| use of the glu-glu-phe c-terminal epitope for rapid purification of the catalytic domain of normal and mutant ras gtpase-activating proteins. | the c-terminal catalytic domain (residues 704-1047) of the human ras gtpase-activating protein (gap) has been engineered so as to incorporate the tripeptide, glu-glu-phe, at its c terminus. this motif is recognized by the commercially available yl1/2 monoclonal antibody to alpha-tubulin and has previously been used for the immunoaffinity purification of hiv enzymes engineered to contain this epitope (stammers, d. k., tisdale, m., court, s., parmar, v., bradley, c., and ross, c. k. (1991) febs le ... | 1991 | 1713577 |
| hp 0.35, a cephalosporin degradation product is a specific inhibitor of lentiviral rnases h. | penicillins, cephalosporins and other betalactam antibiotics are widely used antibacterial drugs. recently it was found that some of them also have effects on proliferating eukaryotic cells (neftel, k.a. and hübscher, u. (1987) antimicrob. agents chemother. 31, 1657-1661), and one such effect was shown to be the inhibition of dna polymerase alpha (huynh do,u., neftel, k.a., spadari, s. and hübscher, u. (1987) nucl. acids res. 15, 10495-10506). the data suggested that degradation products of beta ... | 1991 | 1714562 |
| expression of the f glycoprotein gene from human respiratory syncytial virus in escherichia coli: mapping of a fusion inhibiting epitope. | a cdna copy of the gene encoding the entire amino acid sequence of the fusion (f) protein of human respiratory syncytial virus (strain a2) was inserted into a bacterial expression vector containing the lambda pr promoter. upon heat induction, escherichia coli cells harboring the vector produced a 45-kda peptide which reacted with rabbit polyclonal antiserum to the native f protein. expression of the f gene resulted in severe inhibition of bacterial growth, which was overcome by deletion of the d ... | 1991 | 1714666 |
| generation of recombinant, carbohydrate-free intercellular adhesion molecule-1 (icam-1) and icam-1 fragments in escherichia coli and mapping of epitopes recognized by anti-icam-1 monoclonal antibodies. | intercellular adhesion molecule-1 (icam-1) has been shown to interact with the integrin leukocyte function associated antigen-1 (lfa-1) in a variety of cell-cell adhesion phenomena. furthermore, it serves as a receptor for the majority of the rhinoviruses and for plasmodium falciparum-infected human erythrocytes. we generated recombinant, carbohydrate-free icam-1 and several icam-1 fragments by expression in escherichia coli using the fusion protein expression system puex1-3. in western blot and ... | 1991 | 1715847 |
| [the range of antigenic specificity of bifidobacterium peptidoglycan]. | the antigenic relationships of bifidobacterium bifidum 1 peptidoglycans with different strains of this species (lva-3, 791, go-4), bifidobacteria of other species (b. adolescentis go-13, b. breve 79-38, b. lactentis 79-41, b. longum go-3) and bacteria of remote taxonomic groups (streptococcus faecalis 6-3. staphylococcus aureus com 885, s. epidermidis com 2124. lactobacillus plantarum 1, escherichia coli m-17) were studied on the basis of a highly sensitive test system permitting the registratio ... | 1991 | 1716036 |
| [synthesis, cloning, and expression of artificial genes, coding antigenic determinants of the foot-and-mouth virus substrain a22]. | chemical-enzymatic synthesis and cloning in escherichia coli of double-stranded dnas, coding for simple and complex antigenic determinants of foot-and-mouth disease virus (fmdv) strain a22, have been carried out. the simple antigenic determinants are a part of the viral coat protein vp1 (amino acid sequence 131-152 or 131-160) whereas the complex antigenic determinants comprise additionally the amino acid sequence 200-213 of vp1 linked to n-terminus of simple antigenic determinants through a tet ... | 1991 | 1716100 |
| human t cell clone identifies a potentially protective 54-kda protein antigen of toxoplasma gondii cloned and expressed in escherichia coli. | protective immunity against toxoplasma gondii is recognized to be cell mediated and ifn-gamma is considered to be the major mediator of resistance. thus, protective ag of the parasite must induce ifn-gamma-producing t cells. in order to identify such ag, we have constructed a t. gondii cdna library in the cloning/expression vector lambda gt11, screened this library with a pool of sera of immune donors, and further screened the set of selected recombinant ag using, as probe, a t. gondii-reactive ... | 1991 | 1716289 |
| glycosylated and unglycosylated recombinant-derived human stem cell factors are dimeric and have extensive regular secondary structure. | we have recently described the identification, isolation, and characterization of a factor, termed stem cell factor (scf), which acts on primitive hematopoietic progenitors of the marrow. a soluble form of the factor was isolated from the conditioned medium of a rat cell line (zsebo, k. m., wypych, j., mcniece, i. k., lu, h. s., smith, k. a., karkare, s. b., sachdev, r. k., yuschenkoff, v. n., birkett, n. c., williams, l. r., satyagal, v. n., tung, w., bosselman, r. a., mendiaz, e. a., and langl ... | 1991 | 1717457 |
| a bacterial system for investigating transport effects of cystic fibrosis--associated mutations. | liv-i, a high-affinity system that transports neutral, branched-chain amino acids into escherichia coli, has two components, livg and livf, that are homologous to the cystic fibrosis (cf) transmembrane conductance regulator (cftr). cf-associated mutations of human cftr were introduced into corresponding regions of livg, and their effects on leucine transport could be grouped into three classes. mutations were found that (i) abolished liv-i--directed transport, (ii) retained about a quarter of wi ... | 1991 | 1718037 |
| cloning and expression of antigenic epitopes of the human 68-kda (u1) ribonucleoprotein antigen in escherichia coli. | autoantibodies directed against the 68-kda (u1) ribonucleoprotein antigen are mainly found in sera of patients with mixed connective tissue disease. the corresponding cdna was fragmented into four regions coding for the major antigenic epitopes a', b', c' and d'. all the epitopes were subcloned and expressed as fusion proteins with the glutathione s-transferase in escherichia coli using the novel expression system pgex that allows very high yields of recombinant proteins after a single-step puri ... | 1991 | 1718330 |
| coronary thrombolytic properties of a novel recombinant plasminogen activator (bm 06.022) in a canine model. | we studied the thrombolytic dose-response relationship of a recombinant plasminogen activator (rpa) (bm 06.022) compared with alteplase in a canine model of coronary artery thrombosis. bm 06.022 consists of the kringle 2 and protease domains of human tissue pa (tpa) and lacks oligosaccharide side chains because of its expression in escherichia coli. thrombus formation in anesthetized, open-chest dogs was induced by electrical injury to the intimal surface of the left circumflex coronary artery i ... | 1991 | 1719279 |
| evidence for defective repair of cyclobutane pyrimidine dimers with normal repair of other dna photoproducts in a transcriptionally active gene transfected into cockayne syndrome cells. | cockayne syndrome (cs) and xeroderma pigmentosum (xp), autosomal recessive diseases with clinical and cellular hypersensitivity to uv radiation, differ in ability to repair uv dna photoproducts in their overall genome: normal repair in cs, defective repair in xp. in order to characterize a dna repair defect in an active gene in cs, we measured the capacity of cells from patients with cs and xp to reactivate 2 major types of uv-induced dna damage, photoreactivatable (i.e., cyclobutane pyrimidine ... | 1991 | 1719400 |
| glycosylation of insulin-like growth factor binding protein-3 (igfbp-3) is not required for potentiation of igf-i action: evidence for processing of cell-bound igfbp-3. | insulin-like growth factor binding protein-3 (igfbp-3) is unique among the igf binding proteins in its extensive glycosylation in the native state. to determine the functional significance of carbohydrate moieties on igfbp-3, we examined the effects of nonglycosylated escherichia coli-derived recombinant human igfbp-3 (higfbp-3e. coli) and glycosylated chinese hamster ovary cell-derived higfbp-3 (higfbp-3cho) on igf-i action in cultured bovine fibroblasts. both higfbp-3 preparations bound igf-i ... | 1991 | 1720092 |
| crystals of a ternary complex of human immunodeficiency virus type 1 reverse transcriptase with a monoclonal antibody fab fragment and double-stranded dna diffract x-rays to 3.5-a resolution. | two crystal forms of complexes have been grown that contain human immunodeficiency virus type 1 reverse transcriptase and a monoclonal antibody fab fragment. one of the crystal forms (form ii, space group p3112, a = 168.7 a, c = 220.3 a) diffracts x-rays to 3.5-a resolution and appears suitable for moderate-resolution structure determination. the form ii crystals have the unusual property that their maximum resolution of diffraction and resistance to radiation damage are enhanced by either cryst ... | 1991 | 1720554 |
| reconstitution and properties of homologous and chimeric hiv-1.hiv-2 p66.p51 reverse transcriptase. | metal chelate affinity chromatography has been used to follow reconstitution of the 66- and 51-kda human immunodeficiency (hiv)-1 and hiv-2 reverse transcriptase (rt) subunits into heterodimer, as well as chimeric enzymes comprised of heterologous subunits. by adding a small n-terminal polyhistidine extension to the 51-kda subunit of either enzyme, reconstituted rt could be recovered from a cell lysate by chromatography on ni(2+)-nitrilotriacetic acid-sepharose. homologous rt subunits rapidly as ... | 1991 | 1720776 |
| three individual regulatory elements of the promoter positively activate the transcription of the murine gene encoding granulocyte colony-stimulating factor. | at least three regulatory elements gpe1, gpe2 and gpe3 (g-csf promoter elements) controlling the gene (g-csf) encoding granulocyte colony-stimulating factor (g-csf) are indispensable for the constitutive expression of the g-csf gene in human chu-2 cells and for its lipopolysaccharide(lps)-inducible expression in macrophages. the enhancer activities of each regulatory element were examined with or without the sv40 enhancer element placed downstream from the reporter gene. a gpe1 tetramer mediated ... | 1991 | 1721032 |
| [reverse transcriptase of the human immunodeficiency virus: cloning, expression in escherichia coli, purification of the enzyme, and production of monoclonal antibodies]. | to express hiv-1 reverse transcriptase in e. coli a number of genetic constructions containing reverse transcriptase and virus protease nucleotide sequences was obtained. the products of expression were characterized; monoclonal antibodies to reverse transcriptase were produced. the purification of reverse transcriptase was carried out. the substantial proteolysis of reverse transcriptase during purification was shown. the purified preparation is predominantly, an active protein with mr 57 kda. ... | 1991 | 1721676 |
| a transposition of the reverse transcriptase gene reveals unexpected structural homology to e. coli dna polymerase i. | the rational design of antiviral agents targeting the reverse transcriptase (rt) of the human immunodeficiency virus (hiv) would greatly benefit from a more intimate knowledge of the structure of rt. until now, the degree of sequence similarity between rt and e. coli dna polymerase i (pol i) has been thought to be confined to several small regions, suggesting little basis for homology molecular modeling. however, we have found that a region in the c terminal of the rt polymerase domain is homolo ... | 1991 | 1721884 |
| the dna-dependent and rna-dependent dna polymerase activities of the reverse transcriptases of human immunodeficiency viruses types 1 and 2. | we have constructed a series of plasmids which, when introduced into escherichia coli, induce the overexpression of soluble wild-type and mutated forms of the reverse transcriptases (rts) from human immunodeficiency viruses types 1 and 2 (hiv-1 and hiv-2, respectively). these proteins were analyzed previously for their rna-dependent dna polymerase (rddp) and ribonuclease h (rnase h) activities. in the present study we assayed the different mutant rts for their dna-dependent dna polymerase (dddp) ... | 1991 | 1722105 |
| site-directed mutagenesis and epitope-mapped monoclonal antibodies define a catalytically important conformational difference between human placental and germ cell alkaline phosphatase. | placental (plap) and germ cell (gcap) alkaline phosphatases were probed immunologically with a library of 18 murine monoclonal antibodies reacting with different conformational epitopes on plap. three main antigenic domains (i, ii and iii) were mapped by antibody competition experiments and the relative binding of the antibodies to site-directed plap mutants. relative affinities of each of the antibodies for the wild type (wt) gcap were 2-3-fold lower than the values found for wt plap. relative ... | 1991 | 1722150 |
| cloning and expression of ape, the cdna encoding the major human apurinic endonuclease: definition of a family of dna repair enzymes. | abasic (ap) sites are common, potentially mutagenic dna damages that are attacked by ap endonucleases. the biological roles of these enzymes in metazoans have not been tested. we have cloned the human cdna (ape) that encodes the main nuclear ap endonuclease. the predicted ape protein, which contains likely nuclear transport signals, is a member of a family of dna repair enzymes that includes two bacterial ap endonucleases (exoa protein of streptococcus pneumoniae and exonuclease iii of escherich ... | 1991 | 1722334 |
| molecular cloning and expression of the cdna coding for a new member of the s100 protein family from porcine cardiac muscle. | we isolated a new calcium-binding protein from porcine cardiac muscle by calcium-dependent hydrophobic and dye-affinity chromatography. it showed an apparent molecular weight of 11,000 on sds-page. amino acid sequence determination revealed that the protein contained two calcium-binding domains of the ef-hand motif. the cdna gene coding for this protein was cloned from the porcine lung cdna library. sequence analysis of the cloned cdna showed that the protein was composed of 99 amino acid residu ... | 1991 | 1722468 |
| immunoadjuvant activity of oral lactobacillus casei: influence of dose on the secretory immune response and protective capacity in intestinal infections. | lactobacilli, often used as effectors of host functions, could play an important role in maintaining human health by controlling other intestinal microorganisms capable of producing harmful effects. using an experimental model, we studied the effect of different oral doses of lactobacillus casei on the secretory iga response and the protective capacity of the microorganism in preventing intestinal infections. the optimization of the protective dose of lb. casei by previous feeding and the use of ... | 1991 | 1722492 |
| use of antibodies against the p36 protein of mycoplasma hyopneumoniae for the identification of m. hyopneumoniae strains. | mycoplasma hyopneumoniae, the principal aetiological agent of porcine enzootic pneumonia, synthesizes a 36 kda protein (p36) which is an early and strong immunogenic factor in experimentally and naturally infected swine. polyclonal antibodies were made against the recombinant p36 protein in rabbits and used for the identification of m. hyopneumoniae by the immunoblot technique. the proteins from the m. hyopneumoniae reference strains and from 13 m. hyopneumoniae field strains isolated from natur ... | 1991 | 1723490 |
| scd14 prevents endotoxin inducible oxidative burst response of human monocytes. | luminol-enhanced chemiluminescence (lecl) was used to determine the effect of soluble cd14 (scd14) on the endotoxin inducible generation of reactive oxygen species in human monocytes. lps is unable to activate monocytes under serum free conditions, but lecl responses were measured after pretreatment of lps stock solution with serum, according to wright et al., who described a lps-binding protein (lbp), necessary for mediating lps binding to the receptor cd14 on monocyte surfaces. in normal human ... | 1991 | 1724353 |
| nitric oxide from vascular smooth muscle cells: regulation of platelet reactivity and smooth muscle cell guanylate cyclase. | 1. incubation of smooth muscle cells (smc) from bovine aorta for 3 min with human washed platelets treated with indomethacin (10 microm) promoted a cell number-related inhibition of platelet aggregation induced by thrombin (40 mu ml-1). this inhibition was not attributable to products of the cyclo-oxygenase pathway for the smc were also treated with indomethacin (10 microm). 2. the inhibitory activity of the smc on platelet aggregation was enhanced by incubating the smc with e. coli lipopolysacc ... | 1991 | 1724627 |
| pharmacokinetic and hemostatic properties of the recombinant plasminogen activator bm 06.022 in healthy volunteers. | in a randomized, single-blind, placebo-controlled, cross-over phase-i study pharmacokinetic and hemostatic properties of bm 06.022 were investigated in seven healthy, male human volunteers. the novel recombinant plasminogen activator bm 06.022 consists of the kringle 2 domain and the protease domain of human t-pa and is unglycosylated due to its expression in escherichia coli cells. vehicle or 6 mu (= 10.4 mg) bm 06.022 was administered as a single i.v. bolus injection of 10 ml over 2 min. bm 06 ... | 1991 | 1725068 |
| removal of 3' nontranslated cdna sequence improves interferon gamma synthesis in escherichia coli. | the cdna coding for human interferon gamma contains approximately 600 basepairs not translated sequence with 4 adenine/thymidine (at)-rich clusters at its 3'end. the influence of this sequence on the expression of recombinant human interferon gamma in escherichia coli was investigated. removal of the non-translated sequence and especially of the at-rich clusters yielded an increase in expression of interferon gamma from 10 to 40% of total protein. these results may also be important for the prod ... | 1991 | 1726133 |
| expression and characterization of chimeric rdna proteins engineered for purification and enzymatic cleavage. | a strategy for the purification and cleavage of chimeric recombinant proteins based on a genetically engineered metal-binding peptide and a human renin cleavage site is described. vectors were constructed to direct the synthesis of chimeric human immunodeficiency virus (hiv) reverse transcriptase (rt) or beta-galactosidase in escherichia coli. as shown below, two control chimerics without the metal-binding peptide were also included: 1. pro-ile-his-asp-his-asp-his-pro-phe-his-leu-val-ile-his-ser ... | 1991 | 1726560 |
| rapid and efficient cloning of alu-pcr products using uracil dna glycosylase. | by incorporating dump residues into the 5' end of pcr primers, one can generate products which, after treatment with uracil dna glycosylase (udg), contain 3' overhangs. these overhangs can be annealed to vector molecules with complementary overhangs generated in a similar fashion and transformed directly into escherichia coli without the need for ligase. we have tested this method of ligation-independent cloning by using udg to create complementary single-stranded sticky ends between vector and ... | 1991 | 1726854 |
| antibacterial and protective properties of monoclonal antibodies reactive with escherichia coli o111:b4 lipopolysaccharide: relation to antibody isotype and complement-fixing activity. | in vitro and in vivo antibacterial and protective properties of murine monoclonal antibodies (mabs) to escherichia coli o111:b4 lipopolysaccharide (lps) were evaluated in relation to antibody isotype and complement-fixing activity. six o side chain-specific mabs, including two igms and one of each igg subclass, were analyzed for quantitative binding and c3 deposition on intact bacteria, complement-mediated bactericidal and opsonophagocytic activity, and protection against intraperitoneal infecti ... | 1992 | 1727896 |
| class ii (b) general transcription factor (tfiib) that binds to the template-committed preinitiation complex is different from general transcription factor btf3. | a class ii (b) general transcription factor of 34 kda has been purified from hela cells to apparent homogeneity. this factor appears to be transcription factor iib (tfiib), since it binds in vitro to template-committed preinitiation complexes formed between a template containing the tata box/cap-site elements of the adenovirus type 2 major late promoter (ad2mlp) and recombinant human or yeast tfiid (previously called btf1) expressed in escherichia coli. dnase i footprint studies show an extended ... | 1992 | 1729710 |
| 8-hydroxyguanine, an abundant form of oxidative dna damage, causes g----t and a----c substitutions. | mutations caused by oxidative dna damage may contribute to human disease. a major product of that damage is 8-hydroxyguanine (oh8gua). because of differences in experimental design, the base pairing specificity of oh8g in vivo is not completely resolved. here, oh8dgtp and dna polymerase were used in two complementary bacteriophage plaque color assays to examine the mutagenic specificity of oh8gua in vivo. the first is a reversion assay that detects all three single-base substitutions caused by m ... | 1992 | 1730583 |
| (a-c-b) human proinsulin, a novel insulin agonist and intermediate in the synthesis of biosynthetic human insulin. | the hormone insulin is synthesized in the beta cell of the pancreas as the precursor, proinsulin, where the carboxyl terminus of the b-chain is connected to the amino terminus of the a-chain by a connecting or c-peptide. proinsulin is a weak insulin agonist that possesses a longer in vivo half-life than does insulin. a form of proinsulin clipped at the arg65-gly66 bond has been shown to be more potent than the parent molecule with protracted in vivo activity, presumably as a result of freeing th ... | 1992 | 1730606 |
| saccharomyces cerevisiae elongation factor 2. genetic cloning, characterization of expression, and g-domain modeling. | the elongation factor 2 (ef-2) genes of the yeast saccharomyces cerevisiae have been cloned and characterized with the ultimate goal of gaining a better understanding of the mechanism and control of protein synthesis. two genes (eft1 and eft2) were isolated by screening a bacteriophage lambda yeast genomic dna library with an oligonucleotide probe complementary to the domain of ef-2 that contains diphthamide, the unique posttranslationally modified histidine that is specifically adp-ribosylated ... | 1992 | 1730643 |
| asparagine 26, glutamic acid 31, valine 45, and tyrosine 64 of ras proteins are required for their oncogenicity. | ras and rap1 proteins are related gtp-dependent signal transducers which require gly-12, the effector domain (residues 32-40), and ala-59 for stimulation of their gtpase activities by gap1 and gap3, respectively. the replacement of gly-12 by val or ala-59 by thr potentiates the ras oncogenicity and rap1a antioncogenicity. however, the mutations in the effector domain, in particular the replacement of thr-35 by ala, abolish both ras oncogenicity and rap1a antioncogenicity, indicating that the eff ... | 1992 | 1730690 |
| role of trat protein, an anticomplementary protein produced in escherichia coli by r100 factor, in serum resistance. | escherichia coli k12 strain w3110/sm bearing a plasmid containing the trat gene (trat+ strain) was more resistant to the bactericidal activity of guinea pig serum than the same strain bearing this plasmid without the trat gene (trat- strain). a murine mab was generated against synthetic trat peptide (86-99). this antibody reacted only with denatured trat protein, but it was used for monitoring trat protein by immunoblotting during purification of the protein. six mab were then generated against ... | 1992 | 1730875 |
| inefficient bacteriolysis of escherichia coli by serum from human neonates. | to assess bacteriolysis in human neonates, escherichia coli o7w:k1:nm were incubated with sera from eight healthy neonates, serum pooled from the eight neonates, and serum pooled from healthy adults. the adult serum killed e. coli. in contrast, the bacteria were not killed during incubation with sera from the eight neonates, the pooled neonatal serum, or with heat-inactivated adult serum. however, the combination of pooled neonatal serum and heat-inactivated adult serum killed the bacteria. supp ... | 1992 | 1730895 |
| human immunodeficiency virus type 1 and type 2 protease monomers are functionally interchangeable in the dimeric enzymes. | human immunodeficiency virus type 1 (hiv-1) and hiv-2 proteases are dimers of identical subunits. we made a construct for the expression of recombinant one-chain hiv-2 protease dimer, which, like the previously described one-chain hiv-1 protease dimer, is fully active. the constructs for the one-chain dimers of hiv-1 and hiv-2 proteases were modified to produce hybrid one-chain dimers consisting of both hiv-1 and hiv-2 protease monomers. although the monomers share only 47.5% sequence identity, ... | 1992 | 1731102 |
| mutagenesis of some conserved residues in human 5-lipoxygenase: effects on enzyme activity. | recombinant human 5-lipoxygenase (arachidonate:oxygen 5-oxidoreductase, ec 1.13.11.34) was expressed in escherichia coli. in incubations of e. coli supernatants with arachidonic acid, 5-hydroxy-7,9,11,14-eicosatetraenoic acid and leukotriene a4 were formed, while incubation with 8,11,14-eicosatrienoic acid gave 8-hydroxy-9,11,14-eicosatrienoic acid. six conserved histidine residues in 5-lipoxygenase were subjected to site-directed mutagenesis. exchanges of his-367, -372, or -551 gave mutants for ... | 1992 | 1731317 |
| nucleotide sequences of the arb genes, which control beta-glucoside utilization in erwinia chrysanthemi: comparison with the escherichia coli bgl operon and evidence for a new beta-glycohydrolase family including enzymes from eubacteria, archeabacteria, and humans. | the phytopathogenic bacterium erwinia chrysanthemi, unlike other members of the family enterobacteriaceae, is able to metabolize the beta-glucosides, arbutin, and salicin. a previous genetic analysis of the e. chrysanthemi arb genes, which mediate beta-glucoside metabolism, suggested that they were homologous to the escherichia coli k-12 bgl genes. we have now determined the nucleotide sequence of a 5,065-bp dna fragment containing three genes, arbg, arbf, and arbb. deletion analysis, expression ... | 1992 | 1732212 |
| evaluation of thrombolytic and systemic effects of the novel recombinant plasminogen activator bm 06.022 compared with alteplase, anistreplase, streptokinase and urokinase in a canine model of coronary artery thrombosis. | the thrombolytic and systemic effects of bm 06.022 were evaluated and compared with those of alteplase, anistreplase, streptokinase and urokinase in a canine model of coronary artery thrombosis. bm 06.022 consists of the kringle-2 and protease domains of human tissue plasminogen activator (t-pa) and is unglycosylated because of its expression in escherichia coli cells. thrombus formation in anesthetized open chest dogs was induced by electrical injury to the intimal surface of the left circumfle ... | 1992 | 1732372 |
| search for hepatitis b virus cell receptors reveals binding sites for interleukin 6 on the virus envelope protein. | the major target organ for hepatitis b virus (hbv) is the liver. however, cells other than hepatocytes, including peripheral blood lymphocytes and monocytes, may become infected with hbv. the cell receptor binding site was assigned to the pres(21-47) segment of the hbv envelope protein. hbv receptors were detected on human liver and hepatoma cells, on b lymphocytes, and, as shown here, on monocytes, and t cell lines, activated by escherichia coli lipopolysaccharide and concanavalin a, respective ... | 1992 | 1732412 |
| structural differences between the two human complement c4 isotypes affect the humoral immune response. | an animal model has been used to address the question of the biological importance of the known structural difference between the two isotypes of human c4, i.e., c4a and c4b. guinea pigs deficient in c4 were reconstituted transiently with either human c4a or c4b protein and immunized with the bacteriophage phi x174. results from this study showed that c4a-reconstituted animals made a secondary response, i.e., switch from igm to igg; whereas the c4b-reconstituted animals did not. | 1992 | 1732415 |
| marker profile, enzyme activity, and function of a human myelomonocytic leukemia cell line. | morphological and functional characteristics of a permanent human leukemia cell line (dd) that possesses myelomonocytic features were investigated. the cells bear a second type fc gamma receptor and form rosettes with sheep erythrocytes sensitized with rabbit igg (ea). however, the surface-bound ea is not internalized. the cell line lacks the surface markers cd2, cd19, cd14, hla-dr, fc gamma receptor i, fc gamma receptor iii, and cr3. alpha 1-antitrypsin, lysozyme, factor xiii a subunit of blood ... | 1992 | 1733517 |
| cloning and expression of iddm-specific human autoantigens. | a dna cloning approach was taken to identify islet cell protein antigens that are recognized specifically by insulin-dependent diabetes mellitus (iddm) sera. a human islet cdna library was generated and screened with diabetic sera. in this article, identification of two clones is described. proteins expressed by these lambda phages appeared to react specifically with newly diagnosed diabetic sera. islet cell antibody 12 (ica12) was tested by western blotting. ica512 was not reactive with sera in ... | 1992 | 1733807 |
| polyethylene glycol-conjugated superoxide dismutase attenuates septic lung injury in guinea pigs. | reactive oxygen species (ros), including superoxide anions, play an important role in mediating acute lung injury. we examined whether polyethylene glycol-conjugated superoxide dismutase (peg-sod) attenuates lung injury in escherichia coli-treated guinea pigs. twenty-four guinea pigs were divided into four groups: (1) control group; (2) septic group, in which live e. coli (2 x 10(9)/kg) were injected intravenously; (3) pretreatment group, in which peg-sod (2,000 iu/kg) was injected intravenously ... | 1992 | 1736747 |
| development and characterization of a panel of monoclonal antibodies against the novel subtilisin-like proprotein processing enzyme furin. | monoclonal antibodies were raised against the recently discovered subtilisin-like proprotein processing enzyme furin. as immunogen, a bacterially expressed hybrid protein was used which consisted of glutathione s-transferase fused to almost the entire human furin protein. ten monoclonal antibodies were obtained and these could be divided into four categories on the basis of their reactivity towards a number of bacterially expressed hybrid proteins, each of which contained a different portion of ... | 1992 | 1737642 |
| expression of human il-1 beta in salmonella typhimurium. a model system for the delivery of recombinant therapeutic proteins in vivo. | the feasibility of using salmonella typhimurium aroa mutant (sl3261) to deliver protein therapeutic agents was investigated in a murine model system. we have constructed an escherichia coli expression plasmid designed to express the human protein il-1 beta. this plasmid expresses il-1 beta to high levels (greater than 30% total cell protein) in e. coli. in salmonella the il-1 beta is expressed constitutively to about 10% total cell protein, as verified by western blotting analysis using polyclon ... | 1992 | 1737934 |
| haemolysin-derived synthetic peptides with pore-forming and haemolytic activity. | escherichia coli haemolysin (hlya) is a pore-forming protein which belongs to the family of 'repeat-toxins' (rtx) (lo et al., 1987; lally et al., 1989; kraig et al., 1990). a model for the pore-forming structure of hlya has been proposed (ludwig et al., 1991) which consists of eight transmembrane segments all present in this hydrophobic region of hlya. we report here that two synthetic peptides of 10 and 8 amino acids in length (pep1 and pep2, respectively), which are derived from transmembrane ... | 1992 | 1738310 |
| stimulation of dna polymerase alpha activity by microtubule-associated proteins. | microtubule-associated protein 2 (map2) isolated from porcine brains stimulated the activity of dna polymerase alpha immunopurified from calf thymus or human lymphoma cells, in a dose-dependent manner. this stimulation was pronounced when activated dna or poly(da).(dt)10 was used as the template-primer. dna polymerase alpha bound to a map2-immobilized column, whereas preincubation of the enzyme with unbound map2 prevented binding to the column. these events suggested that a physical binding occu ... | 1991 | 1742279 |
| effect of probenecid on phagocytosis and intracellular killing of staphylococcus aureus and escherichia coli by human monocytes and granulocytes. | the present study concerns the effects of probenecid on the phagocytosis and intracellular killing of staphylococcus aureus and escherichia coli by human monocytes and granulocytes. in both monocytes and granulocytes the inhibitory effect on phagocytosis was very small. inhibition of intracellular killing of s. aureus by monocytes and granulocytes by probenecid was concentration dependent, being half-maximal at about 2 mm probenecid, and near-maximal at about 5 mm probenecid. the intracellular k ... | 1991 | 1748482 |
| purification, characterization, cloning, and amino acid sequence of the bifunctional enzyme 5,10-methylenetetrahydrofolate dehydrogenase/5,10-methenyltetrahydrofolate cyclohydrolase from escherichia coli. | we have purified the enzyme 5,10-methylenetetrahydrofolate dehydrogenase (ec 1.5.1.5) from escherichia coli to homogeneity by a newly devised procedure. the enzyme has been purified at least 2,000-fold in a 31% yield. the specific activity of the enzyme obtained is 7.4 times greater than any previous preparation from this source. the purified enzyme is specific for nadp. the protein also contains 5,10-methenyltetrahydrofolate cyclohydrolase (ec 3.5.4.9) activity. sodium dodecyl sulfate-polyacryl ... | 1991 | 1748668 |
| properties of lipoamide dehydrogenase altered by site-directed mutagenesis at a key residue (i184y) in the pyridine nucleotide binding domain. | the binding of pyridine nucleotide to human erythrocyte glutathione reductase, an enzyme of known three-dimensional structure, requires some movement of the side chain of tyr197. moreover, this side chain lies very close to the isoalloxazine ring of the fad cofactor. the analogous residue, ile184, in the homologous enzyme escherichia coli lipoamide dehydrogenase has been altered by site-directed mutagenesis to a tyrosine residue (i184y) [russell, g. c., allison, n., williams, c. h., jr., & guest ... | 1991 | 1751496 |
| [elimination of introns from the interleukin 1 beta genome by dna amplification and expression of interleukin 1 beta in escherichia coli]. | the use of the polymerase chain reaction was proposed for intron excision from genomic genes with known nucleotide sequences. three exons (5, 6 and 7) of genomic interleukin 1 beta gene were amplified by means of thermostable dna polymerase tthi from thermus thermophilus on the base of cloned in m13 phage human genomic interleukin 1 beta gene. synthetic oligonucleotides complementary to sequences flanking exons were used as primers. the fragments obtained by exon dna amplification were joined in ... | 1991 | 1753956 |
| [laboratory and clinical study of sulbactam/cefoperazone (sbt/cpz) on bacterial prostatitis]. | the cefoperazone and sulbactam concentrations in human prostatic fluid were measured following intravenous administration of sulbactam/cefoperazone (sbt/cpz) and its clinical efficacy and safety in the treatment of 11 patients with acute or chronic bacterial prostatitis were evaluated. cefoperazone concentrations in prostatic fluid (pf) one hour after an intravenous infusion of sbt/cpz at a dose of 1 g and 2 g were 0.57 +/- 0.26 micrograms/ml and 1.37 +/- 0.86 micrograms/ml, respectively, both e ... | 1991 | 1755429 |
| development of verotoxin 2- and verotoxin 2 variant (vt2v)-specific oligonucleotide probes on the basis of the nucleotide sequence of the b cistron of vt2v from escherichia coli e32511 and b2f1. | we and others have noted that there are serological differences between verotoxin 2 (vt2) (also known as shiga-like toxin ii) produced by escherichia coli c600(933w) and the vt2 variant (vt2v) produced by strain e32511. recent reports have described nucleotide sequence differences between the vt2v b subunit cistron of e32511 and b2f1 and that of vt2. we have confirmed the sequence differences and have used them to design oligonucleotide probes which differentiate the b subunit cistron of vt2v fr ... | 1991 | 1757536 |
| [the characteristics of staphylococcus aureus peptidoglycan in the spectrum of the reactivity of human lymphocytes to bacterial peptidoglycans]. | the sensitivity of lymphocytes of healthy persons to s. aureus peptidoglycan as compared with that to the polyclonal stimulator zymosan c3b and peptidoglycans of other bacteria (streptococcus faecalis, escherichia coli, bacterium bifidum) was analyzed with a test system permitting the determination of specific reactivity to peptidoglycans. the analysis showed that at the peak of luminol-dependent chemiluminescence (25-30 minutes) individual reactivity to s. aureus peptidoglycan varied within wid ... | 1991 | 1759526 |
| production and characterization of functional domains of human fibronectin expressed in escherichia coli. | an efficient expression system was constructed in escherichia coli that produced a 33-kda fragment, c-274, of human fibronectin with a strong cell-adhesive activity. the entire sequence of the heparin-binding domain with 271 amino acids, h-271, was also expressed. deletion analysis of the type iii repeats showed that the heparin-binding site was at type iii-13. the cell-adhesive activity of a fusion protein, ch-271, containing the cell- and the heparin-binding domains was twice that of c-274 whe ... | 1991 | 1761524 |
| cell attachment activity of the carboxyl-terminal domain of human thrombospondin expressed in escherichia coli. | thrombospondin (ts) is a multidomain, adhesive glycoprotein that associates with cells through multiple cell attachment sites. one of these has been located in or near the globular cooh-terminal region of ts by the monoclonal antibody (mab) c6.7, which inhibits the attachment of human melanoma cells (g361) to ts. the epitope for c6.7 lies within the last 122 residues of the cooh-terminal domain of ts. this domain is distant from two known cell attachment sites in ts, namely the nh2-terminal hepa ... | 1991 | 1761530 |
| inhibitory activity and conformational transition of alpha 1-proteinase inhibitor variants. | several variants of alpha 1-proteinase inhibitor (alpha 1-pi) were investigated by spectroscopic methods and characterized according to their inhibitory activity. replacement of thr345 (p14) with arg in alpha 1-pi containing an arg residue in position 358 (yielding [thr345----arg, met358----arg]alpha 1-pi) results in complete loss of its inhibitory activity against human alpha-thrombin; whereas an exchange of residue met351 (p8) by glu [( met351----glu, met358----arg]alpha 1-pi) does not alter a ... | 1991 | 1765073 |
| stimulation of human fetal astrocyte proliferation by bacterial lipopolysaccharides and lipid a. | this report concerns the effect of bacterial endotoxin [lipopolysaccharide(lps) and lipid a] on cultured human fetal astrocytes. exposure to 1 micrograms/ml lps or lipid a caused a striking stimulation of the rate of proliferation of the cells. the effect was most pronounced with exponentially growing cultures. stimulation was associated with enhance dna synthesis as ascertained by [3h]thymidine incorporation. these findings at the cellular level may be of relevance in the elucidation of the eff ... | 1991 | 1767632 |
| localization of the human o6-methylguanine-dna methyltransferase gene to chromosome 10q24.33-qter. | | 1991 | 1769664 |
| [a chemically synthesized gene assures the biosynthesis of a polypeptide in escherichia coli cells, the structure of which corresponds to human leukocytic interferon alpha 2]. | | 1991 | 1773723 |
| enteroinvasive escherichia coli: a cause of bacteremia in patients with aids. | a strain of enteroinvasive escherichia coli was isolated from the blood of a patient with advanced human immunodeficiency virus disease on repeated occasions, associated with severe diarrheal illness. the isolate was killed in vitro by control sera but not by sera collected from the patient before or after his bacterial illnesses. | 1991 | 1774287 |
| stabilization of recombinant proteins from proteolytic degradation in escherichia coli using a dual affinity fusion strategy. | a dual affinity fusion approach has been used to study the expression and secretion of labile recombinant proteins in escherichia coli. here we show that three small eukaryotic proteins (human proinsulin, a thioredoxin homologous domain of rat protein disulfide isomerase, and the extracellular domain of the alpha 1.2-chain of a human t-cell receptor) are stabilized in vivo using a dual affinity fusion strategy, where the gene encoding the desired product is fused between two genes encoding two d ... | 1991 | 1777118 |
| molecular genetics and pathogenesis of clostridium perfringens. | clostridium perfringens is the causative agent of a number of human diseases, such as gas gangrene and food poisoning, and many diseases of animals. recently significant advances have been made in the development of c. perfringens genetics. studies on bacteriocin plasmids and conjugative r plasmids have led to the cloning and analysis of many c. perfringens genes and the construction of shuttle plasmids. the relationship of antibiotic resistance genes to similar genes from other bacteria has bee ... | 1991 | 1779929 |
| [cloning of the gene and immunochemical specificity of recombinant immunoglobulin binding protein v7 from streptococcus valente (group g)]. | the fragment of the structural gene coding for the fc-receptor of streptococcus valente (g group) has been cloned. the resulting recombinant plasmid ppgsv1 contains the o, kb hindiii fragment of streptococcal chromosomal dna inserted into the vector plasmid puc19 and determines the expression of the 31 kd protein in escherichia coli cells. the protein binds the immunoglobulins of human, rabbit, guinea pig origin, but in contrast to the g protein of another g group streptococcus it is nonreactive ... | 1991 | 1784298 |
| purification of recombinant hiv-1 protease. | a method is described to purify recombinant hiv-1 protease from soluble extracts of escherichia coli. the isolation involves qae-sepharose anion exchange chromatography, hexyl agarose hydrophobic interaction chromatography, monos cation exchange chromatography, and superose 6 size exclusion chromatography. approximately 100 micrograms of protease was obtained from 18 g e. coli paste. the protein was judged to be homogeneous due to the presence of a single band on a silver-stained sds polyacrylam ... | 1991 | 1798693 |
| recombinant human hemoglobin: expression and refolding of beta-globin from escherichia coli. | a plasmid analogous to the one described by nagai and thogersen (nature, 309, 810-812, 1984) has been constructed for the expression of globins in e. coli. induction with nalidixic acid produces high yields of a fusion protein, ns1-fx-beta-globin, where ns1 represents 81 residues of a flu virus protein and fx represents a blood-clotting factor xa recognition sequence, ile-glu-gly-arg. this fusion protein is readily solubilized in 50 mm naoh and remains in solution when the ph is adjusted to 8.6. ... | 1991 | 1799407 |
| thrombin and h64a subtilisin cleavage of fusion proteins for preparation of human recombinant parathyroid hormone. | human parathyroid hormone, hpth, an 84 amino acid polypeptide, was produced intracellularly in escherichia coli as a fusion protein, linked to the c-terminus of a 15 kd igg-binding protein. approximately 100 mg fusion protein was obtained per liter fermentation medium. to test the efficiency of two alternative enzymatic cleavage methods, two fusion proteins differing only in the linker region were constructed. cleavage of a phe-phe-pro-arg linker was obtained with bovine thrombin and cleavage of ... | 1991 | 1799410 |
| the three-dimensional structure of the aspartyl protease from the hiv-1 isolate bru. | the crystal structure of the aspartyl protease encoded by the gene pol of the human immunodeficiency virus (hiv-1, isolate bru) has been determined to 2.7 a resolution. the enzyme, expressed as an insoluble denatured polypeptide in inclusion bodies of escherichia coli has been renatured and crystallized. it differs by several amino acid replacements from the homologous enzymes of other hiv-1 isolates. a superposition of the c alpha-backbone of the bru protease with that of the sf2 protease gives ... | 1991 | 1799632 |
| impact of transfer from animal-source insulins to biosynthetic human insulin (rdna e coli) in patients with diabetes mellitus. | six hundred forty-eight patients (50.5% men; 49.5% women) with diabetes mellitus on animal-source insulin therapy for at least five years were studied. in this patient population, approximately 68.7% had type i insulin-dependent diabetes mellitus and 31.3% had type ii noninsulin-dependent diabetes mellitus, nonetheless requiring insulin therapy. patients were voluntarily transferred from animal-source insulin to biosynthetic human insulin derived by recombinant dna technology from genetically al ... | 1991 | 1799920 |
| [an immunoenzyme test system for the detection of antibodies to campylobacter]. | an enzyme immunoassay system for the detection of antibodies to bacteria of the genus campylobacter in human blood serum has been developed. the system is based on the use of ethanol-treated c. jejuni and c. coli whole cells as antigen. the study of sera obtained from healthy donors in this assay has made it possible to establish the value of the tentative diagnostic titer: 320. | 1991 | 1801490 |
| variants of human seminal acrosin inhibitor (husi-ii) which inhibit human leukocyte elastase. | a cdna coding for human seminal inhibitor ii was fused to the ompa-gene leader peptide for the expression in e. coli. the secreted protein is biologically active and correctly processed. inhibitors of human leukocyte elastase were constructed by site-directed mutagenesis. | 1991 | 1801743 |
| detection of a heat-labile enterotoxin gene in enterotoxigenic escherichia coli by densitometric evaluation using highly specific enzyme-linked oligonucleotide probes. | two alkaline phosphatase-conjugated 24-mer oligonucleotide probes were developed to detect the heat-labile enterotoxin gene in enterotoxigenic escherichia coli. probes were antisense codon sequences, which are transcribed into mrna, of the heat-labile enterotoxin gene of enterotoxigenic escherichia coli of human origin. using dot-blot hybridization, probes were tested with 100 clinical isolates and evaluated by a reflectance-type densitometer. results agreed very well with those of an immunologi ... | 1991 | 1802695 |
| inhibitory effects of recombinant human cystatin c on human coronaviruses. | cystatin c, a potent inhibitor of cysteine proteases such as papain and cathepsin b, was examined for its effect on human coronaviruses oc43 and 229e. both viruses were greater than 99% inhibited by 0.1 mm inhibitor. endpoint titrations showed that inhibiting activity paralleled that of leupeptin, a serine and cysteine protease inhibitor, and indicated that 1 to 2 microm inhibitor, slightly above physiologic levels, was effective. | 1991 | 1804023 |
| preparation and characterization of monoclonal antibodies against recombinant human tumor necrosis factor alpha. | tumor necrosis factor (tnf alpha) plays an important role in cytotoxicity and inhibition of tumor cells. further studies on the structure, function and clinical application of tnf alpha will be useful. nine clones of hybridoma secreting monoclonal antibodies against recombinant human tumor necrosis factor alpha (rhtnf alpha) were obtained by using cell fusion technology. none of the monoclonal antibodies cross-reacted with ril-1, ril-2, rifn gamma, rifn alpha and e. coli lysates. western blot de ... | 1991 | 1806022 |
| the effect of human milk on the adherence of enterohemorrhagic e. coli to rabbit intestinal cells. | | 1991 | 1808994 |
| hybrid genes expressing fusion peptides. a strategy for bacterial production of recombinant human interleukin-3 with a defined nh2-terminus. | | 1991 | 1809185 |
| correlation between human lactoferrin binding and colicin susceptibility in escherichia coli. | escherichia coli h10407 demonstrated low 125i-human lactoferrin (hlf) binding (7%) and was insusceptible to group a (a, e1, e2, e3, e6, and k) and group b (b, d, ia, ib, and v) colicins. conversely, a spontaneous hlf high-binding (44%) variant, h10407(lf), demonstrated an increase susceptibility to both colicin groups. colicin-insusceptible e. coli wild-type strains 75colt, 84colt, and 981colt showed a low degree of hlf binding, i.e., 4, 8, and 10%, respectively. the hlf binding capacity was hig ... | 1991 | 1810187 |
| a potential approach for gene therapy targeting hepatoma using a liver-specific promoter on a retroviral vector. | recent technological advances made in molecular biology and in vitro culture of human and other mammalian cells have led to broad medical and scientific acceptance of the feasibility of gene therapy for genetic diseases. cancer might practically be one of the attractive targets for such therapy. for the treatment of cancer, it is important to manipulate the gene of interest such that it is expressed solely in cancer cells. we have developed a tissue-specific gene expression system, based on a ti ... | 1991 | 1813147 |
| immunogold labelling of human ifn alpha 2 and an ifn alpha 1/ alpha 2 hybrid produced by recombinant escherichia coli. | in recombinant escherichia coli strains the subcellular location of human interferon (ifn) alpha 2 and a hybrid ifn alpha 1/alpha 2 was investigated by immunogold labelling techniques. the gold label was scattered throughout the cytoplasm in cells containing the gene for mature ifn alpha 2 under the control of heterologous staphylokinase sak42d transcription and translation initiation signals. in contrast, in cells containing in addition the sak42d signal peptide coding region in front of the if ... | 1991 | 1813621 |
| high-level bacterial expression, purification and characterization of human calreticulin. | to investigate its cellular function and role in autoimmune disease pathogenesis, we have bacterially expressed human calreticulin, a major calcium-binding protein in the endoplasmic reticulum and a human autoantigen. this is the first report describing the heterologous expression of calreticulin from any source. the recombinant calreticulin constituted approximately 32% of the soluble escherichia coli proteins, and was purified to apparent homogeneity by ion exchange and hydrophobic liquid chro ... | 1991 | 1817262 |
| congo red binding test in enteroinvasive and nonpathogenic escherichia coli strains. | out of 6 variants the appropriate media to perform congo red binding test for enteroinvasive e. coli strains were established (trypto-soy agar eiken, t.s.a.--cantacuzino institute and b.t.s.d.). 12 e. coli strains belonging to enteroinvasive o-serogroups formed on congo red agar red-coloured, non-coloured colonies or both; cultures from 59 red colonies and 61 white colonies were inoculated in guinea pig eyes. the correlation between positive congo red binding test and positive sereny test was 91 ... | 1991 | 1820187 |
| expression of multivalent pre-s1 antigen of hepatitis b virus in escherichia coli (synthetic oligodeoxynucleotides, surface antigens, recombinant dna, fusion protein, beta-galactosidase). | the nucleotide sequence encoding 30 amino acids (aa) of the pre-s1 envelope region of the human hepatitis b virus has been constructed from twenty chemically synthesized oligodeoxynucleotides by simultaneous ligation. the dna fragment containing four repeated sequences encoding the pre-s1 region (aa 20-49) has been inserted into the lacz gene of the plasmid pwr450.1, yielding the recombinant pwx4 plasmid. the escherichia coli dh5 strain transformed with pwx4 produces a beta-galactosidase-[-pre-s ... | 1991 | 1821612 |
| expression of recombinant human apolipoprotein a-i in chinese hamster ovary cells and escherichia coli. | human recombinant apolipoprotein (apo) a-i was produced by chinese hamster ovary (cho) cells and escherichia coli with expression vectors containing cdnas encoding preproapoa-i or apoa-i, respectively. the apoa-i from cho cells was purified from the culture medium by ammonium sulfate precipitation, phenyl-sepharose chromatography, and affinity purification on anti-apoa-i immunoabsorber. human apoa-i was produced in e. coli as a fusion protein with glutathione s-transferase. a four amino acid lin ... | 1991 | 1821801 |
| altered hemolysin production in urine-grown uroisolates of escherichia coli. | fifteen uroisolates of e. coli were studied for both cell-free and cell-bound hemolysin production. estimations were done in trypticase soy broth (tsb, providing iron-replete medium) tsb + 2,2'-bipyridine (providing experimentally created iron-depleted conditions) and pooled normal human urine (providing natural iron-depleted growth medium). in tsb 40% of strains showed no detectable cell-free hemolysin, they were able to produce it in the presence of 2,2'-bipyridine and more so when grown in ur ... | 1991 | 1822841 |
| virulence factors of escherichia coli in urinary isolates. | 1. escherichia coli strains isolated from 100 urine samples taken from patients with urinary tract infections (uti) and from 20 normal fecal (nf) samples were examined for serum resistance, mannose-resistant hemagglutination of human erythrocytes (mrha) and for production of aerobactin, hemolysin and colicin. 2. among the uti e. coli strains, 79% produced aerobactin, 69% showed serum resistance, 44% produced mrha, 32% were beta-hemolytic and 22% were colicinogenic. a greater proportion of uti e. ... | 1991 | 1823249 |
| rna-binding domain of the a protein component of the u1 small nuclear ribonucleoprotein analyzed by nmr spectroscopy is structurally similar to ribosomal proteins. | an rna recognition motif (rrm) of approximately 80 amino acids constitutes the core of rna-binding domains found in a large family of proteins involved in rna processing. the u1 rna-binding domain of the a protein component of the human u1 small nuclear ribonucleoprotein (rnp), which encompasses the rrm sequence, was analyzed by using nmr spectroscopy. the domain of the a protein is a highly stable monomer in solution consisting of four antiparallel beta-strands and two alpha-helices. the highly ... | 1991 | 1826055 |
| lung vascular injury after administration of viable hemolysin-forming escherichia coli in isolated rabbit lungs. | escherichia coli hemolysin, a transmembrane pore-forming exotoxin, is considered an important virulence factor. in the present study, the possible significance of hemolysin production was investigated in a model of septic lung failure through infusion of viable bacteria in isolated rabbit lungs; 10(4) to 10(7) e. coli/ml perfusate caused a dose- and time-dependent appearance of hemolysin, accompanied by release of potassium, thromboxane a2, and pgi2 into the perfusate. concomitantly, marked pulm ... | 1991 | 1826193 |
| selection by two powerful antigens may account for the presence of the major population of human peripheral gamma/delta t cells. | v gamma 9/v delta 2 cells represent a fraction of human gamma/delta cells that is expanded after birth in the periphery, carries markers of activated cells, and becomes a major population in peripheral blood. we found that these cells do not comprise a single population but actually represent two nested sets, the smaller of which, specific for mycobacterium tuberculosis-pulsed antigen-presenting cells (apc), is contained in a larger set specific for an antigen found on the molt-4 lymphoma. the l ... | 1991 | 1827824 |
| specific 33-residue repeat(s) of erythrocyte ankyrin associate with the anion exchanger. | erythrocyte ankyrin contains an 89-kda domain (residues 2-827) comprised almost entirely of 22 tandem repeats of 33 amino acids which are responsible for the high affinity interaction of ankyrin with the anion exchanger (davis, l., and bennett, v. (1990) j. biol. chem. 265, 10589-10596). the question of whether the repeats are equivalent with respect to binding to the anion exchanger was addressed using defined regions of erythrocyte and brain ankyrins expressed in bacteria. the conclusion is th ... | 1991 | 1828247 |
| surveys of human enterotoxigenic escherichia coli from three different geographical areas for possible colonization factors. | enterotoxigenic escherichia coli (etec) from burma, central africa (rwanda and zaire) and peru, were screened by enzyme-linked immunoassays for the colonization factor antigens (cfas) and putative colonization factors (pcfs): cfa/i, cfa/ii, which consists of three coli surface-associated (cs) antigens, cs1, cs2 and cs3, cfa/iii, cfa/iv (cs4, cs5, cs6), cs7, pcfo9, pcfo159. h4, pcfo166, and cs17. the highest proportion of etec with identifiable colonization factors (71%) were found in the strains ... | 1991 | 1828771 |
| direct interaction between adenovirus e1a protein and the tata box binding transcription factor iid. | adenovirus e1a has long been known to activate/repress cellular and viral transcription. the transcriptional activity of nuclear extracts was depleted after chromatography on immobilized e1a protein columns that specifically retained the transcription factor (tf) iid. stronger direct interactions between e1a and human tfiid than between e1a and yeast tfiid suggest that the unique sequences of the human protein may be involved. we have demonstrated that this interaction occurs directly between ba ... | 1991 | 1828892 |
| expression of a human monoclonal anti-(rhesus d) fab fragment in escherichia coli with the use of bacteriophage lambda vectors. | a human anti-(rhesus d) antibody (igg1 lambda) fab fragment was cloned from an epstein-barr-virus-transformed cell line and expressed in escherichia coli with the use of bacteriophage lambda vectors. the cloned protein is active in binding to human erythrocytes and permits the development of a recombinant reagent for the prevention of haemolytic disease of the newborn. the method offers a rapid and effective means of rescuing human fabs from potentially unstable cell lines secreting human antibo ... | 1991 | 1830475 |
| a 25-kda stretch of the extracellular domain of the human interferon gamma receptor is required for full ligand binding capacity. | we investigated which is the shortest fragment of the interferon gamma receptor with ligand binding capacity. a recombinant soluble interferon gamma receptor produced in escherichia coli was subjected to controlled digestion with several proteolytic enzymes. the fragments generated were assayed by four approaches for interferon gamma binding. a 25-kda polypeptide comprising residues 6-227 of the mature protein was produced by sequential digestion with trypsin and proteinase k. it was identified ... | 1991 | 1831199 |
| accumulation of the c-mos protein is correlated with post-natal development of skeletal muscle. | previously we reported that c-mos proto-oncogene rna was developmentally up-regulated during post-natal maturation of the rat skeletal muscle. using two different site-directed affinity-purified antipeptide antibodies we can observe that c-mos product (p43 c-mos) accumulates increasingly during post-natal development of the skeletal muscle and exhibits protein kinase activity. we find that in adult rat p43 c-mos is 10-fold higher in skeletal muscle than in ovaries, and 20- to 40-fold higher than ... | 1991 | 1833718 |
| the regulatory effects of monocytes on human natural killer cells activated by lipopolysaccharides. | lipopolysaccharides (lps) rapidly enhance cytotoxicity of human natural killer (nk) cells against tumor targets. the regulatory effects of peripheral blood monocytes (mo) on this activation were measured. when lymphocytes were kept at a constant number in culture containing lps from oral and enteric bacteria, increasing the percentage of mo caused a dose-dependent suppression of nk cytotoxicity. this suppression was reversed by adding the prostaglandin (pg) inhibitor indomethacin which indicates ... | 1991 | 1837053 |
| bacterial translocation from the gastrointestinal tract in various mouse models for human diabetes. | bacterial translocation from the gastrointestinal (gi) tract to other internal organs was examined in multiple low-dose streptozotocin-injected (m-stz), single large-dose streptozotocin-injected (s-stz), alloxan-injected (alloxan), and non-obese diabetic (nod) mice. the incidence of bacterial translocation from the gi tract to the tested organs among diabetic mice was in the order of m-stz mice greater than s-stz mice greater than nod, alloxan, and control mice. the injections of insulin to m-st ... | 1991 | 1839693 |