Publications

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src-homology 2 (sh2) domain ligation as an allosteric regulator: modulation of phosphoinositide-specific phospholipase c gamma 1 structure and activity.phosphoinositide-specific phospholipase c gamma 1 (pi-plc gamma 1) catalyses the hydrolysis of ptdins(4,5)p2 to generate the second messengers diacylglycerol and ins(1,4,5)p3. pi-plc gamma 1, an src-homology 2/3 (sh2/sh3)-domain-containing enzyme, is activated in response to growth-factor-induced tyrosine phosphorylation, and, in vivo, is translocated from the cytosol to the particulate cell fraction. here we report the bacterial expression of rat brain pi-plc gamma 1 under the control of the t7 ...19957531435
the role of tau phosphorylation in transfected cos-1 cells.tau cdnas from each of the six human isoforms were transfected into cos-1 cells and, in every case, more than one peptide was observed. the diversity of expressed isoforms was due to different levels of tau phosphorylation. tau phosphorylation results in a decrease of the protein electrophoretic mobility. the major contribution to this mobility shift is due to the phosphorylation at the at the c-terminus of the molecule, as inferred from the expression of tau fragments. phosphorylation takes pla ...19957476937
isolation of genomic and cdna clones encoding bovine poly(a) binding protein ii.cdna clones for bovine poly(a) binding protein ii (pab ii) were isolated. their sequence predicts a protein of 32.8 kda, revising earlier estimates of molecular mass. the protein contains one putative rna-binding domain of the rnp type, an acidic n-terminal and a basic c-terminal domain. analyses of authentic pab ii were in good agreement with all predictions from the cdna sequence except that a number of arginine residues appeared to be post-translationally modified. poly(a) binding protein ii ...19957479061
[determination of escherichia coli shiga-like toxins by means of the mtt bioassay].tissue culture cells' metabolism and viability are measured by the mitochondrial reduction rate of a yellow tetrazolium salt (mtt) to blue formazan crystals in the mtt-bioassay. thus the mtt-bioassay is a standardizable and reproducible bioassay for measuring cytotoxicity or cytostimulation. it is shown that the mtt-bioassay is also very suitable for determining bacterial cytotoxins using escherichia coli's shiga-like toxins as example. 177 strains of e. coli, isolated from carcasses and organs ...19957483864
effects of staphylococcus aureus mastitis after endotoxin application on milk yield and composition during subsequent lactation of guinea-pigs.the effects of staphylococcus aureus mastitis on milk yield and composition throughout subsequent lactation in lactating guinea-pigs and the role of endotoxin pretreatment on these phenomena were investigated. primiparous lactating guinea-pigs were intramammarily inoculated with sterile saline (group 1), s. aureus strain uc 6097 (group 2), or with s. aureus uc 6097 after endotoxin pretreatment (group 3). clinical signs and survival rate were monitored. during the second lactation, daily milk yie ...19957483905
effect of phenylbutazone and flunixin meglumine on acute toxic mastitis in dairy cows.a double-blinded randomized prospective clinical trial was designed to evaluate the effectiveness of flunixin meglumine and phenylbutazone for treatment of acute toxic mastitis in dairy cows. all cows were treated 4 times at 12-hour intervals by intramammary infusion of gentamicin (150 mg). a total of 45 dairy cows with toxic mastitis were randomly assigned to 1 of 3 treatment groups: group 1 (control), saline solution, iv; group 2, 1 g of flunixin meglumine, iv; or group 3, 4 g of phenylbutazon ...19957486401
recombinant human dihydroorotate dehydrogenase: expression, purification, and characterization of a catalytically functional truncated enzyme.an n-terminally truncated cdna for human dihydroorotate dehydrogenase (dhodase) was placed under the control of the inducible t7 lac promoter in a pyrimidine auxotrophic strain of escherichia coli lacking the endogenous enzyme. induction of gene expression rescued growth in media lacking exogenous pyrimidines. the recombinant enzyme was purified to homogeneity from detergent extracts of bacterial membranes by two chromatographic steps. the purity of the resulting enzyme was judged to be > 95% ba ...19957487077
recombinant human pancreatic ribonuclease produced in e. coli: importance of the amino-terminal sequence.human pancreatic ribonuclease 1 (hrnase 1) in the mature form has been produced in e. coli using t7 expression system. the recombinant hrnase 1 protein was solubilized from the inclusion bodies, refolded in glutathione redox system, and purified through chromatographic procedures by utilizing cation-exchange and reversed-phase columns. the ribonucleolytic activity of recombinant hrnase 1 was examined on yeast rna and cytidylyl-3',5'-adenosine revealing the distinctive ribonucleolytic activity. t ...19957488119
molecular basis of antigenic variation between the glycoproteins c of respiratory bovine herpesvirus 1 (bhv-1) and neurovirulent bhv-5.herpesvirus glycoprotein c (gc) functions as a major virus attachment protein. the gc sequence of the neurovirulent bovine herpesvirus type 5 (bhv-5) virus was determined and compared with the gc sequence of the nonneurovirulent bhv-1. alignment of the predicted amino acid sequences of bhv-1 and bhv-5 gc orfs showed that the amino-terminal third of the protein differed between the two viruses. whole or subgenomic fragments of gc coding regions from both viruses were expressed as trpe-gc fusion p ...19957491780
molecular characterization of a hamster oviduct-specific glycoprotein.there is growing evidence that the oviduct is not a passive conduit for gamete and embryo transport but serves a function for the gametes and/or embryos. the oviductal epithelium secretes one or more specific glycoproteins that associate with the egg after ovulation. several published reports including our preliminary studies have suggested that the egg-associating glycoprotein(s) from the oviduct exists in several mammalian species including golden hamster. however, little or almost no biochemi ...19957492686
proton-translocating nicotinamide nucleotide transhydrogenase. reconstitution of the extramembranous nucleotide-binding domains.the nicotinamide nucleotide transhydrogenase of bovine mitochondria is a homodimer of monomer m(r) = 109,065. the monomer is composed of three domains, an nh2-terminal 430-residue-long hydrophilic domain i that binds nad(h), a central 400-residue-long hydrophobic domain ii that is largely membrane intercalated and carries the enzyme's proton channel, and a cooh-terminal 200-residue-long hydrophilic domain iii that binds nadp(h). domains i and iii protrude into the mitochondrial matrix, where the ...19957499307
virulence markers of shiga-like toxin-producing escherichia coli strains originating from healthy domestic animals of different species.shiga-like toxin (verotoxin)-producing strains of escherichia coli (sltec) originating from healthy cattle, sheep, goats, pigs, cats, and dogs were investigated for properties which are related to virulence of e. coli for humans. the slt-ii (shiga-like toxin ii) and slt-iic genes were frequent in sltec from healthy cattle and dogs but were rarely found in sltec from other animals. the slt-iie gene was detected only in porcine sltec. sltec from goats and sltec from sheep were found to carry diffe ...19957538509
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 activity.here 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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
an actin-related protein from dictyostelium discoideum is developmentally regulated and associated with mitochondria.an 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
immunization of dairy cows with an escherichia coli j5 lipopolysaccharide vaccine.development of a lipopolysaccharide-protein conjugate vaccine and the immunological response to the vaccine were investigated. lipopolysaccharide derived from escherichia coli j5 was detoxified by mild alkaline hydrolysis. detoxification reduced endotoxin activity 2500-fold compared with that of native j5 lipopolysaccharide. the conjugate vaccine was synthesized by covalently coupling detoxified lipopolysaccharide to chicken serum albumin by reductive amination. dairy cows were immunized with 8. ...19958598402
interaction of mitochondrial elongation factors tu.ts with aminoacyl-trna.the interaction between the bovine mitochondrial translational elongation factor tu.ts complex (ef-tu.tsmt) and aminoacyl-trna has been investigated using a nuclease protection assay and fluorescence enhancement of [aedans-s2c]tyr-trna(tyr). the equilibrium dissociation constant, kd, for the ef-tu.tsmt:gtp:e. coli phe-trna complex is approximately 50 nm. a similar binding constant (30 nm) is obtained using bovine mitochondrial phe-trna. the equilibrium binding constant for the ef-tu.tsmt:gtp:yea ...19958643359
purification and characterization of protease ci, a cytoplasmic metalloendoprotease in escherichia coli.protease ci, a cytoplasmic metalloprotease in escherichia coli, has been purified to apparent homogeneity by conventional chromatographic procedures using 125i-labeled oxidized insulin b-chain as a substrate. the purified enzyme behaves as a 54-kda protein under both denaturing and nondenaturing conditions, suggesting that it consists of a single polypeptide chain. it is inhibited by metal-chelating agents, including o-phenanthroline and nacn, but not by inhibitors of serine proteases or thiol-b ...19958530373
phosphorylation of both serine residues in cardiac troponin i is required to decrease the ca2+ affinity of cardiac troponin c.the phosphorylation of cardiac muscle troponin i (ctni) at two adjacent n-terminal serine residues by camp-dependent protein kinase (pka) has been implicated in the inotropic response of the heart to beta-agonists. phosphorylation of these residues has been shown to reduce the ca2+ affinity of the single ca(2+)-specific regulatory site of cardiac troponin c (ctnc) and to increase the rate of ca2+ dissociation from this site (robertson, s. p., johnson, j. d., holroyde, m. j., kranias, e. g., pott ...19958530519
cloning, sequence analysis and expression of mammalian mitochondrial protein synthesis elongation factor tu.the bovine liver mitochondrial protein synthesis elongation factor tu.ts complex (ef-tu.tsmt) has been purified and partial peptide sequence information has been obtained for ef-tumt. a complete cdna has been obtained encoding bovine ef-tumt and a nearly complete cdna has been obtained for human ef-tumt. the bovine cdna has a 5' untranslated leader, an open reading frame of 1356 nucleotides and a 3' untranslated region of 189 base pairs. nh2-terminal sequencing of the mature protein indicates th ...19958547323
determination of the efficiency of k99-f41 fimbrial antigen vaccine in newborn calves.semipurified k99 and f41 fimbrial antigens were used to prepare an oil-emulsified vaccine against bovine enterotoxigenic colibacillosis. nine nelore cows about 7 months pregnant were divided into 3 groups (a, b and c) of 3 animals each, which received different doses of vaccine (1,500 hu, 750 hu and 380 hu, respectively) 8 and 2 weeks before delivery, in the neck by the subcutaneous route. as a control (group d), 3 pregnant cows of the same breed were not vaccinated for later challange of their ...19958547847
studies on the suitability of alpha-hybrid interferon application in cattle.twelve cattle with body wts ranging from 100 to 250 kg were treated using various doses and routes for four days with an e. coli derived alpha-hybrid interferon. the lowest parenteral doses (10(4) units per kg body wt) and the orally administered interferon did not lead to any disturbances, whereas the higher dosages led to marked changes in body temperature, pulse and respiration rates. animals with the highest dose (10(8) units per kg body wt) became extremely distressed. the blood picture sho ...19958549112
veterinary use of new quinolones in japan.five new quinolones are used as veterinary medicines in japan. benofloxacin and ofloxacin are orally given in feed or in drinking water for respiratory diseases due to mycoplasma spp. and escherichia coli in poultry. enrofloxacin is subcutaneously, intramuscularly or orally administered to cattle and swine for pneumonia due to pasteurella spp., mycoplasma spp. and actinobacillus pleuropneumoniae and diarrhoea due to e. coli, and is used orally for respiratory diseases in poultry. danofloxacin is ...19958549286
in vitro efficacy of cefquinome (inn) and other anti-infective drugs against bovine bacterial isolates from belgium, france, germany, the netherlands, and the united kingdom.the in vitro antibacterial activity of cefquinome (inn), an aminothiazolyl-cephalosporin of the fourth generation of cephalosporins, was investigated by determining the minimal inhibitory concentration (mic, microgram/ml) for 714 bacterial isolates of bovine origin and comparing it with those of amoxicillin, amoxicillin and clavulanic acid, ceftiofur, cephapirin, enrofloxacin, gentamicin, kanamycin and oxytetracycline. drug resistance was determined by using break-points, which consider the dosa ...19958578918
cloning, expression and characterization of a single-chain antibody ps-9 targeted to pancreatic cancer.genes encoding single-chain antibodies have been first constructed, which consist of the heavy and light chain variable domains of antibody ps-9 joined together by a flexible peptide linker. the genes were cloned into coat protein g3p genes of pcantab5 phagemids, and expressed as fusion proteins on the phage tips. immunological assay demonstrated that the engineered antibodies specifically bound to cancer cells ls-174-t as well as to pure bovine submaxillary gland mucin. their specificity and af ...19958554673
a fluorometric beta-glucuronidase assay for analysis of bacterial growth in milk.the growth of common mastitis-causing bacteria in milk was followed by a fluorometric technique based on the release of fluorescent 4-methylumbelliferone (4-mu) from 4-methylumbelliferyl-beta-d-glucuronide by the beta-glucuronidase of bacterial or milk origin. three of four escherichia coli strains, all four strains of streptococcus uberis (4/4) and streptococcus agalactiae (4/4) produced beta-glucuronidase. four staphylococcus aureus strains (4/4) and one e. coli strain, though unable to produc ...19958560733
bactericidal activity of the bovine myeloperoxidase system against bacteria associated with mastitis.myeloperoxidase (mpo) is a lysosomal enzyme found in the primary granules of mammalian neutrophils. together with mpo, peroxide and halide form a system of defense against bacteria. the present investigation was undertaken to study the bactericidal effects of the bovine-mpo/peroxide/halide system on pathogenic bacteria associated with bovine mastitis. we demonstrated that mpo together with oxidizing agents generated by xanthine oxidase, hypoxanthine and chloride form a potent antibacterial syste ...19958560739
analysis of the loop-helix interaction in bundle motif protein structures.molecular dynamics simulations and energy analysis have been carried out to study the structural mobility and stability of the four alpha-helix bundle motifs. the simulation results as well as the x-ray data show that the atomic rms fluctuation is larger at the loop region for four representative proteins investigated: methemerythrin, cytochrome b-562, cytochrome c', and bovine somatotropin. the loop-loop, helix-helix, and loop-helix interactions are computed for the unfolded and folded proteins ...19958561852
partitioning of proteins in dextran/hydrophobically modified dextran aqueous two-phase systems.partitioning of proteins was studied in aqueous two-phase systems composed of the polymers dextran and hydrophobically modified dextran. the modified dextrans were benzoyl dextran with a degree of substitution of 0.17 and valeryl dextran with a degree of substitution of 0.20. phase diagrams for the systems of dextran/benzoyl dextran and dextran/valeryl dextran were determined at room temperature. the proteins studied were beta-galactosidase, bovine serum albumin, beta-lactoglobulin, lysozyme, my ...19958767927
antimicrobial resistance of escherichia coli isolates from the faecal flora of veterinarians with different professional specialties.the prevalence of antibiotic resistant escherichia coli isolates from faecal samples from 110 veterinarians with different specialties (predominantly working with cattle, swine, poultry, or small animals or working as a non-practitioner, e.g. in government or industry) was investigated. in 22% and 13% of the veterinarians e. coli isolates showed a high level of resistance to oxytetracycline and ampicillin respectively. a significantly higher percentage of cattle practitioners had a high level of ...19958751277
effects of amino acid substitutions in the hydrophobic core of alpha-lactalbumin on the stability of the molten globule state.five mutant alpha-lactalbumins, with one or two amino acid substitution(s) in the b helix, were engineered to examine the relation between the stability of the molten globule state and the hydrophobicity of these amino acids. the mutation sites (thr29, ala30 and thr33) have been chosen on the basis of comparison of the amino acid sequences of goat, bovine and gunea pig alpha-lactalbumin, in which the guinea pig protein shows a remarkably more stable molten globule than the other proteins. the re ...19958819981
seeding of a beta fibril formation is inhibited by all three isotypes of apolipoprotein e.apolipoprotein e is immunochemically localized to amyloid plaque in alzheimer's brains, and the allelic distribution of apoe in individuals is associated with a disposition toward alzheimer's disease. we show here that all three apoe isotypes exhibit a strong and specific ability to inhibit both nucleation and seeding of fibril formation by the a beta peptide in vitro. a beta (1-40) depleted of aggregates requires long incubation times before the onset of fibril formation, but addition of very l ...19968823200
lactoferrin or a fragment thereof inhibits the endotoxin-induced interleukin-6 response in human monocytic cells.human milk is in several ways anti-inflammatory. this study investigates whether or not human milk lactoferrin (lf) in comparison with bovine lf can affect the il-6 release from human cells. human, as well as bovine, lf and a bactericidal pepsin-derived fragment of bovine lf (lactoferricin b) were found to suppress the il-6 response in a monocytic cell line (thp-1) when stimulated by lipopolysaccharide (lps). the suppression of bovine lf was similar to or higher than that of human lf. lactoferri ...19968827774
evaluation of a nutritive oral rehydration solution for the treatment of calf diarrhoea.the essential constituents of a conventional oral rehydration solution (ors) are sodium, glucose and a bicarbonate precursor. the glucose promotes sodium uptake but because these solutions are isotonic, it is insufficient to sustain calorie requirements. this paper examines the performance of a novel ors with over three times the conventional glucose concentration, by comparing it with two leading commercial orss in calves with induced escherichia coli diarrhoea. this solution showed greater abi ...19968979427
characterization of a novel hemagglutinin of diarrhea-associated escherichia coli that has characteristics of diffusely adhering e. coli and enteroaggregative e. coli.escherichia coli 73-1 (serotype o73:h33) and 5-2 (serotype o89:h-) isolated from patients with diarrhea adhered to tissue culture cells (hela and hep-2) as well as coverslips (plastic and glass) in a diffuse pattern. adherence of strain 73-1 was mediated by a 110-kbp plasmid designated peda1 and correlated with d-mannose-resistant hemagglutinin (mrha) detected with bovine, sheep, or human erythrocytes. the mrha region was duplicated on peda1 and mediated the production of the 57-kda outer membra ...19968751919
structure and importance of the dimerization domain in elongation factor ts from thermus thermophilus.elongation factor ts (ef-ts) functions as a nucleotide-exchange factor by binding elongation factor tu (ef-tu) and accelerating the gdp dissociation from ef-tu; thus ef-ts promotes the transition of ef-tu from the inactive gdp form to the active gtp form. thermus thermophilus ef-ts exists as a stable dimer in solution which binds two molecules of ef-tu to form a (ef-tu.ef-ts)2 heterotetramer. here we report the crystal structure of the dimerization domain of ef-ts from t. thermophilus refined to ...19968756682
escherichia coli hemolysin mutants with altered target cell specificity.in order to understand the functional significance of hlyc-dependent acylation of the escherichia coli hemolysin structural protein (hlya), random as well as site-directed substitutions at the known regions of modification, i.e., those at lysine residues at amino acid positions 563 and 689 (hlyak563 and hlyak689, respectively), were isolated. sixteen random hlya mutations were identified on the basis of a screen for loss of immunoreactivity to the hemolysin-neutralizing d12 monoclonal antibody t ...19968757837
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