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protective antibody titres and antigenic competition in multivalent dichelobacter nodosus fimbrial vaccines using characterised rdna antigens.the relationship between k-agglutination antibody titres and protection against experimental challenge with dichelobacter nodosus, the effect of increasing the number of d. nodosus fimbrial antigens, and the importance of the nature of additional antigens in multivalent vaccines on antibody response and protection against experimental challenge with d. nodosus were examined in merino sheep. a total of 204 merino sheep were allocated to one of 12 groups, and vaccinated with preparations containin ...19947909183
the prevalence of escherichia coli o157.h7 in dairy and beef cattle in washington state.escherichia coli o157.h7 was found in 10 of 3570 (0.28%) faecal samples from dairy cattle in 5 of 60 herds (8.3%). several tentative associations with manure handling and feeding management practices on dairy farms were identified. faecal/urine slurry samples, bulk milk samples, and milk filters from dairy herds were negative for e. coli o157.h7. e. coli o157.h7 was also isolated from 10 of 1412 (0.71%) faecal samples from pastured beef cattle in 4 of 25 (16%) herds. the prevalence of e. coli o1 ...19947925659
expression of recombinant bovine gamma b-, gamma c- and gamma d-crystallins and correlation with native proteins.despite the use of bovine gamma-crystallins in numerous biophysical and chemical studies, characterization of these proteins at the molecular level is incomplete. bovine lenses have at least six gamma-crystallin protein fractions currently assigned as gamma s/i, gamma a/ivb, gamma b/ii, gamma c/iiib, gamma d/iiia and gamma e/iva. a lack of primary sequence data for corresponding gamma-crystallin genes and proteins, however, has made these assignments tenuous. to clarify these assignments, we hav ...19947925695
recombinant human erythrocyte cytochrome b5.the gene encoding the human erythrocyte form of cytochrome b5 (97 residues in length) has been prepared by mutagenesis of an expression vector encoding lipase-solubilized bovine liver microsomal cytochrome b5 (93 residues in length) (funk et al., 1990). efficient expression of this gene in escherichia coli has provided the first opportunity to obtain this protein in quantities sufficient for physical and functional characterization. comparison of the erythrocytic cytochrome with the trypsin-solu ...19947918357
isolation of escherichia coli synthesized recombinant eukaryotic proteins that contain epsilon-n-acetyllysine.recombinant porcine (rpst) and bovine somatotropins (rbst) synthesized in escherichia coli contain the amino acid, epsilon-n-acetyllysine. this amino acid was initially discovered in place of the normal lysine144 in a modified reversed-phase hplc (rp-hplc) species of rpst. mass spectrometry and amino acid sequencing of a tryptic peptide isolated from this rp-hplc purified protein were used to identify this altered residue as epsilon-n-acetyllysine. ion-exchange chromatography was utilized to pre ...19947920255
further oxidation of hydroxycalcidiol by calcidiol 24-hydroxylase. a study with the mature enzyme expressed in escherichia coli.the coding region of the cdna for rat kidney calcidiol 24-hydroxylase (p450cc24), which is involved in calcium homeostasis in animals, was inserted into an expression vector pkk223-3. the recombinant plasmid was formed in a specific manner without deletion or substitution of any parts of the coding region of the cdna. when the resulting plasmid was introduced into escherichia coli jm109, the recombinant cells produced a protein which was immunoreactive to an antibody against p450cc24. when the c ...19947925346
putative adhesins of anaplasma marginale: major surface polypeptides 1a and 1b.genes for the msp1a and msp1b subunits of the anaplasma marginale surface antigen complex msp1 were previously cloned and expressed in escherichia coli. we report here the localization of msp1a and msp1b polypeptides on the surface of recombinant e. coli by using a live cell indirect immunofluorescent antibody assay. recombinant e. coli cells expressing the msp1 alpha gene or the msp1 beta gene encoding the msp1a and msp1b polypeptide subunits, respectively, were shown by a culture recovery adhe ...19947927726
a phosphatidylinositol 3-kinase is induced during soybean nodule organogenesis and is associated with membrane proliferation.phosphatidylinositol 3-kinase (pi3k) is an important component of various receptor tyrosine kinase complexes in mammalian cells and a key enzyme required for cell division and vacuolar protein sorting in yeast. to our knowledge, this enzyme has not been characterized in plants. we report the cloning and characterization of soybean pi3k cdnas and present evidence for the induction of a distinctive form of this enzyme specific to nodule organogenesis. expression of the root form of pi3k is repress ...19947937816
the fpg protein, a dna repair enzyme, is inhibited by the biomediator nitric oxide in vitro and in vivo.nitric oxide has been shown to be a mediator molecule in the regulation of many physiological functions. however, this small diatomic molecule in the presence of o2 generates reactive intermediates which modify dna bases and inactive enzymes at high concentrations (100 microm). we report that no generated by 1,1-diethyl-2-hydroxy-2-nitrosohydrazine (dea/no, et2nn(o)no-na+), a compound known to release no in a predictable manner, caused irreversible damage at physiological concentrations to the z ...19947955043
[occurrence of antibiotic resistance in bacteria causing mastitis in dairy cows].in 1986-1992 the susceptibility to antibiotics was investigated in 799 strains of causative agents of bovine mastitis. of these, streptococci, staphylococcus aureus, coagulase-negative staphylococci and other bacteria presented 43.5%, 22.2%, 17.9% and 16.6%, respectively. the strains examined were obtained from herds in which mastitis had been treated. within the period of investigation, the resistance of s. aureus to antibiotics reached the following values: penicillin (pnc) 33.0-20.3%, chloram ...19947975048
[therapy of clinically apparent forms of mastitis in lactating dairy cows using intra-mammary sulphamycin (polfa, pr)].sulphamycin (polfa, poland) is an intramammary preparation for the treatment of clinically apparent forms of mastitis in dairy cows. its effects were observed in 141 dairy cows treated according to the manufacturer's instructions. the animals were selected after clinical examination of the mammary gland and bacteriological examination of udder secreta. in 37 subclinically diseased cows the efficiency of treatment depended on the infectious agent and amounted to 85.2, 77.8, 73.3 and 60.0%, strept ...19947975049
isolation and characterization of the cdna encoding the channel catfish (ictalurus punctatus) form of cytochrome p450arom.cytochrome p450arom (aromatase) is responsible for the conversion of androgens to estrogens. a cdna library was constructed from poly(a)-enriched mrna isolated from channel catfish (ictalurus punctatus) ovary and ligated into ecori-cut lambda arms. the amplified library was screened using a human aromatase dna probe. the longest clone isolated (2.1 kb) contained 20 bp of the 5'-untranslated region, a 1572-bp open reading frame, and a 509-bp 3'-untranslated region. northern blot analysis indicate ...19947958747
smggds stabilizes nucleotide-bound and -free forms of the rac1 gtp-binding protein and stimulates gtp/gdp exchange through a substituted enzyme mechanism.the rac proteins, rac1 and rac2, are essential components of the nadph oxidase system of phagocytes and regulate the actin assembly associated with membrane ruffling. these functions are controlled by the gtp-bound form of rac. the biochemical interaction between rac and its only known gdp-dissociation stimulator (termed smggds) was characterized. smggds was able to stimulate the incorporation of guanosine 5'-[gamma-thio]-triphosphate gtp[gamma s] into the rhoa, rac2, rac1, rap1a and cdc42hs gtp ...19947980444
binding characteristics of s fimbriated escherichia coli to isolated brain microvascular endothelial cells.to assess the role of s fimbriae in the pathogenesis of escherichia coli meningitis, transformants of e. coli strains with or without s fimbriae plasmid were compared for their binding to microvessel endothelial cells isolated from bovine brain cortices (bmec). the bmec's displayed a cobblestone appearance, were positive for factor viii, carbonic anhydrase iv, took up fluorescent-labeled acetylated low density lipoprotein, and exhibited gamma glutamyl transpeptidase activity. binding of s fimbri ...19947977653
baculovirus expression of bovine cytochrome p450c17 in sf9 cells and comparison with expression in yeast, mammalian cells, and e. coli.expression of bovine 17 alpha-hydroxylase cytochrome p450 (p450c17) in insect sf9 cells using baculovirus is the fourth heterologous expression system developed for studying this enzyme. the enzyme in sf9 cell membranes has all the expected activities and closely resembles that from the other systems: cos1 cells, yeast, and escherichia coli. one curious feature of baculovirus expression of this hemoprotein is that the immunodetectable p450c17 is present in an insoluble pellet when produced in th ...19947986097
enhancement of serine-sensitivity by a gene encoding rhodanese-like protein in escherichia coli.when cells of escherichia coli are grown on lactate (or other carbon sources), an addition of serine to the medium causes growth inhibition. this growth inhibition is caused by inhibition by serine of homoserine dehydrogenase i, which is involved in threonine-isoleucine biosynthesis [hama, h., sumita, y., kakutani, y., tsuda, m., & tsuchiya, t. (1990) biochem. biophys. res. commun. 168, 1211-1216]. we have cloned and sequenced genes which enhance the serine-sensitivity. two open reading frames w ...19947982894
phospholipase a2 engineering. structural and functional roles of the highly conserved active site residue aspartate-49.site-directed mutagenesis and high-resolution two-dimensional (2d) proton nuclear magnetic resonance (nmr) were used to probe the structural and functional roles of a highly conserved residue, asp-49, in the interfacial catalysis by bovine pancreatic phospholipase a2 (pla2, overexpressed in escherichia coli). according to crystal structures, the side chain carboxylate of asp-49, along with the carbonyl oxygens of tyr-28, gly-30, and gly-32, and two water molecules, provides the necessary ligands ...19947993900
a mechanism of proton translocation by f1f0 atp synthases suggested by double mutants of the a subunit.three amino acid residues in the a subunit of the escherichia coli f1f0 atp synthase are essential for proton translocation: arg210, glu219, and his245. in this study, the essential glutamic acid has been relocated to position 252 with retention of function. it had been known that gln252 can be replaced by glu without significant effect. to test whether q252e would function in the absence of glu219, a "site-directed second-site suppressor" experiment was designed. saturation mutagenesis was appl ...19947982950
functional properties of beta(na1)val-deleted,(na2)his-->met hemoglobin synthesized in escherichia coli.bovine hb (hemoglobin) has a low oxygen affinity in the absence of chloride ions and dpg. because of the increasing interest of this hb as a potential blood substitute we have engineered a human hb mutant with the aim of mimicking the functional properties of bovine hb. this was achieved by deleting residue beta na1 val and substituting a methionine for histidine at the beta na2 position as previously suggested by perutz and imai in 1980. our results show that the artificial mutant exhibits some ...19947994396
molecular cloning, sequence analysis and expression of human pituitary glutaminyl cyclase.a cdna clone for glutaminyl cyclase was isolated from a human pituitary cdna library and the complete dna sequence determined. the cdna clone had 1573 bp and contained an open reading frame of 1086 bases, coding for a protein of 361 amino acids and molecular mass of 40,876 da. the predicted amino acid sequence of the human cdna showed 86% sequence identity to the previously reported bovine glutaminyl cyclase sequence. a comparison of the amino acid sequences derived from the human and bovine cdn ...19947999256
nadph binding and control of catalase compound ii formation: comparison of bovine, yeast, and escherichia coli enzymes.1. nadph binds to bovine catalase and to yeast catalases a and t, but not to escherichia coli catalase hpii. the association was demonstrated using chromatography and fluorimetry. bound nadph fluoresces in a similar way to nadph in solution. 2. bound nadph protects bovine and yeast catalases against forming inactive peroxide compound ii either via endogenous reductant action or by ferrocyanide reduction during catalytic activity in the presence of slowly generated peroxide. 3. bound nadph reduce ...19948002960
sequence heterogeneity of the eae gene and detection of verotoxin-producing escherichia coli using serotype-specific primers.the distribution of the escherichia coli attaching and effacing (eae) gene in strains of verotoxin-producing e. coli (vtec) isolated from cattle and humans was studied. the majority of strains isolated from humans with bloody diarrhoea or hus and cattle with severe diarrhoea were eae positive (82 and 83% respectively). in contrast, 59% of vtec isolated from asymptomatic cattle were eae negative and of the remaining 41% that were eae positive, the majority were serotype o157. h7. the nucleotide s ...19948005211
m1 protein and protein h: iggfc- and albumin-binding streptococcal surface proteins encoded by adjacent genes.m1 protein and protein h are surface proteins simultaneously present at the surface of certain strains of streptococcus pyogenes, important pathogenic bacteria in humans. the present study concerns the structure, protein-binding properties and relationship between these two molecules. the gene encoding m1 protein (emm1) was found immediately upstream of the protein h gene (sph). both genes were preceded by a promoter region. comparison of the sequences revealed a high degree of similarity in the ...19948010973
prediction and site-specific mutagenesis of residues in transmembrane alpha-helices of proton-pumping nicotinamide nucleotide transhydrogenases from escherichia coli and bovine heart mitochondria.nicotinamide nucleotide transhydrogenase from bovine heart consists of a single polypeptide of 109 kd. the complete gene for this transhydrogenase was constructed, and the protein primary structure was determined from the cdna. as compared to the previously published sequences of partially overlapping clones, three residues differed: ala591 (previously phe), val777 (previously glu), and ala782 (previously arg). the escherichia coli transhydrogenase consists of an alpha subunit of 52 kd and a bet ...19948011636
domain structure of a mammalian myosin i beta.we have determined the primary structure of a myosin i (called mammalian myosin i beta, mmi beta) from bovine brain and identified its functional domains. the protein was previously purified from brain and adrenal gland. several constructs were generated and expressed in escherichia coli as glutathione s-transferase fusion proteins and the recombinant proteins were recognized by monoclonal antibodies that recognize either "head" or "tail" domains of native myosin i. a gel overlay method was used ...19948022785
emerging infectious diseases in the united states, 1993.three outbreaks of disease in the united states in 1993 caused by escherichia coli o157:h7, cryptosporidium organisms, and a previously unrecognized hantavirus clearly illustrate the increasing challenges posed by emerging infectious diseases. the largest us outbreak of e. coli o157:h7 infection reported occurred as a result of contaminated hamburgers served at a fast-food restaurant chain. the largest recorded waterborne disease outbreak in us history was due to contamination of a municipal wat ...19948035009
the high-level expression in escherichia coli of the membrane-bound form of human and rat cytochrome b5 and studies on their mechanism of function.a t7 expression system is described for the high-level production in escherichia coli of the membrane-bound form of human and rat cytochrome b5. the cdnas of b5 have been engineered to contain a coding sequence for a four-member histidine domain at the amino-terminus of the recombinant protein permitting the use of a nickel-chelate affinity column for rapid purification of the detergent-solubilized hemoprotein. results are presented demonstrating the ability of the purified recombinant b5 protei ...19948037471
animals as a source of escherichia coli pathogenic for human beings.symptoms of slt e coli-induced enteric disease in human beings include watery diarrhea, hemorrhagic diarrhea, and, in some cases, hus. the most frequent serotype associated with hus is o157:h7, although several other serotypes have also been implicated. these organisms produce slt-i, slt-ii, or both toxins. factors other than slt are implicated as virulence attributes, such as adhesins and enterohemolysins, but roles for these factors in the pathogenicity of these organisms have not been defined ...19948014086
the 86-kda subunit of autoantigen ku is a somatostatin receptor regulating protein phosphatase-2a activity.we previously reported the immunopurification of a somatostatin receptor from the human tumoral gastric cell hgt1 using the monoclonal antibody 30f3 (reyl-desmars, f., le roux, s., linard, c., benkouka, f., and lewin, m. j. m. (1989) j. biol. chem. 264, 18789-18795). screening of a lambda gt11 hgt1-cdna library with 30f3 led us to isolate a cdna encoding an 86-kda polypeptide displaying 100% structural identity with the 86-kda subunit (p86-ku) of the ku autoantigen. recombinant p86 expressed in ...19948021251
characterization of mouse phosphatidylinositol transfer protein expressed in escherichia coli.the cdna encoding mouse phosphatidylinositol transfer protein (pi-tp) was isolated by means of reverse transcriptase polymerase chain reaction. the nucleotide sequence of this cdna has a high similarity (98%) with that of rat pi-tp; the predicted amino acid sequence is 99.6% identical to that of rat pi-tp. the cdna encoding mouse pi-tp was cloned into the expression vector pet3d and the escherichia coli strain bl21(de3) was transformed with the resulting plasmid. after induction of the bacteria ...19948049244
infrared linear dichroism reveals that a-, b-, and c-dnas in films have bases highly inclined from perpendicular to the helix axis.infrared linear dichroism has been employed to investigate the inclination of the bases in films of poly[d(ac)].poly[d(gt)], poly[d(ag)].poly[d(ct)], and natural dnas (from escherichia coli and calf thymus). all dnas investigated assume the b-form at high (> 94%) relative humidity. poly[d(ac)].poly[d(gt)], e. coli dna, and calf thymus dna assume the a-form at low (75%) relative humidity, whereas poly[d(ag)].poly[d(ct)] assumes the c-form at low (66%) relative humidity. infrared linear dichroism ...19948031766
molecular cloning and characterization of yeast rho gdp dissociation inhibitor.we have previously isolated rho gdp dissociation inhibitor (rho dgi) from bovine brain and characterized it. bovine rho gdi is a protein of a m(r) of 23,421 with 204 amino acids. rho gdi inhibits the gdp/gtp exchange reaction of post-translationally lipid-modified small gtp-binding proteins (g proteins) of the rho family, including the rho, rac, and cdc42 subfamilies, and keeps them in the gdp-bound inactive form. in the present study, we first purified rho gdi from the cytosol fraction of the y ...19948051050
[expression of hybrid genes containing sequences coding for human adrenocorticotropic hormone in escherichia coli strains].e. coli strains producing a hybrid protein containing human adrenocorticotropic hormone (acth) and protein a of s. aureus were obtained. the sequence coding for actg was obtained from the bovine one using oligonucleotide-directed mutagenesis. the actg gene was linked with the protein a gene and its derivatives by synthetic adaptors. it was shown that each of the constructed plasmids directed the synthesis of hybrid protein in e. coli. this protein was purified on igg-sepharose. then acth was obt ...19948052250
different peptide binding specificities of hsp70 family members.a set of heptapeptides was used to compare the relative peptide affinities of three proteins of the hsp70 family: bacterial dnak, mammalian cytosolic hsc70, and bip from mammalian er. each hsp displays a characteristic pattern of relative affinities. dnak and hsc70 are more similar to each other than to bip. a difference in peptide binding specificity may be an important determinant in adjusting an hsp70 family member to its particular cellular function.19948057353
clonal relationships among escherichia coli serogroup o78 isolates from human and animal infections.we investigated the clonal relationships among 63 escherichia coli strains of antigen serogroup o78 isolated from infections in humans, cattle, sheep, pigs, and chickens. both septicemic and enterotoxigenic isolates were included in the study. a main group of 55 e. coli strains consisting of 52 septicemic isolates and 3 human enterotoxigenic e. coli isolates were clustered in related clones. the remaining eight strains, four human and four animal isolates, were clonally heterogeneous. the main g ...19948051245
expression of the carbohydrate recognition domain of lung surfactant protein d and demonstration of its binding to lipopolysaccharides of gram-negative bacteria.surfactant protein d is a collagenous c-type lectin (collectin) that is found almost exclusively in the lung. a recombinant protein, composed of the neck-region and the carbohydrate binding domain of bovine lung surfactant protein d, has been overexpressed in e. coli. the recombinant protein showed the same sugar binding specificity as the native protein and was able to bind to the lipopolysaccharides of several strains of gram-negative bacteria, such as klebsiella pneumoniae, pseudomonas aerugi ...19948060356
peptidase activity of escherichia coli aminopeptidase a is not required for its role in xer site-specific recombination.xer site-specific recombination is required for the stable inheritance of multicopy plasmids and the normal segregation of the bacterial chromosome in escherichia coli. two related recombinases and two accessory proteins are essential for xer-mediated recombination at cer, a recombination site in the plasmid cole1. the accessory proteins, argr and pepa, function in ensuring that the xer recombination reaction acts exclusively intramolecularly, converting plasmid dimers into monomers and not vice ...19948057849
purification, characterization, and localization of subunit interaction area of recombinant mouse ribonucleotide reductase r1 subunit.mammalian ribonucleotide reductase is a heterotetramer formed by the two non-identical homodimers proteins r1 and r2. we have succeeded in expressing the 90-kda mouse r1 protein in escherichia coli in an active, soluble form using the t7 rna polymerase pet vector system. to avoid inclusion bodies, the bacteria were grown at 15 degrees c with minimal concentration of the inducer isopropyl-1-thio-beta-d-galactopyranoside. after a rapid purification procedure, approximately 20 mg of pure r1 protein ...19948083221
a single arabidopsis gf14 isoform possesses biochemical characteristics of diverse 14-3-3 homologues.arabidopsis cdna clones of gf14 proteins originally were isolated on the basis of their association with the g-box dna/protein complex by a monoclonal antibody screening approach. gf14 proteins are homologous to the 14-3-3 family of mammalian proteins. here we demonstrate that recombinant gf14 omega, one member of the arabidopsis gf14 protein family, is a dimeric protein that possesses many of the attributes of diverse mammalian 14-3-3 homologues. gf14 omega activates rat brain tryptophan hydrox ...19948061318
two-year study of endemic enteric pathogens associated with acute diarrhea in new caledonia.a longitudinal study of diarrheal disease among patients of all ages with acute diarrhea was carried out in new caledonia from january 1990 to december 1991. stool samples from 2,088 diarrheal patients were examined for parasites, rotavirus, and bacterial pathogens. potential sources of contamination (drinking water, seawater and bovine and porcine feces) were investigated. one or more enteric pathogens were identified in 41.8 and 40.6% of the persons with diarrhea, in 1990 and 1991, respectivel ...19948077399
a modified form of the cytochrome p450scc precursor: a new approach in studies on protein import into mitochondria.recombinant dna was constructed providing hypersynthesis of a hybrid protein with a mrgsh6gir sequence preceding the nh2-terminus of the bovine cytochrome p450scc precursor (6his-pp450scc) in escherichia coli cells. a large-scale procedure for isolation and purification of this protein was elaborated. 6his-pp450scc was imported into isolated rat liver mitochondria and processed to the mature-sized form. as a similar procedure can be applied to other proteins the results of this work offer new op ...19948093069
interaction of the small interstitial proteoglycans biglycan, decorin and fibromodulin with transforming growth factor beta.we have analysed the interactions of three proteoglycans of the decorin family, decorin, biglycan and fibromodulin, with transforming growth factor beta (tgf-beta). the proteoglycan core proteins, expressed from human cdnas as fusion proteins with escherichia coli maltose-binding protein, each bound tgf-beta 1. they showed only negligible binding to several other growth factors. intact decorin, biglycan and fibromodulin isolated from bovine tissues competed with the fusion proteins for the tgf-b ...19948093006
structure and copy number analyses of pap-, sfa-, and afa-related gene clusters in f165-positive bovine and porcine escherichia coli isolates.pathogenic f165-positive escherichia coli isolates of porcine and bovine origin possess gene clusters related to extraintestinal e. coli fimbrial operons pap, sfa, and afai. probes from different segments of the pap, sfa, and afai operons were used in southern hybridization to analyze 18 f165-positive, mannose-resistant hemagglutinating e. coli isolates possessing pap- and sfa-, pap- and afa-, or pap-related sequences. only single copies of the pap-, sfa-, or afa-related sequences were found amo ...19938099065
chaperonins dependent increase of cu,zn superoxide dismutase production in escherichia coli.over-expression of the chaperonins groel and groes significantly suppressed the temperature-dependent pattern of expression of cu,zn superoxide dismutases in escherichia coli and increased the yield of active enzyme. the results obtained indicate that chaperonins prevent degradation of metal-deficient enzyme molecules. groel was shown to form a complex with unfolded cu,zn superoxide dismutase in vitro, confirming that groel can interact with beta-stranded proteins.19938097729
complementary dna sequence of bovine cpn10 (hsp10), a chaperone protein from mitochondria.a cdna sequence encoding a chaperone protein from bovine heart mitochondria is described. it is deduced from overlapping partial cdnas amplified in polymerase chain reactions from bovine heart cdna, using in the first instance mixtures of synthetic oligonucleotide primers based on the incomplete sequence of the cpn10 (hsp10) chaperone protein from rat liver mitochondria. the encoded bovine protein sequence is 101 amino acids in length. by analogy with the rat homologue it is likely that the init ...19938104547
oxidation, cross-linking, and insolubilization of recombinant tropoelastin by purified lysyl oxidase.the use of recombinant human tropoelastin (rte) and selected variants thereof as substrates for the assay of lysyl oxidase activity in vitro was explored. the possibility was also assessed that an insoluble elastin-like product could be generated from this elastin precursor in the absence of other macromolecules found associated with elastin in vivo. rte was more efficiently oxidized by lysyl oxidase than the insoluble chick aorta elastin substrate conventionally used. anionic amphiphilic elasti ...19938098038
preparation of the extracellular domain of the rabbit prolactin receptor expressed in escherichia coli and its interaction with lactogenic hormones.the cdna of the extracellular domain of the rabbit prolactin receptor (rbprlr-ecd) was cloned in the prokaryotic expression vector ptrc99a to enable its expression in escherichia coli after induction with isopropyl-1-thio-beta-d-galactopyranoside. the bacterially expressed rbprlr-ecd protein, contained within the refractile body pellet, was solubilized in 4.5 m urea, refolded, and purified on a q-sepharose column by stepwise elution with nacl. the bioactive monomeric fraction was eluted in 0.05 ...19948106371
resolution of recombination intermediates by a mammalian activity functionally analogous to escherichia coli ruvc resolvase.a mammalian endonuclease that resolves holliday junctions has been partially purified from extracts of calf thymus and chinese hamster ovary cells. the activity acts upon (i) synthetic holliday junctions and (ii) recombination intermediates made by the escherichia coli reca protein and appears to be functionally analogous to the e. coli ruvc protein. cleavage occurs by the introduction of symmetrically related nicks in strands of like polarity to produce nicked duplex dna products. the nicks can ...19948106502
differential expression of bovine adseverin in adrenal gland revealed by in situ hybridization. cloning of a cdna for adseverin.adseverin is a ca(2+)-dependent actin filament-severing protein that is presumed to have a regulatory function in exocytosis by affecting the organization of the microfilament network underneath the plasma membrane. as the first step to investigate whether adseverin has the expected function in vivo, we have cloned a cdna for bovine adseverin. analysis of the nucleotide sequence revealed the following points. 1) adseverin consisted of 715 amino acid residues, and its predicted molecular mass was ...19948119933
the extracellular nuclease of serratia marcescens: studies on the activity in vitro and effect on transforming dna in a groundwater aquifer microcosm.a quantitative endonuclease assay, which relies on the introduction of single and double strand breaks into supercoiled plasmid dna, was used to study the activity of the extracellular nuclease of serratia marcescens sm6 in buffer and in groundwater. the parallel enzyme concentration-dependent production of relaxed and linear plasmid molecules suggests that the nuclease produces single and double strand breaks in duplex dna. bovine serum albumin stimulated the nuclease activity towards dna and r ...19948141644
isolation and characterization of endonuclease viii from escherichia coli.endonuclease viii, a novel presumptive dna repair enzyme, was isolated from escherichia coli by fplc1 purification. the enzyme was found in strains that contained or lacked endonuclease iii and was purified by radial flow s-sepharose, mono s, phenyl-superose, and superose 12 fplc. examination of the properties of endonuclease viii showed it to have many similarities to endonuclease iii. dna containing thymine glycol, dihydrothymine, beta-ureidoisobutyric acid, urea residues, or ap sites was inci ...19948110759
refolding and characterization of human recombinant heparin-binding neurite-promoting factor.heparin-binding neurite-promoting factor (hbnf) is a highly basic, cysteine-rich 136-residue protein, and a member of a new class of heparin-binding proteins. it exhibits a neurite-outgrowth promoting activity and its expression is both temporally and spacially regulated during fetal and postnatal development. a high interspecies sequence conservation suggests important, presently unknown, biological functions. hbnf is structurally and most likely functionally related to the product of a develop ...19948167469
recombinant bovine somatotropin blunts plasma tumor necrosis factor-alpha, cortisol, and thromboxane-b2 responses to endotoxin in vivo.in vivo studies determined the effects of recombinant bovine somatotropin (bst; sometribove) administration (0.1 mg/kg.day, im) to calves on the increases in plasma immunoreactive tumor necrosis factor-alpha (tnf alpha), prostacyclin [6-keto-prostaglandin f1 alpha (6kp)], thromboxane-b2 (txb), and cortisol (c) that occurred after endotoxin challenge (et). two ets were administered 5 days apart to test the effect of bst on the natural attenuation of hormone and cytokine responses that occurs afte ...19948119146
effects of recombinant human cytokines on mitogen-induced bovine peripheral blood mononuclear cell proliferation.the effects of interleukin 1 alpha (il-1 alpha), il-1 beta, il-2, il-3, il-4, il-5, il-6, il-7, il-8, and insulin growth factor-1 (igf-1) on proliferation of mitogen-stimulated bovine peripheral blood mononuclear cells (pbmc) were determined. four concentrations of each cytokine were incubated 48 or 96 h with pbmc alone or with pbmc and three concentrations of three different mitogens. the mitogens included concanavalin a (con a) phytohemagglutinin (pha), and escherichia coli 055:b5 lipopolysacc ...19938142606
characterization of the saccharomyces cerevisiae nuclear gene cyb3 encoding a cytochrome b polypeptide of respiratory complex ii.computer-assisted structural analysis of the predicted product of the previously described open reading frame (orf) ykl4 located on the left arm of chromosome xi of saccharomyces cerevisiae revealed a high degree of similarity (> 50%) to bovine cytochrome b560, the sdhc polypeptide of the escherichia coli succinate dehydrogenase (sdh) complex and the protein specified by orf137 located on the chloroplast dna of marchantia polymorpha. disruption of the yeast gene severely impaired mitochondrial f ...19948152421
development of a novel type of cloning vector for suicide selection of recombinants.based on the primary structure of the rat corticostatin r4 (antimicrobial defensin ratnp-1), a synthetic gene was designed, synthesized, and inserted into the iptg-inducible prokaryotic expression vector pflag, with an additional 13 codons between the flag sequence and the synthetic r4 sequence. this construct, n-p1.2, was further developed by inclusion of multiple cloning sites right after the flag sequence, forming a new plasmid pscv-1. escherichia coli transformants containing pscv-1 or n-p1. ...19948172659
factors affecting milk somatic cells and their role in health of the bovine mammary gland.milk somatic cells play a protective role against infectious disease in the bovine mammary gland. many genetic and environmental factors affect the number and kinds of leukocytes that account for the vast majority of somatic cells in milk. neutrophils constitute the vast majority of somatic cells in mammary glands that are infected with mastitis pathogens. the recruitment of neutrophils into the infected mammary gland is a normal part of the cow's defense mechanisms that is very effective for er ...19948182187
recombinant gst-human osteopontin fusion protein is functional in rgd-dependent cell adhesion.osteopontin (opn) is a secreted phosphoprotein expressed by many tumor cells, as well as a limited set of normal cells. native opn has been shown to support cell adhesion in an rgd-peptide-inhibitable fashion. here we expressed human opn in e. coli as a recombinant fusion protein with glutathione-s-transferase (gst). we report that the gst-opn fusion protein has functional activity. pap2 (ras-transformed, metastatic murine nih 3t3) and mda-mb-435 human mammary carcinoma cells bound to gst-opn in ...19948175899
efficacy of two therapy regimens for treatment of experimentally induced escherichia coli mastitis in cows.the objective of the study was to monitor the effect of two therapy regimens on experimental escherichia coli mastitis. single udder quarters of 12 cows that were at least 30 d postpartum were inoculated with 1500 cfu of e. coli. the inoculation was repeated in the contralateral quarter after a 3- to 4-wk interval. initially, half of the cows were treated with antimicrobials, and the remaining half were left untreated. at the second inoculation, the cows that were originally treated were not tre ...19948182170
[effect of platelet-derived growth factor pdgf on replication of cultivated bovine lens epithelial cells].it has previously been reported that pdgf isoforms ab and bb induce an increase of cytosolic free calcium in cultured bovine lens epithelial cells in a dose-dependent manner. to evaluate the biological capacity of pdgf, we investigated the proliferative response of bovine lens epithelial cells to stimulation with pdgf-aa, -ab and -bb. since various unspecific components of serum-containing media act as mitogenes and mask the effect of pdgf, serum-free culture conditions were a prerequisite for g ...19948173260
detection of antibody igg to hiv-1 in urine by ultrasensitive enzyme immunoassay (immune complex transfer enzyme immunoassay) using recombinant p24 as antigen for diagnosis of hiv-1 infection.anti-hiv-1 igg in urine was detected by an ultrasensitive enzyme immunoassay (immune complex transfer enzyme immunoassay) using recombinant p24 gag protein (p24) of hiv-1 as antigen and beta-d-galactosidase from escherichia coli as label. anti-hiv-1 igg in urine was reacted simultaneously with 2,4-dinitrophenyl-bovine serum albumin-recombinant p24 conjugate and recombinant p24-beta-d-galactosidase conjugate. the complex formed, consisting of the three components, was trapped onto polystyrene bal ...19948189327
characterization of the foot-and-mouth disease virus 3c protease expressed in escherichia coli.we have constructed a clone encoding the foot-and-mouth disease virus (fmdv) 3c protease gene (p3c) using the polymerase chain reaction. the construct was engineered to contain initiation and termination codons and cloned into a plasmid under the control of the bacteriophage t7 promoter. the p3c gene was expressed both in an in vitro transcription-translation system and in vivo in an escherichia coli system containing an inducible t7 rna polymerase gene. in both systems the expressed products we ...19938212567
molecular cloning and characterization of two rab gdi species from rat brain: brain-specific and ubiquitous types.rab gdp dissociation inhibitor (gdi) is a regulatory protein for rab proteins that controls not only the gdp/gtp exchange reaction of rab proteins but also their translocation between the cytosol and cell membranes. recently, rab gdi cdnas have been isolated from human, bovine, rat, and drosophila, and these rab gdi proteins indicated an important role in the regulation of intracellular vesicle traffic. in this study, we have isolated two different rab gdi cdnas, designated rat rab gdi alpha and ...19948188702
hemostasis in cows with endotoxin-induced mastitis.hemostasis was evaluated in cows with experimentally induced endotoxemia and mastitis, caused by intramammary infusion of endotoxin (1 mg) derived from escherichia coli. hemostatic tests included prothrombin time; activated partial thromboplastin time; thrombin time; fibrinogen, fibrin(ogen) degradation products, and platelet concentrations; and antithrombin-iii and plasminogen activities. significant alterations were observed in the mean values of most analytes (prothrombin time was increased; ...19938214888
the effect of nutritional additives on anti-infective factors in human milk.it has become a common practice to supplement human milk with a variety of additives to improve the nutritive content of the feeding for the premature infant. twenty-two freshly frozen human milk samples were measured for lysozyme activity, total iga, and specific iga to escherichia coli serotypes 01, 04, and 06. one ml aliquots were mixed with the following: 1 ml of similac, similac special care, enfamil, enfamil premature formula, and sterile water; 33 ml of poly-vi-sol, 33 mg of moducal, and ...19948200164
portal infusion of low dosage endotoxin: a model simulating translocation of ruminal endotoxin in cattle. 19948209817
cloning, sequencing and expression of a pasteurella haemolytica a1 gene encoding a purk-like protein.a membrane protein antigen of pasteurella haemolytica a1 encoded on the recombinant plasmid pyfc13 is isolated and characterized. nucleotide sequence analysis of the insert dna in pyfc13 identified the gene mpa1, which codes a protein of approximately 45 kda without signal sequence. the deduced amino acids from the dna sequence are homologous to bacillus subtilis purk by 29.4%; to schizosaccharomyces pombe pur6 by 29.34%, to saccharomyces cerevisiae pur6 by 25.867%; and to e. coli purk by 25.223 ...19938219279
substrate specificity of the escherichia coli endonuclease iii: excision of thymine- and cytosine-derived lesions in dna produced by radiation-generated free radicals.the excision of modified bases from dna by escherichia coli endonuclease iii was investigated. modified bases were produced in dna by exposure of dilute buffered solutions of dna to ionizing radiation under oxic or anoxic conditions. the technique of gas chromatography/mass spectrometry (gc/ms) was used to identify and quantify 16 pyrimidine- and purine-derived dna lesions. dna substrates were incubated either with the native enzyme or with the heat-inactivated enzyme. subsequently, dna was prec ...19938218289
escherichia coli producing cnf1 and cnf2 cytotoxins in animals with different disorders.two dna probes were used for the detection of cnf1- and cnf2-positive e coli strains in a collection of 553 e coli isolates from cattle, sheep, goats, pigs, horses, dogs, cats and poultry. cnf-positive e coli were frequently associated with septicaemia in cattle, dogs, and cats, with diarrhoea in calves, cats and dogs, and with abortion in bovine and porcine species. cnf2-positive strains were observed among adult healthy cattle. they were also found in cases of pneumonia, metritis, mastitis in ...19938220498
atp hydrolysis is not stoichiometrically linked with proteolysis in the atp-dependent protease la from escherichia coli.protein degradation in escherichia coli involves the atp-dependent serine protease la. protease la is a homotetramer with one proteolytic and one atp binding site per monomer. its proteolytic activity has been shown to be highly increased by simultaneous hydrolysis of atp, which is essential for the degradation of protein substrates by this enzyme. we have cloned and purified a proteolytically inactive la mutant, in which the catalytically active serine residue at position 679 was replaced by al ...19938226758
forms of lactoferrin: their antibacterial effect on enterotoxigenic escherichia coli.the antibacterial effects of various forms of lactoferrin on enterotoxigenic strains of escherichia coli were tested in vitro using a microassay for bacterial growth. native and apo-lactoferrin exhibited variable activity against 19 strains, whereas holo-lactoferrin had no effect. at a concentration of .2 mg/ml of apo-lactoferrin, strains could be distinguished as either sensitive or resistant to inhibition. zinc-saturated lactoferrin was as inhibitory as apo-lactoferrin when sensitive and resis ...19938227660
bovine acute mastitis: effects of intravenous sodium salicylate on endotoxin-induced intramammary inflammation.effects of the nonsteroidal antiinflammatory agent sodium salicylate on endotoxin-induced mastitis were evaluated in lactating cows. escherichia coli endotoxin was administered to a mammary quarter 1 h after initiation of a 12-h i.v. infusion of sodium salicylate. milk scc, bsa concentrations in milk, mammary inflammation, rectal temperature, appetite, milk production, and plasma and lymph pgf2 alpha were monitored. gross mammary inflammation was not reduced by salicylate infusion, nor did sodiu ...19938227658
characterisation of verocytotoxin-producing escherichia coli isolated from pigs and cattle in northern italy. 19938236671
a cdna derived from pig bone marrow cells predicts a sequence identical to the intestinal antibacterial peptide pr-39.we have recently shown that a group of antimicrobial peptides of bovine neutrophils share highly identical pro-sequences. in this paper we report the cdna sequence of a 172 amino acid residue pig myeloid protein showing a similar pro-sequence of 101 residues. the carboxyl-moiety of the predicted protein is identical to the mature form of the proline- and arginine-rich antibacterial peptide named pr-39, isolated from pig intestine.19938250863
isolation and characterization of the rickettsia prowazekii gene encoding the flavoprotein subunit of succinate dehydrogenase.the gene (sdha) coding for the flavoprotein subunit (sdha) of succinate dehydrogenase of the obligate intracellular parasitic bacterium, rickettsia prowazekii, has been isolated using an oligodeoxyribonucleotide probe to the conserved flavin adenine dinucleotide (fad)-binding region of characterized flavoproteins. nucleotide (nt) sequence analysis revealed an open reading frame (orf) of 1791 bp capable of encoding a protein of 596 amino acids (aa) with a deduced m(r) of 65,444. the deduced aa se ...19938224887
neonatal septicemia in calves: 25 cases (1985-1990).historical, physical, and clinicopathologic findings in 25 septicemic calves were examined to further characterize the clinical features of naturally induced bovine neonatal septicemia. owners often reported single organ disease, but physical examination revealed multiple organ disease in more than half the calves. a third of the calves were admitted as representative of a herd problem. laboratory findings were variable, but commonly included changes in the differential wbc count and plasma fibr ...19938253629
protection against chloroethylnitrosourea cytotoxicity by eukaryotic 3-methyladenine dna glycosylase.a eukaryotic 3-methyladenine dna glycosylase gene, the saccharomyces cerevisiae mag gene, was shown to prevent n-(2-chloroethyl)-n-nitrosourea toxicity. disruption of the mag gene by insertion of the ura3 gene increased the sensitivity of s. cerevisiae cells to n-(2-chloroethyl)-n-nitrosourea, and the expression of mag in glycosylase-deficient escherichia coli cells protected against the cytotoxic effects of n-(2-chloroethyl)-n-nitrosourea. extracts of e. coli cells that contain and express the ...19938265637
comparative efficacy of flunixin, ketoprofen, and ketorolac for treating endotoxemic neonatal calves.saline (0.9% nacl) solution or 1 of 3 nonsteroidal anti-inflammatory drugs (nsaid) was administered i.v. to 5 neonatal calves 15 minutes after the start of a 3-hour i.v. infusion of escherichia coli lipopolysaccharide (lps; 2 micrograms/kg/h). four additional calves were given a 3-hour i.v. infusion of saline solution alone. clinical attitude, mean arterial blood pressure, pcv, wbc, and plasma lactate, glucose, and eicosanoid concentrations (thromboxane b2, 6-keto-pgf1 alpha) were monitored for ...19938239142
[physiological function of the gastrointestinal tract and pathophysiological changes in neonatal diarrhea of calves].firstly, the basic principles of absorption and secretion in the intestine of healthy animals are described. the etiology and the pathophysiologic mechanisms of neonatal diarrhea in the calf due to e. coli and rota-/coronavirus are discussed. enterotoxins of e. coli stimulate primarily the secretion of chloride (and thereby water) in the small intestine without damaging the intestinal mucosa. the sodium-dependent transport systems for the absorption of glucose and amino acids remain intact. in c ...19938261915
[infectious diarrhea of calves: therapeutic and preventive possibilities based on etiological, pathophysiological and immunological data].in this article the current knowledge on the development mechanisms of bacterial, viral and cryptosporidial neonatal calf diarrhoea are briefly reviewed as basis for an efficacious prophylaxis strategy. hygienic measures will prevent the infection of the calf before colostrum intake and will diminish the infection pressure during the first weeks of life. moreover, local intestinal immunity will be provided by early administration of immune colostrum for the prevention of e.coli diarrhoea and pro ...19938266306
multiresistant strains of escherichia coli isolated from the rumen of young calves.five multiresistant strains of escherichia coli were isolated from the rumen fluid of young calves. resistance to tetracycline and ampicillin was found to be associated with the transfer of a 6.4 kbp plasmid present in two investigated strains.19938262445
photoaffinity-labeling peptide substrates for farnesyl-protein transferase and the intersubunit location of the active site.--caax motif peptides, which are substrates for isoprenylation, were synthetically derivatized with the light-sensitive benzophenone (bz) group in order to determine their potential use as catalytic site-directed covalent photocross-linking ligands for one of the enzymes catalyzing protein isoprenylation, farnesyl-protein transferase (fptase). bz-peptides could be synthesized with [3h]benzophenone and possessed eiter one or two benzophenone groups located at or near the peptide's nh2 terminus (e ...19948276838
cattle as a possible source of verocytotoxin-producing escherichia coli o157 infections in man.in may-june 1992 cases of infection with verocytotoxin-producing (vt+) escherichia coli o157 in south yorkshire could have been associated with prior consumption of beef from a local abattoir. during investigation of the abattoir, bovine rectal swabs and samples of meat and surface swabs from beef carcasses were examined for e. coli o157, isolates of which were tested for toxigenicity, plasmid content and phage type. e. coli o157 was isolated from 84 (4%) of 2103 bovine rectal swabs; of these 84 ...19938270004
severity of experimental escherichia coli mastitis in ketonemic and nonketonemic dairy cows.the severity of experimental escherichia coli mastitis in relation to in vitro chemotaxis of polymorphonuclear leukocytes was investigated in cows during negative energy balance. the negative energy balance was induced by feed restriction. cows were classified into two groups, ketonemic and nonketonemic, based on the beta-hydroxybutyrate concentration in the peripheral blood at the moment of inoculation. bacterial growth in the inoculated quarter was used as a parameter to indicate the severity ...19938270685
vasoactive intestinal peptide and helodermin inhibit phospholipase a2 activity in vitro.we recently reported that the widely distributed neuropeptide vasoactive intestinal peptide (vip) reduces inflammatory lung injury due to a variety of agents and inhibits the associated generation of cyclo-oxygenase and lipoxygenase products. we therefore investigated whether vip may inhibit phospholipase a2 activity, thus reducing the release of arachidonic acid, the common precursor of all eicosanoids. vip dose-dependently inhibited pla2 of porcine pancreas and of naja naja venom, as assessed ...19938278623
possible link between cattle and e coli o157 infection in a human. 19938296437
sugar-binding sites with specificity for glucosamine in the guinea pig middle ear mucosa.glucosamine-binding sites were detected in lowicryl k4m-embedded guinea pig middle ear mucosa by electron microscopy, using glucosaminyl bovine serum albumin. incubation of ultrathin tissue sections with gold-labeled glucosaminyl bovine serum albumin (glcn/bsa/gold) resulted in binding mainly on cilia, microvilli, rough endoplasmic reticulum and nuclei. the sugar binding was not inhibited after ultrathin sections had been digested with trypsin or neuraminidase. various carbohydrates and glycocon ...19938286107
overproduction of the toxic protein, bovine pancreatic dnasei, in escherichia coli using a tightly controlled t7-promoter-based vector.a synthetic gene coding for bovine pancreatic dnasei has been cloned under the control of a t7 promoter present on the plasmid pet11. this construct yields a stable escherichia coli transformant only when transcription from this promoter is tightly controlled. production of recombinant dnasei (rednasei) is achieved by infection of the cells with a mutant lambda phage, ce6, which carries the gene encoding t7 rna polymerase. induced bacterial cultures yield in excess of 2 mg per litre of rednasei ...19938294027
growth of lactobacilli, staphylococcus aureus and escherichia coli in normal and mastitic milk and whey.the growth of three lactobacilli (lactobacillus acidophilus, l. bulgaricus and l. casei), staphylococcus aureus and escherichia coli was followed in normal and mastitic milk and whey using the standard plate count method. l. acidophilus, l. bulgaricus 6032 and l. casei 6028 grew well in normal milk, but had decreased growth in mastitic milk if not pre-adapted in mastitic whey. s. aureus 26003 and e. coli 44102 showed enhanced growth in mastitic milk as compared with their growth in normal milk. ...19938296441
characterization of the nr1, nr2a, and nr2c receptor proteins.n-methyl-d-aspartate (nmda) receptor subunits were characterized with seven polyclonal antibodies. the antibodies were directed against nr1-a, nr2a-n1, and nr2c-n1, representing n-terminal sequences of the nr1, nr2a, and nr2c subunits, and against nr1-e, nr2a-c1, and nr2c-c1, derived from c-terminal sequences of these subunits. the anti-nr1-d antibody was raised against the putative internal loop of nr1. a size of 118 kda was found in sodium dodecyl sulfate-polyacrylamide gel electrophoresis for ...19938298456
expression of the 25-kilodalton iron-sulfur subunit of the energy-transducing nadh-ubiquinone oxidoreductase of paracoccus denitrificans.the energy-transducing nadh-ubiquinone (q) oxidoreductase of paracoccus denitrificans is composed of 14 dissimilar subunits and contains at least four iron-sulfur clusters [yagi, t. (1993) biochim. biophys. acta 1141, 1-17]. the complete dna sequence of the gene cluster encoding the energy-transducing nadh-q oxidoreductase of p. denitrificans has been determined. this paper reports the expression of the 25-kilodalton (kda) (nqo2) subunit of the p. denitrificans enzyme complex in escherichia coli ...19948286379
reverse transphosphorylation by ribonuclease a needs an intact p2-binding site. point mutations at lys-7 and arg-10 alter the catalytic properties of the enzyme.bovine pancreatic ribonuclease a interacts with rna along multiple binding subsites that essentially recognize the negatively charged phosphates of the substrate. this work gives additional strong support to the existence of the postulated phosphate-binding subsite p2 (parés, x., llorens, r., arús, c., and cuchillo, c. m. (1980) eur. j. biochem. 105, 571-579) and confirms the central role of lys-7 and arg-10 in establishing an electrostatic interaction with a phosphate group of the substrate. th ...19948300580
two binding sites of inhibitors in nadh: ubiquinone oxidoreductase (complex i). relationship of one site with the ubiquinone-binding site of bacterial glucose:ubiquinone oxidoreductase.the effect of ten naturally occurring and two synthetic inhibitors of nadh:ubiquinone oxidoreductase (complex i) of bovine heart, neurospora crassa and escherichia coli and glucose:ubiquinone oxidoreductase (glucose dehydrogenase) of gluconobacter oxidans was investigated. these inhibitors could be divided into two classes with regard to their specificity and mode of action. class i inhibitors, including the naturally occurring piericidin a, annonin vi, phenalamid a2, aurachins a and b, thiangaz ...19948307034
the expression of bovine microsomal cytochrome b5 in escherichia coli and a study of the solution structure and stability of variant proteins.the dna sequence of bovine microsomal cytochrome b5 has been amplified from a liver cdna library using a polymerase chain reaction. the amplified cdna when cloned into plasmids that support the high-level production of cytochrome b5 in e.coli leads to protein overexpression and results in cell colonies bearing a strong red colouration. using cassette mutagenesis, truncated versions of the cytochrome b5 cdna have been made that encode the first 90 amino acid residues (ala1-lys90), the first 104 a ...19938309945
expression, purification and characterization of the recombinant kringle 2 and kringle 3 domains of human plasminogen and analysis of their binding affinity for omega-aminocarboxylic acids.the kringle 2 (e161t/c162s/eee[k2hpg/c169s]tt) and the kringle 3 (tyq[k3hpg]ds) domains of human plasminogen (hpg) were expressed in escherichia coli in an expression vector with the phage t5 promotor/operator element n250psn250p29 and the cdna sequence for a hexahistidine tail to facilitate the isolation of the recombinant protein. a coagulation factor xa (fxa)-sensitive cleavage site was introduced to remove the n-terminal histidine tag. in r-k2, mutations e161t and c162s were introduced to en ...19948307012
milk from hyperimmunized dairy cows as a source of a novel biological response modifier.laboratory investigations have established that hyperimmunization of dairy cows with a polyvalent bacterial vaccine results in the secretion of biologically active substances into the milk. one of these factors, a low molecular weight anti-inflammatory agent (himf), has been studied in detail. the evidence supports the hypothesis that himf suppresses inflammation by inhibiting neutrophil emigration. additionally, the experiments suggested that himf was capable of modifying the host response to i ...19938317311
studies on the proton-translocating nadh:ubiquinone oxidoreductases of mitochondria and escherichia coli using the inhibitor 1,10-phenanthroline.mitochondrial nadh:ubiquinone oxidoreductase (complex i) is uncompetitively inhibited by 1,10-phenanthroline (op). epr spectroscopy of submitochondrial particles indicates that op, similarly to rotenone, inhibits electron transfer between the fe-s clusters of complex i and the ubiquinone pool. the proton-translocating nadh dehydrogenase (ndh1) of e. coli is more sensitive to op than is ndh1 of paracoccus. epr spectroscopy of membranous e. coli ndh1 shows that two slow- and one fast-relaxing fe-s ...19948313963
radiotelemetry temperature responses of mammary gland and body to intramammary injection of escherichia coli endotoxin or streptococcus agalactiae in lactating dairy cows.to investigate the feasibility of using changes in body or mammary temperature to detect mastitis, radiotransmitters were implanted midway between rear udder quarters and in the peritoneal cavity of 5 holstein cows (1 to 3 months in lactation) housed in an environmental chamber (16 +/- 2 c; lights on 7:00 am to 11:00 pm). after a 6-week control period, escherichia coli endotoxin (0.5 mg) was injected after the morning milking into left rear teat cisterns via the teat canal. wisconsin mastitis te ...19938317774
endotoxemia and brain bilirubin in the rat.to investigate the possible role of sepsis with endotoxemia in kernicterus, we studied the effect of endotoxin on accumulation of bilirubin and albumin in rat brain. male sprague-dawley rats were given escherichia coli endotoxin i.v. after 150 min 10 microci 125i-bovine serum albumin was given intravenously, followed by a 1-hour bilirubin infusion. brain bilirubin was significantly higher in the endotoxin group than in the controls (1.34 +/- 0.47 vs. 0.83 +/- 0.31 microgram/g, p < 0.05). however ...19938324097
analysis of tandem, multiple genes encoding 30-kda membrane proteins in pasteurella haemolytica a1.a number of outer membrane proteins (omps), including a 30-kda protein, may be important in eliciting immunity to pasteurella haemolytica a1, the causative agent of bovine pneumonic pasteurellosis. to better understand the nature of the 30-kda antigen, several genes encoding this protein were sequenced. sequence analysis revealed that three separate genes encoding similar, yet distinct, versions of the 30-kda protein are tandemly arranged on the p. haemolytica a1 chromosome. the genes appear to ...19938335249
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