| inhibition of sterol synthesis by citrinin in a cell-free system from rat liver and yeast. | citrinin, a fungal metabolite known as an antibiotic, strongly inhibited the labeled acetate incorporation into nonsaponifiable lipids by a cell-free system from rat liver but not the labeled mevalonate incorporation. of the enzymes involved in cholesterol synthesis, two enzymes, acetoacetyl-coa thiolase (ec 2.3.1.9) and 3-hydroxy-3-methylglutaryl-coa reductase (ec 1.1.1.34), were specifically inhibited by the antibiotic. the concentration required for 50% inhibition was 0.2 mm for the former en ... | 1977 | 13847 |
| isocitrate dehydrogenase of tetrahymena pyriformis. | we have studied the isocitrate dehydrogenase of tetrahymena pyriformis. this enzyme is able to utilize both nad and nadp, but kinetic studies suggest that the enzymatic activity with nad is not of physiological signifance. some of the factors that might regualte the nadp-dependent isocitrate dehydrogenase were also studied. this enzyme has an absolute requirement for divalent cations; mg,+ and mn2+ will serve as cofactors but the latter is more effective than the former. it is known that this en ... | 1977 | 22034 |
| molecular aspects of cytochrome c oxidase: structure and dynamics. | in the last few years much attention has been dedicated to the elucidation of some of the molecular aspects of cytochrome c oxidase. it has been shown conclusively that the enzyme from several sources (yeast, neurospora, heart, liver) contains seven different subunits, which are asymmetrically inserted in the membrane. all of these are in contact with the lipid bilayer (except subunits v and vi) and to a greater or lesser extent with the water phase as well (except for subunit i). subunit ii of ... | 1979 | 43469 |
| [immunochemical comparison of tryptophanyl-trna-synthetases]. | a fraction of immunoglobulins was isolated from the sera of rabbit immunised by a homogeneous beef pancreas tryptophanyl-trna-synthetase (trsase). the igg fraction was shown to inhibit the enzymatic activity during aminoacylation of yeast trnatrp and tryptophan activation. by using the radioimmunoadsorption technique, the interaction of igg was tested with trsaes from beef pancreas and identical enzymes from other sources (contained in the total preparation). beef liver trsase efficiently inhibi ... | 1978 | 78439 |
| enzymic polyadenylation of 5s ribosomal ribonucleic acid and synthesis of a complementary deoxyribonucleic acid. | the 5s ribosomal rna has been isolated, pure and intact, from rat liver (5 mg of 5s rna from 150g of liver). the 5s rna serves as a primer for calf thymus poly(a) polymerase with 20% of the efficiency of (ap)3a. bacterial 5s rna and transfer rna also serve as primers; rat liver 18s and 28s ribosomal rnas support poly(a) synthesis poorly. neither the 5s rna primer nor the appended poly(a) tract is nicked or degraded by poly(a) polymerase, and initiation of poly(a) tracts on 5s rna primers continu ... | 1979 | 88957 |
| studies on transfer rna from mycobacteria. | active preparations of trna and aminoacyl-trna synthetases have been isolated from exponentially growing cells of mycobacterium smegmatis and mycobacterium tuberculosis h37rv. though the aminoacyl-trna synthetases of older cells retain their activity, the trnas seem to undergo modification and show poorer activity. the mycobacterial enzyme preparations catalyse homologous and heterologous aminoacylation between trna from the two species (m. smegmatis and m. tuberculosis h37rv) or from escherichi ... | 1978 | 96929 |
| rat plasma clearance of horseradish peroxidase and yeast invertase is mediated by specific recognition. | | 1978 | 202501 |
| effect of a brewer's yeast extract on growth and glucose metabolism of cells in culture. | | 1979 | 217884 |
| membrane-bound phospholipid desaturases. | this review covers studies on membrane-bound phospholipid desaturases in yeast and rat liver carried out in this laboratory. in yeast the desaturase system was shown to effect the direct desaturation of dioleoyl-lecithin to dilinoleoyl-lecithin. in rat liver the desaturase was capable of converting 2-eicosatrienoyl-lecithin to 2-arachidonoyl-lecithin. both systems required reduced pyridine nucleotides, o2 and cytochrome b5. eicosatrienoyl-lecithin desaturase along with eicosatrienoyl-coa desatur ... | 1979 | 218072 |
| induction of mitotic crossing over in saccharomyces by p-toluidine. | p-toluidine, a carcinogen for rats, does not cause genetic damage when tested directly in saccharomyces cerevisiae; however, certain chemical derivatives of p-toluidine do induce gene conversion when tested directly. it may be suspected by analogy with other aromatic amines that p-toluidine, a monocyclic aromatic amine, requires conversion to breakdown products which are then the genetically active and carcinogenic entities. the udenfriend hydroxylation medium, which has been used previously to ... | 1977 | 325360 |
| substrate selectivity of squalene synthetase. | six 1-3h-labeled analogues of farnesyl pyrophosphate have been studied as potential substrates for yeast and rat liver squalene synthetases: 2-methylfarnesyl pyrophosphate (4), 3-demethylfarnesyl pyrophosphate (5), 7,11-dimethyl-3-ethyl-2,6,10-dodecatrienyl pyrophosphate (6), 6,7,10,11-tetrahydrofarnesyl pyrophosphate (7), 4-methylthiofarnesyl pyrophosphate (8), and 4-fluorofarnesyl pyrophosphate (9). analogues 4 and 5 are enzymatically incorporated into 11-methylsqualene (10) and 10-demethylsqu ... | 1977 | 329862 |
| differences between alcohol dehydrogenases. structural properties and evolutionary aspects. | comparisons of the primary structures of yeast and horse liver alcohol dehydrogenases reveal that the enzymes are homologous but distantly related. the overall positional identity is 25% between common regions, and several deletions/insertions occur in either enzyme, the longest apparently corresponding to 21 residues, showing that the different subunit sizes are largely explained by internal differences. variabilities in the structural similarities can be coupled with functional requirements bu ... | 1977 | 320001 |
| factors causing release of ribosomal subunits from isolated nuclei of regenerating rat liver in vitro. | incubation medium ii causes release of ribosomal subunits from isolated prelabeled nuclei of regenerating rat liver in vitro (sato, t., ishikawa, k. and ogato, k. (1976) biochim. biophys. acta 000, 000-000). the effects of individual components of this medium on release of subunits were studied and the following results were obtained. 1. dialyzed cytosol was effective in causing release of total labeled rna, but its effect on release of labeled ribosomal subunits was rather lower than that of lo ... | 1977 | 319833 |
| studies on the mechanism of action of halofenate. | this paper reviews most of the clinical studies on the mode of action of halofenate, an established hypolipidemichypouricemic agent in man. in yeast cutlures and in isolated rat adipocytes, halofenate was found to inhibit the conversion of pyruvate to acetyl coa. while pyruvate dehydrogenase was inhibited in vitro, halofenate also inhibited the activety of various other isolated enzymes. in rats maintained on halofenate in the diet (0.02-0.10%) for 2-14 days, there were 20-40% decreases in plasm ... | 1977 | 319318 |
| toxicity studies with decamethrin, a synthetic pyrethroid insecticide. | decamethrin is a synthetic pyrethroid insecticide that has been under investigation by the world health organization for use in some vector control programs. decamethrin proved to be a highly toxic pyrethroid ester. the acute ld50 for adult female rats was 31 mg/kg by the oral route and 4 mg/kg by the intravenous route of administration. the ld50 was observed to be sex and age dependent, with higher values recorded for weanlings and males. initial signs of decamethrin poisoning include profuse s ... | 1979 | 370325 |
| effects of selenium on azo dye hepatocarcinogenesis. | groups of male sprague--dawley rats were maintained on three regimens: i. basal diet plus 0.05% 3'-methyl-4-dimethylaminoazobenzene (3'-medab), ii. same as i plus 6 ppm selenium (na2seo3) in the drinking water, and iii. same as i plus 6 ppm selenium added to the diet in the form of a high selenium yeast. the 3'-medab was incorporated in the diet for 8 weeks and then removed. the selenium supplements in groups ii and iii were continued for an additional 4 weeks. at sacrifice the liver tumor incid ... | 1977 | 198114 |
| structural analyses of mammalian ribosomal ribonucleic acid and its precursors. nucleotide sequence of ribosomal 5.8 s ribonucleic acid. | the nucleotide sequence of ribosomal 5.8 s rna (also known as 7 s or 5.5 s rrna) from novikoff hepatoma ascites cells has been determined to be (see article). estimations of the secondary structure based upon maximized base pairing and the fragments of partial ribonuclease digestion indicate that there may be five base-paired regions in the molecule, three forming a folding of the termini and two forming secondary hairpin loops. the sequence of novikoff hepatoma 5.8 s rrna is about 75% homologou ... | 1975 | 171258 |
| marcaine, a selective inhibitor of eucaryotic aminoacylation. | the effects of marcaine, a myotoxic drug, on the aminoacylation of transfer ribonucleic acid (rrna) have been studied. the drug is a potent inhibitor of the acylation of rat liver trna with leucine and isoleucine but is only mildly inhibitory (or not inhibitory) to acylation with a number of other amino acids which were tested. further, marcaine inhibited aminoacylation in cell-free systems using components from several mammalian tissues, including muscle, from yeast, and from wheat germ. no eff ... | 1979 | 387072 |
| biogenesis of mitochondrial atpase. | | 1977 | 142510 |
| ribonucleic acid stimulation of mammalian liver nuclear-envelope nucleoside triphosphatase. a possible enzymic marker for the nuclear envelope. | 1. the specific activity of rat and pig liver nuclear-envelope nucleoside triphosphatase (ec 3.6.1.3) decreases when the system is depleted of rna. the activity can be restored by adding high concentrations of yeast rna to the assay medium. 2. exogenous rna also increases the activity of the enzyme in control envelopes (not rna-depleted). the effect appears to be largely specific for poly(a) and poly(g); it is not stimulated by rrna or trna preparations, ribonuclease-hydrolysed rna, amp, or doub ... | 1977 | 141276 |
| relationship between the structure of carbonylcyanide phenylhydrazones and inhibition of growth of microorganisms, stimulation of respiration of yeast cells and rat liver mitochondria. | the effect of ten derivatives of carbonylcyanide phenylhydrazone on growth of bacteria, yeast and different species of filamentous fungi was investigated. in yeast and mitochondria isolated from rat liver the effect of these derivatives on the respiratory activity was also followed. the relative efficiency of the individual derivatives of carbonylcyanide phenylhydrazone was determined on the basis of the results obtained. it was shown that derivatives, in which the substituent on the benzene rin ... | 1977 | 411721 |
| acrolein. | | 1978 | 415230 |
| nadph-cytochrome p-450 reductase of yeast microsomes. | | 1978 | 415662 |
| [mechanism of action of some quinoline alkaloids on respiratory chain of mitochondria]. | the mechanism of action of some quinoline alkaloids and their derivatives on respiratory chain of rat liver and candida lipolytica yeast mitochondria was studied. the alkaloids were shown to inhibit electron transfer in the respiratory chain. the site of their action is localized between b and c cytochromes. besides their ability to inhibit electron transfer in the respiratory chain, alkaloids are shown to be specific inhibitors of "exogenous" nadh-dehydrogenase of c. lipolytica yeast mitochondr ... | 1976 | 139172 |
| analgesic and anti-inflammatory activity of 6-chloro-alpha-methyl-carbazole-2-acetic acid (c-5720). | the carbazole, c-5720, has the same order of analgesic, antipyretic and anti-inflammatory activity as indomethacin and is more potent than phenylbutazone and acetylsalicylic acid in the yeast inflamed paw, the carrageenin foot edema, the mycobacterium butyricum-induced pyrexia, and the acute and chronic adjuvant arthritis tests. in chronic adjuvant arthritis in rats, c-5720 lowers the elevated serum mucopolysaccharide and plasma fibrinogen levels, and partially restores the depressed liver n-dem ... | 1976 | 133645 |
| plasma lipid and lipoprotein responses of rats to starch and sucrose diets with and without brewer's yeast. | the effect of starch and sucrose diets, with and without brewer's yeast, on plasma total cholesterol and triglyceride concentration and on the lipoprotein distribution in plasma was studied in male rats. the rats were fed a cereal based stock diet, a starch or a sucrose diet, plus or minus brewer's yeast, for 4 weeks. the plasma cholesterol concentration increased to similar levels in rats fed the starch or the sucrose diets but remained unchanged in rats fed the stock diet. the plasma triglycer ... | 1979 | 448446 |
| mutagenicity assays on fluorescent whitening agents using microorganisms. | six fluorescent whitening agents (fwas) have been re-examined for their activity as inducers of cytoplasmic petite mutants and mitotic gene conversion in diploid yeast saccharomyces cerebisiae and reversion from auxotrophy to prototrophy in neurospora crassa, escherichia coli and salmonella typhimurium. the results provide no indication that the fwas examinded produce mutagenic changes or any other alterations in the gene material. in a recent re-examination with salmonella using the method of a ... | 1975 | 132347 |
| biochemistry and immunochemistry of membrane-bound enzymes. | membrane-bound enzymes have certain specific differences compared with soluble enzymes. membrane-binding often enables greater catalytic activity of associated enzymatic reactions, their regulation by low molecular weight substances (substrates and allosteric effectors, hormones) and compartmentation, etc. on the other hand, the binding of enzymes to membranes causes considerable difficulties as regards their isolation and the determination of their homogeneity and substrate specificity. membran ... | 1977 | 97930 |
| binding of trna to reverse transcriptase of rna tumor viruses. | the interaction of trna with the reverse transcriptase (rna-dependent dna polymerase) of mammalian rna viruses, such as moloney murine leukemia virus and simian sarcoma virus, has been studied. whereas the purified reverse transcriptase of mammalian viruses sedimented in glycerol gradients as a globular protein with a molecular weight of 70,000, after interaction with trna the enzyme cosedimented with a protein of 150,000 molecular weight. the twofold increase in molecular weight could be a resu ... | 1978 | 77907 |
| total rna content and blood flow in rat brain after rna administration. | the changes in blood flow through selected brain structures and the changes in the total rna content of cells of these structures were examined after a single administration of yeast rna to 6-month-old male rats. the total content of ribosomal rna in cells of the limbic system (septum, hippocampus, hypothalamus) increased 48 hrs after the administration of 100 mg i.p. yeast rna , dropped after 7 days (in hypothalamus), 21 and 30 days (in hippocampus), 30 days (in septum). in cells of the limbic ... | 1979 | 517073 |
| in vitro binding of 2-acetaminofluorene to rna and protein with rat liver microsomes. | covalent binding of 2-acetaminofluorene[9-14c] with exogenous torula yeast rna and endogenous protein was investigated in liver microsome system in vitro. the binding to protein was 100 times higher than that to rna. requirement of nadph, effectiveness of methylcholanthrene treatment, and inhibition by 7,8-benzoflavone suggest possible involvement of mixed-function oxidases in this binding. the binding was not due to contaminated cytosol in the microsome fraction. addition of cytosol, sulfate io ... | 1978 | 30668 |
| effects of phthalate esters on glucose 6-phosphate dehydrogenase and other enzymes in vitro. | | 1977 | 17933 |
| n4-acetylcytidine. a previously unidentified labile component of the small subunit of eukaryotic ribosomes. | the nucleoside content of 18 s rrna from rat liver is determined under conditions known to prevent the destruction of chemically labile modified nucleosides. two base-modified nucleosides, not completely identified before, are shown to be n6-methyladenosine and 7-methylguanosine. the results further demonstrate the presence of a hitherto unidentified component of 18 s rrna whose spectra and chromatographic properties are identical with that of n4-acetylcytidine. in addition, this compound is not ... | 1978 | 624721 |
| the enzymic conversion of protoporphyrinogen ix to protoporphyrin ix in mammalian mitochondria. | protoporphyrinogen oxidase, an enzyme which catalyzes the oxidation of protoporphyrinogen ix to protoporphyrin ix in yeast cells, has been found in several mammalian tissues. it has been extracted from rat liver mitochondria by sonication in the presence of salt and detergent and partially purified. the enzyme is similar in many respects to yeast protoporphyrinogen oxidase. based on its behavior on sephadex g-200 the molecular weight of the enzyme is approximately 35,000. catalysis by protoporph ... | 1976 | 6461 |
| hepatic nucleases. extrahepatic origin and association of neutral liver ribonuclease with lysosomes. | in the large granule fraction of rat liver, the density distribution of inhibitor-sensitive neutral ribonuclease is similar to that for acid hydrolases and its density distribution is similarly modified by triton wr-1339 accumulation in lysosomes. particulate neutral ribonuclease is latent; the enzyme is unmasked by very low digitonin concentrations or hypoosmotic shock. these observations demonstrate that the bulk of liver neutral ribonuclease is associated with the lysosomal system. in view of ... | 1975 | 1273 |
| multimer forms of eukaryotic 5.8s ribosomal rna. | | 1978 | 365235 |
| a new inhibitor protein from rat uterus against yeast proteinase b. | an inhibitor of yeast proteinase b has been enriched from uterine smooth muscle (myometrium) of the rat. this inhibitor behaves like a glycoprotein and has a molecular weight of 90 000. it activity can be clearly distinguished from the proteinase inhibitory activity of serum. proteinase b inhibitory activity has also been demonstrated in liver, lung, heart, skeletal muscle, spleen and brain and these activities, too, are clearly distinguishable from the serum inhibitory activity. the activity in ... | 1978 | 361536 |
| [biological evaluation of food products with protein and amino acid additives]. | | 1978 | 658692 |
| transcription of dna-histone complexes by yeast rna polymerase b. | transcription of denatured dna complexed with histones (total, h1 or h2a/h2b/h3/h4) by yeast rna polymerase b is investigated. binding of histones to dna restricts its template activity by decreasing the formation of active, heparin-resistant, rna polymerase initiation complexes. the elongation of pre-initiated rna on denatured dna, complexed with histones, is possible, although resulting in somewhat shorter rna chains. it is suggested that rna polymerase b can elongate on a dna strand covered w ... | 1978 | 353733 |
| an approach to the design of acaricidal enzyme inhibitors. | | 1975 | 773646 |
| mutagenicity of methylated n-nitrosopiperidines in saccharomyces cerevisiae. | n-nitrosopiperidine (np) and a number of methylated derivatives were examined for mutagenicity in saccharomyces cerevisiae. np, 2-methyl-np, 3-methyl-np, 4-methyl-np and 3,5-dimethyl-np were mutagens when metabolic activation (rat-liver microsomes) was provided. 2,6-dimethyl-np was not a mutagen. the nps giving a positive response stimulated forward mutation to canavanine resistance (can1 leads to can1) and reversion of the his1-7 missense marker. neither locus revertants nor suppressors of the ... | 1978 | 351388 |
| trna isopentenyltransferase from zea mays l. characterization of the isopentenylation reaction of trna, oligo (a) and other nucleic acids. | the extraction and purification of the trna isopentenyltransferase from maize root tips and kernels are reported. the relative amounts of this enzyme in different organs of maize have been determined. root tips have the highest enzyme activities, followed by kernels and young leaves. old leaves exhibit very low activity. the molecular mass of the monomeric enzyme was determined to be 57000 - 63000 dalton. ph and mg2 optima are in full agreement with the data reported for the enzymes from yeast a ... | 1978 | 342386 |
| lipid intermediates in the synthesis of the inner core of yeast mannan. | the synthesis by yeast microsomes of compounds that are probably dolichol-pyrophosphate derivatives containing n,n'-diacetylchitobiose and several mannose residues is described. however, the presence of monosaccharide residues other than n-acetylglucosamine and mannose has not been ruled out. the amount of the lipid derivatives synthesized was enhanced by the addition to the incubation mixture of an organic-solvent-soluble extract from rat liver known to contain dolicholpyrophosphate oligosaccha ... | 1978 | 342243 |
| inhibition of the rat clearance system for agalacto-orosomucoid by yeast mannans and by mannose. | | 1977 | 329842 |
| energy-related pollutants in the environment: use of short-term tests for mutagenicity in the isolation and identification of biohazards. | in an effort to gather information on the potential genetic hazards of existing or proposed energy-generating or -conversion systems, we have begun a correlated analytical and genetic analysis of a number of technologies. the work is divided into two phases: one deals with known compounds expected to occur in the environment through energy production, conversion, or use; the other deals with actual samples from existing or experimental processes. to approach the problems of coping with and testi ... | 1978 | 367762 |
| simple agar--urea-gel electrophoretic fractionation of high molecular weight ribonucleic acids. | | 1976 | 793442 |
| protein glycosylation through dolichol derivatives in baker's yeast. | | 1976 | 793861 |
| genetic activities of hycanthone and some other antischistosomal drugs. | | 1978 | 368622 |
| inhibition of 6-phosphogluconate dehydrogenase (decarboxylating) by glucose 1,6-bisphosphate. | glucose 1,6-bisphosphate, the powerful common regulator of several key enzymes in carbohydrate metabolism, was found to exert a potent inhibitory effect on the activity of 6-phosphogluconate dehydrogenase (decarboxylating) from yeast and several rat tissues. these findings suggest that glucose 1,6-bisphosphate may have a regulatory influence on the pentose phosphate pathway. | 1979 | 375989 |
| pharmacological study of a new non-steroidal anti-inflammatory drug: protacine (cr 604). | the pharmacological activities of 3'-(4-[2-(1-p-chlorobenzoyl-5-methoxy-2-methyl-indol-3-yl-acetoxy)-ethyl]-piperazin-1-yl)propyl-4-benzamido-n,n-dipropylglutaramate(+/-)dimaleate (protacine, cr 604), a new indolyl derivative with strong anti-inflammatory, analgesic and antipyretic activities, are described. the dose-dependent activity of protacine on inflammation has been shown both in short-term experiments, like the hind paw edema induced by carrageenin and several other irritants, and long-t ... | 1979 | 315235 |
| binding of [3h]benzo(a)pyrene to natural and synthetic nucleic acids in a subcellular microsomal system. | several carcinogens are bound covalently to cellular nucleic acids. this is also the case with polycyclic hydrocarbon carcinogens, but their precise mechanism of in vivo activation to reactive forms and the structure(s) of the nucleic acid adducts are not known. this study demonstrates that in the presence of rat liver microsomes and reduced nicotinamide adenine dinucleotide phosphate there is covalent attachment of tritiated benzo(a)pyrene (bp) to transfer rna, dna, certain synthetic polyribonu ... | 1975 | 238738 |
| the application of mitotic gene conversion in saccharomyces cerevisiae in a pattern of four assays, in vitro and in vivo, for mutagenicity testing. | the induction of mitotic gene conversion of the nitrofuran derivatives nitrofurantoin (n-(5-nitro-2-furfuryliden)-1-aminohydantoin), nifurprazinum (1-(5-nitro-2-furyl)-2-(6-amino-3-pyridazyl)-ethylenehydrochloride) and fanft (2-formylamino-4-(5-nitro-2-furyl)thiazole) was investigated in the d4-rdii strain of saccharomyces cerevisiae (heteroallelic at the gene loci ade2 and trp5, respiration-deficient). a battery of tests was applied: direct action of the substance to yeasts, the liver microsome ... | 1979 | 381914 |
| nutritive value of geotricum candidum yeast prepared from decaying fruits in egypt. | | 1976 | 987656 |
| structural studies on rna from bombyx mori l. i. nucleoside composition of enriched trna species from the posterior silkgland purified by coutercurrent distribution. | a large scale fractionation of trna from the posterior silkgland of the silkworm bombyx mori l. by countercurrent distribution is described. one single 1,500 transfer distribution carried out with phosphate buffer-fromamide-isopropanol (pfi) solvent system yields highly enriched isoaccepting species with increasing mobility order: trna1gly, trna1-2ala, trnatyr, trna2gly, trna1ser and trna2ser with 75%, 70%, 90%, 60%, 60%, and 90% purities respectively. nucleosides fingerprint analysis of each is ... | 1976 | 999951 |
| [restriction endonucleases as an instrument for analyzing the structure of mitochondrial genomes]. | | 1979 | 388901 |
| inhibitory effect of ethanol on growth and solute accumulation by saccharomyces cerevisiae as affected by plasma-membrane lipid composition. | incorporation of ethanol (1.0 or 1.25 m) into exponential-phase cultures of saccharomyces cerevisiae ncyc 366 growing anaerobically in a medium supplemented with ergosterol and an unsaturated fatty acid caused a retardation in growth rat, which was greater when the medium contained oleic rather than linoleic acid. ethanol incorporation led to an immediate drop in growth rate, and ethanol-containing cultures grew at the slower rate for at least 10 h. incorporation of ethanol (0.5 m) into buffered ... | 1979 | 391174 |
| structure of the fluorescent nucleoside of yeast phenylalanine transfer ribonucleic acid. | | 1975 | 1092270 |
| donor substrate specificity and thiol reduction of glutathione disulfide peroxidase. | by isolation of a mixed disulfide product of glutathione and cysteine, glutathione peroxidase was shown to be highly specific for only one donor substrate. using the coupled assay of nadph and yeast glutatione reductase, which is highly specific for flutathione disulfide, it was shown that the apparent inhibition of glutathione peroxidase by mercaptoethanol can be described kinetically and that it is competitive with glutathione. also, when limiting amounts of hydroperoxide were present in the r ... | 1979 | 429326 |
| active site-specific reagents and transition-state analogs for enolase. | | 1975 | 1092960 |
| glutathione peroxidase acitvity in intestinal and liver tissues of rats fed various levels of selenium, sulfur and alpha-tocopherol. | the effects of various levels of selenium, alpha-tocopherol and sulfur on glutathione peroxidase (gsh-px) activity in intestinal and liver tissues were determined in male rats fed corn-soybean or torula yeast diets. rats fed corn-soybean diets had greater gsh-px activity in the small intestine, colon and liver tissues, catalase activity and selenium in the liver, and body weight gains than those fed torula yeast diets. gsh-px activity in the small intestine, colon, and liver tissues as well as c ... | 1979 | 430245 |
| structural defects in rat liver deoxyribonucleic acid. endogenous single-strained regions in comparison with damage induced in vivo by a carcinogen. | rat liver dna may be separated into two fractions by stepwise elution from benzoylated-deae-cellulose with nacl and caffeine solutions respectively. other studies using bacterical and yeast dna suggested that the first fraction contains native dna, whereas the second may exhibit some degree of single-stranded character. in the present experiments, chromatography of dna was monitored by labelling in vivo with [methyl-3h]thymidine in rats previously subjected to partial hepatectomy. in animals kil ... | 1979 | 486085 |
| [methods of identifying carcinogenic factors in medication, food and cosmetics]. | the removal of carconogenic factors would be a most efficient measure to prevent cancer. as far as known chemicals are concerned, every effort is made to avert them, or at least to reduce the exposure to such compounds, but is necessary to detect unknown chemicals, especially those, drugs and foodstuffs for example, to which large populations are exposed. giving suspected chemicals to laboratory animals is a standard carcinogenicity test. studies of the carcinogenicity of unknown chemicals in an ... | 1979 | 495385 |
| identification of some products from the reaction of trans-4-aminostilbene metabolites and nucleic acids in vivo. | esters of n-hydroxy-n-acetylaminostilbene react with guanosine, adenosine and cytidine in vitro and yield a number of different reaction products, some of which have been recently identified. we have now demonstrated that urd-n3,alpha-beta,oh-aabb, guo-n1,alpha-beta,oh-aabb, adon1,alpha-n6,beta-aabb and a guo-o6 derivative are also formed in vivo, when the precarcinogen trans-4-dimethylaminostilbene is orally administered to female wistar rats. however, these reaction products constitute only a ... | 1979 | 498359 |
| assay for free and total choline activity in biological fluids and tissues of rats and man with torulopsis pintolopessi. | the sensitive, specific growth response to choline activity of the thermophilic enteric yeast torulopsis pintolopessi enables estimation of free and bound choline activity in rat and human fluids and tissues- as little as 10 ng/ml of choline is measurable. unlike other microbial assays, estimation of unbound (free) choline activity is not influenced by methionine or phospholipids. the method also distinguishes differences in choline activity of fluids and tissues from choline-deficient and choli ... | 1978 | 564602 |
| [effect of yeast rna on the phagocytic capacity of the leukocytes under conditions of experimental focal myocardial necrosis]. | | 1977 | 610269 |
| free and membrane-bound polysomes from rat liver. 2. recovery of large free and membrane-bound polysomes. | techniques allowing the recovery of large free and membrane-bound polysomes in high yield are reported. subcellular fractions were prepared from rat liver homogenates as described in the preceding paper. purified microsomal membranes (obtained from the post-lysosomal supernatant) were adjusted to 50 mm mg(ch3coo)2 and treated with 2% triton x-100 and 0.3% sodium deoxycholate in the presence of yeast rna and cell sap, and polysomes were purified by overnight centrifugation through low-ionic-stren ... | 1978 | 627209 |
| inhibition of adenylosuccinase by adenylophosphonopropionate and related compounds. | adenylosuccinase from muscle, liver and yeast is strongly inhibited by the substrate analogue adenylophosphonopropionate (n6-(dl-1-carboxy-2-phosphonoethyl)-adenosine 5'-monophosphate). the inhibition is freely reversible and of the competitive type, with apparent k1 values between 5.4 and 86 nm depending on the source of enzyme. ratios of km/k1 with adenylosuccinate as substrate fall in the range of 44 to 1350. comparison of four carboxyl analogues of adenylosuccinate with the corresponding pho ... | 1978 | 646988 |
| isolation and properties of the trypsin-derived adp-ribosyl peptide from diphtheria toxin-modified yeast elongation factor 2. | we have developed a method for the purification in micromole amounts of the trypsin-derived adp-ribosyl peptide from diphtheria toxin-modified yeast elongation factor 2 (ef-2). ef-2 was partially purified (15 to 20% purity) by ammonium sulfate precipitation and deae-sephadex chromatography. after [3h]adp-ribosylation by [3h]nad+ and diphtheria toxin, ef-2 was digested with trypsin and a homogeneous [3h]adp-ribosyl peptide was isolated by chromatography on deae-sephadex and dihydroxyboryl-substit ... | 1978 | 721806 |
| evaluation of mannich bases and related compounds as inhibitors of mitochondrial function in yeast and inhibition of blood platelet aggregation, blood clotting, and in vitro metabolism of 5-dimethylamino-1-phenyl-1-penten-3-one hydrochloride. | dimethylamino-1-phenyl-1-penten-3-one hydrochloride (ia) and 32 analogs were tested for inhibition of respiratory-dependent growth in saccharomyces cerevisiae. thirteen of the 33 compounds tested appeared to affect mitochondrial function, since the inhibition of respiratory-dependent growth was statistically greater than the inhibition of growth on fermentable energy sources. inhibition of mitochondrial function in yeast and growth inhibition of an in vitro culture of human epidermoid carcinoma ... | 1976 | 775052 |
| [effects of candida albicans on wound-healing in an animal model (author's transl)]. | the effects of candida albicans on the healing of experimental wounds in rats was investigated. granulation tissue developing in implated polyvinylchloride chambers was quantified. the amount of granulation tissue in the yeast-contaminated wounds is significantly less in comparison to controls. the inhibitory effect is directly proprotional to the amount of inoculated yeasts and dependes on the presence of living yeast cells. the repair of ulcers is supposedly retarded by yeast contamination, as ... | 1976 | 786185 |
| safety evaluation of yeast grown on hydrocarbons. iv. two-year feeding and multigeneration study in rats with yeast grown on pure n-paraffins. | | 1975 | 1205436 |
| [ribonuclease activity following partial hepatectomy in the liver of healthy and alloxan diabetic rats and histological findings in the islets of langerhans (author's transl)]. | question: what changes in the level of ribonuclease activity (rnase activity) can be observed in the regenerating liver of healthy and alloxan diabetic rats following partial hepatectomy? what coincidental alterations of the ratio a-cells to b-cells do occur in the islets of langerhans? materials and methods: 120 male wistar rats of averagely 180 g body weight were fed a standard diet ("rehbrücke") with drinking water ad libitum. after deprivation of food for 15 hours the animals were sacrificed ... | 1975 | 786709 |
| gastrointestinal candidiasis in rats treated with antibiotics, cortisone, and azathioprine. | conventional albino rats treated with peroral chloramphenicol, gentamicin, and/or parenteral cortisone were challenged with candida albicans antibiotics and cortisone were equally effective in predisposing the animals to colonization by the fungus. all animals treated with both antibiotics and cortisone developed defined, focal, superficial invasion of the cornified squamous epithelium of the stomach next to its junction with the glandular mucosa, as well as focal superficial invasion of the eso ... | 1976 | 786882 |
| protocols for the dominant lethal test, host-mediated assay, and in vivo cytogenetic test used in the food and drug administration's review of substances in the gras (generally recognized as safe) list. | protocols are described for the dominant lethal and in vivo cytogenetics test in rats and the host-mediated assay, using salmonella typhimurium and saccharomyces cerevisiae in mice, as used by the food and drug administration in its mutagenicity review of substances from the generally recognized as safe (gras) list. in addition proctolols are described for in vitro mutagenicity tests with s. typhimurium and s. cerevisiae and for statistical treatment for evaluation of data from dominant lethal t ... | 1976 | 787548 |
| putrescine-insensitive s-adenosyl-l-methionine decarboxylase from tetrahymena pyriformis. | extracts of tetrahymena pyriformis contain a soluble s-adenosyl-l-methionine decarboxylase which, in contrast to the enzyme from most eukaryotic organisms, is not stimulated by putrescine or spermidine. the protozoan adenosylmethionine decarboxylase, unlike the putrescine-insensitive enzyme form escherichia coli, did not require any metal ions for catalytic activity either. adenosylmethionine decarboxylase from tetrahymena resembled the prokaryotic enzyme as far the inhibition by methylglyoxal b ... | 1975 | 813467 |
| osmotic and peroxidative fragilities of erythrocytes from vitamin e-deficient lead-poisoned rats. | weanling male rats were fed either a vitamin e-deficient torula yeast diet fortified with selenium or the same diet supplemented with 100 ppm vitamin e. one group of rats fed each diet received plain distilled water, whereas another group received 250 ppm lead as lead acetate in the drinking water. after a 3 month feeding period, erythrocyte osmotic and peroxidative fragilities were determined in an osmotic test recorder. dietary vitamin e had little or no effect on the osmotic fragility of red ... | 1977 | 845674 |
| [problem of nitrogen metabolism in monogastric animals]. | a new method has been developed for determining the proportion of endogenic and exogenic faecal n by measuring the degree of specific labelling in the feeding-stuff (administered orally) and in the excreta (faeces and urine). the method has also been developed to find out whether the endogenic excretion of intestinal n is actually independent of the n intake. the present technique had been worked out on the basis of the model that had been originally established by czarnetzki et al. in 1969 with ... | 1976 | 962585 |
| catalytic activation of transfer ribonucleic acid by a mammalian protein. | a trna activator has been isolated from mammalian organs which increases the capability of trna to accept certain amino acids through the action of mammalian aminoacyl-trna synthetases. this activity may be separated from the aminoacyl-trna synthetases for isoleucine, lysine, serine, and methionine by fractionation of liver or pancreas cytosol with ammonium sulfate or by chromatography over sephadex g-200. the trna activating material is nondialyzable and is destroyed by trypsin or short heating ... | 1976 | 963009 |
| organella-targeted expression of rat liver cytochrome p450c27 in yeast. genetically engineered alteration of mitochondrial p450 into a microsomal form creates a novel functional electron transport chain. | a modified rat cytochrome p450c27, whose mitochondrial targeting signal had been replaced by a possible microsomal targeting signal of bovine cytochrome p450c17, was expressed in yeast. the modified p450c27 hemoprotein was correctly localized on yeast microsomes and exhibited the p450c27-dependent monooxygenase activity by addition of bovine adrenodoxin (adx) and nadph-adrenodoxin reductase (adr). considering the previous observation that p450c27 with its own mitochondrial targeting signal was i ... | 1992 | 1322905 |
| fatty acid composition of adipose tissue and liver fats of the rats fed yeast grown on n-alkanes. | n-alkane assimilating yeast, candida tropicalis yo-148, was grown on an n-alkane-containing medium. a synthetic diet containing 6.8% of dried yeast was fed to rats. the fatty acid composition of adipose tissue and liver fats was determined after a two week feeding period. the percentage of odd-numbered acids increased in the animals fed the yeast diet. furthermore, it was shown that heptadecenoic acid, the major odd-numbered acid in yeast, was accumulated in neutral lipid fraction of adipose tis ... | 1976 | 966078 |
| nutritional evaluation of the protein of dried tomato pomace in the rat. | 1. nutritional evaluation of dried tomato pomace (dtp-20) as a source of protein was carried out using weanling rats. comparisons were made with casein (cs), soya-bean meal (som-45) and the hydrocarbon-grown yeast toprina (bp-t). the growth-promoting effects of the diets were evaluated over a period of 28 d of ad lib. feeding. 2. the unsupplemented dpt-20 had a protein efficiency ratio (per) of 2-18 +/- 0-13 and a net protein utilization (npu) of 0-55. the addition of dl-methionine (5 g/kg) resu ... | 1976 | 1009071 |
| comparison of the catalytic and inhibitory properties of pachysolen tannophilus xylose reductase to rat lens aldose reductase. | the catalytic and inhibitory profiles of xylose reductase isolated from the yeast pachysolen tannophilus (ptxr) are compared to those of aldose reductase (ar) obtained from rat lens. while both ptxr and rat lens ar are nadph-specific enzymes and have an affinity for a variety of substrates such as d-xylose, d,l-glyceraldehyde, and 4-nitrobenzaldehyde, the enzymes differ in their substrate affinity profiles. also, ptxr is not inhibited by standard inhibitors of ar thus supporting a hypothesis tha ... | 1992 | 1368496 |
| taxonomical examination and characterization of a methanol-utilizing yeast. | the morphological, cultural, and physiological characteristics are described of a yeast, li70, which uses methanol as its source of energy and carbon; these characteristics have made it possible to identify the strain as candida boidinii ramirez. the identification was confirmed by a dna-dna genetic homology of 99.43% with the type strain of c. boidinii. strain li70 is not pathogenic. | 1976 | 1087866 |
| a rapid method for measuring the steady state levels of mitochondrial rna in whole mitochondria. | | 1992 | 1371187 |
| sequence homology of nuclear and mitochondrial dnas of different yeasts. | 1. both nuclear and mtdna of four different yeasts show approximately 10% homology as measured by dna-dna filter hybridization. these homologous sequences are mainly attributable to the ribosomal cistrons. 2. melting curve analysis shows that the heterologous mitochondrial dna-dna hybrids contain several times more mismatching than the nuclear dna-dna hybrids. 3. dna-rrna hybridization shows that the sequences of the ribosomal cistrons in both the nuclear and the mitochondrial genome have been c ... | 1975 | 1092349 |
| the isolation of large polysomes in high yield from unfractionated tissue homogenates. | it was found that if large quantities of both exogenous rna and mg-2+ were present during gentle tissue homogenization, the subsequent addition of deoxycholate to the whole homogenate produced a viscous mass from which polysomes could be isolated in large yields. these polysomes were substantially less degraded than those isolated by previous methods. in the case of rat liver, 15 ribosomes per mrna was the species present in highest concentration. the parameters of this method were investigated ... | 1975 | 1095068 |
| evaluation of genotoxicity of tert.-butylhydroquinone in an hepatocyte-mediated assay with v79 chinese hamster lung cells and in strain d7 of saccharomyces cerevisiae. | tert.-butylhydroquinone (tbhq) has been reported to be genotoxic in some short-term assays but non-genotoxic in others. we have examined cytotoxicity and genotoxicity of tbhq, a principal metabolite of the phenolic antioxidant 2(3)-tert.-butyl-4-hydroxyanisole (bha), in an hepatocyte-mediated assay with v79 chinese hamster lung cells including both sister-chromatid exchange (sce) and thioguanine-resistance (tgr) endpoints. the ability of bha and of tbhq to elicit a genotoxic response in saccharo ... | 1992 | 1377341 |
| synthesis of a mixed disulfide of egg white lysozyme and glutathione - a model substrate for enzymatic reduction of protein mixed disulfides. | | 1975 | 1095406 |
| mast cell sensitizing antibody (mcsab) response in experimental candidiasis: chromatographic studies. | a single dose of the yeast-like fungus candida albicans (ca), mixed with complete freund's adjuvant (cfa), and inoculated into guinea-pig foot-pads, provoked the productions of homologous mast cell sensitizing antibodies (mcsab) present in the psii-globulin fraction only, and of agglutinins localized in the same fraction. heterologous mcsab and skin-sensitizing antibodies detectable by passive cutaneous anaphylaxis (pca) were constantly absent. these facts are in contradiction to results of prev ... | 1975 | 1098354 |
| a glyoxalase i inhibitor of a new structural type produced by streptomyces. | many streptomyces strains produced an inhibitor of crude glyoxalase prepared from rat liver which did not inhibit glyoxalase i prepared from yeast. another inhibitor, c11h14o6, which inhibited glyoxalases prepared from both rat liver and yeast was obtained from a cultured broth of streptomyces griseosproeus and crystallized. preincubation of this inhibitor with reuduced glutathione increased its inhibitory activity, which suggested its reaction with reduced glutathione. it showed a strong inhibi ... | 1975 | 1102510 |
| site of aminoacylation of trnas from escherichia coli with respect to the 2'- or 3'-hydroxyl group of the terminal adenosine. | a method is presented by which the site of primary attachment of the amino acids with respect to the 2'- or 3'-hydroxyl group of the terminal adenosine of e. coli trnas can be determined. it is found that the aminoacyl-trna synthetases (ec 6.1.1.-) with specificity for arg, asn, ile, leu, met, phe, thr, trp, and val attach the amino acid to the 2'-position; those with specificity for gly, his, lys, and ser attach the amino acid to the 3'-position; and that tyr and cys can be enzymatically attach ... | 1975 | 1103137 |
| the determination of thiamin pyrophosphate in blood and other tissues, and its correlation with erythrocyte transketolase activity. | a sensitive method for the specific measurement of thiamin pyrophosphate (tpp) has been developed using the apoenzyme recombination concept. yeast pyruvic decarboxylase apoenzyme can be reconstituted by the addition of tpp or samples containing tpp, yielding the holoenzyme with activity proportionate to the amount of tpp added. using this technique, reaction mixtures containing 0.2 to 1.5 ng tpp can be assayed. normal human erythrocyte tpp ranges from 50 to 150 ng per ml packed cells. when rats ... | 1978 | 627916 |
| characterization and purification of a novel datp-binding protein in eukaryotes. | we characterized and purified an acidic datp-binding protein, which, in its active form, resides in the nuclear fraction of a range of cells from mammals (including pig liver) and baker's yeast (saccharomyces cerevisiae). this protein exhibits a high degree of specificity for the deoxy form of the naturally occurring nucleoside triphosphates and shows a marked preference for the purine deoxynucleoside triphosphates datp and dgtp. the protein cleaves the terminal phosphate of datp and appears to ... | 1992 | 1445246 |
| effects of hyperbaric helium-oxygen on the antipyretic actions of aspirin and acetaminophen in rats. | the effects of two antipyretics, aspirin and acetaminophen, were studied under hyperbaric helium-oxygen conditions. groups of yeast-fevered rats were given three different doses of each antipyretic in 1-ata air and 31-ata helium-oxygen. neither agent was as effective an antipyretic in hyperbaric helium as it was in 1-ata air. responses to acetaminophen were reduced an average of 73%, and those to the two lower doses of aspirin by 56%; the highest dose of aspirin (135 mg/kg) caused a significant ... | 1978 | 636074 |
| chemistry and pharmacology of naproxen. | the need for a nonsteroidal anti-inflammatory agent effective in rheumatoid arthritis, osteoarthritis, gout, ankylosing spondylitis and related diseases with reduced side effects when compared to existing drugs led us to develop naproxen: d-2-(6'-methoxy-2'-naphthyl)-propionic acid. this new agent is a highly effective anti-inflammatory, analgetic, and antipyretic agent in the rodent administered orally. in a rat paw edema test for anti-inflammatory activity naproxen was 55 times more active tha ... | 1975 | 1173774 |
| lead poisoning in vitamin e-deficient rats. | weanling male rats were fed either a vitamin e-deficient torula yeast diet or the same diet supplemented with 100 ppm vitamin e for a period of 3 months. one group of animals fed each diet received 250 ppm lead in the drinking water, whereas another group of animals fed each diet received no lead in the water. vitamin e deficiency per se had little or no effect on hematocrit value, reticulocyte count, spleen weight, or erythrocyte mechanical fragility in rats not poisoned with lead. on the other ... | 1975 | 1185284 |
| [comparative study of the influence of yeast mannans on the rate of catalase synthesis in the liver of rats]. | the effect of polysaccharides from rh. rubra and rh. mucilaginosa was studied as applied to the rate of catalase synthesis in rat liver. the constants were calculated for the rates of catalase synthesis and destruction. yeast's mannan from rh. mucilaginosa does not practically affect the rate of catalase synthesis. the mannan from rh. rubra produces an almost three-fold inhibition on the catalase synthesis and the degree of the enzyme synthesis recovery lowers by 20% as compared the control valu ... | 1975 | 1202694 |
| phenylalanyl-trna synthetases of rat liver: differential effects of thyroid hormone. | thyroxine and analogues inhibit rat liver aminoacyl-trna synthetase activity for phenylalanine and tyrosine. a high yield purification of the major cytoplasmic form of phenylalanyl-trna synthetase (c1) and its characterization is reported. polyribosome-bound and other sedimentable forms are found to be indistinguishable from soluble enzyme by immunoprecipitation. mitochondrial phenylalanyl-trna synthetase (m) and cytoplasmic activity (c2) resistant to anti-c1 antibody have been partially purifie ... | 1976 | 1247520 |
| rat liver cytoplasmic glucose-6-phosphate dehydrogenase. steady-state kinetic properties and circular dichroism. | steady-state kinetic studies including initial velocity, nadph product inhibition, dead-end inhibition, and combined dead-end and product inhibition measurements with purified rat liver glucose-6-phosphate dehydrogenase indicate a sequential and obligatory addition of substrates in the order of nadp+, glucose-6-p for the catalytic pathway at ph 8.0. although instability of 6-phosphoglucono-delta-lactone precluded product inhibition experiments which might directly exclude an enzyme-6-phosphogluc ... | 1976 | 1247537 |
| antibodies directed against a yeast carboxyl-terminal peroxisomal targeting signal specifically recognize peroxisomal proteins from various yeasts. | the carboxyl-terminal tripeptide ala-lys-ile is essential for targeting candida tropicalis trifunctional enzyme (hydratase-dehydrogenase-epimerase) to peroxisomes of both candida albicans and saccharomyces cerevisiae (aitchison,j.d., murray, w.w. and rachubinski, r. a. (1991).j. biol. chem. 266, 23197-23203). we investigated the possibility that this tripeptide may act as a general peroxisomal targeting signal (pts) for other proteins in the yeasts c. tropicalis, c. albicans, yarrowia lipolytica ... | 1992 | 1279909 |