| extracellular acid protease of aspergillus oryzae grown on liquid media: multiple forms due to association with heterogeneous polysaccharides. | the acid protease (ec 2.4.23.6) that is produced extracellularly when aspergillus oryzae is grown on liquid media has been isolated and characterized. the enzyme was purified by precipitation with tannic acid, chromatography on duolite a-2, and gel filtration on sephadex g-100. the last step yielded four active components, with varying molecular weights ranging from 42,000 to 60,000. two of them, designated e1 and e1a, with molecular weights of 60,000 and 55,000, respectively, were heterogeneous ... | 1977 | 15987 |
| reversible binding of pi by beef heart mitochondrial adenosine triphosphatase. | beef heart mitochondrial atpase (f1) exhibited a single binding site for pi. the interaction with pi was reversible, partially dependent on the presence of divalent metal ions, and characterized by a dissociation constant at ph 7.5 of 80 micronm. a variety of substances known to influence oxidative phosphorylation or the activity of the soluble atpase (f1) also influenced pi binding by the enzyme. thus aurovertin, an inhibitor of oxidative phosphorylation, which was bound tightly by f1 and inhib ... | 1977 | 16006 |
| adrenodoxin reductase and adrenodoxin. mechanisms of reduction of ferricyanide and cytochrome c. | adrenodoxin reductase, the flavoprotein moiety of the adrenal cortex mitochondrial steroid hydroxylating system, participates in adrenodoxin-dependent cytochrome c and adrenodoxin-independent ferricyanide reduction, with nadph as electron donor for both of these 1-electron reductions. for ferricyanide reduction, adrenodoxin reductase cycles between oxidized and 2-electron-reduced forms, reoxidation proceeding via the neutral flavin (fad) semiquinone form (fig. 9). addition of adrenodoxin has no ... | 1977 | 16008 |
| studies on cultured skin fibroblasts from calves with gm1 gangliosidosis. | | 1977 | 16043 |
| an evaluation of elution techniques in the study of immune complex glomerulonephritis. | antigen and antibody from glomerular immune complex deposits in rabbits with experimental bovine serum albumin-(bsa) induced chronic serum sickness (css) were quantitated in elutes from kidneys in which a portion of the antigen and antibody had been radiolabeled. the largest quantities of 125i bsa eluted with 1 m roprionic acid at ph 2.7 (86%) and 0.1 m borate buffer at ph 11.25 (80%). however, these buffers yielded less functional anti-bsa antibody than 0.02 m citrate buffer at ph 3.2 (344 mug/ ... | 1977 | 16060 |
| use of a competitive protein-binding assay for adenosine 3':5'-phosphate for the study of bovine corpus luteum adenylate cyclase. | the use of a competitive protein-binding assay for cyclic amp, utilizing the binding protein purified from bovine adrenal cortex, for the study of adenylate cyclase activity of the washed 600 g sediment of bovine corpus luteum is validated. a specific assay for cyclic amp could only be achieved by removal of the degradation products of atp on a precipitate of nascent baso4. simple dilution of the sample before assay was not sufficient to eliminate interference from degradation products of atp. a ... | 1977 | 16071 |
| regulation of adenosine cyclic 3',5'-monophosphate and guanosine cyclic 3',5'-monophosphate levels and contractility in bovine tracheal smooth muscle. | | 1977 | 16208 |
| noniatrogenic retrolental fibroplasia. | | 1977 | 16239 |
| studies on the intestinal absorption of bovine xanthine oxidase. | | 1977 | 16272 |
| a pulsed laser study of excited states of aromatic molecules absorbed in globular proteins. | | 1977 | 16314 |
| determination of the effective concentration of jodonal a for the disinfection of the skin and teats after milking. | the bactericidal effectivity of jodonal a in 1:10, 1:5, and 1:3 solutions was tested on human skin and on the teats of cow mammary glands. the 1:3 dilution ratio proved best for three-minute exposure. jodonal a used in this concentration in 522 cows for the post-milking disinfection of teats for 10 months exerted no harmful effect on the skin of the mammary glands. | 1976 | 16377 |
| reaction of n-benzoquinone with aminoderivatives and its use in biochemistry. | | 1977 | 16386 |
| use of potentiometric titration at constant ph for determination of the activity of lipoprotein lipase. | a method is developed for determination of the lipoprotein lipase activity. the method is based on the steady state potentiometric titration at constant ph value of higher fatty acids, liberated during the hydrolysis. an oil emulsion intralipid, activated by human blood serum, was used as a substrate. the sensitivity of the method was equal to 0.004-0.010 micronm of fatty acids per min. the reproducibility of the results was 2-5%. this simple and rapid method enabled to study kinetic of reaction ... | 1976 | 16401 |
| on the enzymatic breakdown of tripolyphosphate and diphosphate in minced meat. v. change in the diphosphatase activity of muscle post mortem (author's transl). | the diphosphatase (dpase) activity of minced bovine muscle decreased during storage of the intact muscle post mortem (p.m.) but there was only little change after development of rigor mortis. the drop in ph p.m. seems to be not the only reason for the decrease in dpase activity. in the postrigor muscle the dpase activity, measured at ph greater than 6, increased during the breakdown of dp. the rise of activity was the slower the longer the muscle was stored. the result of a mathematical regressi ... | 1977 | 16412 |
| on the enzymatic breakdown of tripolyphosphate and diphosphate in minced meat. vi. influence of ph on the tripolyphosphatase and diphosphatase activities in bovine muscle (author's transl). | the ph optimum of the tripolyphosphatase activity of minced bovine muscle post rigor was 5.6. the ph optimum of the diphosphatase activity was in the range between ph 6.7 and 6.8. the prolonged influence of ph values around 7 caused an additional increase in the diphosphatase activity. | 1977 | 16413 |
| the ability of atp-free granule material from bovine adrenal medulla to bind inorganic cations and biogenic amines. | bovine adrenal medullary granules isolated by millipore filtration were depleted of ca and atp by dialysis. the resulting material showed an ability to bind inorganic cations and biogenic amines in a concentration-dependent manner. the similarity of the uptake curves, the identical uptake maxima and the narrow ph range (between 4-7) over which the uptake of the inorganic and organic cations took place indicated a binding of these ions to common sites. in addition, the fact that all the uptake cu ... | 1977 | 16437 |
| the splitting of sperm heads from tails in eight mammalian species and the measurement of their sizes. | ejaculated spermatozoa from man, the euopean wild boar and the bull, and spermatozoa from the cauda epididymes of the rabbit, rat, mouse, hamster and guinea pig were treated with a sonic bath, a sonic probe, trypsin with and without prior treatment with a sulphhydryl reagent, pronase and alkalis. the fragments produced were counted and sized in an accurately calibrated coulter counter, model zb industrial, before and after zaponin treatment to lyse accompanying debris and the peripheral cytoplas ... | 1977 | 16511 |
| induction of antibody-mediated rbc lysis in food extracts. | | 1977 | 16514 |
| fluid mass distribution during extracorporeal circulation. | the author first recalls close relations existing in physiologic conditions between central venous pressure and blood mass. during e.c.c., this relation is out of truth through the action of venous correlations and of outout. then studying distribution of blood mass in the different compartments, he notes that during e.c.c., the total organic fluid mass changes a little, but that the extracellular volume increases when the blood mass grows less. to these modifications shares in a seclusion of bl ... | 1977 | 16541 |
| influence of reagent quality and reaction conditions on the determination of serum albumin by the bromcresol green dye-binding method. | in an age of reference methodologies and sophisticated quality control techniques it is surprising that so little attention is paid to the quality of the reagents that are used. this paper reports on an investigation of the bromcresol green dye-binding procedure for the estimation of serum albumin in which particular attention has been paid to changes in the reagent components that contribute to the performance of the method. it has been shown that detailed attention to the quality control of th ... | 1977 | 16554 |
| effect of imidazoles and ph on aging of phosphylated acetylcholinesterase. | | 1977 | 16611 |
| binding of organic ions by proteins--1. interaction of 1-benzyl-3-indazoleoxyacetate with serum albumin. | | 1977 | 16612 |
| determination of the rate-limiting steps and chemical mechanism of fructokinase by isotope exchange, isotope partitioning, and ph studies. | isotope exchange studies show that beef liver fructokinase has a random kinetic mechanism in which release of fructose from the enzyme is slower than that catalytic reaction. the stickiness of fructose in the presence of mgatp is confirmed by isotope partition studies, which show it to be released 0.53 times as fast as v1/et in the presence, and 80--130 times as fast in the absence of mgatp. fructose-1-p release from it binary complex is not at all rate limiting in the forward direction since no ... | 1977 | 16640 |
| calcium binding site of trypsin as probed by lanthanides. | | 1977 | 16646 |
| interaction of the kunitz soybean trypsin inhibitor with bovine trypsin. evidence for an an acy-enzyme intermediate during complexation. | | 1977 | 16647 |
| the interaction of histone h3 with histone h4 and with other histones studied by 19f nuclear magnetic resonance. | the behaviour, upon variations in ionic strength, ph and temperature of 19f nuclear nuclear magnetic resonance signals of the trifluoroacetonylated derivative of histone h3 is compared with those of the h3-h4 complex and of the hv fraction (an equimolar mixture of h2a, h2b, h3 and h4). the line width of the 19f-labelled histone h3 signals increases with ionic strength or ph, an effect consistent with aggregation of the protein. in the case of h3-h4 complex or hv the line width decreases at inter ... | 1977 | 16662 |
| the effect of ions on the enzymatic properties of beef-liver glutamate dehydrogenase. | | 1977 | 16673 |
| an isolation procedure for the native alpha chain of bovine hemoglobin. a study of the functional properties of this chain and its hybrid with the human beta chain. | in this paper we present a procedure for the isolation of the native bovine alpha chain. the method is based on affinity chromatography. the results show that the ligand-binding properties of the bovine alpha chain are almost identical to those of the human alpha chain. the hybrid alphab2 betah2 prepared by mixing bovine alpha chains and human beta chains shows ligand binding properties similar to those of human hemoglobin and different from those of bovine hemoglobin. | 1977 | 16750 |
| fasciola hepatica and fasciola gigantica: total cholinesterase, characteristics, and effects of specific inhibitors. | | 1977 | 16762 |
| histamine formation by ruminal fluid from cattle in vitro. | | 1977 | 16763 |
| activation by cyclic amp of soluble tyrosine hydroxylase in bovine adrenal medulla. | | 1977 | 16777 |
| a new enzyme, nadph-dihydropteridine reductase in bovine liver. | an enzyme designated as nadph-dihydropteridine reductase was found in the extract of bovine liver and partially purified. in contrast to nadh-dpendent dihydropteridine reductase ec 1.6.99.7, the enzyme catalyzes the reduction of quinonid-dihydropterin to tetrahydropterin in the presence of nadph. the two enzymes were separated by column chromatography on deae-sephadex. tyrosine formation in the phenylalanine hydroxylation system was also stimulated by nadph-dihydropteridine reductase. the existe ... | 1977 | 16875 |
| bovine adrenal tyrosine hydroxylase: purification and properties. | bovine adrenal tyrosine hydroxylase has been obtained in a form that is 85 to 90% pure. sodium dodecyl sulfate-gel electrophoresis and density gradient centrifugation studies have established that the subunit molecular weight of the chymotrypsin-solubilized enzyme is 34,000. the presence of iron in the purified enzyme (0.50 to 0.75 mol of iron/mol of enzyme) has been established. crude particulate tyrosine hydroxylase can be activated by the phospholipid, phosphatidyl-l-serine, or by exposure to ... | 1977 | 16885 |
| n-acetylglutamate synthase of escherichia coli: purification, characterization, and molecular properties. | | 1977 | 16890 |
| comparison of 18o exchange catalyzed by isoenzymes of carbonic anhydrase. | | 1977 | 16893 |
| effect of covalent attachment of polyethylene glycol on immunogenicity and circulating life of bovine liver catalase. | methoxypolyethylene glycols of 1900 daltons (peg-1900) or 5000 daltons (peg-5000) were covalently attached to bovine liver catalase using 2,4,6-trichloro-s-triazine as the coupling agent. rabbits were immunized by the intravenous and intramuscular routes with catalase modified by covalent attachment of peg-1900 to 43% of the amino groups (peg-1900-catalase). the intravenous antiserum did not yield detectable antibodies against peg-1900-catalase or native catalase, as determined by ouchterlony an ... | 1977 | 16907 |
| liver microsomal epoxide hydrase. | 1. the substrate specificity of membrane-bound and purified epoxide hydrase from rat liver microsomes has been studied. both enzyme preparations catalyzed the hydration of a variety of alkene oxidase as well as arene oxides of several polycyclic aromatic hydrocarbons. 2. unlike the membrane-bound enzyme, the rate of hydration for most of the substrates catalyzed by the purified epoxide hydrase was constant for only 1 or 2 min. the addition of dilauroyl phosphatidylcholine or heated microsomes to ... | 1977 | 16912 |
| compartmentalization of adenosine 3':5'-monophosphate and adenosine 3':5'-monophosphate-dependent protein kinase in heart tissue. | in rabbit heart homogenates about 50% of the camp-dependent protein kinase activity was associated with the low speed particulate fraction. in homogenates of rat or beef heart this fraction represented approximately 30% of the activity. the percentage of the enzyme in the particulate fraction was not appreciably affected either by preparing more dilute homogenates or by aging homogenates for up to 2 h before centrifugation. the particulate enzyme was not solubilized at physiological ionic streng ... | 1977 | 16921 |
| studies on the cyclic gmp-dependent protein kinase from bovine aorta. possible existence of a catalytic subunit. | | 1977 | 16929 |
| persistence of bovine milk xanthine oxidase activity after gastric digestion in vivo and in vitro. | | 1977 | 16941 |
| protein binding to monosodium urate monohydrate, calcium pyrophosphate dihydrate, and silicon dioxide crystals. i. physical characteristics. | the protein adsorptive properties of monosodium urate monohydrate (msu), silica (si), and calcium pyrophosphate dihydrate crystals were studied by qualitative and quantitative techniques. immunoglobulin g (igg) was adsorbed preferentially by msu crystals from normal human serum and demonstrated high-affinity binding isotherms when compared with several isolated proteins in solution. the physical characteristics of this reaction suggest principally an ionic mechanism, since adsorption was enhance ... | 1977 | 16976 |
| effect of beta-adrenergic drugs on adenosine 3', 5'-monophosphate in rabbit vagus nerve. | | 1977 | 16990 |
| aminoacylation of trna trp from beef liver, yeast and e. coli by beef pancrease tryptophan-trna ligase. stoichiometry of trnatrp binding. | the michaelis constants and the maximum velocities in the aminoacylation reaction of trnatrp from beef liver, yeast and e. coli by pure beef pancreas tryptophan-trna ligase show that this mammalian enzyme recognizes and charges the two eucaryotic trnas with the same efficiency. the rate of aminoacylation of the procaryotic trnatrp by the enzyme is three orders of magnitude lower. the ph optimum of aminoacylation is 8 for both eucaryotic trnas. the optimum magnesium concentration is different. th ... | 1977 | 17096 |
| studied on cyclic nucleotides in the adrenal gland: vi adenyl and guanyl cyclase in the adrenal medulla. | | 1976 | 17124 |
| acid base equilibrium in experimental acidosis of cows with and without rumen fistula. | acid base equilibrium in experimental acidosis of cows with and without rumen fistula. acta physiol. pol., 1977, 28, (1): 77-84. symptoms of acidosis caused by administration of saccharose into the rumen were more significant and lasted longer in the cows without rumen fistula than in those with it. at the peak of acidosis of ph of arterial blood was 7.29 and it was by 0.07 below that in the group of cows with fistula. the alkali reserve was lower by 6 meq and the bicarbonate level by 5.2. chara ... | 1977 | 17264 |
| photolysis of desmosine and isodesmosine by ultraviolet light. | it is known that the pyridinium ring of a model compound such as n-methyl pyridinium chloride is cleaved by u.v. radiation at 254 nm. at acid ph the products obtained are methylamine and glutaconaldehyde. under the same conditions desmosine and isodesmosine are degraded into lysine and probably into the homologous substituted ketone of glutaconaldehyde. at ph 6.0-7.0, a transient open-chain aminoaldehyde intermediate is observed which can either reform the original compound or be cleaved as at l ... | 1977 | 17269 |
| factors affecting the proteolytic degradation of elastin. | | 1977 | 17270 |
| studies on lysyl oxidase of bovine ligamentum nuchae and bovine aorta. | lysyl oxidase had been purified to near homogeneity from bovine aorta and bovine ligamentum nuchae employing a modification of methods described by harris et al., and stassen and his colleagues. the aortic enzyme gives rise to at least three peaks and the ligament enzyme resolves into at least four peaks upon chromatography on deae cellulose. the molecular weight of each peak of both enzymes is approximately 30,000 daltons in sodium dodecyl sulfate. the aortic enzyme aggregates to species with m ... | 1977 | 17272 |
| host feeding patterns of connecticut mosquitoes (diptera: culicidae). | blood-engorged coquillettidia perturbans, psorophora ferox, culex, culiseta, and aedes mosquitoes were collected principally by sweep net from salt marsh and woodland habitats in connecticut. of the 570 mosquitoes tested, precipitin tests identified the origins of 517 blood meals and revealed distinct host feeding patterns. aedes mosquitoes fed chiefly on mammals; a. abserratus, a. cantator, and a. vexans showed selectivity for cattle and (or) horses. a. cantator also obtained blood from avian h ... | 1977 | 17310 |
| superoxide dismutase: "positive" spectrophotometric assays. | | 1977 | 17332 |
| fetal and neonatal pulmonary circulation. | | 1977 | 17336 |
| thymic hormones: biochemistry, and biological and clinical activities. | | 1977 | 17354 |
| putative peptide neurotransmitters. | | 1977 | 17359 |
| purification of carboxypeptidase b from human pancreas. | carboxypeptidase b of the human pancreas was purified by chromatography on deae-cellulose and cm-cellulose columns. two forms of the enzyme, named carboxypeptidase b1 and b2, were separated. they have similar mol.wts. (34250 +/- 590) as established by polyacrylamide-gel disc electrophoresis and by gel filtration. carboxypeptidase b2 migrates further towards the anode in disc electrophoresis. when the amino acid content of the enzymes was analysed, carboxypeptidase b2 had four more glycine and th ... | 1977 | 17398 |
| occurrence in mammalian liver of a protein which replaces the b protein of e. coli quinolinate synthetase. | | 1977 | 17402 |
| changes in the acid-soluble nucleotide composition of red cells of cattle at various ages. | | 1976 | 17407 |
| multiple forms of dna-dependent rna and polyadenylic acid polymerases from heterotrophically grown rhodospirillum rubrum. | three, two major and one minor, distinct rna polymerases have been isolated and partially purified from heterotrophically grown rhodospirillum rubrum, a facultative photosynethetic bacterium. associated with each of these three enzymes is a distinct polyadenylic acid polyemrase. all of these enzyme activities are dependent on dna templates and are resistant to rifampicin and streptovaricin. the structural subunit composition, the response to various chemical compounds and dna templates, and the ... | 1977 | 17456 |
| aurinetricarboxylic acid: a potent inhibitor of glucose-6-phosphate dehydrogenase. | inhibition by aurinetricarboxylic acid (ata) of glucose-6-phosphate (g6p) dehydrogenase was "competitive" with respect to g6p and "mixed type" with respect to nadp+. inhibited enzyme bound two molecules of ata. kinetic constants, km, ki at varying ph suggested possible binding of the inhibitor by the sulfhydryl of the enzyme; of the several enzymes tested only milk xanthine oxidase and g6p dehydrogenase from bovine adrenal was inhibited by ata. | 1977 | 17474 |
| atp-dependent proton translocation in resealed chromaffin granule ghosts. | | 1977 | 17550 |
| glutamic-oxalacetic transaminase activity in seminal plasma of some domestic animals in dependence of ph value and concentration of l-aspartate (author's transl). | | 1976 | 17556 |
| co-metabolism of the ixodicide amitraz. | | 1977 | 17591 |
| studies on sulfhydryl group modification of mitochondrial pyridine dinucleotide transhydrogenase. | | 1977 | 17599 |
| bovine thioredoxin system. purification of thioredoxin reductase from calf liver and thymus and studies of its function in disulfide reduction. | | 1977 | 17603 |
| adenosine 3':5'-monophosphate-regulated phosphoprotein system of neuronal membranes. ii. solubilization, purification, and some properties of an endogenous adenosine 3':5'-monophosphate-dependent protein kinase. | | 1977 | 17614 |
| mullerian inhibiting substance in human testes after birth. | tiny testicular biopsies from humans were assayed for mullerian inhibiting substances using a graded organ culture technique. mullerian inhibiting substance activity was high during the first year of life, declined during the second year of life, and then disappeared. mullerian inhibiting substance activity is lower in boys with undescended testis than in children with normal or intersex testes at comparable ages under two years. it is possible that mullerian inhibiting substance affects testicu ... | 1977 | 17665 |
| alkaline ribonuclease inhibitor in human thyroid. | thyroids of goitrogen-treated rats contain increased amounts of a protein inhibitor of ribonuclease activity at ph greater than 7 (alkaline ribonuclease inhibitor, ari). we report here that thyroids from hyperthyroid patients contain more ari than normal human thyroids. this increase parallels rna concentration. the inhibitor is heat labile, inactivated by sulfhydryl blocking agents, and has a molecular weight near 50, 000 daltons. ari is quantitated by its activity against bovine pancreatic rna ... | 1977 | 17808 |
| pineal vasotocin: release into cat cerebrospinal fluid by melanocyte-stimulating hormone release-inhibiting factor. | the intracarotid injection of both synthetic melanocyte-stimulating hormone release-inhibiting factor (mif) and purified mif prepared from bovine hypothalami induces arginine vasotocin release into cerebrospinal fluid of cats and significantly decreases the pineal arginine vasotocin content at 5 minutes after the injection. the present results demonstrate an extrapituitary endocrine effect of synthetic and purified bovine mif. | 1977 | 17916 |
| effects of phthalate esters on glucose 6-phosphate dehydrogenase and other enzymes in vitro. | | 1977 | 17933 |
| on the enzymatic breakdown of tripolyphosphate and diphosphate in comminuted meat. vii. influence of sodium chloride on the tripolyphosphatase and diphosphatase activity in bovine muscle (author's transl). | sodium chloride activates the tripolyphosphatase of the muscle tissue. optimum activity occurs at 4--5 percent nac1. the increase in activity seems to be due to the effect of c1-ions. nac1 inhibits the tripolyphosphatase activity of muscle press juice. nac1 decreases the total diphosphatase activity of muscle tissue as well as the diphosphatase activity of muscle press juice. addition of nac1 to pre-rigor muscle increases the ultimate ph value (post-rigor-muscle) and, consequently, causes a lowe ... | 1977 | 17964 |
| on the enzymatic breakdown of tripolyphosphate and diphosphate in comminuted meat. viii. influence of divalent cations on the tripolyphosphatase activity of muscle tissue (author's transl). | the tripolyphosphatase of comminuted muscle tissue is activated by mgc1(2) and ethylenediamine tetraacetate and inhibited by cac1(2) and diphosphate. these results are discussed with reference to the formation of an inactive enzyme-substrate complex. | 1977 | 17965 |
| proof of guanylate cyclase activity in the coronary artery of cattle. | guanylate cyclase activities were identified in a soluble fraction and a particular fraction obtained from the arteria coronaria of cattle. the km-value was 1.0 +/- 0.7 - 10(-4) m for the enzyme substrate complex of the guanylate cyclase of the soluble fraction and 9.2 +/- 1.5 - 10(-4) m for the particular fraction. for the enzyme activity of the soluble fraction mn++ cannot be replaced by ca++ or mg++, whereas for the enzyme activity of the particulate fraction mn++ can be replaced by mg++ but ... | 1976 | 17986 |
| demonstration of protein kinase activities in the coronary artery of cattle. | protein kinase activities were identified in a soluble and a particulate fraction from the a. coronaria of cattle. for both protein kinase activities mg++ is essential. protamine was used as a substrate of the protein kinase activity of the soluble fraction. the ph optimum of the protein kinase activity of the soluble fraction is around 6.5. the km-value of the protein kinase for atp is 1.9 +/- 0.4 - 10(-5) m. camp stimulates the protein kinase activity more effectively than cgmp. ca++ cannot re ... | 1976 | 17987 |
| lens changes occuring as a result of lowered ph (acidosis) (author's transl). | in the lens, disorders of the metabolism occur, and, with them, active permeability (the cation pump with uptake of k and release of na) changes to passive permeability and consequently na ions enter with water. as a result, the lens increases in weight and a subcapsular (permeability) cataract develops. it is shown that the cattle lens in vitro increases in weight the lower the ph (6.5 greater than 7.5 greater than 8.5) of the surrounding fluid becomes. in a further experiment, 1 ml of buffered ... | 1977 | 18065 |
| new techniques to measure blood cholinesterase activity in domesticated animals. | a macromethod and a semimicromethod were developed to measure erythrocyte acetylcholinesterase activity in cattle, sheep, goats, horses, dogs, and swine, and to measure plasma cholinesterase activity in horses, dogs, and swine. comparison of the 2 methods with erythrocytes of sheep, cattle, goats, and horses indicated both methods gave similar results. they can be done in a shorter time and are more sensitive than michel's method. normal deltaph values per minutes, with standard deviations for b ... | 1977 | 18075 |
| significance of fecal coliform-positive klebsiella. | a total of 191 klebsiella pneumoniae isolates of human clinical, bovine mastitis, and a wide variety of environmental sources were tested for fecal coliform (fc) response with the membrane filtration and most probable number techniques. twenty-seven escherichia coli cultures of human clinical and environmental origins were also tested. eighty-five percent (49/58) of known pathogenic k. pneumoniae were fc positive, compared with 16% (19/120) of the environmental strains. e. coli results indicated ... | 1977 | 18086 |
| resonance raman spectra of heme a derivatives. evidence for the reaction of peripheral formyl group with hcn and nahso3. | | 1977 | 18105 |
| reaction of brain hexokinase with tetranitromethane: oxidation of essential thiol groups. | | 1977 | 18114 |
| purification and properties of urease from bovine rumen. | urease (urea amidohydrolase, ec 3.5.1.5) was extracted from the mixed rumen bacterial fraction of bovine rumen contents and purified 60-fold by (nh4)2so4 precipitation, calcium phosphate-gel adsorption and chromatography on hydroxyapatite. the purified enzyme had maximum activity at ph 8.0. the molecular weight was estimated to be 120000-130000. the km for urea was 8.3 x 10(-4) m+/-1.7 x 10(-4) m. the maximum velocity was 3.2+/-0.25 mmol of urea hydrolysed/h per mg of protein. the enzyme was sta ... | 1977 | 18137 |
| specific labelling of a constituent polypeptide of bovine heart mitochondrial reduced nicotinamide-adenine dinucleotide-ubiquinone reductase by the inhibitor diphenyleneiodonium. | 1. nadh-ubiquinone-1 and nadh-menadione reductase activities of complex i were inhibited by diphenyleneiodonium (apparent ki 23 and 30 nmol/mg of protein respectively). reduction of k3fe(cn)6 and juglone was relatively unaffected. 2. iodoniumdiphenyl and derivatives were much less effective inhibitors. compounds with similar ring structures to diphenyleneiodonium, in particular dibenzofuran, were inhibitors of nadh-ubiquinone-1 oxidoreductase. 3. diphenylene125iiodonium specifically labelled a p ... | 1977 | 18140 |
| studies on the in vitro inhibition of prostaglandin synthetase by fenclorac (alpha, m-dichloro-p-cyclohexylphenylacetic acid) and indomethacin. | | 1977 | 18151 |
| modification of brain mitochondrial monoamine oxidase activities by hydroxyethylhydrazide of cyanoacetic acid and some other monoamine oxidase inhibitors. | | 1977 | 18152 |
| a simple procedure for isolating adenosine triphosphatase from mitochondria. | a simple method for isolation of adenosine triphosphatase (ec 3.6.1.3) from mitochondria is described. the enzyme is released from mitochondrial lubrol particles by drastic sonication and purified by gel filtration on sepharose 6-b. the described procedure is effective in isolating adenosine triphosphatase from rat liver as it is from beef heart mitochondria. the enzyme isolated from beef heart has a specific activity of 120 mumol p/min per mg protein and enzyme isolated from rat liver has a spe ... | 1977 | 18170 |
| regulatory effects of purine nucleotide analogs with liver glutamate dehydrogenase. | a total of 26 different purine nucleotides with specific modifications in the base moiety and/or in the polyphosphate chain as well as various combinations of nucleotides were tested as allosteric effectors of beef liver glutamate dehydrogenase (l-glutamate : nad(p)+ oxidoreductase (deaminating), ec 1.4.1.3). the capacity of these nucleotide analogs to activate or to inhibit the glutamate dehydrogenase activity is expressed quantitatively and scaled between the extreme effects of adp and gtp, re ... | 1977 | 18180 |
| studies on the glycosidases of semen. purification and properties of beta-n-acetylglucosaminidase from bull sperm. | | 1977 | 18192 |
| intrinsic catalytic activity of procarboxypeptidase a. a kinetic study using fluorine analogues. | bovine procarboxypeptidase a displays substantial catalytic activity toward halogenated acyl-amino acids, the most active of which is trifluoroacetyl-l-phenylalanine (tfac-l-phe). though this activity is not as great as for the native enzyme, it is quite substantial and far beyond the range of adventitious activation. both dl-benzylcuccinate and beta-phenylpropionate inhibit zymogen hydrolysis of tfac-l-phe, the former with a k1 of 4.1 micrometer and the latter, 900 micrometer (a value much high ... | 1977 | 18193 |
| interactions between alpha-amino acids and cobalt(ii) bovine-carbonic anhydrase. | the results of a study on the interaction between cobalt(ii) bovine carbonic anhydrase and the alpha-amino acids l(+) and d(-)alanine, glycine and betaine are reported. l(+)alanine and glycine have been found to have larger affinity for the enzyme than d(-)alanine whereas no sizable affinity is shown by betaine. the electronic spectra indicate that these systems are similar to that containing the acetate ion. utilizing the inhibition properties of l(+)alanine at various ph an analysis of the spe ... | 1977 | 18213 |
| heavy metal-nucleotide interactions. ix. raman difference spectroscopic studies on the binding of ch3hg(ii) to 1-methylthymine, thymidine-5'-monophosphate, dna models and native dna. | raman spectra have been obtained for dtmp and its complex with ch3hg (ii) in aqueous solution as a function of ph. difference spectroscopy is employed to increase the sensitivity of the raman technique. the binding reaction is essentially quantitative from ph 3 to 9, and the value of the equilibrium constant for ch3hgoh2+ + dthd in equilibrium ch3hg(dthdh--1) + h30+ is estimated from intensity measurements to be 0.6 in reasonable agreement with an earlier value based upon uv spectrophotometric d ... | 1977 | 18215 |
| tyrosine fluorescence of two tryptophan-free proteins: histones h1 and h5. | the fluorescence intensity of the single tyrosine residue in histone h1 increases from rtyr = 0.3 to rtyr = 1.3 as the protein undergoes a conformational change from the random coil state to a folded form. enhanced fluorescence in the folded state has not been observed before in ap protein. histone h5 shows no change in fluorescence intensity on folding. this is interpreted as a result of compensation between enhanced and reduced fluorescence in the three tyrosine residues. | 1977 | 18223 |
| studies related to antitumor antibiotics. part ix. reactions of carzinophillin with dna assayed by ethidium fluorescence. | the reactions of the antitumor antibiotic carzinophillin (cz) with native dnas and synthetic polynucleotides have been examined by an ethidium fluorescence assay. cz rapidly produces covalent linkage of the complementary strands of a variety of dnas without activation. this process is accompanied by extensive alkylation, as detected by reduced fluorescence due to destruction of potential intercalation sites for ethidium. these processes which occur without loss of purine or pyrimidine bases show ... | 1977 | 18267 |
| remineralization of artificial enamel lesions in vitro. | | 1977 | 18285 |
| studies on a soluble thyroid iodotyrosine deiodinase: activation by nadph and electron carriers. | | 1977 | 18336 |
| feed-related urea poisoning in ruminants. | | 1977 | 18387 |
| chymotrypsin-like neutral protease from lysosomes of human polymorphonuclear leukocytes. | | 1977 | 18394 |
| successful separation of x and y and spermatozoa in human and bull semen. | using particle free semen extender and applying a low temperature thermal convection laminar flow to bring the sperm cells in vertical orientation and allowing them to act through the center of buoyancy, a bimodal distribution was achieved. laser scanner for observing sedimentation pattern and f-body technique for identification of male sperm were used. specimens from five human donors and ten bulls were separated, checked for purity, and frozen in liquid nitrogen. the lighter fractions containe ... | 1977 | 18409 |
| interpretation of thermal perturbation spectra of proteins. | the thermal perturbation difference spectrum of reduced lysozyme has a long wave length extremum at 304 nm at ph 6.15 and a very small extremum at 306 nm at ph 1.5. these results differ from those of leach & smith (1972), which showed an extremum at 293 nm, the same as for model tryptophyl compounds. our result may arise from a conformational difference between the two sample temperatures. the interpretation of thermal perturbation spectra of proteins is discussed. contributions from thermally i ... | 1977 | 18420 |
| stabilisation of enzyme structures by inhibitors. a nuclear magnetic resonance study of the effect of phosphate on the acid unfolding of ribonuclease a. | the acid denaturation of bovine pancreatic ribonuclease a in the presence of 0.2m sodium dihydrogen phosphate has been studied by n.m.r. spectroscopy. phenylalanine, tyrosine and methionine resonances serve as monitors of the unfolding process. it is shown that the inhibitor shifts the equilibrium towards the native structure at acid ph. exchange broadening of the c-2 resonances of the active site histidines, 12 and 119, occurs in the presence of phosphate, suggesting an equilibrium between nati ... | 1977 | 18421 |
| studies of binding c3-substitute rifamycins to human and bovine serum albumin. | the interactions of a series of c3-substituted rifamycins with human and bovine serum albumins were studied in order to find possible correlations between the degree of binding and the structural features of the various molecules. the results obtained indicate some of the physicochemical properties and, therefore, of the structural requirements which appear to determine or influence the bonding mechanisms of this series of rifamycins. two types of interaction were found to exist, ionic and hydro ... | 1977 | 18428 |
| morphology of lipid micelles containing lysolecithin. | mixtures of lysolecithin with various phospholipids were studied by electron microscopy using negative staining. mixtures of dipalmitoyllecithin and lysolecithin produced disc-shaped structures which were stacked in aggregates with a 6.0--6.4 nm repeat. the disc were 10--50 nm in diameter. the disc-shaped structures were best observed in equimolar mixtures of dipalmitoyllecithin and lysolecithin. when dipalmitoyllecithin was replaced by dimyristoyllecithin, the structures were rather different f ... | 1977 | 18447 |
| the second bromoacetazolamide reactive site of bovine carbonic anhydrase b. | | 1977 | 18459 |
| stimulation of growth and calcium influx in cultured, bovine, aortic endothelial cells by platelets and vasoactive substances. | | 1977 | 18482 |