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function of the post-translationally modified c-terminal region of rho p21.rhoa p21, a ras p21-like small gtp-binding protein, purified from bovine aortic smooth muscle is similarly modified at its c-terminal region as described for ras p21s. in this study, i examined the role of the post-translational modifications of the c-terminal region of rhoa p21 by comparing bovine rhoa p21 with bacterially-produced rhoa p21 because the bacterial protein was not modified. bovine rhoa p21 bound to plasma membranes, but bacterial rhoa p21 did not. both the stimulatory and inhibito ...19921518273
demonstration of similar calcium dependencies by mammalian high and low molecular mass phospholipase a2.the in vitro ca2+ dependencies of arachidonyl (aa)-selective high molecular mass phospholipase a2 (hmm, 85 kda-pla2) and human low molecular mass (lmm-type ii, 14 kda)-pla2 were compared. when the lmm-pla2 and hmm-pla2 enzymes were examined for hydrolysis against [3h]aa escherichia coli in an ethyleneglycol-bis(beta-aminoethyl ether) n,n,n',n'-tetraacetic acid (egta)-free buffer system, neither enzyme demonstrated activity below 10 microm free ca2+. beyond 11 microm ca2+ both enzyme activities i ...19921449538
three-dimensional structure in solution of acyl-coenzyme a binding protein from bovine liver.the three-dimensional structure of acyl-coenzyme a binding protein as encoded by the recombinant gene in escherichia coli has been determined using nuclear magnetic resonance (n.m.r.) spectroscopy. the structure consists of four alpha-helices a1 (residues 3 to 15), a2 (residues 20 to 36), a3 (residues 51 to 60), and a4 (residues 65 to 85). a1 and a4, and a2 and a3, run in parallel pairs. a2 runs anti-parallel to a1 and a4. the three-dimensional structure of the protein is reminiscent of a shallo ...19921518047
enhancement of the immune response by intradermal vaccination in cattle with enterotoxigenic escherichia coli (etec) vaccine without adjuvant.a comparison was made of the efficiency of intradermal and subcutaneous routes of vaccination in immunizing cattle with a killed vaccine of escherichia coli k99+. in this study 135 heifers aged 8-18 months were included. the effect of the number of intradermal injection sites was examined, as well as the optimal time interval between the initial and booster intradermal vaccination. the intradermal route was found to be significantly superior to the subcutaneous route. the optimal time for intrad ...19921561828
preparation, purification, and determination of the biological activities of 12 n terminus-truncated recombinant analogues of bovine placental lactogen.removal of 13 to 15 amino acids from the n terminus of bovine placental lactogen (bpl), which according to the three-dimensional structure of pgh corresponds to a nonhelical part of bpl, did not effect its secondary structure or change the monomer content of the protein preparation. however, it remarkably decreased the binding of the prolactin (prl) type of receptors on nb2 cells with subsequent reduction in bioactivity. the binding to the growth hormone (somatogen) receptors either did not chan ...19921618771
immune response of cattle to haemophilus somnus lipid a-protein conjugate vaccine and efficacy in a mouse abortion model.immunogenicity of the lipid a component of haemophilus somnus lipooligosaccharide in cattle and mice was examined after purification, detoxification, and covalent conjugation to a protein carrier. after 2 inoculations, a substantial antibody response was induced in most cattle to lipid a and the protein carrier. to determine whether antibodies to lipid a would be protective, 5 x 10(7) colony-forming units of h somnus strain 649 were administered iv to endotoxin-responsive (c3h/hen) mice. in one ...19921575380
distribution and characteristics of verocytotoxigenic escherichia coli isolated from ontario dairy cattle.faecal swabs obtained from a random sample of 1131 cows and 659 calves on 100 southern ontario dairy farms were examined for verocytotoxigenic escherichia coli (vtec) using a vero cell assay. five isolates from each positive culture were tested similarly. positive colonies were examined with dna probes for shiga-like toxin i (slt-i) and slt-ii sequences. probe-negative colonies were tested for neutralization of verocytotoxicity using anti-slt-i and anti-slt-iiv antisera. colonies showing no neut ...19921601076
opsonic activity of bovine serum and mammary secretion after escherichia coli j5 vaccination.six pairs of cows were used to determine the effects of immunization with an escherichia coli (o111:b4) j5 bacterin on in vitro opsonization of a smooth heterologous strain of e. coli. one cow in each pair was either immunized with the vaccine or sham-immunized at drying off, 30 d after drying off, and at calving. opsonizing bacteria with serum collected from vaccinated cows 21 d after calving resulted in higher mean number of intracellular bacteria per phagocytosing neutrophil than opsonizing b ...19921541744
the effect of cyclosporin a on cationized bovine serum albumin-induced nephropathy in nzw rabbits.the effect of cyclosporin a (cya) was studied on the morphology and protein excretion of a rabbit chronic serum sickness nephritis using cationized bovine serum albumin (cbsa). one group of rabbits was given intravenous (i.v.) immunizing doses of cbsa and escherichia coli endotoxin. one week later, these animals began a 6-week i.v. injection schedule of cbsa only. a second group followed the same injection protocol, but was given intramuscular (i.m.) cya for 3 days prior to the immunizing dose o ...19921625057
field trial to determine efficacy of an escherichia coli j5 mastitis vaccine.efficacy of an escherichia coli (o111:b4) j5 bacterin for preventing naturally occurring imi and clinical mastitis was tested in a 2.5-yr field trial in a 225-cow commercial herd. cows with odd-numbered identification were vaccinated, and cows with even-numbered identification served as unvaccinated controls for each lactation during the study. immunizations were subcutaneous on the upper part of the rib cage just posterior to the scapula at drying off, 30 d after drying off, and at calving. per ...19921541745
ubiquitous presence in mammalian cells of enzymatic activity specifically cleaving 8-hydroxyguanine-containing dna.here we report the finding of enzymatic activity that specifically cleaves dna containing 8-hydroxyguanine (oh8gua) residues in various mammalian cells. to detect this activity, we used a synthetic double-stranded dna containing a single oh8gua at a defined position as the substrate, and analyzed the products of enzymatic digestion by polyacrylamide gel electrophoresis. two cleavage sites near the oh8gua residue were detected with partially purified fractions from cow brain and rat liver, and al ...19921506269
high-level expression of functional human cytochrome p450 1a2 in escherichia coli.enzymatically active human cytochrome p450 1a2 was expressed in escherichia coli utilizing the pcwori+ vector containing a modified cdna. the coding sequence for the nh2-terminal region of the protein was modified by the alignment and substitution of a 27 bp segment from a modified bovine p450 17a1 cdna onto the 5' end of the open reading frame of p450 1a2 at amino acid 21. the expressed chimeric p450 was produced at a high level in a functionally intact form, as assayed by the formation in vivo ...19921537466
fate of escherichia coli o157:h7 as affected by ph or sodium chloride and in fermented, dry sausage.the influence of ph adjusted with lactic acid or hcl or sodium chloride concentration on survival or growth of escherichia coli o157:h7 in trypticase soy broth (tsb) was determined. studies also determined the fate of e. coli o157:h7 during the production and storage of fermented, dry sausage. the organism grew in tsb containing less than or equal to 6.5% nacl or at a ph of 4.5 to 9.0, adjusted with hcl. when tsb was acidified with lactic acid, the organism grew at ph 4.6 but not at ph 4.5. a co ...19921514799
renaturation of citrate synthase: influence of denaturant and folding assistants.citrate synthase (cs), which has been denatured in either guanidine hydrochloride (gdnhcl) or urea can be assisted in its renaturation in a variety of ways. the addition of each of the assistants--bovine serum albumin (bsa), oxaloacetate (oaa), and glycerol--promotes renaturation. in combination, the effect of these substances is additive with respect to the yield of folded cs. the report of buchner et al. (buchner, j., schmidt, m., fuchs, m., jaenicke, r., rudolph, r., schmid, f.x., & kiefhaber ...19921363914
plasmid content and localisation of the stai (stap) gene in enterotoxigenic escherichia coli with a non-radioactive polynucleotide gene probe.enterotoxigenic escherichia coli (etec) strain p2200 of porcine origin possessed eight possibly plasmid-determined characters (k88+ raf+ hly+ col+ smr tcr su(r) sta+) and six plasmid dna bands of 4.2-93 kb. analysis of the spontaneous loss of characters and the results of matings with other e. coli strains revealed that the k88, raf, hly, smr, tcr and su(r) characters could be transferred, and that the presence of the k88 and raf characters was associated with an 83-kb plasmid. the presence and ...19921629900
the spectrum of antibiotic resistance in human and veterinary isolates of escherichia coli collected from 1984-86 in northern india.this study was undertaken to assess the spectrum of drug resistance prevalent in escherichia coli isolates from human and animal populations in northern india. three hundred and two isolates of escherichia coli isolated from various infections of humans (47 from diarrhoea; 101 from urinary tract infection) and veterinary animals (17 from poultry septicaemia; 75 from bovine diarrhoea; 14 from ovine diarrhoea and 48 from equine metritis) were studied for their susceptibility to ampicillin, cephalo ...19921506331
characterization of bovine bladder mucin fractions that inhibit escherichia coli adherence to the mucin deficient rabbit bladder.we have previously shown that a dialyzed, lyophilized saline extract from bovine urothelium can restore the antiadherence activity of the rabbit bladder following mucin removal with 50% acetone. this report describes results of initial purification of antiadherence factor(s) from bovine bladder mucin and describes results of biochemical analysis in an attempt to elucidate possible mechanism of this antiadherence activity. separation performed by gel filtration (spectra gel aca 34, 20-350 kd rang ...19921613864
two linked genes for outer membrane proteins are absent in four non-disease strains of haemophilus somnus.linked genes encoding two outer membrane proteins (p76 and a family of proteins, p120) of the bovine pathogen, haemophilus somnus, were investigated. the p120 group was previously shown to have immunoglobulin-binding activity and to react with polyclonal antiserum specific for a 270 kda antigen (p270) which also had immunoglobulin fc-binding activity. by western blotting we showed that the p76 antigen also reacted with this antiserum. the p270, p120, and p76 antigens were undetectable in four se ...19921508038
intramammary administration of gentamicin as treatment for experimentally induced escherichia coli mastitis in cows.in 8 holstein cows, 50 colony-forming units (cfu) of escherichia coli was administered into 1 mammary gland. infections were established in all inoculated glands. in 4 of the 8 cows, 500 mg of gentamicin sulfate was administered by intramammary infusion 14 hours after inoculation; the other 4 cows were untreated controls. infusions of gentamicin also were given after each of the 3 successive milkings after the initial infusion, so that a total dose of 2 g of gentamicin was given to each of the t ...19921595964
mapping of sequential epitopes recognized by monoclonal antibodies on the bovine leukaemia virus external glycoproteins expressed in escherichia coli by means of antipeptide antibodies.a lambda gt11 cdna library prepared from bovine leukaemia virus (blv)-producing ovine cells was screened with a cocktail of anti-blv gp51 monoclonal antibodies (mabs). four recombinant phages with inserts of about 2-5 kbp were isolated. one, lambda blv-gp51-1, was sequenced and shown to encode the c-terminal part of gp51 and all of gp30. this insert was subcloned into pev-vrf1 and expressed in escherichia coli n-4830-1 cells. the blv product and a series of antipeptide antibodies were used to lo ...19921383413
the relation between the soluble factor associated with h(+)-transhydrogenase of rhodospirillum rubrum and the enzyme from mitochondria and escherichia coli.although in mitochondria, escherichia coli and rhodobacter capsulatus the h(+)-transhydrogenases are intrinsic membrane proteins, in rhodospirillum rubrum a water-soluble component (ths) and a membrane-bound component are together required for activity. ths was selectively removed from chromatophore membranes of rhs. rubrum and was purified to homogeneity by precipitation with (nh4)2so4 and ion-exchange, affinity dye and gel exclusion chromatography. the latter indicated an mr of approx. 74,000 ...19921610876
use of probes to detect virulence factor dna sequences in escherichia coli strains isolated from foods.escherichia coli strains were isolated from 96 food samples (32 milks, 4 dairy products, 36 raw meats, 7 meat products, 7 sandwiches and 10 ready-to-eat meals). a total of 306 colonies was submitted to hybridization assays with dna probes for the following virulence factors: heat-labile toxins (lt-i and lt-ii), heat-stable toxins (st-h and st-p). shiga-like toxins (slt-i and slt-ii), adherence factor of enteropathogenic e. coli (eaf) and invasive factor (inv). six colonies isolated from 4 food s ...19911677256
activation of mammalian dna ligase i through phosphorylation by casein kinase ii.mammalian dna ligase i has been shown to be a phosphoprotein. dephosphorylation of purified dna ligase i causes inactivation, an effect dependent on the presence of the n-terminal region of the protein. expression of full-length human dna ligase i in escherichia coli yielded soluble but catalytically inactive enzyme whereas an n-terminally truncated form expressed activity. incubation of the full-length preparation from e. coli with purified casein kinase ii (ckii) resulted in phosphorylation of ...19921639065
high cortisol concentrations and mediation of the hypogalactia during endotoxin-induced mastitis.a series of experiments was conducted to define the role of cortisol in the hypogalactia during endotoxin-induced mastitis. in the first experiment, three of six nonmastitic cows were given a continuous infusion of trilostane, a 3 beta-hydroxysteroid dehydrogenase inhibitor that blocks enhanced cortisol synthesis. trilostane had no effect in these cows. in the second experiment, six midlactation cows were given 10 micrograms of endotoxin in each of two homolateral quarters to induce mastitis. th ...19921569265
cell selection strategies for making antibodies from variable gene libraries: trapping the memory pool.the b cells of immunized animals can be used as a source of variable region (v) gene libraries. such libraries offer a way of making antibodies directly in bacteria: rearranged v genes are amplified using the polymerase chain reaction, cloned and expressed as soluble fragments in bacteria, and then screened for antigen binding. here we have used a model system to investigate antigen-selected b cells as a source of v gene libraries. mice were immunized with (4-hydroxyl-3-nitrophenyl)acetyl (np)-c ...19921547829
the antibacterial peptide seminal plasmin alters permeability of the inner membrane of e. coli.seminal plasmin (spln) a 47-residue peptide, isolated from bovine seminal plasma, exhibits antibacterial activity against gram-positive and gram-negative bacteria. although spln strongly inhibits the transcription of various natural and synthetic templates by e. coli rna polymerase in vitro, it also associates with model membranes of phosphatidylcholine and phosphatidic acid. we have undertaken experiments to ascertain whether spln permeabilizes the bacterial inner membrane and thereby exerts it ...19921535050
meningitis in neonatal calves: 32 cases (1983-1990).case records of 32 neonatal calves with the antemortem diagnosis of meningitis were reviewed. mean age at admission was 6 days (range, 11 hours to 30 days), and the most common concurrent clinical problem was diarrhea (16/32). twenty-seven of the calves were available for necropsy. at postmortem, there was evidence of septicemia in 22 (81%) of these calves. escherichia coli was the organism most frequently isolated (11/16; 69%) from the cns. the major clinical signs of cns disturbance observed o ...19921644635
a bovine papillomavirus e1-related protein binds specifically to bovine papillomavirus dna.the e1 open reading frame of bovine papillomavirus (bpv) was expressed as a reca-e1 fusion protein in escherichia coli. the bacterially expressed reca-e1 protein exhibited sequence-specific dna binding activity; strong binding to the region from nucleotides 7819 to 93 on the bpv genome (designated region a) and weak binding to the adjacent region from nucleotides 7457 to 7818 (region b) were observed. the interaction between the bpv-derived reca-e1 protein and region a appeared to be highly spec ...19911654443
molecular cloning of a cdna encoding chicken t-protein of the glycine cleavage system and expression of the functional protein in escherichia coli. effect of mrna secondary structure in the translational initiation region on expression.dna clones encoding chicken t-protein of the glycine cleavage system were isolated from chicken liver lambda gt10 cdna libraries. three overlapping clones provided an open reading frame of 1176 nucleotides that predicts a polypeptide of 392 amino acids (m(r) 42,056) comprised of a 16-residue mitochondrial targeting sequence and a 376-residue mature protein (m(r) 40,292). the amino acid sequence predicted for the mature protein showed 67% identity with that of bovine t-protein. a cdna encoding ma ...19921526969
dipstick immunoassay to detect enterohemorrhagic escherichia coli o157:h7 in retail ground beef.a sensitive and easy-to-perform dipstick immunoassay to detect escherichia coli o157:h7 in retail ground beef was developed by using a sandwich-type assay (with a polyclonal antibody to e. coli o157 as the capture antibody and a monoclonal antibody to e. coli o157:h7 as the detection antibody) on a hydrophobic polyvinylidine difluoride-based membrane. e. coli o157:h7 in ground beef could be detected within 16 h, including incubation for 12 h in enrichment broth and the immunoassay, which takes 4 ...19921622249
cdna cloning and expression of bauhinia purpurea lectin.bauhinia purpurea lectin (bpa) was purified from seeds of b. purpurea alba. the purified lectin was digested with an endoproteinase, asp-n, or trypsin and then the amino acid sequences of the resultant fragments were analyzed. furthermore, a cdna library for bpa was constructed using rna isolated from germinated bauhinia purpurea seeds. by gene cloning, the nucleotide sequence of bpa cdna and its deduced amino acid sequence were analyzed. the cloned bpa cdna comprised 1,152 nucleotides and the o ...19911657898
[antibody response in mice, rabbits and pigs in response to vaccination with an inactivated oil vaccine containing rotavirus and escherichia coli strains with k88, k99 and 987p fimbrial antigens].in trials with mice, rabbits and weanling piglets, four experimental charges of a combined inactivated oil vaccine against diarrhoeas in mammals were tested: the vaccine was to be implanted to sows and it contained porcine rotavirus (prv); two charges also contained bovine rotavirus and bacterins of enterotoxicogenic strains of e. coli with protective antigens k88, k99 and 987p. at low starting antibody titres the twofold i.m. implantation of 0.2 ml vaccine stimulated in mice the production of a ...19911686823
denaturant-dependent folding of bovine pancreatic trypsin inhibitor mutants with two intact disulfide bonds.the equilibrium and kinetic behavior of the guanidine hydrochloride (gdn-hcl) induced unfolding/refolding of four bovine pancreatic trypsin inhibitor (bpti) mutants was examined by using ultraviolet difference spectroscopy. in three of the mutants, we replaced the buried 30-51 disulfide bond with alanine at position 51 and valine (val30/ala51), alanine (ala30/ala51), or threonine (thr30/ala51) at position 30. for the fourth mutant, the solvent-exposed 14-38 disulfide was substituted by a pair of ...19901693524
isolation and characterization of the adenylate cyclase structural gene of neurospora crassa.a single gene (nac) encoding an adenylate cyclase was cloned from the genomic dna library of neurospora crassa, using the dna fragment encoding the catalytic domain of adenylate cyclase of saccharomyces cerevisiae as a probe. the open reading frame of this gene (6900 base pairs) was interrupted three time by introns. the protein encoded consists of 2300 amino acids and has adenylate cyclase activity. n. crassa adenylate cyclase has a high degree of homology with the catalytic domains of yeast an ...19911680356
diverse proteins homologous to inositol monophosphatase.bovine inositol monophosphatase (imp) and several homologous proteins were found to share two sequence motifs with bovine inositol polyphosphate 1-phosphatase (ipp). these motifs may correspond to binding sites within imp and ipp for inositol phosphates or for lithium, since both substances are bound by these proteins. this suggests that the proteins homologous to imp, which have diverse biological roles but whose function is not clear, may act by enhancing the synthesis or degradation of phosph ...19911660408
expression of bovine leukaemia virus antigens fused to ms2 polymerase in e. coli.the main core protein and segments of envelope proteins of bovine leukaemia virus fused to ms2 polymerase were expressed in e. coli. the synthesis rate varied between 3 and 25% of the total cellular proteins. blv-ms2 polymerase fusion proteins were detected immunologically using rabbit anti-blv sera, monoclonal antibodies and a serum of a blv-infected cow.19911686964
determination of the carbohydrate-binding site of bauhinia purpurea lectin by affinity chromatography.to determine the carbohydrate-binding site of bauhinia purpurea lectin (bpa), a d-galactose- and lactose-binding lectin, a peptide which interacts with lactose was purified from endoproteinase asp-n digests of bpa by chromatography on a lactose-sepharose column. it consists of nine amino acids and its amino acid sequence is asp-thr-trp-pro-asn-thr-glu-trp-ser. a tryptic fragment with the ability to interact with lactose was also purified and found to contain this sequence, consisting of nine ami ...19921517321
small acidic peptides from wheat germ chromatin. i. isolation and biochemical characterization.rna synthesis in cell and cell-free systems is inhibited by a family of acidic, low molecular weight chromatin peptides (cps). these peptides were extracted from deproteinized dna of prokaryotic and eukaryotic cells, but the low yield of purified material by this procedure hinders efforts aimed at understanding their action mechanism in gene regulation. in this report we describe two purification methods of cps from an easily available source, wheat germ. a comparison is made between the method ...19921508994
a genetic screen to identify variants of bovine pancreatic trypsin inhibitor with altered folding energetics.a genetic screening procedure has been developed to identify mutant forms of bovine pancreatic trypsin inhibitor (bpti) that can fold to an active conformation but are inactivated more rapidly than the wild-type protein. small cultures of escherichia coli containing plasmids with mutagenized bpti genes were grown in microtiter plates, lysed, and treated with dithiothreitol (dtt). under these conditions, unfolding and inactivation of the wild-type protein has a half-time of about 10 hours. varian ...19901691852
an f41-k88-related genetic determinant of bovine septicemic escherichia coli mediates expression of cs31a fimbriae and adherence to epithelial cells.a genetic determinant related to that encoding the f41 fimbrial adhesin was cloned from a bovine septicemic isolate of escherichia coli. this determinant was found to mediate expression of morphologically distinct fimbriae in e. coli hb101. the gene encoding the fimbrial subunit protein was identified, and the nucleotide sequence was determined. homology with the amino-terminal amino acid sequence of cs31a (j. girardeau, m. der vartanian, j. ollier, and m. contrepois, infect. immun. 56:2180-2188 ...19911675627
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 ...19911724627
modulation of function of bovine polymorphonuclear leukocytes and lymphocytes by high temperature in vitro and in vivo.function of polymorphonuclear leukocytes (pmnl) and proliferation of lymphocytes after stimulation with mitogens were evaluated in vitro at incubation temperatures of 38.5 and 42 c, and after in vivo heat stress of lactating holstein cows. cytochrome-c reduction and random migration of pmnl were reduced when cells were preincubated or incubated at 42 c, but high incubation temperature had little or no effect on phagocytosis and killing of escherichia coli. proliferation of lymphocytes was reduce ...19911662922
cloning, sequencing, expression, and functional studies of a 15,000-molecular-weight haemophilus somnus antigen similar to escherichia coli ribosomal protein s9.haemophilus somnus is a gram-negative bacterium capable of causing a number of disease syndromes in cattle. this article describes the cloning and characterization of a gene coding for a 15,000-molecular-weight (15k) polypeptide which reacts strongly with antiserum against h. somnus. analysis of plasmid-encoded polypeptides by polyacrylamide gel electrophoresis showed that the corresponding gene is the second in a transcriptional unit. the first gene codes for a protein with a molecular weight o ...19921729207
the g226a mutant of gs alpha highlights the requirement for dissociation of g protein subunits.adenylylcyclase cannot be activated by hormones or guanine nucleotide analogs in membranes from cells that express the g226a mutant form gs alpha instead of the wild-type protein. the mutant gs alpha protein appears incapable of undergoing the conformational change necessary for guanine nucleotide-induced dissociation of the g protein alpha subunit from the beta gamma subunit complex (miller, r.t., masters, s.b., sullivan, k.a., beiderman, b., and bourne, h.r. (1988) nature 334, 712-715). g226a ...19921730644
cloning and expression in escherichia coli of mature e1 beta subunit of bovine mitochondrial branched-chain alpha-keto acid dehydrogenase complex. mapping of the e1 beta-binding region on e2.a cdna encoding the mature e1 beta subunit of the bovine branched-chain alpha-keto acid dehydrogenase complex was isolated from a lambda zap expression library. the bovine e1 beta cdna is 1,393 base pairs in length. it encodes the entire mature e1 beta subunit consisting of 342 amino acid residues and a partial mitochondrial targeting presequence of 26 residues. the calculated molecular mass of the mature bovine e1 beta subunit is 37,776 daltons, and the calculated isoelectric point is pi 5.04. ...19921730724
phospholipase a2 engineering. x-ray structural and functional evidence for the interaction of lysine-56 with substrates.site-directed mutagenesis studies of bovine pancreatic phospholipase a2 (pla2, overproduced in escherichia coli) showed that replacement of surface residue lys-56 by a neutral or hydrophobic amino acid residue resulted in an unexpected and significant change in the function of the enzyme. the kcat for phosphatidylcholine micelles increases 3-4-fold for k56m, k56i, and k56f and ca. 2-fold for k56n and k56t but does not change for k56r. these results suggest that the side chain of residue 56 has s ...19911751497
dietary selenium effects on milk eicosanoid concentration in dairy cows during coliform mastitis.the effect of selenium deficiency on the product profile of arachidonic acid oxidation by enzymatic pathways in holstein cows with experimentally-induced coliform mastitis was investigated. the animals were fed dairy rations containing 0.05 mg se/kg dry matter, with the supplemented group receiving additional se to increase the dietary concentration to approximately 0.35 mg se/kg dry matter. cows were inoculated intracisternally with 30 colony-forming-units of escherichia coli at 14-16 weeks of ...19911665569
cloning, expression and characterization of the human transcription elongation factor, tfiis.the cdna for the human elongation factor, tfiis, has been cloned and expressed in e. coli with the t7 expression system. this 280-amino acid tfiis protein is shorter by 21 residues than that of the mouse. the missing 21 residues are located in the amino-terminal region, which is not thought to be required for transcriptional stimulation. apart from this gap, human and mouse proteins reveal 96% overall identity and 98.5% sequence similarity if conservative substitutions are taken into account. th ...19911708494
the signal for golgi retention of bovine beta 1,4-galactosyltransferase is in the transmembrane domain.the expression and localization of bovine beta 1,4-galactosyltransferase (gal t) has been studied in mammalian cells transfected with gal t cdna constructs, and the role of the amino-terminal domains of gal t in golgi localization examined. here we demonstrate that the transmembrane (signal/anchor) domain of bovine gal t contains a positive golgi retention signal. bovine gal t was characterized in transfected cells with anti-bovine gal t antibodies, affinity-purified from a rabbit antiserum usin ...19921637374
functional interactions of stimulatory and inhibitory gdp/gtp exchange proteins and their common substrate small gtp-binding protein.smg gds and rho gdi are stimulatory and inhibitory gdp/gtp exchange proteins, respectively, for a group of ras p21-related small gtp-binding proteins (g proteins). rho p21 is a common substrate small g protein for both gdp/gtp exchange proteins. we examined here the functional interactions of these gdp/gtp exchange proteins with rho p21 as a substrate. smg gds and rho gdi interacted with the gdp-bound form of rho p21 and thereby stimulated and inhibited, respectively, the dissociation of gdp. th ...19921634508
characterization of a new fimbrial antigen present in escherichia coli strains isolated from calves.thirteen escherichia coli strains isolated from calves with diarrhoea, supposed to carry a common antigen were examined for their hemagglutinating activity and compared by bacterial agglutination, double diffusion in two dimensions and by crossed immunoelectrophoresis (cie). two of the strains were examined also in the electron microscope. most of the strains agglutinated red blood cells of horse, ox, guinea pig and chicken, of which the agglutination of ox erythrocytes was mannose-resistant (mr ...19911686345
swine and cattle enterotoxigenic escherichia coli-mediated diarrhea. development of therapies based on inhibition of bacteria-host interactions.enterotoxigenic escherichia coli (etec) frequently occurs in diarrheal disease afflicting domestic animals. in this paper is summarized the research carried out over the last decade on the two important determinants of virulence that plays a role in the development of the infection, namely the colonizing ability of the small intestine mediated by specific fimbrial adhesins acting as lectins and the production of enterotoxins. recent progress in knowledge of the phenomenon led to alternative stra ...19911723693
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 ...19911742279
[synthesis of the e-antigen of the hepatitis b virus (hbeag) in eukaryotic cells by a recombinant strain of the vaccinia virus].the recombinant plasmids containing the gene for hepatitis b viral core-antigen with the pre-core-sequence controlled by the early-late promoter of the 7.5' k protein gene were constructed. the recombinant strains of vaccinia virus were obtained on their basis (vhbe42-1 and vhbe42-3) selectively expressing hbeag of hepatitis b virus. the kinetics of hbeag synthesis was studied in infected cells as well as secretion of the protein into culturing medium. three proteins were found by blotting techn ...19911745274
potent bactericidal activity of bovine lactoferrin hydrolysate produced by heat treatment at acidic ph.a hydrolysate of bovine lactoferrin produced by heat treatment under acidic conditions had antibacterial activity at concentrations of 10 micrograms/ml in the culture medium. the optimal degree of hydrolysis for this activity was about 10%. heat-treated lactoferrin, treated at ph 2.0 and 120 degrees c for 15 min and degree of hydrolysis of about 10%, had no fe-binding capacity (0%) and less antigenicity (about 10(-6) than untreated lactoferrin. heat-treated lactoferrin increased in antibacterial ...19911757616
rapid procedure for detecting enterohemorrhagic escherichia coli o157:h7 in food.a sensitive, specific procedure was developed for detecting escherichia coli o157:h7 in food in less than 20 h. the procedure involves enrichment of 25 g of food in 225 ml of a selective enrichment medium for 16 to 18 h at 37 degrees c with agitation (150 rpm). the enrichment culture is applied to a sandwich enzyme-linked immunosorbent assay (elisa) with a polyclonal antibody specific for e. coli o157 antigen as the capture antibody and a monoclonal antibody specific for enterohemorrhagic e. col ...19911768144
covalent binding studies on the 14c-labeled antitumor compound 2,5-bis(1-aziridinyl)-1,4-benzoquinone. involvement of semiquinone radical in binding to dna, and binding to proteins and bacterial macromolecules in situ.2,5-bis(1-aziridinyl)-1,4-benzoquinone (babq) is a compound from which several antitumour drugs are derived, such as trenimone, carboquone and diaziquone (azq). the mechanism of dna binding of babq was studied using 14c-labeled babq and is in agreement with reduction of the quinone moiety and protonation of the aziridine ring, followed by ring opening and alkylation. the one-electron reduced (semiquinone) form of babq alkylates dna more efficiently than two-electron reduced or non reduced babq. ...19901699678
protective effect of tissue ferritins in experimental escherichia coli infection of mice in vivo.the effect of ferritins from horse (fh) and bovine (fb) spleen and murine liver (fm) on the survival rate of cfw mice lethally infected with escherichia coli (strain 8440-78 k 80/b) was evaluated. ferritins given intravenously 24 h before intravenous inoculation of bacteria, protected mice most effectively from death due to infection. the effect was dose dependent. at 500 micrograms of ferritin per mouse, the maximum survival rates were 86% (fh), 81% (fm) and 79% (fb), while only 5% of the contr ...19911768608
molecular cloning and expression of biologically active human glia maturation factor-beta.glia maturation factor-beta, a protein found in the brains of all vertebrates thus far examined, appears to play a role in the differentiation, maintenance, and regeneration of the nervous system. using oligonucleotide probes based on the sequences of three tryptic peptides derived from bovine glia maturation factor-beta, we screened a human brainstem cdna library in lambda gt11. a 0.7-kb clone was isolated, sequenced in its entirety, and found to encode a polypeptide of 142 amino acids which co ...19911712830
the effect of lipopolysaccharide on bovine mammary macrophage function.the effect of escherichia coli lipopolysaccharide (lps) on the expression of major histocompatibility complex (mhc) class ii molecules by bovine mammary macrophages was examined. the ability of lps-treated mammary macrophages to support antigen-specific t-cell proliferation, as a measure of their antigen presentation ability, was also evaluated. for this purpose, control and lps-treated macrophages were pulsed with heat-killed staphylococcus aureus and then cultured with s. aureus-sensitized t-c ...19911889031
virulence factors associated with cytotoxic necrotizing factor type two in bovine diarrheic and septicemic strains of escherichia coli.forty-three bovine isolates of escherichia coli producing a second type of cytotoxic necrotizing factor (cnf2) and three k-12 strains carrying different vir plasmids coding for cnf2 were tested for the presence of several virulence factors. most of the strains were serum resistant (79%), produced an aerobactin (70%), and adhered to calf villi (53%); some of them produced a colicin (32%) and a hemolysin (9%). these strains were also tested by a colony hybridization assay with gene probes for six ...19911774259
conglutinin exhibits a complement-dependent enhancement of the respiratory burst of phagocytes stimulated by e. coli.conglutinin is a mammalian c-type lectin which shows anti-bacterial activity when tested in vivo and in vitro. this study concerns the effect of conglutinin on the respiratory burst of murine spleen cells, using a chemiluminescence assay for measurement of generated reactive oxygen metabolites. conglutinin enhances, in a dose-dependent manner, the respiratory burst of spleen cells stimulated with serum-opsonized escherichia coli. the enhancement was only demonstrable in the presence of a functio ...19911783427
potent antibacterial peptides generated by pepsin digestion of bovine lactoferrin.the antibacterial properties of enzymatic hydrolysates of bovine lactoferrin were examined to determine whether active peptides are produced from this protein. hydrolysates prepared by cleavage of lactoferrin with porcine pepsin, cod pepsin, or acid protease from penicillium duponti showed strong activity against escherichia coli o111, whereas hydrolysates produced by trypsin, papain, or other neutral proteases were much less active. low molecular weight peptides generated by porcine pepsin clea ...19911787185
isolation of a cdna encoding a mammalian multiubiquitinating enzyme (e225k) and overexpression of the functional enzyme in escherichia coli.the ubiquitin (ub)-conjugating enzyme e2(25k) catalyzes the synthesis of multi-ub chains in which successive ub units are linked by an isopeptide bond involving the epsilon-amino group of lys-48 of ubn, and the cooh-terminal gly residue of ubn+1 (chen, z., and pickart, c. m. (1990) j. biol. chem., 265, 21835-21842). we now describe the polymerase chain reaction (pcr)-based cloning of an e2(25k)-encoding cdna from a bovine thymus library, using degenerate oligonucleotide primers based on the sequ ...19911714895
antigenic homology among gram-negative organisms isolated from cattle with clinical mastitis.this study examined the degree of serologic homology among mastitis pathogens. antibodies were raised against the rc mutant, escherichia coli o111:b4 (strain j5) and affinity purified against lipopolysaccharide derived from the ra mutant, salmonella typhimurium tv119. these antibodies reacted with a battery of unrelated gram-negative bacteria in whole cell elisa. bacteria with strong cross-reactions included a heterologous, smooth e. coli, salmonella dublin, s. typhimurium, salmonella newport, a ...19911907303
a new diarrhoeic syndrome with ataxia in young charolais calves: clinical and microbiological studies.a new diarrhoeic syndrome was examined clinically in 19 one to two-week old charolais calves. it differs from other digestive disorders in calves of this age in the discrete diarrhoeic signs, the absence of dehydration and the presence of signs of ataxia. the microbiological study carried out for three consecutive years in 58 sick calves and nine healthy control calves demonstrated the special role of e coli possessing virulence markers from septicaemic strains (cs31a, col v). the clinical signs ...19911853535
expression of bovine inhibin beta subunit in escherichia coli.1. a dna fragment encoding the beta subunit of bovine inhibin was amplified using the polymerase chain reaction and was cloned in plasmids puc8 and pur291. 2. cultures of escherichia coli tg2 harbouring pkdk37, a pur291-derived recombinant plasmid, produced a novel protein with a molecular weight of 130,000 corresponding to a beta-galactosidase-inhibin beta fusion protein. 3. the fusion protein was purified from inclusion bodies by solubilization in 8 m urea followed by an ion-exchange and gel p ...19911794452
comparative immunochemical analysis of the antigenic structures of the dna-binding histone-like hu protein from escherichia coli and eukaryotic histones.the general antigenic structures of the dna-binding hu protein from e. coli, histones h1, h2a, h2b, h3, and h4 from calf thymus, and histone h5 from chick erythrocytes were compared in immunoassays with the aid of monospecific polyclonal antibodies to the hu protein and the individual histones. a partial cross-reaction between the hu protein and antibodies to histones h1 and h5 was demonstrated. the reaction titres obtained in a solid-phase enzyme immunoassay indicated that the cross-reactions w ...19911797140
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 ...19911799410
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 ...19911799920
[the immunogenicity of mono- and associated vaccines made from strains of opportunistic bacteria].in experiments on white mice the immunogenic potency of two variants of combined vaccines prepared from strains of opportunistic bacteria was compared with that of monovaccines used as the components of the combined vaccines. all the vaccines under study were found highly immunogenic. decrease of monovaccine share in the combined vaccine did not reduce the immunogenic potency to any of the strains. an 8- to 16-fold increase in the level of specific antibodies in the colostric lactosera of cows i ...19911801485
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 ...19911714562
simian virus 40 vp2/3 small structural proteins harbor their own nuclear transport signal.we have used a microinjection approach to identify a domain of the simian virus 40 (sv40) structural proteins vp2 and vp3(vp2/3) responsible for their nuclear transport. by using both synthetic peptides, containing small regions of vp2/3 conjugated to bovine serum albumin (bsa), and beta-galactosidase-vp3 fusion proteins, we have narrowed this nuclear transport signal (nts) to 9 amino acids (198 to 206 of vp3 or 316 to 324 of vp2), gly-pro-asn-lys-lys-lys-arg-lys-leu. the porter proteins carryin ...19911847270
in vitro studies on mild alkali induced lesions in dna.s1 nuclease hydrolysis, benzoylated naphthoylated deae cellulose (bnd-cellulose) chromatography as well as certain immunological and genetic techniques have been used to evaluate the effect of mild alkali (ph10.0) on the dna molecule. native calf thymus dna after exposure to alkaline ph10.0 when subjected to s1 nuclease hydrolysis released significant amount of acid soluble nucleotides as compared to the untreated control. with pbr322 dna, the population of linear dna species increased on s1 dig ...19911789792
the amino-terminal half of rotavirus sa114fm vp4 protein contains a hemagglutination domain and primes for neutralizing antibodies to the virus.we have previously reported the synthesis in escherichia coli of polypeptide ms2-vp8', which contains the amino-terminal half of the sa114fm vp4 protein fused to ms2 bacteriophage polymerase sequences (c. f. arias, m. lizano, and s. lópez, j. gen. virol. 68:633-642, 1987). in this work we have synthesized the carboxy-terminal half of the vp4 protein also fused to the ms2 polymerase. this protein, designated ms2-vp5', was recognized by sera to the complete virion and was able to induce antibodies ...19911847459
endometrial biopsy in holstein-friesian dairy cows. iii. bacteriological analysis and correlations with histological findings.this study examines the results of bacterial culture from 159 endometrial biopsy samples from 97 commercial dairy cows and correlations between bacteriological and histological findings. bacteria were isolated from approximately 80% of biopsies taken at day 26 and day 40 postpartum. eleven percent of biopsies were positive for both aerobic and anaerobic culture. streptococci, escherichia coli and actinomyces pyogenes were the most common isolates. isolation of a. pyogenes from a biopsy at day 26 ...19911884297
controlling acute escherichia coli mastitis during the periparturient period with recombinant bovine interferon gamma.the efficacy of recombinant bovine interferon (rboifn)-gamma against experimentally induced escherichia coli mastitis during the periparturient period was investigated. dairy cows intramammarily treated with rboifn-gamma 24 h before the e. coli challenge had fewer infected quarters, lower clinical scores, and infections of shorter duration when compared to placebo-treated animals. all rboifn-gamma treated cows survived the experimental e. coli challenge. however, placebo treated cows had a 42% m ...19911908159
effect of site-directed mutagenic alterations on adp-ribosyltransferase activity of the a subunit of escherichia coli heat-labile enterotoxin.previous studies of the s1 subunit of pertussis toxin, an nad(+)-dependent adp-ribosyltransferase, suggested that a small amino-terminal region of amino acid sequence similarity to the active fragments of both cholera toxin and escherichia coli heat-labile enterotoxin represents a region containing critical active-site residues that might be involved in the binding of the substrate nad+. other studies of two other bacterial toxins possessing adp-ribosyltransferase activity, diphtheria toxin and ...19911908825
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 ...19911720092
dna hybridization and latex agglutination for detection of heat-labile- and shiga-like toxin-producing escherichia coli in meat.dna-hybridization and latex-agglutination tests were used for screening of a group of escherichia coli isolates for heat-labile enterotoxin (lt)- and shiga-like toxin (slt1 or vt1) -producing strains, respectively. strains tested originated from 162 meat samples (poultry, pigs and beef) chosen at random. additionally lt- and slt1-producing reference strains were tested. the dna-hybridization technique allowed screening of large numbers of strains, whereas large scale testing of strains by latex ...19911863526
rsr1 and rap1 gtpases are activated by the same gtpase-activating protein and require threonine 65 for their activation.the rsr1 protein of saccharomyces cerevisiae has been shown to be essential for bud site selection (bender, a., and pringle, j. (1989) proc. natl. acad. sci. u.s.a. 86, 9976-9980). this protein of 272 amino acids shares approximately 50% sequence identity with both ras and rap gtpases. however, neither gtp binding nor gtpase activity of the rsr1 protein has been reported. the rsr1 protein shares with human rap1 gtpases the four specific motifs, i.e. gly-12, residues 32-40, ala-59, and residues 6 ...19911910037
initiation of protein synthesis in animal mitochondria. purification and characterization of translational initiation factor 2.bovine liver mitochondrial translational initiation factor 2 (if-2mt) has been purified to near homogeneity. the scheme developed results in a 24,000-fold purification of the factor with about 26% recovery of activity. sds-polyacrylamide gel electrophoresis indicates that if-2mt has a subunit molecular mass of 85 kda. if-2mt promotes the binding of formyl(f)met-trna to mitochondrial ribosomes but is inactive with the nonformylated derivative. if-2mt is active on chloroplast 30 s ribosomal subuni ...19911939122
prevalence of antibiotic-resistant escherichia coli in danish pigs and cattle.the present paper reports on the antibiotic resistance of e. coli isolated from danish piglets and calves in 1987-1988, and compares the results with similar investigations performed during the periods 1971-1972 and 1977-1978. rectal swabs from 52 piglets and from 78 calves were examined. all the animals studied harboured resistant e. coli. this is a significant increase compared to the previously conducted investigations. the number of strains having three or more resistance markers did not dif ...19911772647
rhizobium meliloti adenylate cyclase is related to eucaryotic adenylate and guanylate cyclases.a gene from rhizobium meliloti coding for an adenylate cyclase was sequenced, and the deduced protein sequence was compared with those of other known adenylate cyclases. no similarity could be detected with the procaryotic counterparts. however, striking similarity was found with the catalytic region of saccharomyces cerevisiae adenylate cyclase, the cytoplasmic domains of bovine adenylate cyclase, and two mammalian guanylate cyclases. the gene was fused to the enteric beta-galactosidase, and th ...19901970565
effect of milking without pulsation on teat duct colonization with streptococcus agalactiae and penetrability to endotoxin.forty quarters of 10 cows were milked for a 9-d period with one of four treatments: 1) no liner pulsation, 2) conventional milking, 3) no pulsation for 4 d followed by conventional milking for 5 d, and 4) conventional milking for 4 d followed by milking without pulsation for 5 d. all teat orifices were inoculated with approximately .5 million cfu of streptococcus agalactiae and streptococcus dysgalactiae on d 1 and 5. recoveries of strep. agalactiae from the teat end were increased for teats mil ...19911779054
cryptosporidiosis in neonatal calves: 277 cases (1986-1987).from january 1986 through december 1987, 277 cases of cryptosporidiosis in calves were diagnosed by the south dakota state university diagnostic laboratory. cryptosporidium sp was the only pathogen identified in 142 (51.3%) of the calves. concurrent infections with rotavirus, coronavirus, escherichia coli, salmonella sp, bovine viral diarrhea virus, or other pathogens were identified in the remaining 135 calves. after elimination of cases involving autolyzed specimens or calves with chronic diar ...19911874678
antibodies to iron-regulated outer membrane proteins of coliform bacteria isolated from bovine intramammary infections.expression of iron-regulated outer membrane proteins (omp) by escherichia coli and klebsiella pneumoniae initially isolated from bovine intramammary infections (imi) was investigated. additionally, the presence of antibodies in bovine serum and mammary secretion directed against the iron-regulated omp was examined. outer membrane proteins were separated by sodium-dodecyl polyacrylamide electrophoresis. detection of immunoglobulin g directed against omp was by immunoblotting. all gram-negative ba ...19911866891
cdna and deduced amino acid sequence of a mouse dna repair enzyme (apex nuclease) with significant homology to escherichia coli exonuclease iii.we purified a mouse dna repair enzyme having apurinic/apyrimidinic endonuclease, dna 3'-phosphatase, 3'-5'-exonuclease and dna 3' repair diesterase activities, and designated the enzyme as apex nuclease. a cdna clone for the enzyme was isolated from a mouse spleen cdna library using probes of degenerate oligonucleotides deduced from the n-terminal amino acid sequence of the enzyme. the complete nucleotide sequence of the cdna (1.3 kilobases) was determined. northern hybridization using this cdna ...19911939131
clonal relationships among escherichia coli serogroup 06 isolates from human and animal infections.the clonal relationship of thirty e. coli strains of 0 antigen serotype 06 isolated from human, dog, pig or cow infections were investigated. two main clones with serotypes 06 : h1 or 06 : h31, h- were identified. isolates from humans, dogs, pigs and cows were found in both clones, indicating that animals are a possible source for human extraintestinal escherichia coli strains. two human etec (06 : h16) and two pig isolates (06 : h10) were not related to the 06 : h1 or 06 : h31, h- e. coli clone ...19911884980
interaction of animal mitochondrial ef-tu.ef-ts with aminoacyl-trna, guanine nucleotides, and ribosomes.the mammalian mitochondrial complex consisting of elongation factors ef-tu and ef-ts (ef-tu.tsmt) is capable of efficiently binding aminoacyl-trna to the ribosome in the presence and absence of guanine nucleotides. in the presence of gtp the binding reaction is catalytic. in the absence of guanine nucleotides, or in the presence of a non-hydrolyzable gtp analog, only one round of ribosome binding occurs. ef-tu.tsmt is capable of forming a ternary complex with gtp and escherichia coli phe-trna as ...19911885567
sensitive immunoassay for rat parvalbumin: tissue distribution and developmental changes.a sensitive enzyme immunoassay for measurements of rat parvalbumin was established using antibodies raised in rabbits with parvalbumin purified from skeletal muscles. antibodies in the antiserum were purified with a parvalbumin-coupled sepharose column. the sandwich-type immunoassay system for parvalbumin was composed of polystyrene balls with immobilized purified antibodies and the same antibodies labeled with beta-d-galactosidase from escherichia coli. the assay was highly sensitive and the mi ...19911892868
16s ribosomal dna amplification for phylogenetic study.a set of oligonucleotide primers capable of initiating enzymatic amplification (polymerase chain reaction) on a phylogenetically and taxonomically wide range of bacteria is described along with methods for their use and examples. one pair of primers is capable of amplifying nearly full-length 16s ribosomal dna (rdna) from many bacterial genera; the additional primers are useful for various exceptional sequences. methods for purification of amplified material, direct sequencing, cloning, sequenci ...19911987160
[coliform bacilli which produce cytotoxins: importance in veterinary medicine and public health].this article reviews published data (october 1st, 1990) on 4 types of cytotoxins produced by animal and human pathogenic strains of e coli, ie, verotoxins, also named shiga-like toxins, cytotoxic necrotizing factors, haemolysin, and cytolethal distending toxin. the biological and molecular properties are described for each type of cytotoxin, the association of producing strains with animal pathology, and the role of domestic animals as reservoirs of strains pathogenic for man.19911897865
escherichia coli o157:h7 and its significance in foods.escherichia coli o157:h7 was conclusively identified as a pathogen in 1982 following its association with two food-related outbreaks of an unusual gastrointestinal illness. the organism is now recognized as an important cause of foodborne disease, with outbreaks reported in the u.s.a., canada, and the united kingdom. illness is generally quite severe, and can include three different syndromes, i.e., hemorrhagic colitis, hemolytic uremic syndrome, and thrombotic thrombocytopenic purpura. most out ...19911854598
fibroblast adhesion to recombinant tropoelastin expressed as a protein a-fusion protein.a bovine tropoelastin cdna encoding exons 15-36 that includes the elastin-receptor binding site was expressed in escherichia coli as a fusion protein with protein a from staphylococcus aureus. after isolation of the fusion protein by affinity chromatography on ig-sepharose, the tropoelastin domain was separated from plasmid-pr1t2t-encoded protein a (protein a') by cnbr cleavage. cell-adhesion assays demonstrated specific adhesion to the recombinant tropoelastin. furthermore, the data indicate th ...19911996952
antibacterial activities in vitro and in vivo and pharmacokinetics of cefquinome (hr 111v), a new broad-spectrum cephalosporin.cefquinome is a new injectable aminothiazolyl cephalosporin derivative. it is stable against chromosomally and plasmid-encoded beta-lactamases and has a broad antibacterial spectrum. staphylococcus aureus, streptococci, pseudomonas aeruginosa, and members of the family enterobacteriaceae (escherichia coli, salmonella spp., klebsiella spp., enterobacter spp., citrobacter spp., and serratia marcescens) are inhibited at low concentrations. cefquinome is also active against many strains of methicill ...19912014969
development of genomic probes to sarcocystis cruzi (apicomplexa).a genomic library of sarcocystis cruzi sporozoite dna was constructed in bacteriophage lambda gt10. recombinant phages containing insert dna were selected by growth on escherichia coli strain c600 hfla150. of 14 clones examined, 11 contained dna inserts ranging in size from approximately 1.45 kilobase (kb) to 6.18 kb. insert dna from four of these clones specifically hybridized to 32p-labelled s. cruzi merozoite dna. one of these insert dna, clone sl41, was selected and labelled with 32p. this p ...19911837193
pathogenic escherichia coli o157:h7 and their detection.enterohaemorrhagic escherichia coli o157:h7 is of major concern to the food industry due to high pathogenicity of this foodborne organism. for the detection of these bacteria a special agar medium with a fluorogenic substrate has been developed. the medium uses the characteristics of this e. coli serotype not to ferment sorbitol and not to produce beta-glucuronidase. in contrast, approximately 96% of all other strains of e. coli are sorbitol-positive and nearly all of them are beta-glucuronidase ...19911817428
characterization of a new putative colonization factor (cs17) from a human enterotoxigenic escherichia coli of serotype o114:h21 which produces only heat-labile enterotoxin.enterotoxigenic escherichia coli (etec) of serotype o114:h21, which produced only heat-labile enterotoxin (lt), gave mannose-resistant hemagglutination (mrha) with bovine erythrocytes. one strain, e20738a, was shown to possess fimbriae of approximately 7.5 nm diameter. on sds-page two possible fimbrial polypeptides of molecular masses 17.5 and 15.5 kda were seen; the 17.5-kda band was the most prominent. loss of lt and mrha together from strain e20738a was associated with loss of a 100-mda plasm ...19901967623
inhibitory effects of quinolones on pro- and eucaryotic dna topoisomerases i and ii.as a means of gaining information on the selectivity of quinolone antibacterial agents, we examined their effect on four topoisomerases, topoisomerases i and ii purified from escherichia coli and calf thymus. the inhibition of supercoiling and relaxation activities was monitored by using the classical gel electrophoresis assay. eight quinolones were assayed by using the four enzymes. gyrase was much more sensitive to quinolones than the other topoisomerases which can therefore be inhibited by mo ...19901963290
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