| characterization of two site-specifically mutated human dihydrolipoamide dehydrogenases (his-452----gln and glu-457----gln). | two site-specifically mutated human dihydrolipoamide dehydrogenases (his-452----gln and glu-457----gln) were expressed in pyruvate dehydrogenase complex-deletion mutant escherichia coli jrg1342. the expressed mutant e3s were purified to near homogeneity using deae-sephacel and hydroxyapatite columns. the initial velocity measurements in the absence of products for the gln-452 mutant e3 in the direction of nad+ reduction showed parallel lines in double-reciprocal plots, indicating that the mutant ... | 1992 | 1347528 |
| coob is required for assembly but not transport of cs1 pilin. | cs1 pili are filamentous proteinaceous appendages found on many enterotoxigenic escherichia coli (etec) strains isolated from human diarrhoeal disease. they are thought to effect colonization of the upper intestine by facilitating binding to human ileal epithelial cells. we have identified a gene, coob, which lies directly upstream of cooa, the gene that encodes the major structural cs1 protein. when translated in vitro, the protein product of coob migrates in sodium dodecyl sulphate/polyacrylam ... | 1992 | 1348100 |
| the replication of dna containing the simian virus 40 origin by the monopolymerase and dipolymerase systems. | the influence of dna polymerase (pol) alpha and dna primase on sv40 dna replication was examined in both the monopolymerase and dipolymerase systems. the synthesis of oligoribonucleotides in the monopolymerase and dipolymerase systems, followed by pulse labeling with deoxynucleoside triphosphates, yielded short okazaki fragments approximately 35 nucleotides in length that were chased into full-length okazaki fragments with time. in the presence of activator 1 and proliferating cell nuclear antig ... | 1992 | 1348504 |
| ability of enteroaggregative escherichia coli strains to adhere in vitro to human intestinal mucosa. | a collection of 44 enteroaggregative escherichia coli (eaggec) strains isolated from infants with diarrhea in india and the united kingdom were examined for their ability to adhere in vitro to human intestinal mucosa and by electron microscopy for production of putative adherence factors. none of the strains adhered to human duodenal mucosa, and six strains tested did not adhere to ileal mucosa; all 44 strains, however, adhered to human colonic mucosa in localized aggregates. electron microscopy ... | 1992 | 1348724 |
| serotype, hemolysin production, and adherence characteristics of strains of escherichia coli causing urinary tract infection in dogs. | virulence factors were studied in 82 strains of escherichia coli isolated from the urine of dogs with urinary tract infections. the most frequently expressed o antigens were 2, 4, 6, 25, and 22/83. most strains were k nontypeable. mannose-sensitive hemagglutination (msh) with canine erythrocytes was observed in 71 strains and mannose-resistant hemagglutination (mrh) was observed in 32 strains. strains that caused msh of erythrocytes from dogs also caused msh of erythrocytes from guinea pigs. mos ... | 1992 | 1350184 |
| aggregative adherence fimbriae i of enteroaggregative escherichia coli mediate adherence to hep-2 cells and hemagglutination of human erythrocytes. | strains of enteroaggregative escherichia coli (eaggec) have been implicated in several studies as important agents of persistent diarrhea among infants in the developing world. we have previously shown that the aggregative adherence (aa) property of eaggec is associated with the presence of a 60-mda plasmid which confers aa when introduced into e. coli hb101. here, we report the cloning of the aa determinant from eaggec strain 17-2 into the 21.5-kb cosmid vector pcvd301. tnphoa mutagenesis of th ... | 1992 | 1350273 |
| the importance of p and type 1 fimbriae for the persistence of escherichia coli in the human gut. | the faecal escherichia coli flora was studied in 89 infants. each infant was followed with a mean of 12 faecal samples (range 5-21) between 0 and 18 months of age. all isolates were assayed for p fimbriae and biochemically phenotyped and the persistence of each strain (phenotype) in the infant's gut was determined. in a subset of strains the occurrence of type 1 fimbriae and adherence to hela cells was studied. thirty-one per cent of isolates belonging to strains colonizing for longer than 6 mon ... | 1992 | 1350997 |
| antigen binding thermodynamics and antiproliferative effects of chimeric and humanized anti-p185her2 antibody fab fragments. | the murine monoclonal antibody 4d5 (anti-p185her2) inhibits the proliferation of human tumor cells overexpressing p185her2 in vitro and has been "humanized" [carter, p., presta, l., gorman, c. m., ridgway, j. b. b., henner, d., wong, w.-l. t., rowland, a. m., kotts, c., carver, m. e., & shepard, h. m. (1992) proc. natl. acad. sci. u.s.a. (in press)] for use in human cancer therapy. we have determined the antigen binding thermodynamics and the antiproliferative activities of chimeric 4d5 fab (ch4 ... | 1992 | 1351741 |
| regulation of recombinant human tyrosine hydroxylase isozymes by catecholamine binding and phosphorylation. structure/activity studies and mechanistic implications. | three isozymes of human tyrosine hydroxylase (hth1, hth2 and hth4) were expressed in escherichia coli and purified to homogeneity. natural catecholamines and related synthetic compounds were found to be potent inhibitors, competitive to the tetrahydrobiopterin cofactor, of all the isozymes. combining visible spectroscopy and equilibrium-binding studies, it was found that catecholamines bind to hth1 and hth2 with a stoichiometry of about 1.0 mol/mol enzyme subunit, interacting with the catalytic ... | 1992 | 1356768 |
| the adherence of verocytotoxin-producing escherichia coli to rabbit intestinal cells. | verocytotoxin-producing escherichia coli (vtec) have been recognised recently as an important cause of human disease. the adherence of vtec to rabbit intestinal tract and the relationship between adherence and other virulence traits were studied. twenty clinical isolates of vtec (o157:h7 and other serotypes) and a control, commensal e. coli strain, were examined. bacteria were evaluated for the presence of surface fimbriae, plasmid profile and hybridisation with a 3.4 kb dna probe derived from t ... | 1992 | 1359147 |
| regulation of intestinal guanylate cyclase by the heat-stable enterotoxin of escherichia coli (sta) and protein kinase c. | the heat-stable enterotoxin of escherichia coli (sta) stimulates membrane-bound guanylate cyclase in intestinal epithelium and induces fluid and ion secretion. using the t84 human colon carcinoma cell line as a model, we observed that phorbol esters markedly enhanced sta-stimulated cyclic gmp accumulation in t84 cells (c. s. weikel, c. l. spann, c. p. chambers, j. k. crane, j. linden, and e. l. hewlett, infect. immun. 58:1402-1407, 1990). in this study we document that the phorbol ester treatmen ... | 1992 | 1360449 |
| the use of consensus sequence for amplification and oriented cloning of human alpha interferon genes. | a clone from human cdna library was amplified in polymerase chain reaction (pcr) by the synthetic oligonucleotides. the final construct after linker ligation and digestion with restriction endonucleases was suitable for oriented cloning into e. coli expression vector. the interferon (ifn) expression could be detected by sds-page electrophoresis. western blotting and biological antiviral assay. this set of oligonucleotides can be used also for amplification of genomic dna or cdna libraries. | 1992 | 1364027 |
| expression of hiv-2 gag and env antigens in e. coli. | | 1992 | 1364028 |
| production of a protein a--lymphotoxin hybrid protein for cancer-targeted therapy. | a hybrid protein between staphylococcal protein a and human lymphotoxin, alt, was produced in escherichia coli by expression of a recombinant plasmid containing the respective genes. igg-binding activity of alt was confirmed by western blotting analysis and by affinity purification with igg-sepharose column chromatography. the purified alt had cytotoxicity on mouse l-929 cells and its specific activity was approximately 3.5-5.0 x 10(6) u mg-1. alt was partially degraded by a protease including i ... | 1990 | 1366561 |
| high level expression of interleukin-1 beta in a recombinant escherichia coli strain for use in a controlled bioreactor. | a recombinant bacterial strain for the large scale production of human interleukin-1 beta (il-1 beta) was constructed. the lambda pr and the tryptophan systems were compared for efficiency of transcription and regulation. the efficiency of il-1 protein production from these constructs was analyzed. enhanced protein synthesis was achieved by the fusion of lambda pr promoter sequences with trp leader sequences which included the trp rbs. a strain (jm101) was selected for use as a host and tested i ... | 1990 | 1366581 |
| cytoplasmic and periplasmic expression of a highly basic protein, human interleukin 4, in escherichia coli. | human il-4 (hil-4) has been cloned from a human t cell line based on its homology to the murine il-4 cdna sequence. we have compared cytoplasmic and extra-cytoplasmic expression of this basic protein in escherichia coli using various combinations of promoters, replicons and host strains. strains producing a cytoplasmic product were most successful at heterologous protein expression, producing up to 500 mg/l of an inactive aggregated form of the protein. the biological activity of the protein cou ... | 1990 | 1366607 |
| large-scale production of recombinant proteins: human leukocyte interferon. | | 1990 | 1366819 |
| high-level direct expression of semi-synthetic human interleukin-6 in escherichia coli and production of n-terminus met-free product. | we have developed a direct expression system for high-level production of recombinant human interleukin-6 (rhil-6) in escherichia coli. in this system, (i) the natural n-terminal coding region of the hil-6 gene was replaced by a synthetic sequence containing a-t rich codons, (ii) dual shine-dalgarno (sd) sequences were employed, (iii) an a-t rich segment was inserted in front of the initiation codon to avoid putative mrna secondary structure in the region and (iv) the natural amber termination c ... | 1990 | 1366931 |
| high-level secretion of human apolipoprotein e produced in escherichia coli: use of a secretion plasmid containing tandemly polymerized ompf-hybrid gene. | a gene encoding the mature form of human apolipoprotein e (h-apoe) was fused to the secretion signal coding sequence of the escherichia coli major outer membrane protein f (ompf) which was preceded by a consensus shine-dalgarno sequence. two copies of this hybrid gene were inserted tandemly into an expression vector and expressed in e. coli under the transcriptional control of two tac promoters regulated by lac repressors. by the addition of isopropyl-beta-d-thiogalactopyranoside (iptg) to the g ... | 1991 | 1366982 |
| production of human interleukin-3 using industrial microorganisms. | we expressed a cdna encoding the multicolony stimulating factor interleukin-3 in a variety of cell types, including bacteria, yeast and mammalian cells. after evaluation of the advantages and disadvantages of each potential system, we designed a production and purification scheme using bacillus licheniformis. the purification consists of hydrophobic interaction chromatography, two steps of ion exchange chromatography and gel filtration. the purified and formulated product entered clinical trials ... | 1991 | 1367211 |
| optimizing the promoter and ribosome binding sequence for expression of human single chain urokinase-like plasminogen activator in escherichia coli and stabilization of the product by avoiding heat shock response. | the expression of recombinant single-chain urokinase-like plasminogen activator (rscupa) in escherichia coli was optimized by fusing the puk gene to different promoters and ribosome binding sequences. comparison of the tac, trp and lambda pl promoters showed that expression was maximal under tac control. variation in the ribosome binding sequence and its distance to the aug start codon yielded a further slight improvement of expression. the largest increase in rscupa expression was achieved by v ... | 1991 | 1367523 |
| production of recombinant human interferon-alpha 1 by escherichia coli using a computer-controlled cultivation process. | genetically engineered e. coli k12 bmh-71-18 with plasmid pbv-867 was used for constitutive expression of human interferon-alpha 1 (ifn) with a defined medium. a manual, time-based, fed-batch cultivation process produced a cell density of 26.3 g l-1 (od550 89), an ifn activity of 1.55 x 10(8) iu l-1 and a specific ifn productivity of 0.65 x 10(6) iu g-1. an analysis was conducted to characterize the problems involved in the high density microbial processes of recombinant protein production. the ... | 1992 | 1368247 |
| effect of glycosylation on properties of soluble interferon gamma receptors produced in prokaryotic and eukaryotic expression systems. | we investigated the influence of glycosylation on solubility, chromatographic behavior and resistance to heat- and chaotrope-dependent denaturation and proteolytic digestion of three recombinant human interferon gamma receptors produced in escherichia coli, spodoptera frugiperda and chinese hamster ovary cells. the proteins produced in the eukaryotic expression systems were glycosylated, carrying different, heterogeneous carbohydrate moieties. they were assayed fully glycosylated and after remov ... | 1992 | 1368793 |
| overproduction of biologically-active human nerve growth factor in escherichia coli. | a gene coding for human nerve growth factor (hngf) was constructed for expression under control of the trp promoter in e. coli. the plasmid ptrsngf contained a synthetic hngf gene fused, in frame, to the region encoding the beta-lactamase signal peptide. the plasmid ptrlngf contained the same coding sequence as hngf attached downstream from the n-terminal fragment of the trp l gene. e. coli cells harboring ptrsngf produced an amount of hngf constituting 4% of the total cellular protein, and remo ... | 1992 | 1369095 |
| flocculation: an alternative process to ion-exchange chromatography: (a scale-up study using recombinant human superoxide dismutase as model protein). | flocculation using pellicular charged flocculants was investigated as an alternative process to conventional chromatography in purification of recombinant proteins using human recombinant superoxide dismutase expressed in e. coli as a model system. the removal of pyrogens, proteins, debris and the yield were determined. at laboratory scale, the starting conditions were optimized to yield a stable solution and the flocculation process fitted into a purification scheme. 100 l fermentation broth wa ... | 1992 | 1369245 |
| improvement of recombinant gene expression in escherichia coli for glucose-controlled continuous and fed-batch cultures. | escherichia coli tg1 (phrw500) permanently expressed the human interferon alpha 1 gene (ifn alpha 1) directed by the tryptophan promoter (trpp.o) during continuous and fed-batch cultivation with a limited supply of glucose. the expression of ifn alpha 1 could be improved after insertion of the catabolite activator region (cap) upstream to trpp.o during cultivation of the modified e. coli tg1(phrw500cap) in glucose-controlled continuous and fed-batch cultures. the cap-mediated stimulatory effect ... | 1992 | 1369371 |
| production of a site specifically cleavable p-glycoprotein-beta-galactosidase fusion protein. | we have fused full length and the carboxyl-half of human mdr1 cdna with the e. coli lacz gene via a collagen linker and allowed their expression in yeast saccharomyces cerevisiae. using antibodies against beta-galactosidase we partially purified the fusion proteins by immunoprecipitation and show here that the full length fusion protein has atpase activity. by contrast, the fusion protein containing the carboxyl-half of p-glycoprotein did not show atpase activity, indicating that both domains of ... | 1991 | 1369454 |
| expression of the human blood coagulation protein factor xiiia in saccharomyces cerevisiae: dependence of the expression levels from host-vector systems and medium conditions. | the human blood coagulation protein factor xiiia (fxiiia) was expressed in saccharomyces cerevisiae employing escherichia coli-yeast shuttle vectors based on a 2-mu plasmid. several factors affecting high production yield of recombinant fxiiia were analysed. the use of the regulatable gal-cyc1 hybrid promoter resulted in higher fxiiia expression when compared with the constitutive adci promoter. screening for suitable yeast strains for expression of fxiiia under the transcriptional control of th ... | 1991 | 1369455 |
| dnak-mediated alterations in human growth hormone protein inclusion bodies. | protein overproduction in microbes frequently results in protein misfolding and aggregation though the molecular basis for this process is unclear. the hsp70 chaperonin, dnak, was identified as an important factor controlling heterologous protein aggregation in escherichia coli. co-overproduction of dnak significantly reduced human growth hormone (hgh) protein inclusion body formation and the extent of hgh aggregation. | 1992 | 1369475 |
| a cd4+ cytotoxic t-lymphocyte clone to a conserved epitope on human immunodeficiency virus type 1 p24: cytotoxic activity and secretion of interleukin-2 and interleukin-6. | a cd4+ cytotoxic t-lymphocyte (ctl) clone, established from the peripheral blood of a human immunodeficiency virus (hiv)-seropositive donor, lysed autologous target cells that were infected with a recombinant vaccinia virus containing the gag gene of hiv type 1 and target cells pulsed with p24gag construct expressed in escherichia coli. the recognition of the hla-dq-restricted epitope by this clone was further defined by using overlapping synthetic peptides. the epitope recognized by this cd4+ c ... | 1992 | 1370094 |
| epitopes on the outer surface protein a of borrelia burgdorferi recognized by antibodies and t cells of patients with lyme disease. | we have characterized immunogenic epitopes of the 31-kda outer surface protein a (ospa) protein of borrelia burgdorferi, which is a major surface ag of the spirochete causing lyme disease. full length and truncated forms of rospa proteins were expressed in escherichia coli, and their reactivities with antibodies and human t cell clones isolated from patients with lyme disease were determined. the epitopes recognized by three of four ospa-reactive t cell clones are contained within the 60 cooh-te ... | 1992 | 1370170 |
| catalytic domains of the lar and cd45 protein tyrosine phosphatases from escherichia coli expression systems: purification and characterization for specificity and mechanism. | the cytoplasmic domains of two human transmembrane protein tyrosine phosphatases (ptpases), lar and cd45, have been expressed in escherichia coli, purified to near-homogeneity, and compared for catalytic efficiency toward several phosphotyrosine-containing peptide substrates. a 615-residue lar fragment (lar-d1d2) containing both tandemly repeated ptpase domains shows almost identical specific activity and high catalytic efficiency as the 40-kda single-domain lar-d1 fragment, consistent with a si ... | 1992 | 1370625 |
| lipooligosaccharides (los) of some haemophilus species mimic human glycosphingolipids, and some los are sialylated. | the lipooligosaccharides (los) of strains of haemophilus ducreyi, neisseria gonorrhoeae, neisseria meningitidis, and neisseria lactamica contain epitopes that are antigenically and structurally similar to carbohydrates present in human glycosphingolipids. los from strains of haemophilus influenzae and h. influenzae biogroup aegyptius were tested for the binding of monoclonal antibodies (mabs) that bind to human glycosphingolipids possessing gal beta 1-4glcnac (mab 3f11) and gal alpha 1-4gal beta ... | 1992 | 1372291 |
| small cytoplasmic rna of bacillus subtilis: functional relationship with human signal recognition particle 7s rna and escherichia coli 4.5s rna. | small cytoplasmic rna (scrna; 271 nucleotides) is an abundant and stable rna of the gram-positive bacterium bacillus subtilis. to investigate the function of scrna in b. subtilis cells, we developed a strain that is dependent on isopropyl-beta-d-thiogalactopyranoside for scrna synthesis by fusing the chromosomal scr locus with the spac-1 promoter by homologous recombination. depletion of the inducer leads to a loss of scrna synthesis, defects in protein synthesis and production of alpha-amylase ... | 1992 | 1372600 |
| mechanism of interferon action: identification of a rna binding domain within the n-terminal region of the human rna-dependent p1/eif-2 alpha protein kinase. | a molecular cdna clone of the human rna-dependent p1/eif-2 alpha protein kinase was expressed in escherichia coli. mutant p1 proteins were examined for rna binding activity by northwestern blot analysis using the reovirus s1 mrna, an activator of the kinase; the adenovirus vai rna, an inhibitor of kinase activation; or human immunodeficiency virus (hiv) tar rna as probe. analysis of trpe-p1 deletion mutant fusion proteins revealed that the 11-kda n-terminal region of the p1 protein bound reoviru ... | 1992 | 1373554 |
| mutants of human insulin-like growth factor ii (igf ii). expression and characterization of truncated igf ii and of two naturally occurring variants. | insulin-like growth factor ii (igf ii) and four structural analogs, constructed by site-directed mutagenesis, were expressed as protein a fusion proteins in escherichia coli bl21plyss cells, cleaved with cyanogen bromide and purified by affinity chromatography and hplc. two mutants (ser29 substituted by arg-leu-pro-gly, and ser33 substituted by cys-gly-asp) represent two naturally occurring variants of igf ii. the other two mutants, (7-67)igf ii and (9-67)igf ii, are truncated at the amino-termi ... | 1992 | 1374027 |
| purification and characterization of soluble forms of human and rat stem cell factor recombinantly expressed by escherichia coli and by chinese hamster ovary cells. | stem cell factor (scf) is a novel, early-acting hematopoietic factor. it was isolated from the medium of a rat cell line in a soluble, processed form (zsebo et al., 1990, cell 63, 195). the cloned human and rat genes encode the soluble form plus additional c-terminal amino acids including a hydrophobic transmembrane domain (martin et al., 1990, cell 63, 203). we have recombinantly expressed forms of human and rat scf corresponding to the soluble, processed form in escherichia coli and in chinese ... | 1992 | 1374224 |
| reactivity of human serum antibody with lipopolysaccharide o 78 antigen from enterotoxigenic escherichia coli. | fifteen and five of 20 volunteers challenged with the enterotoxigenic escherichia coli strain o 78.h11 showed a fourfold titre increase of serum elisa antibody to the homologous o 78 and the heterologous o 8 lipopolysaccharide antigen, respectively. sixty-three of 191 sera from 1- to 48-month-old german children showed serum antibody reactive with o 78 antigen, all but two of these o 78-positive sera also showed reactivity with at least one further o antigen. only 14 of the o 78 reactive sera al ... | 1992 | 1374719 |
| molecular and immunological characterization of adp-ribosylarginine hydrolases. | mono-adp-ribosylation is a reversible modification of proteins with nad:arginine adp-ribosyltransferases and adp-ribosylarginine hydrolases catalyzing the forward and reverse reactions, respectively. hydrolase activities were present in a variety of animal species, with the highest specific activities found in rat and mouse brain, spleen, and testis. rat and mouse hydrolases were dithiothreitol- and mg(2+)-dependent, whereas the bovine and guinea pig enzymes were dithiothreitol-independent. a ra ... | 1992 | 1375222 |
| isolation and expression of a gene encoding l-14-ii, a new human soluble lactose-binding lectin. | in the course of screening a human hepatoma cdna library with antibody raised against a mammalian lectin with subunit molecular weight of about 14,000, we detected a partial cdna encoding a related but distinct protein that was possibly a homologous lectin (gitt and barondes, 1986). we here report the isolation and sequencing of a full-length cdna for this protein from a hepg2 cdna library. the cdna encodes a protein with subunit molecular weight of 14,650. expression of the coding sequence in e ... | 1992 | 1375225 |
| molecular cloning of a 25-kda high affinity rapamycin binding protein, fkbp25. | two fk506 binding proteins of molecular mass 12 kda (fkbp12) and 13 kda (fkbp13) have been identified as common cellular receptors of the immunosuppressants fk506 and rapamycin. here we report the molecular cloning and overexpression of a 25-kda rapamycin and fk506 binding protein (termed fkbp25) with peptidylprolyl cis-trans-isomerase (ppiase) activity. the amino acid sequence, predicted from the fkbp25 cdna, shares identity with fkbp12 (44%) and fkbp13 (47%) in the c-terminal 97 amino acids. u ... | 1992 | 1375932 |
| the sequence of the flavoprotein subunit of bovine heart succinate dehydrogenase. | the cdna sequence of the flavoprotein subunit of bovine heart succinate dehydrogenase is reported. this is the first complete eukaryotic sequence of the flavoprotein subunit to be characterized, and it encodes a 665-amino acid protein that consists of a presequence and a 621-residue mature protein. the deduced bovine sequence shows homology to the corresponding peptides of prokaryotic succinate dehydrogenase and the related fumarate reductases; in particular, there is good overall homology (48%) ... | 1992 | 1375942 |
| a molecular defect in human protoporphyria. | protoporphyria is generally an autosomal dominant disease that is characterized clinically by photosensitivity and hepatobiliary disease and that is characterized biochemically by elevated protoporphyrin levels. the enzymatic activity of ferrochelatase, which catalyzes the last step in the heme biosynthetic pathway, is deficient in all tissues of patients with protoporphyria. in this study, sequencing of ferrochelatase cdnas from a patient with protoporphyria revealed a single point mutation in ... | 1992 | 1376018 |
| high level expression in e. coli of an alternate reading frame of ps2 mrna that encodes a mimotope of human breast epithelial mucin tandem repeat. | the high molecular weight mucin found in human milk fat globule and on the surface of mammary and other epithelial cells contains a 20 amino acid tandem repeat sequence that is highly immunogenic. we have immunoscreened lambda gt11 cdna expression libraries from mcf7 cells and lactating breast tissue with 5 anti-mucin monoclonal antibodies. we isolated a group of cdna clones that had the repeat sequence (hb11-2, hb11-6, hb11-10) and a group that had little or no homology with the repeat sequence ... | 1992 | 1376717 |
| granulocyte colony-stimulating factor (g-csf) gene transduction in murine adenocarcinoma drives neutrophil-mediated tumor inhibition in vivo. neutrophils discriminate between g-csf-producing and g-csf-nonproducing tumor cells. | we have previously demonstrated that the murine colon adenocarcinoma c-26 cell line transduced with the human gene for the granulocyte csf (g-csf) loses tumorigenic activity through a mechanism that involved massive targeting of neutrophils at the site of tumor injection. the suppression of tumorigenicity by g-csf was limited to the g-csf-producing cells and was not transferred to nonproducing c-26 cells in a mixed tumor transplantation assay. we present direct evidence that neutrophils are invo ... | 1992 | 1376745 |
| infection of hematopoietic progenitor cells by human cytomegalovirus. | the susceptibility of hematopoietic progenitor cells to infection by human cytomegalovirus (hcmv) was investigated using several strains of hcmv, including the recombinant strain rc256. rc256 is derived from the laboratory strain towne and contains the escherichia coli lacz gene coding for beta-galactosidase (beta-gal) regulated by an early hcmv promoter. expression of lacz allowed the detection of hcmv in individual hematopoietic cells. clonogeneic bone marrow (bm) progenitors, including cd34+ ... | 1992 | 1377049 |
| highly sensitive enzyme-linked immunosorbent assay for marograstim (kw-2228), a mutant of human granulocyte colony-stimulating factor. | an enzyme-linked immunosorbent assay (elisa) for marograstim (kw-2228) was established. this elisa proved to be highly sensitive with the detection limit of 0.01 ng/ml (about 0.5 fmol/ml) of kw-2228 and the assay range between 0.01 and 2 ng/ml. when 0.02 to 2 ng/ml of kw-2228 added to human plasma was determined, the variation coefficiencies of intra-day and inter-day assays were 0.4 to 7.6% and 5.2 to 15.8%, respectively, with good recoveries. these results indicate that this elisa will be appl ... | 1992 | 1378090 |
| molecular cloning, stage-specific expression and cellular distribution of a putative protein kinase from plasmodium falciparum. | a putative protein kinase gene (pfpk2) has been isolated from the human parasite plasmodium falciparum by using a mixed oligonucleotide pool which corresponds to a highly conserved region of serine/threonine protein kinases. the complete nucleotide sequence of 5 kb suggests the existence of a second transcriptional unit besides that of the pfpk2 gene, separated by a highly (a+t)-rich region and transcribed in a different orientation. no intron sequence exists in pfpk2. the predicted amino acid s ... | 1992 | 1378403 |
| inhibition of human immunodeficiency virus type 1 reverse transcriptase by 3'-blocked oligonucleotide primers. | human immunodeficiency virus type 1 (hiv-1) reverse transcriptase (rt) (ec 2.7.7.49) with a high specific activity has been purified from the overexpressing escherichia coli strain dh5 alpha [pjs3.7]. steady-state kinetics of dna synthesis catalysed by rt were analysed on polyriboadenylate 20-mer of (3'-5')deoxythymidylate [poly(ra).(dt)20] and polyribouridylate 20-mer of (3'-5')-deoxyadenylate [poly(ru).(da)20] homopolymeric template-primers. km values of 40 and 140 nm (3'-oh ends) and kcat val ... | 1992 | 1378738 |
| mip protein of legionella pneumophila exhibits peptidyl-prolyl-cis/trans isomerase (pplase) activity. | legionella pneumophila is an intracellular parasite which is able to survive and multiply in human monocytes and alveolar macrophages. the mip (macrophage infectivity potentiator) protein has been shown to be an essential virulence factor. a search of translated nucleic acid data bases has shown that the mip protein from strain wadsworth possesses regions homologous to those found in the fk506-binding proteins (fkbps) of several different eukaryotic organisms. fkbps are able to bind to the immun ... | 1992 | 1379319 |
| characterization of two high affinity human interleukin-8 receptors. | interleukin 8 (il-8) and melanocyte growth-stimulatory activity/gro (mgsa) are structurally related proinflammatory cytokines that are chemoattractants and activators of neutrophils. recently, cdna clones encoding a high affinity il-8 receptor (il-8r-a) and a "low affinity" il-8 receptor (il-8r-b) have been isolated from human cdna libraries. these two receptors have 77% amino acid identity and are members of the g protein-coupled superfamily of receptors with seven transmembrane domains. we hav ... | 1992 | 1379593 |
| the genotoxicity of organotin compounds in sos chromotest and rec-assay. | in these days pollution by organotin compounds in the environment extends widely and effects on human health are feared. we studied the genotoxicity of various organotin compounds (butyltins, phenyltins, methyltins) and inorganic tin (sncl4), which are present in the environment, with the sos chromotest and the rec-assay. mono-n-butyltin oxide, n-butyltin trichloride and di-n-butyltin dichloride showed high sos-inducing potency in the sos chromotest with escherichia coli pq37. di-n-butyltin dich ... | 1992 | 1381483 |
| detection and quantitation of recombinant granulocyte colony-stimulating factor charge isoforms: comparative analysis by cationic-exchange chromatography, isoelectric focusing gel electrophoresis, and peptide mapping. | routine quantitation of recombinant human granulocyte colony-stimulating factor charge isoforms in the purified protein product requires development of a reliable analytical method. in this report, isoelectric focusing gel electrophoresis, peptide mapping, and cation-exchange high-performance liquid chromatography are compared and evaluated in the analysis of charge isomers that may be present in the recombinant factor. due to a lack of sensitivity and reliability, isoelectric focusing gel elect ... | 1992 | 1381566 |
| identification and analysis of the gap region in the 23s ribosomal rna from actinobacillus actinomycetemcomitans. | actinobacillus actinomycetemcomitans is a gram-negative coccobacillus which can cause certain severe extra-oral infections as well as forms of human periodontal disease such as localized juvenile periodontitis. in contrast to many prokaryotic and eukaryotic species which exhibit an intact 23s ribosomal rna (rrna) molecule, examination of six a. actinomycetemcomitans strains--including three serogroup representative strains and two strains from non-human primates--revealed that this micro-organis ... | 1992 | 1381732 |
| [chemical-enzymatic synthesis and cloning in escherichia coli of a gene coding for human granulocyte-colony stimulating factor]. | two artificial genes, encoding two forms of human granulocyte colony stimulating factor as products of a normal and an alternative splicing, have been by a chemical-enzymatic way synthesized and cloned in escherichia coli. the genes are supplied with recognition sites of restriction endonucleases to facilitate the further cassette mutagenesis. | 1992 | 1381918 |
| functional analysis of novel selective mutants of the reverse transcriptase of human immunodeficiency virus type 1. | we have generated by site-directed mutagenesis plasmids that induce the synthesis of specific mutants of the reverse transcriptase (rt) of human immunodeficiency virus type 1 (hiv-1). these recombinant mutants of hiv-1 rt, designed on the basis of our previous studies of hiv-1 and hiv-2 rts, were analyzed for structure-function relationship by assessing their rna-dependent and dna-dependent dna polymerase as well as the ribonuclease h activities. three groups of mutants were studied. 1) we have ... | 1992 | 1382052 |
| flow cytometric detection of drugs altering the dna methylation pattern. | we have developed a model system for assessing the demethylating potential of external agents. disruption in the dna methylation pattern was evaluated at the translational level of the escherichia coli beta-galactosidase coding gene (lacz). we have constructed a clonal cell line (a4/4 cells) derived from the adenovirus-transformed human embryonic kidney 293 strain. the a4/4 cells contain the e. coli lacz gene under the control of the mouse metallothionein 1 promoter which is down-regulated by a ... | 1992 | 1382840 |
| sequence and structural analysis of the rfb (o antigen) gene cluster from a group c1 salmonella enterica strain. | the rfb (o antigen) gene cluster of a group c1 salmonella enterica strain was sequenced; it comprised seven open reading frames which precisely replaced the 16 open reading frames of a group b strain. two genes of the mannose biosynthetic pathway were present: rfbk (phosphomannomutase) had a g+c content of 0.61 and had only 40% identity to rfbk of group b but was very similar to cpsg of the capsular polysaccharide pathway with 96% identity, whereas rfbm [guanosine diphosphomannose (gdp-man) pyro ... | 1992 | 1383393 |
| requirements for strand transfer between internal regions of heteropolymer templates by human immunodeficiency virus reverse transcriptase. | we have examined the ability of the reverse transcriptase (rt) from human immunodeficiency virus (hiv) to carry out strand transfer synthesis (i.e., switching of the primer to a new template) from internal regions of natural-sequence rna. a 142-nucleotide rna template (donor) primed with a specific 20-nucleotide dna oligonucleotide was used to initiate synthesis. dna oligonucleotides with homology to internal regions of the donor were used as acceptors. in this system, hiv rt produced strand tra ... | 1992 | 1383563 |
| inhibition of dna polymerase activity by thymine hydrates. | ultraviolet irradiation of dna results in various pyrimidine modifications. we have demonstrated formation of both cis-thymine hydrate and trans-thymine hydrate (6-hydroxy-5,6-dihydrothymine) in uv-irradiated poly(da-dt):poly(da-dt). both are released from dna as free bases by bacterial and human glycosylases. thymine hydrates are stable in dna and can be detected in control, unirradiated substrates. we examined the effects of thymine hydrates in uv-irradiated substrate poly(da-dt):poly(da-dt) o ... | 1992 | 1383813 |
| intracellular localization of human dna repair enzyme methylguanine-dna methyltransferase by antibodies and its importance. | the human dna repair enzyme, methylguanine-dna methyltransferase (mgmt, m(r) 21,000), which protects cells against the mutagenic effect of alkylating carcinogens, was found to be localized in the cell nucleus (except the nucleolus) by immunofluorescence staining using polyclonal and monoclonal antibodies. the supporting experiments came from differential staining of the mgmt-deficient (mer-) and -proficient (mer+) cells, western blotting analysis, and specific antibody depletion studies with the ... | 1992 | 1384961 |
| conversion of human interleukin-4 into a high affinity antagonist by a single amino acid replacement. | interleukin-4 (il-4) represents a prototypic lymphokine (for a recent review see paul, 1991). it promotes differentiation of b-cells and the proliferation of t- and b-cell, and other cell types of the lymphoid system. an antagonist of human il-4 was discovered during the studies presented here after tyr124 of the recombinant protein had been substituted by an aspartic acid residue. this il-4 variant, y124d, bound with high affinity to the il-4 receptor (kd = 310 pm), but retained no detectable p ... | 1992 | 1387082 |
| the cell cycle regulator, human p50weel, is a tyrosine kinase and not a serine/tyrosine kinase. | the human weel protein, a homologue of the yeast weel protein, was expressed in e. coli and purified to homogeneity. the purified weel protein phosphorylated the tyrosine residue of cdc2 kinase in hela cell extracts in the presence of human cyclin b1. it also phosphorylated the tyrosine but not the threonine residue in the peptide of the amino-terminal of cdc2 kinase, although both these residues have been shown to be phosphorylated in higher eukaryotes in vivo. furthermore, serine and tyrosine ... | 1992 | 1387308 |
| overproduction of a human snrnp-associated sm-d autoantigen in escherichia coli and saccharomyces cerevisiae. | to conduct functional and autoimmunity studies, we overproduced human sm-d1 (hsm-d1), a small nuclear ribonucleoprotein 'core' protein and autoantigen, in escherichia coli and saccharomyces cerevisiae. optimal expression in these organisms was achieved by designing vectors that synthesized abundant hsm-d1 mrna under the control of the strong, regulatable promoters: t7 phi 10 (e. coli) and gal1 (yeast). in addition, efficient translation initiation of the hsm-d1 coding sequence was effected in e. ... | 1992 | 1387379 |
| pyruvic acid is attached through its central carbon atom to the amino terminus of the recombinant dna-derived dna-binding protein ner of bacteriophage mu. | ner protein of bacteriophage mu, produced by recombinant dna techniques in escherichia coli, has been found to possess a molecule of pyruvic acid attached covalently through carbon-2 to the amino-terminal cysteine residue. the intact protein and the amino-terminal chymotryptic peptide were found by mass spectrometry to be 70 mass units heavier than expected. the modified peptide was unstable under mildly acid or mildly basic conditions. two-dimensional nuclear magnetic resonance spectroscopy of ... | 1992 | 1388164 |
| human hemoglobin expression in escherichia coli: importance of optimal codon usage. | the overexpression of a nonfusion product of human beta-globin in escherichia coli from its cdna sequence has been accomplished for the first time. expression of beta-globin from its native cdna required the use of the strong bacteriophage t7 promoter. in this system, beta-globin accumulated to approximately 10% of total e. coli proteins. alpha-globin was not expressed in the t7 system using the native cdna. for the expression of alpha-globin, synthetic genes containing optimal e. coli codons we ... | 1992 | 1390646 |
| expression and secretion of an assembled tetrameric ch2-deleted antibody in e. coli. | we have expressed in e. coli a functional assembled antibody variant that is secreted into the media. the antibody variant is a ch2-deleted chimeric antibody 14.18, which was previously shown to be a potentially useful reagent for radioimmunodetection of human tumors. the bacterial expression vector contains a dicistronic unit comprised of a l-chain cdna and a ch2-deleted h-chain cdna. for translocation across the bacterial membranes, we have replaced the natural signal peptides of the h and l c ... | 1992 | 1391661 |
| stable expression of cloned human antibody genes in murine myeloma cells. | human monoclonal antibodies (mabs) offer potential advantages over murine mabs for therapy because they are not likely to elicit immune responses and are expected to interact more efficiently with the human immune system to activate therapeutically useful functions. traditional methods for obtaining human mabs (i.e., immortalization of b cells by cell fusion or transformation) can result in low and unstable antibody secretion. recently, methods have been devised for direct cloning of human varia ... | 1992 | 1391662 |
| cloning of tetracycline-resistance genes from various strains of clostridium perfringens and expression in escherichia coli. | one hundred strains of clostridium perfringens and 52 strains of other clostridia of human and animal origins were screened for tetracycline resistance. fifty-six strains were resistant to tetracycline in the c. perfringens group. ten strains were selected for their high level of resistance. in all of them, the tetracycline-resistance genes were found to be residing in large plasmids of about 50 kb, all showing homologies. several tetracycline-resistance genes from plasmids of various strains of ... | 1992 | 1393823 |
| marked enhancement of rat urinary bladder carcinogenesis by heat-killed escherichia coli. | chronic urinary tract infection is an important risk factor for the development of carcinoma in the human urinary bladder. to test the effect of chronic persistent inflammation on bladder carcinogenesis, we instilled heat-killed escherichia coli (1 x 10(8) cells suspended in 0.5 ml of phosphate-buffered 2.1% nacl solution) twice a week into the heterotopically transplanted rat urinary bladders in which carcinogenesis was initiated by a single dose (0.25 mg) of n-methyl-n-nitrosourea. when compar ... | 1992 | 1394138 |
| [chemical synthesis and cloning of plasmodium falciparum 45 peptide antigen gene]. | we have synthesized a 162 bp gene of human plasmodium falciparum hybrid peptide antigen by the solid-phase phosphoramidite method with abi 381a dna synthesizer. the gene encodes three fragments of the relative molecules 83 kda, 55 kda and 35 kda merozoite-specific proteins and two cs repeats or four peptides. the gene with the designed two cohesive ends was divided into 8 fragments to be synthesized. all synthetic fragments were annealed and ligated with t4 dna ligase to form double dna chain. t ... | 1992 | 1394913 |
| efficacy of different irrigation methods and concentrations of root canal irrigation solutions on bacteria in the root canal. | the effectiveness of two different root canal irrigating solutions, each in two different concentrations or formulations, with two different irrigation methods was compared in vitro by means of bacterial survival determinations. 75 human root canals were enlarged, sterilized and inoculated with a mixed culture of escherichia coli and streptococcus mutans. after inoculation, the root canals were irrigated either manually or with an ultrasonic device for equal times (20s) with the same amount (5 m ... | 1992 | 1396362 |
| only some members of a gene family in trypanosoma cruzi encode proteins that express both trans-sialidase and neuraminidase activities. | trypomastigotes, the blood stage form of the human parasite trypanosoma cruzi, contain an enzyme on their surface, trans-sialidase, which catalyses the transfer of sialic acid from host glycoconjugates to acceptors on its own cell surface. at least a subset of the sialic acid-bearing acceptor molecules are involved in parasite invasion of host cells, an essential step in the life cycle of the parasite. another trypomastigote surface enzyme that affects host cell invasion is neuraminidase and rec ... | 1992 | 1396577 |
| analysis of human/mouse interleukin-6 hybrid proteins: both amino and carboxy termini of human interleukin-6 are required for in vitro receptor binding. | the multifunctional cytokine interleukin-6 (il-6) is a single polypeptide chain consisting of 184 amino acids in man and 187 amino acids in mouse. despite the relatively high degree of sequence similarity of these two molecules (about 57%), the biological activity in mouse and human il-6 shows species specificity. starting with this observation, we constructed interspecies hybrids with the goal of defining which segments of the human il-6 molecule are involved in human receptor binding. in this ... | 1992 | 1396966 |
| enterotoxigenic and necrotizing escherichia coli in human diarrhoea in spain. | enterotoxigenic escherichia coli (etec) strains of serotype 0153: k-:h45 cfa/i+ sta+ were associated with two outbreaks of neonatal diarrhoea that occurred in two different hospitals of madrid, in one of which several children died. two other outbreaks were associated with etec strains of serotypes 0159: k-:h21 (lt+) and 0159: k-:h4 (lt+ sta+) without cfa/i and cfa/ii colonization factors. necrotizing e. coli (ntec) strains of serotype 06:k13, producing the cytotoxic necrotizing factor cnf1 and ... | 1992 | 1397224 |
| serogroups of escherichia coli strains producing cytotoxic necrotizing factors cnf1 and cnf2. | the serogroups of 396 necrotizing escherichia coli of human and bovine origin isolated in spain between 1979 and 1991 have been determined. the 270 cytotoxic necrotizing factor strains belonged to 22 different o serogroups; however, 84% (226 of 270) were of one of seven serogroups (o2, o4, o6, o14, o22, o75 and o83). although necrotizing e. coli producing cytotoxic necrotizing factor 2 belonged to 28 different serogroups, only six of them (o1, o3, o15, o55, o88 and o123) accounted for 60% (76 of ... | 1992 | 1398031 |
| human c5a anaphylatoxin: gene cloning and expression in escherichia coli. | a gene coding for the human anaphylatoxin c5a was cloned and expressed in escherichia coli. a combination of reverse transcription of mrna of the u937 cell line with subsequent preparative polymerase chain reaction was employed to obtain the gene. the sequence was cloned into the plasmid vector pkk 233-2 behind an atg initiation codon under the control of a trc promotor. after purification by ion exchange chromatography and reversed phase fplc a mixture of predominantly non-glycosylated recombin ... | 1992 | 1398741 |
| identification of tumor necrosis factor as a transcriptional regulator of the phosphoenolpyruvate carboxykinase gene following endotoxin treatment of mice. | the decreased synthesis of hepatic phosphoenolpyruvate carboxykinase (pepck), the rate-limiting enzyme of gluconeogenesis, that occurs during endotoxemia was shown previously in rats to occur at the transcriptional level. in the current study, the exogenous administration of human recombinant tumor necrosis factor (tnf), a proximal mediator of endotoxic shock, reduced the pepck transcription rate, mrnapepck levels, and pepck enzyme activity in a time- and dose-dependent manner in cd-1 mice. comp ... | 1992 | 1398916 |
| experimental verocytotoxemia in rabbits. | the clinicopathologic effects of intravenously administered purified verocytotoxin 1 (vt1; shiga-like toxin 1) in 2-kg male rabbits was studied. the 50% lethal dose was 0.2 micrograms of protein per kg of body weight (2 x 10(4) 50% cytotoxic doses per kg). the clinical features included nonbloody diarrhea and a progressive flaccid paresis, usually culminating in death. the histopathology was characterized by edema and hemorrhage in the mucosa and submucosa of the cecum and edema, hemorrhage, and ... | 1992 | 1398926 |
| pathogen and host differences in bacterial adherence to human buccal epithelial cells in a northeast brazilian community. | the adherence of several strains of escherichia coli to human buccal epithelial cells was studied, using cells obtained from five groups: healthy adults, healthy children, children with acute diarrhea, children with persistent diarrhea associated with cryptosporidial parasites, and children with noncryptosporidial persistent diarrhea. all groups lived or worked in an urban slum in northeastern brazil. samples of buccal epithelial cells from subjects in each of these groups were incubated with wi ... | 1992 | 1398990 |
| specific detection of campylobacter jejuni and campylobacter coli by using polymerase chain reaction. | development of a routine detection assay for campylobacter jejuni and campylobacter coli in clinical specimens was undertaken by using the polymerase chain reaction (pcr). an oligonucleotide primer pair from a conserved 5' region of the flaa gene of c. coli vc167 was used to amplify a 450-bp region by pcr. the primer pair specifically detected 4 strains of c. coli and 47 strains of c. jejuni; but it did not detect strains of campylobacter fetus, campylobacter lari, campylobacter upsaliensis, cam ... | 1992 | 1400961 |
| identification of a motif for hla-dr1 binding peptides using m13 display libraries. | oligonucleotides encoding peptides known to bind to hla-dr1 molecules have been inserted into the gene iii of filamentous m13 phages. dr1 molecules purified from human lymphoblastoid cell lines could specifically bind to these peptide sequences expressed on the phage surface. a m13 phage peptide library was next constructed and screened with dr1 molecules. after four rounds of selection, more than 80% of the phages were able to bind to dr1. competition experiments with both isolated phages and c ... | 1992 | 1402647 |
| a recombinant human fab expressed in escherichia coli neutralizes rabies virus. | a recombinant human anti-rabies monoclonal antibody (mab-57) fab was prepared by cloning the heavy (fd)- and light-chain domains into the same bacterial expression vector. to construct the recombinant fab, mrna was extracted from mab-57-producing hybridoma cells, reverse transcribed, and then amplified by polymerase chain reaction (pcr) by using oligonucleotides specific for immunoglobulin heavy- and light-chain dna sequences. pcr-amplified fd-chain cdna was fused, in frame, between a bacterial ... | 1992 | 1404611 |
| yeast rnc1 encodes a chimeric protein, rhonuc, with a human rho motif and deoxyribonuclease activity. | the yeast saccharomyces cerevisiae contains an endoexonuclease ynucr that has been implicated in both recombination and repair. we describe the isolation and characterization of the corresponding gene. within the predicted n-terminal half of the protein there is extensive homology (approximately 50%) with human rho genes, which are related to the ras oncogene, particularly in the proposed gtp-binding region. the c-terminal region, which is related to the escherichia coli recc protein, presumably ... | 1992 | 1408836 |
| precursor structure, expression, and tissue distribution of human guanylin. | heat-stable enterotoxins (sta) are small, cysteine-rich peptides secreted by escherichia coli that are able to induce diarrhea through the stimulation of an intestine-specific receptor-guanylyl cyclase known as star. a 15-amino acid peptide, guanylin, was recently purified from rat jejunum and proposed to be a potential endogenous activator of this receptor. we describe here the cloning and characterization of human and mouse cdnas encoding precursor proteins of 115 and 116 amino acids, respecti ... | 1992 | 1409606 |
| release of n2,3-ethenoguanine from chloroacetaldehyde-treated dna by escherichia coli 3-methyladenine dna glycosylase ii. | the human carcinogen vinyl chloride is metabolized in the liver to reactive intermediates which form n2,3-ethenoguanine in dna. n2,3-ethenoguanine is known to cause g----a transitions during dna replication in escherichia coli, and its formation may be a carcinogenic event in higher organisms. to investigate the repair of n2,3-ethenoguanine, we have prepared an n2,3-etheno[14c]guanine-containing dna substrate by nick-translating dna with [14c]dgtp and modifying the product with chloroacetaldehyd ... | 1992 | 1409640 |
| characterization of the proto-oncogene pim-1: kinase activity and substrate recognition sequence. | the human pim-1 proto-oncogene was expressed in escherichia coli as a glutathione-s-transferase (gst)-fusion protein and the enzymatic properties of its kinase activity were characterized. likewise, a pim-1 mutant lacking intrinsic kinase activity was constructed by site-directed mutagenesis (lys67 to met) and expressed in e. coli. in vitro assays with the mutant pim-1 kinase showed no contaminating kinase activity. the wild-type pim-1 kinase-gst fusion protein showed a ph optimum of 7 to 7.5 an ... | 1992 | 1416988 |
| [expression of a synthetic gene for human interleukin-4 in e. coli cells. preparation of a biologically active protein]. | expression e. coli plasmid were constructed in which the human interleukin-4 (hil4) synthetic gene is controlled by tac promoter. the expression level of the gene depends on the distance between rbs and the initial codon atg, with the maximal production in case of the nine base pair distance. the recombinant protein, accumulated in the inclusion bodies, was solubilized, renaturated, and purified to homogeneous, biologically active preparation, the yield being 2 mg/g wet cells. | 1992 | 1417993 |
| comparison of antimicrobial resistant escherichia coli in wild and captive japanese serows. | the fecal escherichia coli isolated from wild japanese serows living in mountainous areas away from humans and those from captive serows kept in human areas were examined for antimicrobial resistance and the possession of transferable r plasmids. of 874 e. coli strains isolated from 283 wild serows in 1980-1981, only 11 (1.3%) were resistant to at least one of 6 antimicrobial drugs; ampicillin, streptomycin, tetracycline, chloramphenicol, kanamycin and sulfadimethoxin. seven (2.5%) individuals w ... | 1992 | 1420561 |
| synthesis in e. coli of a polypeptide with human leukocyte interferon activity. 1980. | | 1992 | 1422029 |
| [synthesis of biologically active recombinant human interleukin-1alpha in escherichia coli cells]. | | 1992 | 1425186 |
| secretion of peptides and proteins lacking hydrophobic signal sequences: the role of adenosine triphosphate-driven membrane translocators. | in this review, we will emphasize the role of atp-dependent membrane transporters in protein export and intracellular protein trafficking in prokaryotic and eukaryotic cells. atp-binding-cassette (abc)-transport proteins, also termed "traffic atpases," belong to a superfamily of ubiquitous atp-driven membrane transporters that share extensive sequence similarity and highly conserved domain organization. they are implicated in a remarkable variety of transmembrane transport processes, including t ... | 1992 | 1425485 |
| lipopolysaccharide (lps) inhalation in healthy subjects increases neutrophils, lymphocytes and fibronectin levels in bronchoalveolar lavage fluid. | bacterial endotoxin has been suggested as responsible for the development of subjective symptoms and transient or chronic lung function impairment seen after exposure to organic dusts in cotton mills, poultry houses, swine confinement buildings and saw mills. animal experiments have demonstrated bronchoalveolar neutrophilia being the most prominent cell response in animals following bacterial lipopolysaccharide (lps) inhalation. the present study was conducted to obtain information on some aspec ... | 1992 | 1426208 |
| activity, disulphide mapping and structural modelling of the fifth domain of human beta 2-glycoprotein i. | complexes formed by the interaction of negatively charged phospholipids and beta 2-glycoprotein i (beta 2-i) are the target of autoantibodies in systemic lupus erythematosus. the highly positively charged fifth (c-terminal) domain of human beta 2-i was produced as a fusion protein in an escherichia coli expression system and was shown to bind to the negatively charged phospholipid, cardiolipin, almost as well as the intact protein. in an attempt to define the 3d structure of this domain, the dis ... | 1992 | 1426288 |
| segments of escherichia coli genome similar to the exons of human prothymosin alpha gene. | identification of the putative prothymosin alpha homolog in escherichia coli cells prompted the search for a prothymosin alpha-coding gene in the e. coli genome. a set of interspersed dna segments was identified, which match various parts of the human prothymosin alpha molecule. their location in the e. coli genome and high degree of similarity with the appropriate regions of the human prothymosin alpha gene suggest that some kind of trans-splicing should exist in e. coli, which could be respons ... | 1992 | 1426289 |
| prevalence of ompt among escherichia coli isolates of human origin. | ompt is a protease associated with the outer membrane of escherichia coli and possesses a high degree of homology to the plasminogen activator, pla, of yersinia pestis. we show here that ompt from intact cells can indeed activate plasminogen. clinical specimens of e. coli were examined for protease activity and for the ompt gene. few isolates (12%) were found to be positive for ompt activity, whereas most (77%) carried the ompt gene and expressed the cloned protease gene. in this report we prese ... | 1992 | 1427004 |
| reveromycins, new inhibitors of eukaryotic cell growth. ii. biological activities. | reveromycins a, b, c and d showed inhibitory activity against egf-stimulated mitogen response in balb/mk cells. furthermore reveromycins a, c and d exhibited morphological reversion of srcts-nrk cells, antiproliferative activity against human tumor cell lines and antifungal activity. the effects of reveromycins a, c and d on eukaryotic cells were closely similar to each other, but those of reveromycin b were very weak. in vitro studies revealed that reveromycin a is a selective inhibitor of prot ... | 1992 | 1429226 |
| subunit 4 of the 26 s protease is a member of a novel eukaryotic atpase family. | ubiquitinated proteins are degraded by a 26 s atp-dependent protease. sds-polyacrylamide gel electrophoresis analysis of the purified 26 s enzyme reveals more than 20 polypeptides ranging in apparent molecular masses from 20 to 110 kda. although many of the subunits smaller than 30 kda are members of the multicatalytic protease family, the identity and function of the larger polypeptides have remained unknown. we report here the cdna sequence for subunit 4, a 51-kda chain of the 26 s protease. s ... | 1992 | 1429620 |
| alanine scanning mutagenesis identifies surface amino acids on domain ii of pseudomonas exotoxin required for cytotoxicity, proper folding, and secretion into periplasm. | pseudomonas exotoxin a (pe) is a single polypeptide chain that contains 613 amino acids and is arranged into three major structural domains. domain ia is responsible for cell recognition, domain ii for translocation of pe across the membrane, and domain iii for adp-ribosylation of elongation factor 2. recombinant pe can be produced in escherichia coli and is efficiently secreted into the periplasm when an ompa signal sequence is present. to investigate the role of the amino acids located on the ... | 1992 | 1429683 |
| studies of the catalytic activities and substrate specificities of saccharomyces cerevisiae myristoyl-coenzyme a: protein n-myristoyltransferase deletion mutants and human/yeast nmt chimeras in escherichia coli and s. cerevisiae. | saccharomyces cerevisiae myristoyl-coa:protein n-myristoyltransferase (nmt1p) is an essential, 455-residue, monomeric enzyme. amino- and carboxyl-terminal deletion mutants of nmt1p were genetically engineered to determine the minimal domain necessary to maintain catalytic activity. enzyme activity was assessed by (i) sequentially inducing nmt1p or its mutant derivatives and one of two eukaryotic substrates for the wild type enzyme (s. cerevisiae gpa1p and rat go alpha) in escherichia coli, a bac ... | 1992 | 1429724 |