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efficacy of brahman characters in reducing weight loss of steers exposed to mosquito attack. 19768472
purification, specificity, and hypervariable region sequence of anti-pneumococcal polysaccharide antibodies elicited in a single rabbit.four homogeneous antibodies to type viii pneumococcal polysaccharide (s8) were isolated from the serum of a single rabbit (3322) by affinity chromatography on an s8 immunoadsoebent by utilizing gradient elution with cellobiose and nacl. the binding properties of these antibodies were determined by a radioimmunoassay with 125i-bovine gamma-globulin-s8. cellobiose (a disaccharide unit of s8) was the immunodominant group of each of the four antibodies, but each antibody bound to this disaccharide w ...19768570
mechanism of action of some bitter-tasting compounds on frog taste cells.effects of some bitter-tasting compounds on frog taste receptors were examined by recording glossopharyngeal nerve responses. the order of effectiveness of the compounds was quinine greater than brucine greater than formanilide greater than caffeine greater than urea. when the effects of quinine, brucine and caffeine on electrical responses in taste cells were examined, they all produced a depolarization associated with an increased input resistance. the action of the three compounds on taste re ...19768659
the haemolytic effect of phallolysin.phallolysin from the toadstool, amanita phalloides, is a basic protein that causes direct haemolysis of red cells. the dose-response curve is steep; the ph optimum is in the weakly acid range. the rate of haemolysis increases with the concentration of the lysin, the optimal temperature is 20 degrees c. the percentage haemolysis-time curves are s-shaped. haemolysis is of the non-osmotic type. ca2+ is not required but inhibits haemolysis in a concentration-dependent fashion, as do mg2+ and zn2+. t ...19768736
the action of a binary nonionic detergent on a kidney membrane fraction.the disruption of a kidney cortex microsomal membrane preparation by a binary, nonionic detergent, was followed by using as markers, the changes in total protein content, and (na+, k+)-atpase in a supernatant fraction. both markers responded similarly to changes in ph, microsome concentration and detergent concentration, but responded differently for time-dependent studies. the (na+, k+)-atpase activity was increased 2.2-fold (76.1 mumoles pi/mg protein/h, 95% ouabain-sensitive) by a single dete ...19768217
resistance of alkylated dna to degradation by deoxyribonuclease ii at neutral and acid ph.methylation of a calf thymus dna substrate by dimethyl sulphate (dms) leads to an inhibition of deoxyribonuclease ii activity which is gradually lost with time. the extent of this initial inhibition is linearly related to the amount of methylated products in dna and quantitatively similar effects were found when the enzyme was used under either acid or neutral conditions. deoxyribonuclease ii was shown to produce 3'-phosphate termini under both acid and neutral conditions and thus, irrespective ...19768218
stability of the insoluble form of uridine kinase coupled to zn2+ or pb2+ ions.partially purified calf brain uridine kinase precipitated by bivalent metal cations has been compared with the soluble enzyme fraction regarding its stability in the presence of inactivating factors. the freeze-dried preparations of uridine kinase precipitaated by pb2+ or zn2+ ions, althouth enzymatically highly active, are insoluble in aqueous solutions. the activity of metal-insolubilized enzymes disappears during their preincubation in acidic media or in the presence of silver ions. also tryp ...19768366
letter: the isolation of ephemeral fever virus from mosquitoes in australia. 19769054
distribution and removal of the acrosin of bull spermatozoa.the effects of hyamine 2389, triton x-100, nadeoxycholate, acetic acid and hypertonic kcl and mgcl2 as well as freezing and thawing and sonication were studied on the solubilization of acrosin from washed bull spermatozoa, from hyamine-pretreated spermatozoa (devoid of cell and outer acrosome membrane and of acrosomal material) and from isolated acrosomal caps and vesicles. concurrent ultrastructural changes were observed. hyamine, triton, kcl, and acetic acid effectively solubilized acrosin fro ...19768388
amphibian carbonic anhydrase: purification and partial characterization of the enzyme from erythrocytes of rana catesbeiana. 19769262
the nature of the residual alpha-mannosidase in plasma in bovine mannosidosis.acidic alpha-mannosidase (ec 3.2.1.24), optimum ph 4.25, is absent from the plasma of angus calves with mannosidosis, and the residual alpha-mannosidase activity has an optimum ph of 5.5, intermediate between that of the acidic and neutral alpha-mannosidases. this 'intermediate' alpha-mannosidase differs from the acidic form in its kinetic properties, its lack of marked inhibition by edta and its thermolability at 55 degrees c and physiological ph. isoelectric focusing and ion-exchange chromatog ...19769065
the interaction of reduced nicotinamide--adenine dinucleotide phosphate with reduced nicotinamide--adenine dinucleotide--ubiquinone reductase from bovine heart mitochondria.reduction of the chromophores of mitochondrial nadh-ubiquinone reductase by nadph reaches only 50% of the extent of reduction by nadh, monitored at 450 nm. this effect is due to autoxidation of an enzyme component at a higher rate than its reduction by nadph.19769075
characterization of the binding of human growth hormone to microsomal membranes from rat liver.the binding of 125i-labelled human growth hormone to the 100000g microsomal membrane fraction prepared from the livers of normal female rats was dependent on time, temperature, ph, membrane concentration and concentration of 125i-labelled human growth hormone. at 22 degrees c binding reached a steady state after 16h, with the mean maximal specific binding being 20% of the tracer initially added. dissociation of 125i-labelled human growth hormone from the membranes, after addition of excess of un ...19769079
proceedings: adrenergic and non-adrenergic transmitter systems in vascular smooth muscle. 19769114
formation of anhydrosugars in the chemical depolymerization of heparin.in the reactions used to break heparin down to mono- and oligosaccharides, androsugars are formed at two stages. the first of these is the well-known cleavage of heparin with nitrous acid to convert the n-sulfated d-glucosamines to anhydro-d-mannose residues; this reaction has been studied in detail. it is demonstrated here that only low ph (less than 2.5) reaction conditions favor the deamination of n-sulfated d-glucosamine residues; the reaction proceeds very slowly at ph 3.5 or above. on the ...19769127
conformational changes in subfractions of calf thymus histone h1.this paper presents the first study of conformational changes in the subfractions of calf thymus h1. h1 was fractionated by the method of kincade and cole (kincade, j. m., and cole, r.d. (1966), j. biol. chem. 241. 5790) using a very shallow gdn-hc1 gradient. a possible new h1 subfraction, about 5--8% of the h1, has been found and characterized by amino acid analysis and electrophoresis. the effects of salt concentration and ph on the conformation of each of the four major subfractions have been ...19769134
purification and properties of alkaline ribonuclease from human serum.1. five alkaline ribonucleases (ec 3.1.4.22) were purified about 140- to 1900-fold from human serum by phosphocellulose and deae-cellulose chromatographies and sephadex g-75 filtration, with a total recovery of 22%. these were designated as rnaases 1-5. 2. optimum activities were observed at ph 8.5-8.7 for rnaases 1-4, and at ph 7.5 for rnaase 5. the molecular weights of these enzymes were estimated by gel filtration as 45 000, 32 000, 20 000, 13 000 and 8500, respectively. 3. these rnaases were ...19769140
the interaction of radioiodinated thyrotropin with plasma membranes. evidence for high affinity binding sites in the thyroid.the binding of biologically active 125ithyrotropin to purified plasma membranes prepared from bovine thyroid glands was studied. at 4 degrees c, specific binding reached a maximum after 2 h of incubation and a plateau was maintained for up to 20 h. degradation of 125ithyrotropin was undetectable after 2 h of incubation and was only 10% of the total after 20 h. at ph 6.0, at which binding was maximal, a single class of binding sites, having a dissociation constant of approx. 25 nm, was evident. d ...19769155
relationship between medium ph and that of the lysosomal matrix as studied by two independent methods.1. the method of estimating the intralysosomal ph by measuring the distribution of 14cmethylamine in lysosomes isolated from the livers of triton wr 1339-treated rats has been critically examined. 2. in lysed lysosomes, methylamine is bound to the membrane fragments, but this binding can be completely suppressed by increasing the concentration of monovalent cations in the medium. 3. in intact lysosomes, the binding of 14cmethylamine is only partly inhibited by monovalent cations at 25 degrees c. ...19769156
protein kinases associated with peripheral nerve myelin. 1. phosphorylation of endogenous myelin proteins and exogenous substrates.when highly purified myelin from rat sciatic nerve was incubated with gamma-32patp, protein components of the membrane were phosphorylated indicating the presence of both the substrate (receptor protein) and an endogenous kinase in the membrane. polyacrylamide gel electrophoresis of the phosphorylated membrane proteins followed by scintillation counting of gel slices and autoradiography showed that the polypeptides of molecular weights 28000, 23000 and 19000 were phosphorylated, and 32p from gam ...19769157
the effect of ca2+ on the metarhodopsin i-ii transition. i. experiments.the effect of ca2+ on kinetics and equilibrium of the meta i-ii transition was studied in rhodopsin-digitonin-solutions using flash-photometry. with increasing ca2+-concentrations the meta i-ii-equilibrium is shifted to meta i. the ph-dependence of the meta i-ii equilibrium is suppressed by ca2+. to obtain the same effect as with bivalent cations about the 10-fold concentration of univalent ions is required. ca2+-ions have also an effect on the rate of equilibrating meta i-ii: with increasing ca ...19768762
subunit structure and isozymic forms of gamma-glutamyl transpeptidase.gamma-glutamyl transpeptidase is associated with the membranes of a number of epithelial and lymphoid cells. when the enzyme is isolated from rat kidney by a method involving detergent extraction and affinity chromatography, an aggregate of molecular weight greater than 200,000 (heavy form) is obtained. treatment of the heavy form with bromelain yields a light form of the enzyme (molecular weight of approximately 68,000), which is separable by isoelectric focusing into 12 enzymatically active is ...19768776
comlete vaccination of calves. 19768866
public health importance of buffaloes and cows udder tissues. 19768937
composition and enzymatic properties of the mitochondrial nadh- and nadph-ubiquinone reductase (complex i). 19768962
purification and properties of lung lysyl oxidase, a copper-enzyme. 19768967
arterial elastin. 19768978
inhibition of bovine renal adenylate cyclase by urinary products.the secondary hyperparathyroidism in uremic patients is due to the modification plasma electrolyte concentrations accompanied by a renal resistance to pth action. we postulate that the retention of a uremic toxin could be at least partly responsible for this resistance. we have tested this hypothesis "in vitro" by measuring the action of middle molecules on the adenylate cyclase activity stimulated by naf, pth and isoproterenol.19769162
interpretation and applications of thermal difference spectra of proteins.the technique of thermal perturbation difference spectroscopy for examining chromophores in proteins has been set on a more acceptable theoretical and experimental foundation. (i) the origins of the thermal effect have been analysed to explain changes in spectral band width and wavelength for simple chromophores in various solvents. comparison with theoretical curves shows that the effect of heating chromophore solutions is mainly spectral broadening coupled with an almost negligible blue shift. ...19768401
inhibitory activity of pyridindolol on beta-galactosidase.the activity of pyridindolol in inhibiting beta-galactosidases obtained from various sources has been studied. whereas acid bovine liver beta-galactosidase (optimal ph 4.0) was not affected by this compound, neutral bovine liver beta-galactosidase (ph-optimum = 7.0) was inhibited by pyridindolol in reaction mixtures of ph 4.0 approximately 5.0. there was no inhibition at ph 7.0. the type of inhibition is non-competitive by formation of a pyridindolol-enzyme complex. since beta-galactosidases fro ...19768415
nonisoelectric focusing in buffers. 19769008
staining artifacts following electrophoretic separation of ldh isozymes. 19769009
selective elution of zones from preparative isoelectric focusing gels by ampholytes or buffers. 19769017
cultivation of foot and mouth disease virus in bovine leukocyte cultures for use in the complement fixation test.bovine leukocyte cultures achieved good growth after 72 hours of cultivation. foot-and mouth disease (fmd) virus type 0 multiplied in such cultures to a titre of 10(6) tcid50/0.1 ml. the cell culture-grown virus was found to be suitable for the complement fixation test (cft) after purification and concentration with calcium phosphate.19769808
interaction of plasma membranes with influenza virus. vi. the possible role of the adenylate cyclase system.the amounts of released soluble (s) antigen of influenza a/wsn virus were increased when the virus was allowed to interact with isolated plasma membranes in a medium containing substances enhancing the level of adenosine 3',5' cyclic monophosphate (c'amp) or activating the enzyme adenylate cyclase. by contrast, less s-antigen was released upon addition to the incubation medium of foetal calf serum or calf serum proteins which activate c'amp phosphodiesterase and thus decrease the level of c'amp. ...19769818
mg dependence and other properties of fructose-1, 6-diphosphatase and glucose-6-phosphatase in various organs of cattle.the properties of fructose-1.6-disphosphatase in supernatant of homogenate of liver, kidneys, and adductor muscles of cattle were tested. edta was found to activate the enzyme up to concentrations of 10 mmol. the ph optimum was 7.5 in the presence of edta. even lower concentrations of magnesium ions caused activation of the enzyme, but an activating effect was obtained as well from relatively high mg concentrations. fructose-1.6-diphosphatase could by activated also by 0.2 mmol mn or co ions or ...19769044
quantitative study of secondary structure of histones h1, h2a, and h4 in solution by infrared spectroscopy.the secondary structure of histones h1, h2a, and h4 (f1, f2a2, and f2a1) has been quantitatively studied in heavy water (2h2o) solutions in a wide range of histone concentration, p2h, and concentration of sodium chloride using an improved infrared spectroscopy method. under all conditions there are about 5--10% of alpha helix. conditions favourable for aggregation induce formation of antiparallel pleated sheet structure to an extent of about 15% in h1 and h2a and about 30% in h4. when the p2h an ...19769273
photolysis of desmosine and isodesmosine by ultraviolet light.1. desmosine and isodesmosine were separated by ion-exchange and paper chromatography, after acid hydrolysis of purified elastin from beef ligamentum nuchae. the fractions obtained by ion-exchange chromatography were clearly mixtures of related compounds. the desmosine fraction could be resolved into seven compounds and the isodesmosine into four by paper chromatography. 2. desmosine was maximally degraded by irradiation at 274 nm and isodesmosine at 285 nm. these wavelengths did not correspond ...19769274
isolation and partial characterization of the cytochrome oxidase from rhodopseudomonas palustris.the cytochrome oxidase (ec 1.9.3.1) of rhodopseudomonas palustris was extracted with triton x-100 plus kcl, from the membrane fraction of cells grown aerobically in the dark. the solubilized enzyme was purified by (nh4)2so4 precipitation and chromatography on deae-cellulose. the purification resulted in a 108-fold enrichment of cytochrome oxidase on the basis of specific activity when compared to the membrane fraction. the purified enzyme was phosphate-sensitive (less than mm), oxidized reduced ...19769286
bovine colostral gamma-glutamyltransferase; its localization in skim milk membrane and irrelevance to secretory immunoglobulin a. 19769315
the effect of ion-exchange column chromatography on separation of x and y chromosome-bearing human spermatozoa.separation of x and y chromosome-bearing spermatozoa has been attempted using ion-exchange column chromatography, with cation- and anion-exchange resins of low, intermediate, and high ionic strength. examination of f-bodies on the y chromosome of treated human sperm and progeny resulting from insemination of treated rabbit spermatozoa indicates that in none of the cases investigated did the treatment cause a separation of x and y chromosome-bearing spermatozoa. the treatment does appear to filte ...19769318
higher transpeptidation activity and broad acceptor specificity of gamma-glutamyltransferases of tumors.the gamma-glutamyltransferase (ec 2.3.2.2) (=gamma-glutamyltranspeptidase, gamma-gtp) activity in hepatoma induced by 3'-methyl-4-(dimethylamino)azobenzene (3'-me-dab) was 120-fold higher than that of normal liver and high activity was also found in bovine hepatocellular carcinoma. gamma-gtps from these malignant tissues responded more and showed broader specificity to gamma-glutamyl group acceptors than those from normal tissue such as bovine, rat, and mouse liver and bovine kidney. three speci ...19769327
a kallikrein-specific inhibitor in rat kidney tubules.a kallikrein inhibitor was found in tubules of the rat kidney and purified by chromatography on sephadex g-100. the molecular weight of the inhibitor, estimated by gel filtration and dodecylsulfate electrophoresis, is about 4700. it inhibits the following kallikreins: porcine submanidbular and pancreatic kallikrein, rat kidney and urine kallikrein, and human urine and plasma kallikrein. an inhibition of bovine trypsin was not observed.19769350
comparative rheology of cornea. 19769252
preparation and some properties of immobilized trypsin from the crayfish cambarus affinis say (author's transl).the anionic tryptic enzyme from the crayfish (crayfish trypsin) was adsorbed to deae-sephadex a-50 and covalently coupled to brcn-activated sepharose 4b and porous glass loaded with isothiocyanate propyl groups (itc-glass). the relative activities against p-tosylarginine methyl ester (tosargome) were found to be 30 to 100% for deae-sephadex crayfish trypsin, 20 to 53% for sepharose crayfish trypsin, and 17 to 38% for itc-glass crayfish trypsin. the relative activities rise with declining protein ...19769351
kinetics and control of bovine adrenal glucose-6-phosphate dehydrogenase.michaelis-menten kinetics are observed in studies of highly purified bovine adrenal glucose-6-phosphate dehydrogenase at ph8.0 in 0.1 m bicine. the km for nadp+ is 3.8 mum and for glucose-6-phosphate, 61 mum. at ph 6.9 km for nadp+ increases to 6.5 mum. the enzyme is inhibited by nadph both at ph 6.8 and at 8.0 with a kip of 2.36 mum at ph 8.0. inhibition is competitive with respect to both substrates implying that addition of substrates is random ordered. the data are also interpreted in terms ...19769367
on the mechanism of action of oligomycin and acidic uncouplers on proton translocation and energy transfer in "sonic" submitochondrial particles.a study is presented of the effect of acidic uncouplers and oligomycin on energy-linked and passive proton translocation, oxidative phosphorylation, and energy-linked nicotinamide-adenine-nucleotide transhydrogenase in edta submitochondrial particles from beef-heart. a flow potentiometric technique has been applied to resolve the kinetics of the initial rapid phase of the redox proton pump. rapid kinetics analysis shows that carbonyl-cyanide-p-trifluoromethoxyphenyl-hydrazone (fccp) does not exe ...19769385
identification of a functional arginine residue involved in coenzyme binding by the nadp-specific glutamate dehydrogenase of neurospora.the nadp-specific glutamate dehydrogenase (ec 1.4.1.4) of neurospora crassa is inhibited by reaction with 1,2-cyclohexanedione which binds to arginine residues. with the 14c-labeled reagent, a peptide was isolated with the sequence: gly-gly-leu-arg-leu-his-pro-ser-val-asn-leu, corresponding to residues 78 through 88 in the protein. the arginine, residue 81, was present as n7,n8-(1,2-dihydroxycyclohex-1,2-ylene)-arginyl (or dhch-arginine). present evidence indicates that this arginine residue res ...19769404
utilization of volatile fatty acids in ruminants. 8. acetate activation in mammary tissue. 19769435
some parameters affecting the activity of monoamine oxidase in purified bovine brain mitochondria. 19769476
effects of light on cyclic gmp metabolism in retinal photoreceptors. 19769482
mechanism of uncoupling in mitochondria: uncouplers as ionophores for cycling cations and protons.classical uncouplers such as 2,4-dinitrophenol have been shown to be ionophores with the capability for transporting monovalent or divalent cations with equal efficiency. the conditions appropriate for the maximal expression of this ionophoric capability have been explored. two critical factors are the polarity of the organic phase and the ph of the aqueous phase that is equilibrated with the organic phase. the demonstrated cationic ionophoric capability of uncouplers, taken in conjunction with ...19769641
intestinal digestion of tropical starches by the preruminant calf proceedings. 19769644
choline acetyltransferase--evidence for acetyl transfer by a histidine residue. 19769488
subcellular localization of tryptophan-5-mono-oxygenase in bovine pineal glands and raphe nuclei. 19769489
the role of lipids in the observed lack of phosphatidylcholine exchange in myelin. 19769490
calcium-binding protein in bull seminal vesicle secretion and seminal plasma.a protein which showed high affinity for calcium ions was isolated from bull seminal vesicle secretion and seminal plasma. its calcium-binding activity depended on the ionic strength and ph of the medium. the dissociation constant was 7-7 x 10(-7) m and there were 14 binding sites per protein molecule. the molecular weight of calcium-binding protein from bull seminal vesicle secretion, estimated by the gel filtration method, was 110,000. the protein may be involved in the regulation of the calci ...19769509
trypsin inhibitors in bovine lung and pancreas during development.1. the activity of trypsin inhibitors in lung and pancreas increased with age of the animals. 2. in foetal lung the activity of the basic kunitz-type inhibitor was 1% that, and in calf lung 5-30% that, found in adult animals. 3. in foetal pancreas the basic kunitz-type inhibitor was not detected, and in calf pancreas its activity was much lower than in adult animals. the activity of the acidic kazal-type inhibitor in foetal pancreas was significantly lower than in calf or adult animal.19769760
a study of the inhalation of pentachlorophenol by rats. part v. a protein binding study of pentachlorophenol.this study examined the effects on pcp binding to bsa by varying the temperature, ph ionic strength, pcp concentration and bsa concentration. it also compared the albumin binding of pcp to the plasma binding of pcp for the rat and human.19769173
influence of glutathione on the catalytic properties of leucine aminopeptidase.1. leucine aminopeptidase does not catalyze the hydrolysis of glutathione. 2. glutathione inhibits the hydrolysis of the substrates leucine hydrazide and leucine-p-nitroanilide by leucine aminopeptidase. 3. by means of kinetic experiments the type of the inhibition has been determined as noncompetitive. the inhibition constant ki for the mg2+-activated enzyme is five times higher than for the non-activated enzyme. 4. the degree of inhibition caused by glutathione depends on the ph value indicati ...19769767
binding of tritiated methylated luteinizing hormone to bovine corpus luteum receptors.the binding of luteinizing hormone (lh) to cow corpora lutea homogenates was studied using a tritium labelled hormone obtained by reductive methylation. the kd observed was 0.9 10(-10) m and the number of sites was the equivalent of 0.4 10(-15) moles per mg of wet tissue. the influence of the ph and temperature was examined. hcg and lh produced the same binding inhibition properties of the derivative used for labelling lh were similar to those of native lh. the inhibitory activity of the subunit ...19769768
antifungal properties of alpha,omega-alkanedicarboxylic acids and their dimethyl esters.thirteen alpha, omega-alkanedicarboxylic acids (c2-c12, c14, and c16) and their dimethyl esters were tested against aspergillus niger, trichoderma viride, and myrothecium verrucaria in sabourauc dextrose agar at ph 4.0 and 5.6. toxicity to canadida albicans, trichophyton mentagrophytes, and mucor mucedo was determined in the same medium at ph 5.6 and 7.0 in the absence and presence of 10% beef serum. the dicarboxylic acids possessed very poor to no antifungal activity against all six fungi. the ...19769194
a lysyl oxidase distinct from amine oxidase in bovine dental pulp. 19769924
the effects of oxygen on alkaline solutions of superoxide dismutase. 19769934
bovine brain purine-nucleoside phosphorylase purification, characterization, and catalytic mechanism.bovine brain purine-nucleoside phosphorylase (purine-nucleoside:orthophosphate ribosyltransferase, ec 2.4.2.1) was purified to homogeneity at a specific activity of 78 mumol min-1 mg of protein-1. a molecular weight of 78 000-80 000 was calculated for the native enzyme by fel filtration on sephadex. gel electrophoresis in the presence of sodium dodecyl sulfate indicated subunits of molecular weight of 38 000. chemical and kinetic studies strongly implicated histidine and cysteine as catalytic gr ...19769972
nuclear magnetic resonance determination of intramolecular distances in bovine pancreatic trypsin inhibitor using nitrotyrosine chelation of lanthanides.nitration of tyrosine has been investigated as a means for chemically introducing lanthanide chelating sites at known positions in proteins. the low-field portions of the 250-mhz and 270-mhz 1h nuclear magnetic resonance spectra of native and chemically modified bovine pancreatic trypsin inhibitor have been studied in the presence of lanthanide ions. comparisons of spectral changes observed with native, mononitro (tryosine 10) and dinitro (tyrosines 10 and 21) derivatives enable these changes to ...19769977
polymerization pattern of insulin at ph 7.0.sedimentation equilibrium results, obtained with bovine zinc-free insulin (with and without a component of proinsulin) at ph 7.0, i o.2, 25 degrees c, and up to a total concentration of 0.8 g/l., are shown to be consistent with three different polymerization patterns, all involving an isodesmic indefinite self-association of specified oligomeric species. the analysis procedure, based on closed solutions formed by summing infinite series, yields for each pattern a set of equilibrium constants, it ...19769980
ruminal histamine, lactate and animal performance. 197610270
purification and properties of the extracellular metallo-proteinases of chromobacterium lividum (ncib 10926).four extracellular proteolytic enzymes (i-iv) (ec 3.4.22.-) were identified in static cultures of chromobacterium lividum (ncib 10926) by agar gel electrophoresis and isoelectric focusing. proteinases i-iii were freed of non-enzymic protein by chromatography on teae-cellulose and cm-cellulose. the enzyme mixture was then fractionated in a ph gradient by isoelectric focusing. all three enzymes were shown to be heat-labile metallo-enzymes. optimal activity occurred at ph 5.6 for enzyme i and at ph ...19769995
defence against bacterial drug resistance. 197610047
ammonia toxicity in cattle. i. rumen and blood changes associated with toxicity and treatment methods. 197610271
in vitro activation of glycoprotein hormones. hybridization of subunits from thyrotropin, lutropin and human choriogonadotropin.in vitro assembly of thyrotropin alpha and beta subunits led to an increase in content of alpha helix and beta sheet very similar to that found for gonadotropins. this association-dependent active folding involved the burying of three tyrosine residues tentatively assigned to tyr alpha 41, tyr beta 37 and tyr beta 59 and common to all studied glycoprotein hormones. in vitro hybridizations between alpha and beta subunits of various hormones (thyrotropin, lutropin and choriogonadotropin) from diff ...19769999
effects of acidity, cations and alcoholic fractionation on absorption of heparin from gastrointestinal tract.heparin was introduced into the stomach or duodenum of mice separately in doses of ca. 250 mg/kg. a slight anticoagulant effect in the systemic circulation was detected in whole blood clotting times and factor x inhibition. in contrast to most drugs, more heparin was absorbed from the stomach than from the intestine. suppressing ionization of heparin by simultaneous administration of acid resulted in improved absorption of heparin from the small intestine. heparin was separated with ethanol into ...197610060
effect of temperature and ph on the growth of caryophanon latum colonies. 197610073
different types of synaptic vesicles in axons of the retractor penis muscle of the bull.three types of axon profiles were observed in the smooth muscle of the retractor penis and the penile artery of the bull: 1. profiles containing small granular vesicles, presumably representing adrenergic axons; 2. profiles containing small agranular vesicles, presumably representing cholinergic axons; 3. profiles containing numerous large and small granular vesicles. the third type of profile was not found in the vas deferens or the metatarsal artery. it is therefore possible that this type of ...197610180
induction of the bovine trypsinogen-trypsin transition by peptides sequentially similar to the n-terminus of trypsin. 197610181
evidence against tubulin--actin homology. 197610182
effect of salts on the kinetic parameters and thermal stability of bovine brain acid phosphatase.bovine brain acid phosphatase is inhibited, at any ph, by an increase in ionic strength. the rate decrease is associated at ph 5, with a marked decrease in km and, at ph 8, with a noticeable decrease in vm. the rate of thermal inactivation of the enzyme is unaffected by increasing ionic strength up to 300 mm. these results are discussed in terms of interactions at the active site of the enzyme.197610222
gamma-glutamyl transpeptidase: relation to immunoglobulin a and free secretory component. 19769908
role of atp and beta-gamma-iminoadenosinetriphosphate in the stimulation of epinephrine and protein release from isolated adrenal secretory vesicles. 19769912
on coupling bovine fibrinogen to the surface of malignant murine plasma cells by means of transglutaminase. 197610897
a circular dichroic absorption study of the reaction of oxidized pyridine nucleotides with cyanide ions. 197610898
effect of dextran on clotting time: steric exclusion accelerates fibrin monomer polymerisation. 197610639
activity and variability of aminopeptidases and gamma-glutamyl transpeptidase of the cutaneous mucous membrane in the cow's rumen.the authors studied the activity, chromatographic and electrophoretic distribution of leucylarylamidase, cystinamino peptidase, and gamma-glutamyl transpeptidase of the cytoplasmatic fraction of cow's rumen mucous membrane homogenate. the results of comparative analysis draw attention to the existence of a certain number of the molecular forms of the enzymes studied, to the activation of leucylarylamidase by co2+, cystinamino peptidase by co2+ and ca2+. the possible functions of the amino peptid ...197610665
interaction of diiodo-l-tyrosine and triiodophenol with bovine serum albumin. circular dichroism and fluorescence studies.as a model study to investigate the binding mechanism between thyroid hormones and carrier protein, the interaction of diiodo-l-tyrosine (dit) and triiodophenol (i3phi) with bovine serum albumin (bsa) was investigated by circular dichroism (cd) and fluorescence methods. in both the dit-bsa system and the i3phi-bsa system, induced cotton effect was observed in the wavelength region near 320 nm. this induced cotton effect was measured at various molar ratios of ligands to bsa (l/p). the value of t ...197610286
conversion of proparathyroid hormone to parathyroid hormone by a particulate enzyme of the parathyroid gland.the conversion of proparathyroid hormone (proparathormone) to parathyroid hormone (parathormone) by subcellular fractions of the bovine parathyroid has been investigated. the identification of the conversion product as parathormone was established by its elution postion during ion exchange chromatography and gel filtration, and by partial amino acid sequence analysis of its nh2-terminal region. total homogenates and derived subcellular fractions (600 x g pellet, 5,000 x g pellet, 20,000 x g pell ...197610304
comparison of the inactivation of igm and igg complement fixation sites by acid and base.rabbit igm antibodies to denatured mammalian or t6 bacteriophage dna or poly(a)-poly(u) irreversibly lost complement-(c) fixation reactivity on exposure to low ph and reneutralization, with a halving of the complement-fixation titer occurring after treatment at about ph 3. the titers of igg antibodies to denatured phage dna, to poly(a)-poly(u), or to hemocyanin were halved only after exposure to ph 2. inactivation by acid was enhanced by low protein concentrations, incubation at higher temperatu ...197610334
digestion and absorption of bovine milk xanthine oxidase and its role as an aldehyde oxidase.the effects of acidic and intestinal proteolytic environments on bovine milk xanthine oxidase (xo) activity were determined in order to evaluate the extent to which this enzyme was absorbed in biologically active form. the inhibition of xo by folic acid and the relative affinities of xo for the oxidation of palmitaldehyde, stearaldehyde, and xanthine were compared. the effects of acid and gastric juice on xo activity were measured by incubating purified enzyme, and non-purified enzyme (milk), in ...197610360
5-hydroxytryptamine is a substrate for both species of monoamine oxidase in beef heart mitochondria.the activity of beef heart mitochondrial monoamine oxidase towards 5-hydroxytryptamine (5-ht) is inhibited by the selective inhibitors clorgyline, pco 5-phenyl-3-(n-cyclopropyl)-ethylamine-1,2,4-oxidiazole and deprenyl with a biphasic dependence on the inhibitor concentration. the activities towards tyramine, dopamine and tryptamine were also inhibited in a biphasic manner, but the apparent proportions of the two enzyme species active on dopamine and tryptamine depended on the inhibitor used. ph ...197610387
some aspects of foetal and uteroplacental metabolism in cows with indwelling umbilical and uterine vascular catheters.1. the experiments were carried out on conscious pregnant jersey cows with intravascular catheters implanted during late gestation in umbilical and uterine vessels. all but three of fifteen animals delivered live healthy calves. 2. rountine daily analyses were made of blood gas tensions, ph and packed cell volume in foetal and maternal blood; plasma concentrations of glucose, fructose, lactate and urea were also determined. measurements of plasma free fatty acids and blood acetate concentrations ...197610434
properties of two isolated antigens associated with bovine leukemia virus infection.we isolated an ether-resistant internal antigen and an ether-sensitive antigen previously described in relation to bovine leukemia virus infection. these two antigens have now been isolated by isoelectric focusing and concanavalin a affinity chromatography, respectively. the ether-resistant antigen exhibited isoelectric heterogeneity with a major peak at ph 7.2 and a minor peak at ph 6.2. its molecular weight, estimated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (sds-page), was ...197610447
mucociliary function in the respiratory tract as influenced by physicochemical factors. 197610581
biochemical properties of the prostaglandin/thromboxane synthetase of human blood platelets and comparison with the synthetase of bovine seminal vesicles.the enzyme system which synthesizes prostaglandins and thromboxanes in extracts of washed human platelets has been characterized with respect to kinetic parameters, ph and cofactor dependence, and inhibitor potencies. arachidonate and dihomo-gamma-linolenate were shown to be mutually competitive substrates, thus providing biochemical support for the assumption that both substrates are metabolized by the same cyclooxygenase, although they are ultimately metabolized to different patterns of produ ...197610602
structural studies on des-pentapeptide (b26-30)-insulin. iv. a preliminary investigation on the hydrophobic region by employing a fluorescence probe, 1-p-toluidinylnaphthalene-8-sulphonate.the fluorescnece porperties of 1,8-tns in relation to the polarity and viscosity of the solvents have been studied and found to be just as useful as those of its positional isomer 2,6-tns in the capacity of being a fluorescent probe. the properties of the hydrophobic region of insulin, des-pentapeptide (b26-30)- insulin (dpi), bovine plasma albumin, lysozyme, and ovalbumin have been investigated by employing this fluorescent probe. it has been shown that there is a small but definite hydrophobic ...197610623
production physiology and properties of a novel fungal fibrinolytic enzyme.a potent extracellular fibrinolytic enzyme was obtained from cultures of the imperfect fungus fusarium semitectum under certain growth conditions. nitrate addition to cultures increased enzyme production. the enzyme showed a versatile proteolytic activity against several protein substrates including casein, gelatin, haemoglobin, bovine serum albumin, and fibrin from both buffalo and human sources. optimal fibrinolysis occurred at ph values around 7.0. the fibrinolytic activity exhibited marked h ...197610688
immunological mechanisms in aspirin hypersensitivity. studies on the immunogenicity of free aspirin.anti-aspiryl antibodies were produced in rabbits and guinea pigs by inoculation of aspirin incorporated in complete or incomplete freund's adjuvant. these antibodies were readily detected by passive haemagglutination using rabbit erythrocytes incubated with aspirin at alkaline ph. aspiryl conjugates with ovalbumin, human gamma-globulin, bovine gamma-globulin and rabbit serum were also prepared by incubating the proteins with aspirin at alkaline ph. aspiryl conjugates prepared by this technique b ...197610712
the asymmetric distribution of enzymic activity between the six subunits of bovine liver glutamate dehydrogenase. use of d- and l-glutamyl alpha-chloromethyl ketones (4-amino-6-chloro-5-oxohexanoic acid.a method for the preparation of d- and l-glutamyl alpha-chloromethyl ketones (4-amino-6-chloro-5-oxohexanoic acid) is described. these chloromethyl ketones irreversibly inactivated bovine glutamate dehydrogenase, whereas several other related compounds had no adverse effect on the activity of the enzyme. the inactivation process was shown to be due to the modification of lysine-126. the time-courses for the inactivation and the incorporation of radioactivity from tritiated l-glutamyl alpha-chlor ...197610889
different deoxyribonuclease-activities in bull seminal plasma (author's transl).by means of the in situ assay of deoxyribonucleases in dna-containing polyacrylamide gels after separation by micro-disc-electrophoresis different deoxyribonucleases are detectable in bull seminal plasma. there are two groups of acid deoxyribonuclease-activities with a ph optimum at ph 5.0, one with a ph optimum at ph 7.4 and an additional one with a ph optimum at ph 8.5.197610693
extrinsic signals for monitoring the association reaction of proteins as introduced by fluorescent and non-fluorescent labels.two known dansyl labels (i, ii) and 5-2-(iodoacetamido)ethylamino-1-naphthalene-sulfonic acid (iii) and three new azo-dyes (iv - vi) were covalently attached to alpha-chymotrypsin and to basic pancreatic trypsin inhibitor by four different reactive groups. in order to protect the contact region of the proteins the complex of the two proteins was labeled. advantage was taken of the fact that a group which is buried in the complex reacts about (see article) times slower than a group which is alway ...197611168
some properties of erythrocuprein treated by organic solvents.the effect of various types of organic solvents on the properties of bovine erythrocuprein was studied. three organic solvents were found in which the protein is soluble, these were: dimethyl sulfoxide, formamide and n-methylformamide. it was shown that in formamide and dimethyl sulfoxide media the protein possees superoxide dismutase activity, but in n-methylformamide the protein has negligible activity. in organic solvents the substrate (superoxide radical) and solvated electron result in redu ...197610976
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