recognition by viral and cellular dna polymerases of nucleosides bearing bases with nonstandard hydrogen bonding patterns.the ability of dna polymerases (pols) to catalyze the template-directed synthesis of duplex oligonucleotides containing a nonstandard watson-crick base pair between a nucleotide bearing a 5-(2,4-diaminopyrimidine) heterocycle (d kappa) and a nucleotide bearing either deoxyxanthosine (dx) or n1-methyloxoformycin b (pi) has been investigated. the kappa-x and kappa-pi base pairs are jointed by a hydrogen bonding pattern different from and exclusive of those joining the at and gc base pairs. reverse ...19957541538
diffusion-limited interaction between unfolded polypeptides and the escherichia coli chaperone secb.secb is a chaperone dedicated to protein translocation in escherichia coli. secb binds to a subset of precursor proteins, and targets them in a translocation-competent state to the seca subunit of the translocase. the nature and kinetics of the interaction of secb with polypeptides were studied by spectroscopic techniques using the reduced form of bovine pancreatic trypsin inhibitor (bpti) as a model substrate. binding of secb to bpti resulted in an increase in the fluorescence of the surface-ex ...19957543278
stereospecificity of human dna polymerases alpha, beta, gamma, delta and epsilon, hiv-reverse transcriptase, hsv-1 dna polymerase, calf thymus terminal transferase and escherichia coli dna polymerase i in recognizing d- and l-thymidine 5'-triphosphate as substrate.l-beta-deoxythymidine (l-dt), the optical enantiomer of d-beta-deoxythymidine (d-dt), and l-enantiomers of nucleoside analogs, such as 5-iodo-2'-deoxy-l-uridine (l-idu) and e-5-(2-bromovinyl)-2'-deoxy-l-uridine (l-bvdu), are not recognized in vitro by human cytosolic thymidine kinase (tk), but are phosphorylated by herpes simplex virus type 1 (hsv-1) tk and inhibit hsv-1 proliferation in infected cells. here we report that: (i) l-dt is selectively phosphorylated in vivo to l-dtmp by hsv-1 tk and ...19957544886
[enterotoxigenic, verotoxigenic, and necrotoxigenic escherichia coli in food and clinical samples. role of animals as reservoirs of strains pathogenic for humans].toxigenic escherichia coli of human and animal origin have been classified into three categories: enterotoxigenic e. coli (etec), verotoxigenic e. coli (vtec), and necrotoxigenic e. coli (ntec), etec are a major cause of infant diarrhoea in less-developed countries and frequently cause colibacillosis in domestic animals. human etec strains may synthesize lt-i and/or sta enterotoxins and they may possess the colonization factors cfa/i to cfa/iv; porcine strains synthesize lt-i, sta and/or stb, an ...19957546450
casocidin-i: a casein-alpha s2 derived peptide exhibits antibacterial we report the isolation and characterization of an antibacterial peptide from bovine milk inhibiting the growth of escherichia coli, and staphylococcus carnosus. the primary structure of the peptide was revealed as a 39-amino-acid-containing fragment of bovine alpha s2-casein (position 165-203) by means of edman amino acid sequencing and mass spectrometry. since human milk does not contain any casein-alpha s2, these findings could explain the different influence of human and bovine milk on ...19957556666
potential role of nitric oxide in the pathophysiology of experimental bacterial meningitis in rats.we have investigated the possible role of nitric oxide (no) in the pathophysiology of bacterial meningitis (bm) by using the rat model of experimental bm. the nitrite concentration in cerebrospinal fluid (csf) was used as a measure of no production in vivo since no rapidly degrades to nitrite and nitrate. rats were inoculated intracisternally with live bacteria (5 x 10(6) cfu of haemophilus influenzae type b strain dl42 or rd-/b+/o2), with bacterial endotoxin (20 ng of dl42 lipooligosaccharide [ ...19957558288
sequence, molecular properties, and chromosomal mapping of mouse lumican.lumican is a major proteoglycan of vertebrate cornea. this study characterizes mouse lumican, its molecular form, cdna sequence, and chromosomal localization.19957558724
myositis, lameness, and paraparesis associated with use of an oil-adjuvant bacterin in beef cows.right hind limb lameness, progressing to bilateral paraparesis, was observed in 56 of 610 (9%) beef cows. lameness began 6 days to 4 weeks after vaccination in the right longissimus lumborum (loin) muscle with an escherichia coli/campylobacter bacterin in an oil adjuvant. postmortem examination of 5 affected cows revealed a large inflammatory mass at the site of vaccination. in each cow, the mass spread through adjacent intervertebral foramina into the vertebral canal and compressed the lumbar p ...19957559029
a novel function of escherichia coli chaperone dnaj. protein-disulfide isomerase.molecular chaperones, protein-disulfide isomerases, and peptidyl prolyl cis-trans isomerases assist protein folding in both prokaryotes and eukaryotes. the dnaj protein of escherichia coli and the dnaj-like proteins of eukaryotes are known as molecular chaperones and specific regulators of dnak-like proteins and are involved in protein folding and renaturation after stress. in this study we show that dnaj, like thioredoxin, protein-disulfide isomerase, and dsba, possesses an active dithiol/disul ...19957559385
a residue to residue hydrogen bond mediates the nucleotide specificity of ribonuclease a.bovine pancreatic ribonuclease a (rnase a) catalyzes the cleavage of the p-o5 bond of rna after residues bound in the enzyme's b1 subsite. this subsite binds to cytidine 30-fold more tightly than to uridine and > 10(5)-fold more tightly than to adenine. structural studies had suggested that the hydroxyl group of thr45 can interact directly with the base of a bound nucleotide. in contrast, the carboxylate group of asp83 cannot interact directly with bound substrate but can accept a hydrogen bond ...19957563054
a role for phosphatidylinositol transfer protein in secretory vesicle formation.vesicular traffic in eukaryotic cells is characterized by two steps of membrane rearrangement: the formation of vesicles from donor membranes and their fusion with acceptor membranes. with respect to vesicle formation, several of the cytosolic proteins implicated in budding and fission have been identified. a feature common to all these proteins is that their targets, when known, are other proteins rather than lipids. here we report, using a previously established cell-free system derived from a ...19957566155
investigations into the mechanism of toxicity of lipopolysaccharide (lps) in bovine aortic endothelial cells.the cytotoxic effect of lipopolysaccharide (lps) was examined on bovine aortic endothelial cell proliferation in vitro. these lps-induced cytotoxicity (ic50 = 20 ng/ml) was not inhibitable by substances regulating the formation of nitric oxide (no). e.g. by ng-monomethyl-l-arginine (l-nmma), an inhibitor of no synthesis, and by the glucocorticoid dexamethasone, an inhibitor of the induction of no synthase. also other substances which inhibit the generation or action of oxygen radicals, as glutat ...19957568318
suitability of selective plating media for recovering heat- or freeze-stressed escherichia coli o157:h7 from tryptic soy broth and ground beef.the efficacy of tryptic soy agar (tsa), modified sorbitol macconkey agar (msma), modified eosin methylene blue (memb) agar, and modified sd-39 (msd) agar in recovering a five-strain mixture of enterohemorrhagic escherichia coli o157:h7 and five non-o157 strains of e. coli heated in tryptic soy broth at 52, 54, or 56 degrees c for 10, 20, and 30 min was determined. nonselective tsa supported the highest recovery of heated cells. significantly (p < or = 0.05) lower recovery of heat-stressed cells ...19957574637
molecular cloning and deduced amino acid sequences of the alpha- and beta- subunits of mammalian nad(+)-isocitrate dehydrogenase.a 153 bp fragment of the cdna encoding the beta-subunit of pig heart nad(+)-isocitrate dehydrogenase (nad(+)-icdh) was specifically amplified by pcr, using redundant oligonucleotide primers based on partial peptide sequence data [huang and colman (1990) biochemistry 29, 8266-8273]. this pcr fragment was then used as a probe to isolate cdna clones encoding the complete mature form of the beta-subunit from a monkey testis cdna library. examination of the deduced amino acid sequence of the monkey s ...19957575427
cloning, gene sequencing, and expression of the small molecular mass ubiquinone-binding protein of mitochondrial ubiquinol-cytochrome c reductase.the cdna encoding qpc-9.5 kda (subunit vii) of bovine heart mitochondrial ubiquinol-cytochrome c reductase was cloned and sequenced. this cdna is 665 base pairs long with an open reading frame of 246 base pairs that encodes an 81-amino acid mature qpc-9.5 kda. the insert contains 395 base pairs of a 3'-noncoding sequence with a poly(a) tail. the amino acid sequence of qpc-9.5 kda deduced from this nucleotide sequence is the same as that obtained by protein sequencing except that residue 61 is tr ...19957592738
immunological response to recombinant vp8* subunit protein of bovine roravirus in pregnant cattle.bovine rotavirus vp8*, n-terminal trypsin cleavage product of vp4, was produced in escherichia coli. to examine if this antigen could induce neutralizing antibody responses, different species of animals were immunized with the recombinant vp8* protein. the vp8* antigen was found to stimulate a neutralizing immune response in rabbits. when vp8*-immunized mice were exposed to bovine rotavirus strain c486, significantly higher antibody responses were observed than if they were only exposed to c486. ...19957595351
endogenous tumor necrosis factor (tnf) production and modification of pathological lesions in experimental escherichia coli endotoxemia of piglets.we examined the kinetics of tumor necrosis factor (tnf) production induced by escherichia coli lipopolysaccharide (lps) in relation to lps tolerance and endotoxemic lesions of piglets. the plasma of piglets demonstrated cytotoxicity to tnf-sensitive l929 cells between 0.5 and 4 h after inoculation with 200 micrograms kg-1 of lps. this cytotoxicity was neutralized by anti-bovine tnf serum. these piglets had disseminated intravascular coagulation (dic) and meningoencephalitis. however, if piglets ...19957604537
[udder disinfection and mastitis in cattle: a literature review].postmilking teat disinfection is accepted as an important part of standard preventive measures against mastitis in dairy cattle. the efficacy of postmilking teat disinfection against infections with contagious pathogens such as staphylococcus aureus and streptococcus agalactiae is beyond doubt. however, the efficacy of teat disinfection against infections with environmental pathogens such as escherichia coli is disputed, and a negative effect has even been described in some situations. this arti ...19957610449
thermostability of respiratory terminal oxidases in the lipid environment.the effect of the lipid environment on the thermostability of three respiratory terminal oxidases was determined. cytochrome-c oxidase from beef heart and bacillus stearothermophilus were used as representative proteins from mesophilic and thermophilic origin, respectively. quinol oxidase from the archaeon sulfolobus acidocaldarius represented the model for a extreme thermoacidophilic enzyme. all three integral membrane proteins were tested for their thermal inactivation in detergent and after r ...19957612641
interaction between cardiolipin and the mitochondrial presequence of cytochrome c oxidase subunit iv favours lipid mixing without destabilizing the bilayer structure.we demonstrate the ability of a peptide corresponding to the presequence of the cytochrome c oxidase subunit iv to induce lipid mixing between large unilamellar liposomes. this lipid mixing requires the presence of cl or pe, lipids able to form non-bilayer structures, and is not observed with other negatively charged lipids. however, the fact that this mixing occurs without mixing of the liposome aqueous phases and without destabilizing the lipid organisation is unusual and has not been observed ...19957615071
a novel bacteristatic action of bovine and porcine serum that is reversed by norepinephrine.a previously unreported anti-bacterial activity against escherichia coli has been found in porcine and bovine sera, but not in human or chicken sera. the activity is not affected by heat inactivation of the complement system, and is bacteriostatic rather than bactericidal. growth inhibition is reversible by addition of norepinephrine.19957623610
immunochemical localization of calcium/calmodulin-dependent protein kinase i.ca2+/calmodulin-dependent protein kinase i (cam kinase i) was originally identified in rat brain based on its ability to phosphorylate site 1 of synapsin i. recently a cdna for the rat brain enzyme has been cloned and the primary structure elucidated [picciotto et al. (1993), j. biol. chem., 268:26512-26521]. the rat cdna encoded a protein of 374 amino acids with a calculated m(r) of 41,636. antibodies have now been raised against the recombinant kinase expressed in e. coli as a glutathione-s-tr ...19957624832
identification and characterization of is1296 in mycoplasma mycoides subsp. mycoides sc and presence in related mycoplasmas.is1296, a new insertion sequence belonging to the is3 family of insertion elements has been identified in mycoplasma mycoides subsp. mycoides (mmm) biotype small colony (sc), the agent of contagious bovine pleuropneumonia (cbpp). is1296 is 1485-bp long and has 30-bp inverted repeats. it contains two open reading frames, orfa and orfb, which show significant similarities to the orfs which encode the transposase function of is elements of the is3 family, in particular is150 of escherichia coli. is ...19957628725
expression and characterization of the 66-kilodalton (nqo3) iron-sulfur subunit of the proton-translocating nadh-quinone oxidoreductase of paracoccus denitrificans.the proton-translocating nadh-quinone oxidoreductase (ndh-1) of paracoccus denitrificans is composed of at least 14 dissimilar subunits which are designated nqo1-14 and contains one noncovalently bound fmn and at least five epr-visible iron-sulfur clusters (n1a, n1b, n2, n3, and n4) as prosthetic groups. comparison of the deduced primary structures of the subunits with consensus sequences for the cofactor binding sites has predicted that nqo1, nqo2, nqo3, nqo9, and probably nqo6 subunits are cof ...19957629145
clinical pharmacology of cefixime in unweaned calves.cefixime is a unique third-generation oral cephalosporin. its in vitro activity and pharmacokinetic properties have been studied to assess its potential for use in the therapy of newborn calf infections due to gram-negative bacteria. the minimum inhibitory concentrations of cefixime for 90% (mic90) of field isolates of escherichia coli, salmonella and pasteurella were 0.10-0.40 micrograms/ml. the serum disposition kinetics of cefixime following intravenous and oral administration was evaluated. ...19957629935
[the presence of escherichia coli o157:h7 in healthy cattle]. 19957660091
cloning, expression, and purification of rat brain protein l-isoaspartyl methyltransferase.protein l-isoaspartyl methyltransferase (pimt) methylates isoaspartyl residues in peptides and proteins using s-adenosyl-l-methionine as the methyl donor. a cloned source of this enzyme should be useful in the identification of cellular substrates and for quantitation and localization of isoaspartyl sites in purified proteins, including recombinant proteins used as pharmaceuticals. rat brain pimt cdna was amplified using the polymerase chain reaction. the reaction product was directionally clone ...19957663167
oxidative damage to 5-methylcytosine in dna.exposure of pyrimidines of dna to ionizing radiation under aerobic conditions or oxidizing agents results in attack on the 5,6 double bond of the pyrimidine ring or on the exocyclic 5-methyl group. the primary product of oxidation of the 5,6 double bond of thymine is thymine glycol, while oxidation of the 5-methyl group yields 5-hydroxymethyluracil. oxidation of the 5,6 double bond of cytosine yields cytosine glycol, which decomposes to 5-hydroxycytosine, 5-hydroxyuracil and uracil glycol, all o ...19957667100
interaction of alpha-lipoic acid enantiomers and homologues with the enzyme components of the mammalian pyruvate dehydrogenase complex.lipoic acid (alpha-lipoic acid, thioctic acid) is applied as a therapeutic agent in various diseases accompanied by polyneuropathia such as diabetes mellitus. the stereoselectivity and specificity of lipoic acid for the pyruvate dehydrogenase complex and its component enzymes from different sources has been studied. the dihydrolipoamide dehydrogenase component from pig heart has a clear preference for r-lipoic acid, a substrate which reacts 24 times faster than the s-enantiomer. selectivity is m ...19957669066
nucleotide sequences of two fimbrial major subunit genes, pmpa and ucaa, from canine-uropathogenic proteus mirabilis strains.proteus mirabilis strains were isolated from dogs with urinary tract infection (uti) and fimbriae were prepared from two strains. the n-terminal amino acid sequences of the major fimbrial subunits were determined and both sequences appeared identical to the n-terminal amino acid sequence of a urinary cell adhesin (uca) (wray, s. k., hull, s. i., cook, r. g., barrish, j. & hull, r. a., 1986, infect immun 54, 43-49). the genes of two different major fimbrial subunits were cloned using oligonucleot ...19957670636
polymerization of 70-kda heat shock protein by yeast dnaj in atp.dnak, the escherichia coli hsp70 protein, interacts with dnaj, a protein cofactor that appears to be involved in presenting protein substrates to dnak. the yeast dnaj homolog, ydj1, has also been shown to interact with yeast hsp70, although the function of this interaction is unknown. in the present study, we investigated the interaction of ydj1 with both yeast and bovine brain hsp70. we found that, in the presence of atp, where hsp70 is normally monomeric, ydj1 induced almost all of the yeast a ...19957673245
bovine seminal ribonuclease produced from a synthetic gene.bovine seminal ribonuclease (bs-rnase), a homolog of bovine pancreatic ribonuclease (rnase a), is isolated as a dimer in which the subunits are cross-linked by two disulfide bonds. in addition to this anomalous quaternary structure, the enzyme has extraordinary biological properties, such as antispermatogenic, antitumor, and immunosuppressive activities. the molecular bases for these properties are well-suited for exploration with the techniques of recombinant dna. accordingly, a gene encoding b ...19937688724
[enterotoxigenic escherichia coli k99+, serotype 08:k25, produce cytotoxic necrotizing factor cnf1 and alpha-hemolysin].a total of 54 k99+ and/or f41+ escherichia coli strains isolated of calves and piglets with diarrhoea in different countries were investigated for production of heat-labile (lt) and heat-stable (sta) enterotoxins, verotoxins (vt1 and vt2), cytotoxic necrotizing factors (cnf1 and cnf2), alpha-haemolysin (hly) and enterohaemolysin (enthly). fifty-one (94%) strains were sta+, two (4%) were sta+cnf1+hly+ and one (2%) was not toxigenic. the two sta+cnf1+hly+ e. coli strains expressed the k99 intestin ...19937691086
in vitro detection of bovine immunodeficiency-like virus using monoclonal antibodies generated to a recombinant gag fusion escherichia coli recombinant fusion protein containing the major core protein of bovine immunodeficiency-like virus (biv) was used to immunize mice for generation of monoclonal antibodies to biv p26. eight hybridomas specific for biv p26 were identified and two antibodies, designated 104 and 142, were further characterized. both 104 and 142 antibodies were isotyped as igg1; they reacted specifically with both biv p26 and the recombinant fusion protein in western immunoblot analyses. however, ...19937693743
anti-alpha-galactosyl immunoglobulin a (iga), igg, and igm in human secretions.anti-alpha-galactosyl (anti-gal) is a natural human serum antibody that binds to the carbohydrate gal alpha 1,3gal beta 1,4glcnac-r (alpha-galactosyl epitope) and is synthesized by 1% of circulating b lymphocytes in response to immune stimulation by enteric bacteria. we were able to purify secretory anti-gal from human colostrum and bile by affinity chromatography on silica-linked gal alpha 1,3gal beta 1,4glcnac. we found similar secretory anti-gal antibodies in human milk, saliva, and vaginal w ...19957697518
expression in escherichia coli, purification and functional activity of recombinant human chaperonin 10.we have recently reported the cloning of a cdna coding for a stress inducible human chaperonin 10. the protein was shown to possess 100% identity with the bovine homologue and a single amino acid replacement (glycine to serine at position 52) compared to rat chaperonin 10. here we report the heterologous expression of human chaperonin 10 in escherichia coli, its purification and its functional characterization. the recombinant protein was purified to homogeneity as judged by different analytical ...19957698325
expression, purification and immunologic analysis of three pasteurella haemolytica a1 28-30 kda lipoproteins.three genes, tandemly arranged on the pasteurella haemolytica a1 chromosome and encoding similar 28-30 kda proteins, were previously cloned and sequenced by our laboratory. in this study, we demonstrate that the cloned genes encode lipoproteins, as previously suggested by dna sequence analysis. to further analyze the bovine immune response to these proteins, the individual genes were cloned separately into an expression vector and recombinant forms of the three proteins were purified after expre ...19947700132
the crystal structure of recombinant human neutrophil-activating peptide-2 (m6l) at 1.9-a resolution.neutrophil-activating peptide-2 (nap-2) is a 70-residue carboxyl-terminal fragment of platelet basic protein, which is found in the alpha-granules of human platelets. nap-2, which belongs to the cxc family of chemokines that includes interleukin-8 and platelet factor 4, binds to the interleukin-8 type ii receptor and induces a rise in cytosolic calcium, chemotaxis of neutrophils, and exocytosis. crystals of recombinant nap-2 in which the single methionine at position 6 was replaced by leucine to ...19957706245
molecular characterisation of escherichia coli o157:h7 isolates by pulsed-field gel electrophoresis and plasmid dna analysis.foods of bovine origin have been identified as sources of escherichia coli o157:h7. genomic dna of e. coli o157:h7 isolates from patients (six isolates), food samples (18 isolates from ground beef and six isolates from raw milk) and calf faecal samples (31 isolates) were characterised by pulsed-field gel electrophoresis (pfge) and plasmid dna analysis. these isolates originated from different locations in the usa during 1992 and 1993. twenty-one distinct genomic profiles were generated from the ...19957707333
dna polymerase delta holoenzyme: action on single-stranded dna and on double-stranded dna in the presence of replicative dna helicases.dna polymerase delta requires proliferating cell nuclear antigen and replication factor c to form a holoenzyme efficient in dna synthesis. we have analyzed three different aspects of calf thymus dna polymerase delta holoenzyme: (i) analysis of pausing during dna synthesis, (ii) replication of double-stranded dna in the absence of additional factors, and (iii) replication of double-stranded dna in the presence of the two known replicative dna helicases from simian virus 40 and bovine papilloma vi ...19957711022
solution structure of a low molecular weight protein tyrosine phosphatase.protein tyrosine phosphatases (ptps) are important enzymes involved in signal transduction, cell cycle regulation, and the control of differentiation. despite the importance of this class of enzymes in the control of critical cell processes, very little structural information is available for this family of proteins. in this paper, we present the first solution structure of a protein tyrosine phosphatase. this protein is a low molecular weight cytosolic ptp that was initially isolated from bovin ...19947727361
escherichia coli o157:h7: clinical, diagnostic, and epidemiological aspects of human infection.e. coli o157:h7 is one of many e. coli organisms that contain genes encoding one or more toxins similar in structure and function to shiga toxin. e. coli o157:h7 is the most frequently isolated diarrheagenic type of e. coli isolated in north america today; this pathogen can cause serious, even fatal disease. syndromes caused by e. coli o157:h7 include diarrhea, hemorrhagic colitis, and hus. poorly cooked ground beef has been the most frequently implicated vehicle of transmission, but additional ...19957727633
cloning and expression of a catalytic core bovine brain 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase.a cdna encoding the catalytic core of a novel brain 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase isoenzyme was isolated from a lambda gt10 bovine brain library. this brain cdna begins and ends in an open reading frame encoding a peptide of 476 amino acids. this peptide contains both the catalytic kinase and bisphosphatase domains and has an overall 65% and 67% indentity with the bovine heart and liver isozymes, respectively, whereas the nh2 and cooh-termini are divergent. an active catal ...19957733968
targeting phosphodiesterases as a strategy for killing tumor cells.ribonucleases (rnases) are being employed as alternative cytotoxic proteins to the conventionally used ones such as ricin and pseudomonas exotoxin. mammalian rnases are attractive enzymes because of their comparable cytotoxicity when suitably directed and the likelihood of lower immunogenicity compared to plant and bacterial toxins. bovine seminal rnase (bsrnase) is a member of the rnase superfamily, but differs in many interesting ways. unlike the rest of the family it is dimeric, and possesses ...19947736530
neutralizing antibodies against shiga-like toxins from escherichia coli in colostra and sera of cattle.previous or present infection with shiga-like toxin producing e. coli (sltec) was detected by an indirect neutralization assay of antibody titer. bovine colostra and sera blocked the cytotoxic effects of shiga-like toxin on vero cell monolayers. slt neutralizing antibodies were present in 84.0% (189/225) of the colostrum samples from randomly chosen cows in bavaria, germany. while all of the colostra with neutralizing activity reacted with slt-i, only 14.7% neutralized both slt-i and -ii. approx ...19957740752
the impact of infection on gluconeogenesis in the conscious dog.the effect of infection on gluconeogenesis was assessed in the chronically catheterized conscious dog. dogs were studied 42 h after implantation of a sterile (n = 7) or an escherichia coli containing (n = 7) fibrinogen clot into the peritoneum (54 h fasted). infection increased arterial plasma glucagon and cortisol (4.2- and 2.1-fold, respectively), but it did not alter arterial plasma insulin, catecholamines, or glucose concentrations. infection increased tracer ([3-3h]glucose) determined gluco ...19947743359
processing of chromogranin b in bovine adrenal medulla. identification of secretolytin, the endogenous c-terminal fragment of residues 614-626 with antibacterial activity.chromogranins constitute a family of acidic soluble proteins widely distributed in endocrine cells and neurons. chromogranin a, the major soluble component in bovine adrenal medullary secretory granules in chromaffin cells, has been shown to be actively processed to peptide fragments [metz-boutigue, m. h., garcia-sablone, p., hogue-angeletti, r. & aunis, d. (1993) eur. j. biochem. 217, 247-257]. in the present paper, the structural features of the proteolytic degradation mechanism of chromograni ...19957744058
apparent inhibition of superoxide dismutase activity in vitro by diesel exhaust particles.the inhibitory effects of diesel exhaust particles (dep) on superoxide dismutase (sod) activity were examined in vitro because intratracheal administration of dep to mice resulted in a suppression of the pulmonary enzyme activity (sagai et al., free radic. biol. med. 14:37-47; 1993). superoxide production, based on the reduction of cytochrome c, was suppressed considerably by the soluble fraction of mouse lung and by purified sod from bovine erythrocytes, but the suppression was drastically dimi ...19957744321
isolation of a high affinity inhibitor of urokinase-type plasminogen activator by phage display of ecotin.ecotin, a serine protease inhibitor found in the periplasm of escherichia coli, is unique in its ability and mechanism of inhibiting serine proteases of a broad range of substrate specificity. however, although the catalytic domain of human urokinase-type plasminogen activator (upa) has 40% identity to bovine trypsin and the substrate specificities of these two proteases are virtually identical, ecotin inhibits upa almost 10,000-fold less efficiently than trypsin. ecotin was expressed on the sur ...19957744876
effects of an escherichia coli j5 vaccine on mild clinical coliform mastitis.efficacy of an escherichia coli (o111:b4) j5 bacterin was tested in an experimental challenge trial. nineteen cows were vaccinated with an e. coli j5 bacterin, and 10 cows were injected with a placebo containing adjuvant only. vaccine and placebo were administered at drying off, 30 d after drying off, and within 48 h after calving. cows were challenged approximately 30 d after calving by intramammary infusion with a smooth heterologous strain of e. coli previously shown to cause mild clinical ma ...19957745148
applications of molecular biology to study aldehyde dehydrogenase.liver mitochondrial aldehyde dehydrogenase has been cloned and expressed in e. coli as the mature or the precursor form. this has allowed for site directed mutagenesis to be performed to study active site components of the enzyme. residues investigated were cysteine, histidines and a glutamate. the import of the precursor into mitochondria in the presence and absence of added alcohols was investigated. alcohols, in a dose dependent manner, inhibited the import of the precursor into isolated rat ...19937748349
characterization of an operon encoding an nadp-reducing hydrogenase in desulfovibrio fructosovorans.a genomic dna fragment from desulfovibrio fructosovorans, which strongly hybridized with the hydab genes from desulfovibrio vulgaris hildenborough, was cloned and sequenced. this fragment was found to contain four genes, named hnda, hndb, hndc, and hndd. analysis of the sequence homologies indicated that hnda shows 29, 21, and 26% identity with the 24-kda subunit from bos taurus complex i, the 25-kda subunit from paracoccus denitrificans nadh dehydrogenase type i, and the n-terminal domain of ho ...19957751270
cloning, sequencing and bacterial expression of human glycine trna synthetase.the human glycine trna synthetase gene (glyrs) has been cloned and sequenced. the 2462 bp cdna for this gene contains a large open reading frame (orf) encoding 685 amino acids with predicted m(r) = 77,507 da. the protein sequence has approximately 60% identity with b. mori glyrs and 45% identity with s. cerevisiae glyrs and contains motifs 2 and 3 characteristic of class ii trna synthetases. a second orf encoding 47 amino acids is found upstream of the large orf. translation of this orf may prec ...19957753621
overexpression and characterization of human tetrameric pyruvate dehydrogenase and its individual subunits.pyruvate dehydrogenase (e1), an alpha 2 beta 2 tetramer, is the first component of the pyruvate dehydrogenase complex which catalyzes a two-step oxidative decarboxylation of pyruvic acid. to overexpress human e1 and its subunits individually, cdnas for the mature forms of human e1 alpha and e1 beta were subcloned either individually or together into a plasmid pqe-9 and expressed in escherichia coli m15. a polyhistidine extension was added at the nh2-termini of the recombinant e1 alpha and e1 bet ...19957756842
a native plasmid of pasteurella haemolytica serotype a1: dna sequence analysis and investigation of its potential as a vector.the complete nucleotide sequence of a 4.3 kilobase pair plasmid, pab2, isolated from a bovine strain of pasteurella haemolytica serotype a1, was determined. it encodes a rob-1 type beta-lactamase and a region with homology to the mobilisation (mob) region of the escherichia coli plasmid, cole1. an insertion mutant of pab2 (ptc2/81) carrying a copy of tn5 was transferred to e coli k12 by conjugation. subsequently ptc2/81 could be transferred by transformation to e coli hb101, but not to p haemoly ...19957761696
bovine adrenodoxin--a mitochondrial iron-sulphur protein--binds to chaperonin groel.the interaction of bovine adrenodoxin with the chaperonin groel was investigated using sucrose density centrifugation and analytical ultracentrifugation. it could be clearly established that denatured mature adrenodoxin comigrated in a sucrose density gradient with the groel oligomer, indicating that a complex had been formed. up to 2 moles of adrenodoxin/mol groel can be bound. from the partial concentrations, association constants of 4.3 x 10(5) m-1 for the first adrenodoxin molecule and of 1. ...19957763228
potential for gene transfer from recombinant escherichia coli k-12 used in bovine somatotropin production to indigenous bacteria in river water.this study examined the transfer of the plasmid pbgh1, an expression vector for bovine somatotropin (bst), from escherichia coli k-12 strain w3110g [pbgh1] to indigenous microorganisms present in flasks containing missouri river water. strain lbb269 is a nalidixic acid-resistant derivative of w3110g which was used as a plasmid-free control strain in these studies. water samples were inoculated with strains w3110g [pbgh1] and lbb269; after 21 days of incubation the number of viable colony-forming ...19937763895
escherichia coli k12 does not colonize the gastrointestinal tract of fischer-344 rats.the colonizing potential of escherichia coli k12 containing a vector coding for somidobove (bovine somatotropin) was determined. treated male and female fischer-344 rats were given a single oral gavage inoculum of sucrose with/without tetracycline (15 micrograms/ml). untreated control animals received similar drinking water regimes. all animals survived until termination. there were no clinical signs of toxicity observed and no treatment-related effect upon body weight, food consumption, or effi ...19937763897
absence of persistence and transfer of genetic material by recombinant escherichia coli in conventional, antibiotic-treated mice.strain bst-1 is a derivative of escherichia coli k-12 that carries a plasmid designated pura-4 and is the expression system used by the upjohn company in the production of recombinant bovine somatotropin (rbst). this plasmid also encodes an ampicillin resistance gene. the plasmidless carrier strain, bst-1c, contains a gene for tetracycline resistance which is provided by the chromosomal insertion of the transposon tn10. therefore, bst-1 is resistant to ampicillin and tetracycline, while bst-1c i ...19937763898
high level secretion of calf chymosin using a glucoamylase-prochymosin fusion gene in aspergillus oryzae.a recombinant chymosin was secreted at high levels using fusion genes with a. oryzae glucoamylase gene (glaa) and a wheat bran solid-state culture system. two portions of the a. oryzae glucoamylase, one with almost the entire glucoamylase (ga1-603) lacking 9 amino acids at the carboxyl terminal, and the other (ga1-511) lacking the starch binding-domain, were fused in frame with prochymosin cdna. western blot analysis indicated that the mature chymosin was released from the secreted fusion protei ...19947764977
a carbohydrate biosensor surface for the detection of uropathogenic bacteria.we have developed a new surface for use in biosensors that is based on a gold plate covered with a specific carbohydrate receptor structure. the carbohydrate, gal alpha 1-4gal, was bound covalently via a thioalkylcarboxy-spacer, or adsorbed as a neoglycoprotein, to a two-dimensional gold surface. both types of surfaces showed high specificity in the binding of the uropathogenic bacteria p-fimbriated escherichia coli compared to the binding of non-infectious bacteria. the signal to noise ratio is ...19947765569
inhibitory effects of milk gangliosides on the adhesion of escherichia coli to human intestinal carcinoma cells.the effects of milk gangliosides and their derivatives on the adhesion of enterotoxigenic and enteropathogenic escherichia coli to caco-2 cells, a human intestinal carcinoma cell line, were investigated. human milk gangliosides inhibited the adhesion of enterotoxigenic e. coli to caco-2 cells in the same proportion, regardless of the lactational stage, but bovine milk gangliosides were less effective. the most effective inhibitor was monosialoganglioside 1 (gm1); the adhesion rate of enterotoxig ...19957765978
streptococcal protein mag--a protein with broad albumin binding specificity.protein mag is a cell surface protein from streptococcus dysgalactiae which binds alpha 2-macroglobulin (alpha 2m), serum albumin and immunoglobulin g (igg). in this work protein mag was expressed in escherichia coli, purified and analysed for its albumin-binding specificity. the binding of protein mag to serum albumins of different species origin was studied in a dot-blot assay and compared with the binding of streptococcal protein g, so far the best studied bacterial albumin receptor. the albu ...19957766685
myxococcus xanthus, a gram-negative bacterium, contains a transmembrane protein serine/threonine kinase that blocks the secretion of beta-lactamase by phosphorylation.a gene, pkn2, encoding a myxococcus xanthus protein with significant similarities to eukaryotic protein serine/threonine kinases, was cloned using the polymerase chain reaction. the open reading frame for the protein, beginning with a gug initiation codon, consists of 830 amino acids. the amino-terminal 279 residues show 37% identity to catalytic domain of pkn1, another protein serine/threonine kinase expressed during the development at the onset of sporulation. the catalytic domain of pkn2 cont ...19957774814
ceftiofur distribution in serum and milk from clinically normal cows and cows with experimental escherichia coli-induced mastitis.eight holstein cows, 4 inoculated intracisternally in 1 quarter of the mammary gland with escherichia coli and 4 noninfected controls, were administered ceftiofur sodium (3 mg/kg of body weight, iv, q 12 hours) for 24 hours, beginning at 14 hours after inoculation of infected cows. all challenge-exposed cows became infected, with mean +/- sem peak log10 bacterial concentration in milk of 5.03 +/- 0.69 colony-forming units/ml. the infection resulted in systemic signs (mean peak rectal temperature ...19957785826
hemolytic uremic syndrome in children.the majority of postdiarrheal hemolytic uremic syndrome is caused by escherichia coli o157:h7. the organisms are carried in the intestines of cattle; partially cooked contaminated hamburger is the single most common vector. the e. coli produce a potent cytotoxin that gains access to the circulation, is taken up by glycolipid receptors on glomerular endothelial cells, is internalized, and causes cell death. associated phenomena include the activation of platelets, leukocytes, and the coagulation ...19957787931
characterization of a recombinant pneumolysin and its use as a protein carrier for pneumococcal type 18c conjugate vaccines.pneumolysin from streptococcus pneumoniae was expressed in escherichia coli as a glutathione s-transferase fusion protein and purified by affinity and hydroxylapatite chromatography. the purified recombinant pneumolysin (rpl), with a molecular mass of 53 kda, had a specific activity of 3 x 10(5) hemolytic units per mg of protein on rabbit erythrocytes and reacted identically in immunodiffusion with the antisera against native pneumolysin. the rpl was used as a protein carrier to prepare conjugat ...19957790088
determination of peptide regions exposed at the surface of the bacterial ribosome with antibodies against synthetic peptides.we synthesized six peptides corresponding to regions that are predicted to be surface-exposed of the following ribosomal proteins: protein l2, positions (d263-k272); protein l5, positions (i136-g150); protein l25, positions (q75-d90); protein s3, positions (q222-k232) derived from escherichia coli; and protein l2, positions (k257-k275), and protein s3, positions (r130-t150) from bacillus stearothermophilus. these peptides were employed to raise ribosomal protein-cross-reactive antibodies. the an ...19957794529
direct association of occludin with zo-1 and its possible involvement in the localization of occludin at tight junctions.occludin is an integral membrane protein localizing at tight junctions (tj) with four transmembrane domains and a long cooh-terminal cytoplasmic domain (domain e) consisting of 255 amino acids. immunofluorescence and laser scan microscopy revealed that chick full-length occludin introduced into human and bovine epithelial cells was correctly delivered to and incorporated into preexisting tj. further transfection studies with various deletion mutants showed that the domain e, especially its cooh- ...19947798316
[detection of verotoxin-producing e. coli in field isolates from domestic and agricultural animals in sachsen-anhalt].a report is given on the detection of verotoxin-producing e. coli (vtec) strains from field isolates of healthy or ill cattle (n = 141), pigs (n = 306), sheep (n = 15), cats (n = 29) and dogs (n = 25) in the region of the new federal land sachsen-anhalt. 5% of the strains isolated from cattle, 32% from pigs, 20% from sheep, 4% from dogs and 0% from cats have shown vtec. the e. coli-strains were checked for the presence of other factors of virulence, too. a good correlation (82%) was found betwee ...19947802620
expression and folding of recombinant bovine prethrombin-2 and its activation to thrombin.bovine prethrombin-2 has been produced in escherichia coli using a t7 expression system. the expressed prethrombin-2 formed intracellular inclusion bodies which were solubilized by reversible sulfonation of the cysteines in the presence of 7 m guanidine hydrochloride. sulfonated prethrombin-2 was refolded in the presence of 4 m guanidine hydrochloride, using oxidized and reduced glutathione as the redox couple. the folded protein was purified by heparin affinity chromatography and activated to t ...19957814368
inositol hexakisphosphate binds to clathrin assembly protein 3 (ap-3/ap180) and inhibits clathrin cage assembly in vitro.we have isolated an inositol hexakisphosphate binding protein from rat brain by affinity elution chromatography from mono s cation exchange resin using 0.1 mm inositol hexakisphosphate (insp6). the amino acid sequences of six tryptic peptides from the protein were identical to the sequences predicted from the cdna encoding a previously isolated protein designated as ap-3 or ap180. this protein is localized in nerve endings and promotes assembly of clathrin into coated vesicles. the isolated prot ...19957814377
application of monoclonal antibody-based sandwich elisas to detect verotoxins in cattle faeces.b1p4wich elisas, which use monoclonal antibodies for both the capture and the completion stages, were developed for the detection of verotoxins i and ii (non-variant). the elisas were used to investigate the incidence of verotoxins in 304 samples of bovine faeces collected from cases of enteritis, and 113 samples collected from normal animals. for most samples, the tests were carried out directly on faeces, and on colony sweeps which were taken from cultures grown from the faeces. these colonies ...19947817011
coliform counts and escherichia coli in raw commercial milk from dairy farmers in kiambu district, kenya.the rate of contamination with coliforms and incidence of escherichia coli (e. coli) in raw milk supplied by farmers to dairy cooperative societies for marketing was investigated. about forty two (42.2%) percent of the milk samples from farmers cans and 10.3% of samples from cooperative cans were found to be free of coliforms, while 89.5% of the samples from farmers cans and 50% samples from cooperative cans could be considered to be of good quality with no more than 50,000 coliforms/ml of milk. ...19947821241
induction of inflammatory cytokines in bovine alveolar macrophages following stimulation with pasteurella haemolytica lipopolysaccharide.bovine tumor necrosis factor alpha (tnf-alpha) and interleukin-1 beta (il-1 beta) cdnas were generated by reverse transcription and then by pcr amplification from lipopolysaccharide (lps)-stimulated alveolar macrophage rna. the amplified cdnas were cloned into ppow and expressed in escherichia coli dh5 alpha. the expressed proteins were confirmed as tnf-alpha and il-1 beta by western blot (immunoblot) analysis and bioassays. we then used the cloned genes as probes in northern (rna) blots and inv ...19957822000
characterization of a mammalian homolog of the escherichia coli muty mismatch repair protein.a protein homologous to the escherichia coli muty protein, referred to as myh, has been identified in nuclear extracts of calf thymus and human hela cells. western blot (immunoblot) analysis using polyclonal antibodies to the e. coli muty protein detected a protein of 65 kda in both extracts. partial purification of myh from calf thymus cells revealed a 65-kda protein as well as a functional but apparently degraded form of 36 kda, as determined by glycerol gradient centrifugation and immunoblott ...19957823963
the effect of low temperatures on enzyme activity.the stability of two enzymes from extreme thermophiles (glutamate dehydrogenase from thermococcales strain an1 and beta-glucosidase from caldocellum saccharolyticum expressed in escherichia coli) has been exploited to allow measurement of activity over a 175 degrees c temperature range, from +90 degrees c to -85 degrees c for the glutamate dehydrogenase and from +90 degrees c to -70 degrees c for the beta-glucosidase. the arrhenius plots of these enzymes, and those for two mesophilic enzymes (gl ...19957826325
biological activities and secondary structures of variant forms of human salivary cystatin sn produced in escherichia coli.using an escherichia coli expression system, pgex-2t, that expresses foreign sequences as fusion proteins with a glutathione s-transferase (gst) carrier, we have produced several recombinant human salivary cystatin sn (recsnsn) variants. these include a n-terminal-truncated form (aa 17-121), a c-terminal-truncated form (aa 1-102) and two deletion mutants (delta 12-16 and delta 56-60). a large amount of the insoluble fusion protein (approx. 15 mg/l) was produced in each case. these were solubiliz ...19947828895
brucella abortus serology in cattle naturally infected with escherichia coli o157.h7. 19947831743
a group of novel glutathione s-transferase isozymes showing high activity towards 4-hydroxy-2-nonenal are present in bovine ocular tissues.recently, a mouse glutathione s-transferase (gst) isozyme, mgsta4-4, which belongs to a distinct group of gsts has been characterized in our laboratory. during the present studies, western blot analyses of bovine ocular tissues using the antibodies raised against the recombinant mgsta4-4 obtained by expression in escherichia coli revealed that the orthologs of mgsta4-4 were present in cornea, retina, iris-ciliary body and sclera, but absent in lens. these novel gst isozymes of bovine ocular tiss ...19947835404
effects of housing and colostrum feeding on the prevalence of selected infectious organisms in feces of jersey calves.neonatal jersey calves (n = 96) were used to evaluate effects of housing (individual hutches or wooden pens in a barn) and colostrum feeding (calves were separated from the dam and fed 2 l of colostrum in nipple-bottles or allowed to nurse the dam for 3 d) on the prevalence of selected organisms in feces. prevalence of cryptosporidium and eimeria were reduced, and prevalence of rotavirus tended to be reduced, when calves were housed in hutches. prevalence of coronavirus was unaffected by treatme ...19947836601
energy-transducing nicotinamide nucleotide transhydrogenase: nucleotide sequences of the genes and predicted amino acid sequences of the subunits of the enzyme from rhodospirillum rubrum.based on the amino acid sequence of the n-terminus of the soluble subunit of the rhodospirillum rubrum nicotinamide nucleotide transhydrogenase, two oligonucleotide primers were synthesized and used to amplify the corresponding dna segment (110 base pairs) by the polymerase chain reaction. using this pcr product as a probe, one clone with the insert of 6.4 kbp was isolated from a genomic library of r. rubrum and sequenced. this sequence contained three open reading frames, constituting the genes ...19947844118
sequence and expression of the ns2 protein gene of human coronavirus oc43.the complete nucleotide sequence of the ns2 gene of human coronavirus oc43 (hcv-oc43) was determined. sequence analysis revealed an open reading frame that could encode a protein of 278 amino acids, with an estimated molecular mass of 32.2 kda. six potential phosphorylation sites are present but no sites of n-glycosylation were found. the amino acid sequence of the hcv-oc43 ns2 protein shows 92% identity with that of the mebus strain of bovine coronavirus (bcv). however, a stretch of nine consec ...19957844564
[localization of gh gene to bovine chromosome 5q22-26 by in situ hybridization].the bgh entire gene (3.0kb), as a probe which was cloned into recombinant plasmid pbgh was used for in situ hybridization. the e. coli rr1, as a receptor, was transformed by recombinant plasmid pbgh. recombinant plasmid dnas were amplified, extracted and purified, the bgh fragments were collected and labelled by nicktranslation. the metaphase and early-metaphase chromosome spreads were prepared from tdr-brdu-synchronized peripheral blood lymphocytes in beijing black-white dairy cattle. after in ...19947848663
enhanced binding of enterotoxigenic escherichia coli k99 to amide derivatives of the receptor ganglioside neugc-gm3.a natural receptor in pig small intestine [teneberg, s., willemsen, p., de graaf, f. k., & karlsson, k.-a. (1990) febs lett. 263, 10-14] for the enterotoxigenic bacteria escherichia coli k99 is the ganglioside neugc-gm3 (neugc alpha 3gal beta 4glc beta cer) [e.g., h. smit, w. gaastra, j. p. kamerling, j. f. g. vliegenthart, & f. k. de graaf (1984) infect. immun. 46, 578-584]. chemical modifications of the carboxyl group of this ganglioside were performed, giving five different amides, the methyl ...19957849044
optimal enzymatic hydrolysis of urinary benzodiazepine conjugates.conditions for the enzymatic hydrolysis of benzodiazepine conjugates were systematically examined. optimal recovery of the free drugs occurs when 1 ml of urine buffered to ph 4.5 is incubated with 5000 u of helix pomatia beta-glucuronidase at 56 degrees c for 2 h. urine specimens containing conjugates of temazepam, oxazepam, lorazepam, alpha-hydroxyalprazolam, 2-hydroxyethylflurazepam, and n-desalkyl-3-hydroxyflurazepam as targeted benzodiazepines were used. the freed drugs were quantitated by g ...19947861750
use of a recombinant antigen in an indirect elisa for detecting bovine antibody to capripoxvirus.the gene coding for the capripoxvirus structural protein p32 was cloned, expressed in escherichia coli as a fusion protein with glutathione-s-transferase, and purified on glutathione sepharose. an indirect enzyme linked immunosorbent assay (elisa) using this antigen was developed to screen bovine sera for antibodies to capripoxvirus. sequential serum samples from experimentally infected animals tested by elisa and by virus neutralisation test (vnt) showed that the elisa was more sensitive and de ...19947868646
expression of bovine heart fructose 6-phosphate,2-kinase:fructose 2,6-bisphosphatase and determination of the role of the carboxyl terminus by mutagenesis.bovine heart fructose 6-p,2-kinase:fructose 2,6-bisphosphatase was expressed in escherichia coli. in order to determine the role of the carboxyl-terminal peptide, 49 and 78 amino acids from the c-terminus were deleted using oligonucleotide-directed mutagenesis. the expressed wild-type and mutant enzymes were purified to homogeneity, and the steady-state kinetics of the mutant enzymes were compared to those of the wild-type enzyme. deletion of 49 residues (del 49) resulted in a 35% decrease in km ...19957873535
[participation of the quinone acceptor in the transition of complex i from an inactive to active state].almost complete slow activation of the deactivated purified complex i was observed after the steady-state nadh: cytochrome c reductase reaction turnovers catalyzed by the endogenous (tightly-bound) ubiquinone and contaminant complex iii. the rotenone-sensitive nadh oxidase was reconstituted from bovine heart complex i and escherichia coli quinol-oxidase. the ratio between active and inactive complex i during the steady-state nadh oxidase reaction catalyzed by the reconstituted system was shown t ...19947873673
solution structure of the dna binding domain of a nucleoid-associated protein, h-ns, from escherichia coli.the three-dimensional structure of the c-terminal domain (47 residues) obtained from the hydrolysis of h-ns protein with bovine trypsin was determined by nmr measurements and distance geometry calculations. it is composed of an antiparallel beta-sheet, an alpha-helix and a 3(10)-helix which form a hydrophobic core, stabilizing the whole structure. this domain has been found to bind to dna. possible dna binding sites are discussed on the basis of the solution structure of the c-terminal domain of ...19957875316
enteric pathogens in intensively reared veal calves.observations were made on development of diarrhea in special-fed calves (n = 460) on 8 commercial facilities during 2 successive 16-week production cycles at weeks 0, 2, 4, 8, 12, and 16. a total of 23% were affected, with peak number of calves with diarrhea observed at week 0. suspected enteropathogens were identified in 86% of these calves, most commonly cryptosporidia, coronavirus, and rotavirus. identified potential zoonotic pathogens included giardia and salmonella spp and verotoxigenic esc ...19947879973
an actin-related protein from dictyostelium discoideum is developmentally regulated and associated with actin-related protein (acla) has been identified in the cellular slime mould dictyostelium discoideum. the complete cdna sequence indicates that within the actin superfamily it belongs to the arp3 family of actin-related proteins together with arp66b from drosophila melanogaster, actin2 from bos taurus, act2 from schizosaccharomyces pombe and possibly act2 from caenorhabditis elegans. the acla mrna is regulated during development, showing a maximum between 2 and 4 h after starvation. the prot ...19957883039
laboratory investigation of a multistate food-borne outbreak of escherichia coli o157:h7 by using pulsed-field gel electrophoresis and phage typing.two hundred thirty-three isolates of escherichia coli o157:h7 were analyzed by both pulsed-field gel electrophoresis (pfge) and bacteriophage typing. all 26 isolates from persons whose illness was associated with a recent multistate outbreak of e. coli o157:h7 infections linked to the consumption of undercooked hamburgers and all 27 isolates from incriminated lots of hamburger meat had the same phage type and the same pfge pattern. twenty-five of 74 e. coli o157:h7 isolates from washington state ...19947883892
high incidence of haemorrhagic colitis due to escherichia coli o157 in one scottish town: clinical and epidemiological features.verotoxin-producing strains of escherichia coli (vtec), in particular serotype o157:h7, are now recognised as the major cause of haemorrhagic colitis and the haemolytic uraemic syndrome (hus) in the u.k. and in north america, and increasingly so in other countries. over a 3-year period (1989-1991), 16 cases of e. coli 0157 infection occurred in one town (peterhead) in north-east grampian. four patients required admission to hospital, of whom three developed hus. the bovine source of vtec infecti ...19947884230
detection of verotoxigenic escherichia coli in bull semen using the polymerase chain reaction.oligonucleotide primers used in a polymerase chain reaction (pcr) protocol detected the verotoxin 2 (vt2) gene in e. coli present in experimentally contaminated bull semen. the vt2 (shiga-like toxin ii [slt-ii]) primers targeted a 346-bp fragment of the gene coding for the a subunit of the toxin. pcr products, corresponding to the vt2 gene sequence, were amplified from template e. coli nucleic acid extracted from 18-h broth culture and from e. coli in contaminated semen in the undiluted state, d ...19947886935
immunocytochemical localization of heterologously expressed adrenodoxin and its electron acceptor cytochrome p45011b1 in escherichia coli.adrenal steroid hydroxylase p45011b1 and its electron donor adrenodoxin were localized in the cortex of bovine adrenals by immunogold-silver staining. in order to test recently developed heterologous expression systems for both enzymes to enable structure-function studies, immunocytochemical marker methods were applied. adrenodoxin, the ferredoxin of the adrenal gland, was successfully expressed and for the first time localized in escherichia coli. by use of ultrathin cryosections and the protei ...19947889992
expression of cytochrome p450 3a5 in escherichia coli: effects of 5' modification, purification, spectral characterization, reconstitution conditions, and catalytic activities.cytochrome p450 (p450) 3a5 is a human enzyme with 85% amino acid sequence identity to the more predominantly expressed p450 3a4 and has been reported to have overlapping catalytic specificity. the 5'-terminus of a p450 3a5 cdna was modified for optimal expression in escherichia coli using the vector pcw, by aligning the malllavfl n-terminal sequence of recombinant bovine p450 17a (h. j. barnes, m. p. arlotto, and m. r. waterman, (1991) proc. natl. acad. sci. usa 88, 5597-5601) to the 3a5 cdna. t ...19957893152
truncated groel monomer has the ability to promote folding of rhodanese without groes and atp.similar to chaperonins from other sources, intact chaperonin from escherichia coli (groel) exists as a tetradecamer, and the ability to promote folding of other proteins has been considered to be dependent on this oligomeric structure. however, the peptide fragments of groel of molecular size 34-50 kda, which are produced by limited proteolysis of monomeric groel and are unable to assemble into an oligomer, retain the ability to promote folding of rhodanese even though the yield of productive fo ...19937903258
research note: avidity of chicken yolk antibodies to enterotoxigenic escherichia coli fimbriae.the yolk antibodies from chickens and the serum and colostrum antibodies from cows were obtained after immunization of these animals with inactivated bacterin or purified k99 fimbriae from enterotoxigenic escherichia coli (etec). the avidity of anti-k99 fimbriae antibodies produced from either chickens or cows was measured by competitive binding assay of elisa. the yolk antibodies competed strongly with the serum and colostrum antibodies from immunized cows and inhibited 40 to 80% of the binding ...19937906035
hemagglutinating properties of enteroaggregative escherichia coli.many intestinal bacterial pathogens possess hemagglutinating properties, which are indicative of their adhesive properties to the intestinal mucosal surface. to understand the bacteria-mucosa interaction, 41 strains of enteroaggregative escherichia coli (eaggec), a recently described category of diarrheagenic e. coli, isolated mostly from children with diarrhea in bangladesh, india, thailand, central america, and south america were screened for mannose-sensitive hemagglutination and mannose-resi ...19947908675
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