14 gene of saccharomyces cerevisiae, encoding aps kinase (atp:adenylylsulfate-3'-phosphotransferase, ec 2.7.1.25), has been cloned. the nucleotide sequence predicts a protein of 202 amino acids with a molecular mass of 23,060 dalton. translational fusions of met14 with the beta-galactosidase gene (lacz) of escherichia coli confirmed the results of primer extension and northern blot analyses indicating that the ca. 0.7 kb mrna is transcriptionally repressed by the presence of methionine in ... | 1991 | 1654509 |
| nucleoside diphosphate kinase from escherichia coli; its overproduction and sequence comparison with eukaryotic enzymes. | the gene encoding nucleoside diphosphate (ndp) kinase of escherichia coli was identified by polymerase chain reaction using oligodeoxyribonucleotide primers synthesized on the basis of consensus sequences from myxococcus xanthus and various eukaryotic ndp kinases. the gene (ndk), mapped at 54.2 min on the e. coli chromosome, was cloned and sequenced. the e. coli ndp kinase was found to consist of 143 amino acid residues that are 57, 45, 45, 42, 43, and 43% identical to the m. xanthus, dictyostel ... | 1991 | 1657712 |
| the design, expression, and characterization of human insulin-like growth factor ii (igf-ii) mutants specific for either the igf-ii/cation-independent mannose 6-phosphate receptor or igf-i receptor. | five mutants of recombinant insulin-like growth factor-ii (rigf-ii) that bound with high affinity to either the igf-ii/cation-independent mannose 6-phosphate (igf-ii/cim6-p) or the igf-i receptor were prepared by site-directed mutagenic procedures, expressed as fusion proteins in the larva of bombyx mori or escherichia coli, purified to homogeneity, renatured, and characterized in terms of their receptor binding affinities and specificities as well as their biological activities. class i mutants ... | 1991 | 1657932 |
| unusual cell specific expression of a major human cytomegalovirus immediate early gene promoter-lacz hybrid gene in transgenic mouse embryos. | transgenic mice carrying the human cytomegalovirus immediate early gene promoter driving the e. coli lacz gene displayed an unusual cell specific expression of beta-galactosidase during development. lacz expression was first detected in cells lining the apex of the neural fold of day 8.5 embryos. by day 10 of gestation, expression was prominent in the spinal ganglia, the ganglia of cranial nerves v, vii, viii, ix, and x, in a line of cells marking the ventrolateral pathway adjacent to the dermam ... | 1991 | 1659441 |
| the hygromycin-resistance-encoding gene as a selection marker for vaccinia virus recombinants. | hygromycin b (hy), an inhibitor of rna translation, was shown to block the replication of vaccinia virus (vv) in cultured cell lines. insertion of the escherichia coli hy resistance-encoding gene (hph) into the vv genome under control of early or late synthetic vv promoters could overcome inhibition of viral replication. when hph was inserted into vv in tandem with the human papillomavirus type 16 (hpv16) l1 open reading frame, hph recombinant viruses could be selected which expressed hpv16 l1. | 1991 | 1660832 |
| cloning of a cdna encoding a novel putative g-protein-coupled receptor expressed in specific rat brain regions. | a cdna clone encoding a novel putative g-protein-coupled receptor was isolated from a rat brain cdna library using a pcr-amplified cdna fragment as a hybridization probe. the 3,615-bp-long nucleotide sequence predicts a single open reading frame of 1,173 bp coding for 391 amino acids, giving a calculated molecular weight of 42.75 kd. the amino acid sequence shares features common to many other receptors, including the seven membrane-spanning hydrophobic regions and putative asparagine-linked gly ... | 1991 | 1661599 |
| genomic structure and expression of human guanosine monophosphate reductase. | in vitro translation in the rabbit reticulocyte system and transient expression in cos7 cells were performed to characterize the protein encoded by a chromosome 6-linked human cdna clone, whose nucleotide sequence is homologous to that of escherichia coli guanosine monophosphate reductase (gmp reductase) cdna. the molecular weight of the peptide produced by the cdna was about 37,000 dalton, and the protein produced in the cos7 cells exhibited gmp reductase activity, substantiating that the cdna ... | 1991 | 1661705 |
| characterization of the zinc finger protein encoded by the wt1 wilms' tumor locus. | we analysed the biochemical properties of the transcription factor encoded by the putative tumor-suppressor gene present at the wt1 wilms' tumor locus. a gene containing the full-length amino acid coding sequence of human wt1 was reconstructed from synthetic oligonucleotides and cloned into expression vectors for in vitro and in vivo protein synthesis. polyclonal rabbit antibodies specific for the wt1 protein were raised to an escherichia coli-produced 91 amino acid n-terminal segment and to a 1 ... | 1991 | 1662794 |
| research priorities for diarrhoeal disease vaccines: memorandum from a who meeting. | diarrhoeas caused by rotaviruses, shigella, vibrio cholerae, and enterotoxigenic escherichia coli (etec) represent a major health burden in developing countries, and have stimulated much effort towards vaccine development in order to protect against these four disease agents. this memorandum describes the state of the art and points the way to future research and test trials in this area. | 1991 | 1664785 |
| aspartic acid 50 and tyrosine 108 are essential for receptor binding and cytotoxic activity of tumour necrosis factor beta (lymphotoxin). | single amino acid substitutions were generated in predicted hydrophilic loop regions of the human tumour necrosis factor beta (tnf-beta) molecule, and the mutant proteins were expressed in escherichia coli and purified. mutants with single amino acid changes at either of two distinct loop regions, at positions aspartic acid 50 or tyrosine 108, were found to have greatly reduced receptor binding and cytotoxic activity. these two regions in tnf-beta correspond to known loop regions where mutations ... | 1991 | 1665907 |
| electron microscopic observation of recombinant escherichia coli cells overproducing human tumor necrosis factor-alpha mutant as inclusion bodies. | escherichia coli c600 r-m- carrying plasmid ptnf483 (e. coli [ptnf483]) produces a tumor necrosis factor-alpha (tnf-alpha) mutant protein in an insoluble form. a swollen region was observed in the sem images to encircle the outside of most of the e. coli [ptnf483] cells just like a bandage. on the other hand, inclusion bodies of the tnf-alpha mutant as large as the short axis of the cell were observed in tem images. this position was regarded as coinciding with the swollen region of sem images. ... | 1991 | 1666646 |
| expression of escherichia coli f-18 type 1 fimbriae in the streptomycin-treated mouse large intestine. | escherichia coli f-18, isolated from the feces of a healthy human, makes type 1 fimbriae and is an excellent colonizer of the streptomycin-treated mouse large intestine. recently, it was shown that the inability to produce type 1 fimbriae had no effect on the ability of e. coli f-18 to colonize the streptomycin-treated mouse large intestine, suggesting the possibility that e. coli f-18 does not express type 1 fimbriae in vivo. however, we show here that e. coli f-18 does express type 1 fimbriae ... | 1991 | 1672304 |
| human neutrophil responses to pathogenic escherichia coli are receptor-specific and selectively augmented by recombinant human tumor necrosis factor-alpha. | the effect of recombinant human tumor necrosis factor-alpha (rhtnf alpha) on neutrophil (pmnl) response to uropathogenic escherichia coli was assessed. a strain expressing mannose-sensitive adhesins (type 1 fimbriae) stimulated significant primary granule, secondary granule, and leukotriene b4 (ltb4) release. the same strain grown to suppress fimbrial expression and three non-type 1-fimbriated strains stimulated only background low-level pmnl activation. the binding of the type 1-fimbriated stra ... | 1991 | 1673463 |
| expression of an immunogenic region of hiv by a filamentous bacteriophage vector. | vectors derived from the escherichia coli filamentous phage, fd-tet, expressing parts of the human immunodeficiency virus (hiv) gag genes were constructed and analyzed. the immunoreactive domain of hiv gag antigens was produced in the form of a fusion protein, with a phage minor coat protein, called protein iii, playing an important role in phage infectivity. a micropanning procedure, utilizing the strong affinity of biotinylated antibody to streptavidin, was applied for the selection of clones. ... | 1991 | 1673667 |
| dependence of the mutation spectrum in a shuttle plasmid replicated in human lymphoblasts on dose of gamma radiation. | the frequencies and types of mutations induced in the target gene, supf-trna, of the shuttle vector pz189 were analysed following the replication of the gamma-irradiated plasmid in the human lymphoblastoid cell line, gm606. the mutation frequency measured in progeny of unirradiated pz189 was 1.02 x 10(-4), increasing to 17.5 x 10(-4) at 1000 cgy, and to 63.4 x 10(-4) at 5000 cgy, approximately 17- and 62-fold over background levels, respectively. simultaneously, the number of plasmids capable of ... | 1991 | 1675233 |
| pseudomonas exotoxin fusion proteins are potent immunogens for raising antibodies against p-glycoprotein. | antibodies to specific regions of human p-glycoprotein have been difficult to obtain. we developed a method to express in e. coli fusions between pseudomonas exotoxin and specific regions of human p-glycoprotein. we used the polymerase chain reaction to amplify the desired regions of mdr1 cdna and to introduce appropriate restriction sites. these fragments were cloned into the 3' end of the pseudomonas exotoxin gene. with this system we produced large amounts of fusion proteins for immunizations ... | 1991 | 1676289 |
| fragmentation of escherichia coli type 1 fimbriae exposes cryptic d-mannose-binding sites. | cells of the gram-negative bacterium escherichia coli are able to attach to various host cells by means of a mannose-specific adhesin associated with type 1 fimbriae. here we show that fragmentation of type 1 fimbriae by freezing and thawing results in increased mannose-binding activity as demonstrated by increased hemagglutination, increased stimulation of human lymphocyte proliferation, and increased binding of the mannose-containing enzyme horseradish peroxidase. increased activity in all thr ... | 1991 | 1676398 |
| recombinant human tyrosine hydroxylase isozymes. reconstitution with iron and inhibitory effect of other metal ions. | human tyrosine 3-monooxygenase (tyrosine hydroxylase) exists as four different isozymes (th1-th4), generated by alternative splicing of pre-mrna. recombinant th1, th2 and th4 were expressed in high yield in escherichia coli. the purified isozymes revealed high catalytic activity [when reconstituted with fe(ii)] and stability at neutral ph. the isozymes as isolated contained 0.04-0.1 atom iron and 0.02-0.06 atom zinc/enzyme subunit. all three isozymes were rapidly activated (13-40-fold) by incuba ... | 1991 | 1676967 |
| human vntr sequences in porcine htf-islands. | mapping of complex genomes has been influenced substantially by the isolation of locus-specific, but repetitive dna elements known as vntrs. since a high gc-content is characteristic of most of these elements one might expect them to be clustered at least partially in cpg-islands. to address this question we have constructed a porcine liver dna noti-linkage library in puc18 using isolated htf-islands. hpaii tiny fragments ranging from less than 100 bp to 1 kb in length were randomly selected and ... | 1991 | 1678358 |
| characteristics of adherence of enteroaggregative escherichia coli to human and animal mucosa. | an escherichia coli strain (serotype o127a:h2) that had been isolated from a child with diarrhea in thailand and that was negative for the virulence factors of the four categories of diarrheagenic e. coli (enterotoxigenic, enteropathogenic, enteroinvasive, and enterohemorrhagic) and that showed an aggregative pattern of adherence to hela cells was investigated for adherence to native or formalin-fixed human and animal mucosa. the hemagglutinating activity and adherence ability of the bacteria we ... | 1991 | 1680107 |
| primary structure and functional expression of the human receptor for escherichia coli heat-stable enterotoxin. | heat-stable enterotoxin (sta) produced by escherichia coli induces intestinal secretion in mammals by binding to the brush border membrane of the small intestine and activating guanylyl cyclase. we report here the cloning and expression of a cdna encoding the human receptor for sta. the receptor contains both an extracellular ligand binding site and a cytoplasmic guanylyl cyclase catalytic domain, making it a member of the same receptor family as the natriuretic peptide receptors. stable mammali ... | 1991 | 1680854 |
| identification of the leukocyte adhesion molecules cd11 and cd18 as receptors for type 1-fimbriated (mannose-specific) escherichia coli. | attachment of bacteria to phagocytic cells may be mediated by lectin-carbohydrate interactions, resulting in lectinophagocytosis. the best-studied system is the interaction of type 1-fimbriated (mannose-specific) escherichia coli with human phagocytic cells. here we demonstrate that the leukocyte integrins cd11 and cd18 (cd11/cd18) constitute the major receptors for type 1-fimbriated e. coli. bacteria were bound in a dose-dependent and saturable manner to cd11/cd18, which was immobilized to micr ... | 1991 | 1682263 |
| isolation and sequence analysis of the chlamydia pneumoniae groe operon. | chlamydia pneumoniae has emerged as an important human respiratory pathogen. from a lambda gt11 gene bank constructed from c. pneumoniae isolate ar-39 dna, an immunoreactive plaque containing a 3.0-kb insert was purified. in immunoblots, a 60-kda protein was recognized by anti-c. pneumoniae rabbit immune serum. the recombinant protein was reactive with a chlamydia genus-specific monoclonal antibody recognizing a 60-kda protein found in the sarkosyl-soluble fraction and with rabbit immune serum p ... | 1991 | 1682266 |
| structure of domain 1 of rat t lymphocyte cd2 antigen. | the cd2 antigen is largely restricted to cells of the t-lymphocyte lineage and has been established as an important adhesion molecule in interactions between human t lymphocytes and accessory cells. in the adhesion reaction, cd2 on t cells binds to lfa-3 on other cells, with binding through domain 1 of cd2. cd2 can also be a target for the delivery of mitogenic signals to t lymphocytes cultured with combinations of anti-cd2 antibodies. two predictions that are contradictory have been made for th ... | 1991 | 1682812 |
| ability of uropathogens to bind to tamm horsfall protein-coated renal tubular cells. | epithelial cells were isolated from a healthy human kidney and found to be of normal, renal tubular origin. the cells were maintained in tissue culture and found to secrete tamm horsfall protein (thp). three strains of uropathogenic escherichia coli, and one each of proteus mirabilis and pseudomonas aeruginosa were found to adhere to the thp-coated tubular cells. extraneous thp bound to all the organisms except p fimbriated e. coli, and caused a reduction in the adhesion of type 1 fimbriated e. ... | 1991 | 1683041 |
| interaction of p-fimbriated escherichia coli with human meconium. | the ability of escherichia coli with different receptor specificities to interact with meconium was studied. e. coli strains expressing p-fimbriae, specific for gal alpha 1-4gal beta-containing receptors, were agglutinated by meconium at high titres. this reaction was inhibited by globotetraosylceramide. the attachment of p-fimbriated e. coli to human colonic epithelial cells of the ht-29 cell line was inhibited by meconium. some type 1 fimbriated strains were agglutinated by meconium, but the a ... | 1991 | 1685134 |
| characterization of a new fimbrial antigen present in escherichia coli strains isolated from calves. | thirteen escherichia coli strains isolated from calves with diarrhoea, supposed to carry a common antigen were examined for their hemagglutinating activity and compared by bacterial agglutination, double diffusion in two dimensions and by crossed immunoelectrophoresis (cie). two of the strains were examined also in the electron microscope. most of the strains agglutinated red blood cells of horse, ox, guinea pig and chicken, of which the agglutination of ox erythrocytes was mannose-resistant (mr ... | 1991 | 1686345 |
| production of type 1 fimbriae by escherichia coli hb101. | escherichia coli hb101 is frequently used as a host in the cloning of bacterial virulence genes because of its reported lack of virulence determinants such as fimbriae, adhesins and haemagglutinins. however, passage of hb101 in standing broth culture rapidly induced the production of fimbriae which mediated adhesion to hep-2 cells and mannose-sensitive haemagglutination of human and guinea-pig erythrocytes. fimbrial serology, morphology and pilin molecular mass of 18 kda were consistent with tho ... | 1991 | 1686629 |
| increased uracil-dna glycosylase, ap-dna binding protein and deoxyribonuclease activities in tumor and sv40-transformed cell lines of human origin. | the activities of three human dna metabolizing enzymes--uracil-dna glycosylase, apurinic/apyrimidinic(ap)-dna binding protein (an ap-dna endonuclease) and the major cellular deoxyribonuclease (presumably dnase iii and/or dnase iv)--were measured in logarithmic growing (diploid non-established) fibroblast strains, tumor-derived cell lines and sv40-transformed cell lines. the levels of activity of uracil-dna glycosylase and dnase were increased, on average, 5- to 6-fold in tumor cell lines and 10- ... | 1990 | 1688517 |
| hlyb-dependent secretion of hemolysin by uropathogenic escherichia coli requires conserved sequences flanking the chromosomal hly determinant. | the synthesis and secretion of hemolysin (hlya) by escherichia coli are governed by four contiguous genes (hlycabd) that are closely conserved on plasmids and, among human pathogenic strains, on the chromosome. we have previously shown that in plasmid phly152 the coexpressed synthesis and export functions are uncoupled by intraoperon transcription termination, which is in turn alleviated by antitermination dictated in cis by a region upstream of the hly operon. in this study we describe an analo ... | 1990 | 1689714 |
| identification of an epitope region of the human proliferation-associated nucleolar antigen p120. | an epitope region, located at amino acid residues 173-180 (eaaa-giqw), of a human cell proliferation-associated nucleolar antigen, p120, has been defined by mutational analysis and competition assays. a synthetic peptide corresponding to this epitope region completely blocks the binding of the anti-p120 antibody to escherichia coli-expressed p120 and the hela nucleolar p120 protein. adjacent peptides lack inhibitory effects. the antigenic site includes a hydrophilic residue and a hydrophobic str ... | 1990 | 1691680 |
| fine epitope mapping of the human ss-b/la protein. identification of a distinct autoepitope homologous to a viral gag polyprotein. | to analyze the autoepitopes on the ss-b/la protein, a cdna covering the entire region coding the protein was isolated from a human cdna library. the cdna was subcloned into an expression plasmid vector, pex, to express its protein product as a fusion protein with cro-beta-galactosidase in escherichia coli. a recombinant pex plasmid expressing three-fourths of the protein (amino acid 112-408) was also constructed. the antigenicities of these recombinant proteins were confirmed with a patient's se ... | 1990 | 1692037 |
| the fine specificity of anti-la antibodies induced in mice by immunization with recombinant human la autoantigen. | because of increasing evidence suggesting that anti-la autoantibodies are induced in humans by an ag-specific mechanism, we investigated the antibody response of animals immunized with the human la ag and studied its relationship to the anti-la response of autoimmune patients. anti-la antibodies were raised in 6- to 8-wk-old male mrl(-)+/+, c57bl/6j, balb/c, and a/j mice by immunizing with authentic human la protein obtained by recombinant expression in escherichia coli. as we have shown previou ... | 1990 | 1692063 |
| prevalence of antibodies to the core protein p17, a serological marker during hiv-1 infection. | studies on monitoring the immune response to viral structural proteins during human immunodeficiency virus (hiv-1) infection have established the significance of antibodies to the core protein p24 during the progression of the disease. we have studied the prevalence of antibodies to the core protein p17 in order to study their diagnostic and prognostic significance in the pathogenesis of hiv-1. full-length hiv-1 p17, molecularly cloned and expressed in escherichia coli was purified by immunoaffi ... | 1990 | 1692727 |
| cloning and sequencing of cdnas coding for the human intra-acrosomal antigen sp-10. | cdnas coding for the intra-acrosomal protein sp-10 were cloned and characterized as a first step in understanding the expression of this antigen during spermatogenesis. three overlapping sp-10-specific cdnas were isolated from a human testes cdna expression library. these cdnas hybridized to a 1.35-kb mrna that was present in human testes but was not found in liver or placenta. complete sequencing of these cdnas, designated sp-10-5, sp-10-8, and sp-10-10, produced an 1117-bp sequence containing ... | 1990 | 1693291 |
| host-specificity of uropathogenic escherichia coli depends on differences in binding specificity to gal alpha 1-4gal-containing isoreceptors. | four g adhesins, cloned from uropathogenic escherichia coli strains, were examined for binding to glycolipids and various eukaryotic cells. papgad110 and papgia2 showed virtually identical binding patterns to gal alpha 1-4gal-containing glycolipids, while papgj96 differed slightly and prsgj96 markedly with respect to the effect of neighbouring groups on the binding. their hemagglutination patterns confirmed the existence of three receptor-binding specificities. while the papg adhesins bound to u ... | 1990 | 1693334 |
| crystallization and preliminary diffraction studies of recombinant human granulocyte-stimulating factor (kw2228). | human granulocyte colony-stimulating factor (hg-csf) specifically stimulates proliferation of neutrophils. two crystal forms of a mutant of hg-csf expressed in escherichia coli have been obtained using the hanging drop vapour diffusion method. one form is triclinic, space group p1, with cell dimensions a = 37.3 a, b = 46.4 a, c = 47.7 a, alpha = 105.5 degrees, beta = 98.0 degrees and gamma = 109.4 degrees. the other is monoclinic, space group c2, with cell dimensions a = 82.0 a, b = 49.2 a, c = ... | 1990 | 1695250 |
| influence of rna synthesis on dna-repair replication in human cell extracts. | an in vitro system allowing human cell extracts to carry out excision repair in ultraviolet light-irradiated, closed circular dna was used to study the influence of transcription on repair synthesis. rna synthesis from plasmid dna containing bacterial transcription units was obtained by addition of escherichia coli rna polymerase and ribonucleoside triphosphates to the repair-incubation mixture. no increase in uv-stimulated repair replication was observed under transcriptional conditions; in fac ... | 1990 | 1696681 |
| molecular cloning and overexpression of the human fk506-binding protein fkbp. | the potent immunosuppressive agent fk506 is highly effective in preventing organ transplant rejection in humans. like cyclosporin a, fk506 inhibits the transcription of early t-cell activation genes, apparently by modulating the activity of transcriptional regulators such as nuclear factor of activated t cells. a remarkable finding is that the predominant binding proteins (immunophilins) for cyclosporin a and fk506, cyclophilin and fkbp respectively, are peptidyl-prolyl-cis-trans-isomerases that ... | 1990 | 1696686 |
| the expression of active human reticulocyte 15-lipoxygenase in bacteria. | a cloned cdna that encodes human reticulocyte 15-lipoxygenase was characterized by northern blot analysis and heterologous expression in bacteria. the 2.7 kb cdna specifically hybridizes to reticulocyte rna from anemic rabbits. the rna levels correlate with the appearance of enzymatic activity in anemia. the cdna was subcloned into an inducible bacterial expression vector in frame with the amino terminal ten amino acids of beta-galactosidase (puclox). the soluble fraction of the cell lysate of e ... | 1990 | 1696810 |
| major autoantigenic sites of the (u1) small nuclear ribonucleoprotein-specific 68-kda protein. | a 68-kda protein associated with (u1)snrnp is a major target for human autoantibodies to small ribonucleoprotein particles (snrnp) prevalent in a variety of inflammatory rheumatic diseases. the epitopes recognized by these antibodies were mapped by expression of subfragments of p68 cdna in escherichia coli and testing of the corresponding recombinant proteins for immunoreactivity with sera of patients with autoimmune diseases. three of four antigenic regions were analysed in detail. the immunodo ... | 1990 | 1697098 |
| antigenic conservation of primary structural regions of s-adenosylmethionine synthetase. | although the physical and kinetic properties of s-adenosylmethionine (adomet) synthetases from different sources are quite different, it appears that these enzymes have structurally or antigenically conserved regions as demonstrated by studies with adomet synthetase specific antibodies. polyclonal anti-human lymphocyte adomet synthetase crossreacted with enzyme from rat liver (beta isozyme), escherichia coli and yeast. in addition, polyclonal anti-e. coli enzyme and antibodies to synthetic pepti ... | 1990 | 1698095 |
| overproduction of human immunodeficiency virus type i reverse transcriptase in escherichia coli and purification of the enzyme. | overexpression of the reverse transcriptase was designed in e. coli. for a high level of expression, hiv protein was expressed as a protein fusion with beta-galactosidase. when the proviral dna fragment covering the 3' half of the gag gene and the entire pol gene was ligated to the 3' end of the lacz gene to fuse the truncated gag to lacz in frame, a small quantity of reverse transcriptase was produced, indicating that frameshifting and post-translational processing have occurred. much more reve ... | 1990 | 1699113 |
| high-level production of human acidic fibroblast growth factor in e. coli cells: inhibition of dna synthesis in rat mammary fibroblasts at high concentrations of growth factor. | recombinant human acidic fibroblast growth factor has been produced in e. coli cells at a level of at least 50 mg/l culture. the recombinant and natural acidic fibroblast growth factors are almost identical to one another when tested on rat mammary fibroblasts for their ability to stimulate dna synthesis, to bind to the high-affinity surface receptors of the cells and to inhibit dna synthesis when present in the culture medium at high concentrations. the recombinant acidic fibroblast growth fact ... | 1990 | 1699532 |
| possible dissociation of the heparin-binding and mitogenic activities of heparin-binding (acidic fibroblast) growth factor-1 from its receptor-binding activities by site-directed mutagenesis of a single lysine residue. | the fibroblast or heparin-binding growth factors (hbgfs) are thought to be modulators of cell growth and migration, angiogenesis, wound repair, neurite extension, and mesoderm induction. a better understanding of the structural basis for the different activities of these proteins should facilitate the development of agonists and antagonists of specific hbgf activities and identification of the signal transduction pathways involved in the mechanisms of action of these growth factors. chemical mod ... | 1990 | 1699952 |
| human monocytes release plasma serine protease inhibitors in vitro. | the ability of human peripheral blood monocytes to secrete plasma serine protease inhibitors was studied. monocytes from blood obtained from healthy young adult volunteers were cultured for up to 36 h with and without lipopolysaccharide from escherichia coli. the concentrations of plasma serine protease inhibitors in monocyte culture supernatants were measured by using rocket immunoelectrophoresis. the study showed that human monocytes stimulated with lipopolysaccharide in vitro release antithro ... | 1990 | 1700759 |
| influenza a virus potentiates bacteria-induced histamine release. examination of normal individuals and patients allergic to bacteria. | influenza a virus was found to enhance basophil histamine release induced by escherichia coli, salmonella enteritidis, staphylococcus aureus, streptococcus pneumoniae and streptococcus sanguis, but did not per se release histamine. this potentiating effect of the virus was seen both when the bacteria-induced mediator release was ige-dependent (i.e. patient allergic to bacterium) and when the bacterium caused histamine release by a non-immunological mechanism independent of ige (putative sugar-le ... | 1990 | 1700889 |
| binding of il-1 beta to alpha-macroglobulins and release by thioredoxin. | human alpha 2-macroglobulin (h alpha 2m) is a major il-1 beta binding plasma protein. the characteristics of the h alpha 2m il-1 beta complex formation suggested, that cleavage of the internal thiol ester in other members of the alpha-macroglobulin family (alpha m) could enable these proteins to bind il-1 beta. characterization of optimal conditions for binding 125i il-1 beta to h alpha 2m showed that h alpha 2m-il-1 beta complex formation could be obtained over a ph range of 6.3 to 9 in the pre ... | 1990 | 1700994 |
| mutational analysis of the dna polymerase and ribonuclease h activities of human immunodeficiency virus type 2 reverse transcriptase expressed in escherichia coli. | we have constructed a plasmid that, when introduced into escherichia coli, induces the synthesis of large quantities of a polypeptide with an apparent molecular weight of 68 kda. the hiv-2 reverse transcriptase (rt) made in e. coli is soluble in bacterial extracts and possesses both rna-dependent dna polymerase and ribonuclease h (rnase h) activities typical of retroviral rts. the hiv-2 rt expression clone was used to generate mutations in hiv-2 rt. there is a strong correlation between the effe ... | 1991 | 1701948 |
| mucopolysaccharidosis type vii: characterization of mutations and molecular heterogeneity. | we identified two different exonic point mutations causing beta-glucuronidase (beta g1) deficiency in two japanese patients with mucopolysaccharidosis type vii (mpsvii). enzyme assay of lysates of the lymphocytes and cultured fibroblasts showed little residual activity. the beta g1-specific mrna levels were normal, as determined by northern blot analysis. mutated cdna clones, including the entire coding sequence, were isolated using the polymerase chain reaction (pcr) products derived from beta ... | 1991 | 1702266 |
| [production of human g-csf and its derivatives by recombinant dna technology]. | | 1990 | 1702549 |
| screening for enteropathogenic escherichia coli in infants with diarrhea by the fluorescent-actin staining test. | the attaching effacing (ae) adherence property is now recognized as an important virulence characteristic of enteropathogenic escherichia coli (epec). the fluorescent-actin staining (fas) test (s. knutton, t. baldwin, p. h. williams, and a. s. mcneish, infect. immun. 57:1290-1298, 1989), which is diagnostic for the ae lesions produced by epec (and vero cytotoxin-producing e. coli), has provided an additional tool with which to investigate this important class of enteric pathogens. in this study, ... | 1991 | 1702763 |
| analysis of the altered mrna stability (ams) gene from escherichia coli. nucleotide sequence, transcriptional analysis, and homology of its product to mrp3, a mitochondrial ribosomal protein from neurospora crassa. | the product of the altered mrna stability (ams) gene of escherichia coli is involved in decay of mrna. the complete nucleotide sequence of a 4-kilobase bamhi restriction fragment containing the ams coding sequence was determined. transcription of the ams gene was analyzed by high resolution s1 mapping. a promoter was found with a homology score of 58% 361 nucleotides upstream from the start codon of ams. the ams structural gene consists of an open reading frame of 2,445 nucleotides. the protein ... | 1991 | 1704367 |
| cholesteatoma debris as an activator of human monocytes. potentiation of the production of tumor necrosis factor. | tumor necrosis factor (tnf) is a cytokine which stimulates osteoclastic bone resorption and inhibits collagen synthesis in vitro. in this study the effect of human cholesteatoma debris and its constituents on the production of tnf-alpha by human monocytes in vitro was studied. cultured human peripheral monocytes secreted tnf into the culture medium when exposed to cholesteatoma debris in a dose-dependent manner. the tnf production, however, was partially inhibited by the treatment of the debris ... | 1990 | 1704675 |
| reconstitution in vitro of rnase h activity by using purified n-terminal and c-terminal domains of human immunodeficiency virus type 1 reverse transcriptase. | two constituent protein domains of human immunodeficiency virus type 1 (hiv-1) reverse transcriptase were expressed separately and purified to homogeneity. the n-terminal domain (p51) behaves as a monomeric protein exhibiting salt-sensitive dna polymerase activity. the c-terminal domain (p15) on its own has no detectable rnase h activity. however, the combination of both isolated p51 and p15 in vitro leads to reconstitution of rnase h activity on a defined substrate. these results demonstrate th ... | 1991 | 1705027 |
| complement-mediated lysis of trypanosoma cruzi trypomastigotes by human anti-alpha-galactosyl antibodies. | antibodies that lyse trypomastigotes in a complement-mediated reaction are believed to be the main participants in the protection against virulent trypanosoma cruzi. antibodies with a specificity for alpha-galactosyl-containing determinants--generally called antigal--were studied to determine their role in the lysis of trypomastigote forms. the titers of antigal markedly increase in chagas's disease. in the present study we demonstrate binding of this antibody to t. cruzi and the complement-medi ... | 1991 | 1706399 |
| inhibition of tumor growth in mice by an analogue of platelet factor 4 that lacks affinity for heparin and retains potent angiostatic activity. | an analogue of human platelet factor 4 (pf4) lacking affinity for heparin was specifically designed to evaluate the importance of this property in the antitumor effects of recombinant pf4. the purified protein, recombinant pf4-241 (rpf4-241), failed to bind heparin but retained the ability to suppress the growth of tumors in mice. daily intralesional injections of rpf4-241 significantly inhibited the growth of the b-16 melanoma in syngeneic mice without direct inhibitory effects on b-16 cell gro ... | 1991 | 1706960 |
| molecular approaches to leucotoxin as a virulence component in actinobacillus actinomycetemcomitans. | a strategy has been developed to examine the hypothesis that leucotoxin is a critical virulence factor of actinobacillus actinomycetemcomitans in a non-human primate (macaca fascicularis). firstly the leucotoxin gene from a. actinomycetemcomitans was cloned and sequenced. this dna contained a functional leucotoxin gene, as protein extracts of escherichia coli with the cloned sequences lysed appropriate human cell lines. the protein encoded by lkta shared at least 42% identity with p. haemolytica ... | 1990 | 1708231 |
| characterization of monoclonal antibodies against alpha-hemolysin of escherichia coli. | monoclonal antibodies (mabs) were raised against native and denatured alpha-hemolysin (hlya) of escherichia coli. binding of the mabs to native, denatured, and erythrocyte-complexed active wild-type hemolysin and mutant derivatives was tested. all 15 mabs analyzed bound to native hemolysin, even when the toxin was complexed with human erythrocytes. while some mabs were unable to bind to a specific native mutant hemolysin, others could not even bind to mutant hemolysin carrying deletions remote f ... | 1991 | 1708360 |
| cloning, expression and characterization of the human transcription elongation factor, tfiis. | the cdna for the human elongation factor, tfiis, has been cloned and expressed in e. coli with the t7 expression system. this 280-amino acid tfiis protein is shorter by 21 residues than that of the mouse. the missing 21 residues are located in the amino-terminal region, which is not thought to be required for transcriptional stimulation. apart from this gap, human and mouse proteins reveal 96% overall identity and 98.5% sequence similarity if conservative substitutions are taken into account. th ... | 1991 | 1708494 |
| t cell and antibody reactivity with the borrelia burgdorferi 60-kda heat shock protein in lyme arthritis. | the reactivity of cloned t cells and serum antibodies, obtained from patients with chronic lyme arthritis, with expressed recombinant b. burgdorferi 60-kda heat shock protein homologue (hsp60) was analyzed. the expressed recombinant borrelia burgdorferi hsp60 was bound by antibodies in the sera of patients with lyme arthritis, but not by control sera. a t cell clone (cr253), isolated from one of four patients examined, exhibited an hla-dr2 restricted proliferative response to the expressed recom ... | 1991 | 1709664 |
| production of a recombinant human t-cell leukemia virus type-i trans-activator (tax1) antigen and its utilization for generation of monoclonal antibodies against various epitopes on the tax1 antigen. | a 42-kda recombinant protein, px141, consisting of the trans-activator protein encoded by human t-cell leukemia virus (htlv-1) (tax1 antigen) and the amino-terminal fusion peptide of 12 amino acid residues of the alpha-peptide encoded by the plasmid puc19 was produced. in order to investigate the immunogenicity of the tax1 antigen, mice were immunized with the purified px141 and 4 anti-tax1 monoclonal antibodies (mabs) designated taxy-1, taxy-6, taxy-7 and taxy-8 were generated, and their reacti ... | 1991 | 1710610 |
| characterization of the decay-accelerating factor gene promoter region. | decay-accelerating factor (daf) expression modulates susceptibility of cells to autologous complement attack. to characterize the regulatory region controlling daf gene transcription, genomic dna extending from 815 base pairs (bp) upstream to approximately 4 kilobases downstream of daf's aug codon (designated +1) was cloned and sequenced. the 5' flanking sequence showed 59-76% g + c content (-355 to +1), at least one gc box(es) (-135 to -131), and variable length sequences (from -629 to -285) co ... | 1991 | 1711208 |
| the p15 carboxyl-terminal proteolysis product of the human immunodeficiency virus type 1 reverse transcriptase p66 has dna polymerase activity. | the reverse transcriptase of human immunodeficiency virus type 1 is a heterodimeric protein consisting of two polypeptides with masses of 66 and 51 kda and has, as a second enzymatic activity, rnase h activity. the 66-kda polypeptide can be cleaved by the virus-encoded protease to yield polypeptides of 51 and 15 kda. the latter has been characterized as possessing rnase h activity [hansen, j., schultze, t., mellert, w. & moelling, k. (1988) embo j. 7, 239-243]. we have purified simultaneously th ... | 1991 | 1711222 |
| cloning, sequence and chromosomal location of a mel gene from saccharomyces carlsbergensis ncyc396. | yeast strains producing alpha-galactosidase (alpha gal) are able to use melibiose as a carbon source during growth or fermentation. we cloned a mel gene from saccharomyces carlsbergensis ncyc396 through hybridization to the mel1 gene cloned earlier from saccharomyces cerevisiae var. uvarum. the alpha gal encoded by the newly cloned gene was galactose-inducible as is the alpha gal encoded by mel1. a probable gal4-protein recognition sequence was found in the upstream region of the ncyc396 mel gen ... | 1991 | 1711992 |
| substrate inhibition of the human immunodeficiency virus type 1 reverse transcriptase. | substrate inhibition was observed with the heterodimeric (p66/p51) and the homodimeric (p66/p66, p51/p51) forms of human immunodeficiency virus type 1 reverse transcriptase (rna-dependent dna polymerase, ec 2.7.7.49). an apparent ki value of 195 +/- 37 microm was determined for dttp using the bacterial cloned and expressed heterodimer. similar values were obtained with the homodimeric and the virus-encoded enzymes. when poly-(rc).p(dg)10 was used as template-primer, dgtp exhibited substrate inhi ... | 1991 | 1712479 |
| the stable prostacyclin analog, iloprost, and prostaglandin e1 inhibit monocyte procoagulant activity in vitro. | exposure of human peripheral blood to 100 ng/ml of bacterial endotoxin for 2 hours resulted in a 20-fold increase in monocyte procoagulant activity. the activity was functionally identified as tissue factor, because it was not expressed in plasma deficient in factor vii and was specifically inhibited by a monoclonal antibody directed against human tissue factor. when the stable prostacyclin analog, iloprost, was added to blood 30 minutes before endotoxin, a dose-dependent inhibition of monocyte ... | 1991 | 1712648 |
| requirements for the catalysis of strand transfer synthesis by retroviral dna polymerases. | we have examined the properties of reverse transcriptases (rts) required for strand transfer synthesis on poly(ra). in this process, a primer is elongated on one template and then switches to other templates for additional elongation until it is much longer than the templates on which it was made. models of retrovirus replication require the rt to catalyze two distinct strand transfers. additionally, they propose that the rt ribonuclease h (rnase h) activity is involved in both transfers. rts fr ... | 1991 | 1712774 |
| molecular cloning and expression of biologically active human glia maturation factor-beta. | glia maturation factor-beta, a protein found in the brains of all vertebrates thus far examined, appears to play a role in the differentiation, maintenance, and regeneration of the nervous system. using oligonucleotide probes based on the sequences of three tryptic peptides derived from bovine glia maturation factor-beta, we screened a human brainstem cdna library in lambda gt11. a 0.7-kb clone was isolated, sequenced in its entirety, and found to encode a polypeptide of 142 amino acids which co ... | 1991 | 1712830 |
| an hla-c-restricted cd8+ cytotoxic t-lymphocyte clone recognizes a highly conserved epitope on human immunodeficiency virus type 1 gag. | a unique epitope on the gag protein of human immunodeficiency virus type 1 (hiv-1), located at amino acid 145 to 150, has been mapped by using a cd8+ cytotoxic t-lymphocyte (ctl) clone. this epitope is highly conserved among 18 hiv-1 strains. the hiv-1 gag-specific human leukocyte antigen (hla) class i-restricted cd8+ ctl clone was generated from fresh peripheral blood mononuclear cells of an hiv-seropositive donor by stimulation with gamma-irradiated allogeneic peripheral blood mononuclear cell ... | 1991 | 1712857 |
| ribosomal protein genes are overexpressed in colorectal cancer: isolation of a cdna clone encoding the human s3 ribosomal protein. | we have isolated a cdna clone encoding the human s3 ribosomal protein from a normal human colon cdna library. the clone was identified as one of many that detected genes whose level of expression was increased in adenocarcinoma of the colon relative to normal colonic mucosa. increased levels of the s3 transcript were present in the tumors of all eight patients examined. moreover, the s3 mrna was also more abundant in 7 of 10 adenomatous polyps, the presumed precursor of carcinoma. additional stu ... | 1991 | 1712897 |