Publications
| Title | Abstract | Year(sorted ascending) Filter | PMID Filter |
|---|
| genotoxicity studies on selected organosilicon compounds: in vitro assays. | a series of 12 organosilicon compounds representing potential intermediates in the synthesis and degradation of polydimethylsiloxanes were evaluated for genotoxic potential with a battery of in vitro assays. microbial assays included the ames bacterial reverse mutation in salmonella, mitotic gene conversion in saccharomyces cerevisiae d4 and dna repair in e. coli pol a +/-. these assays were conducted with and without a metabolic activation system containing aroclor 1254-induced rat-liver homoge ... | 1988 | 3284798 |
| identification and characterization of a yeast nucleolar protein that is similar to a rat liver nucleolar protein. | we have produced monoclonal antibodies against purified nuclei from the yeast saccharomyces cerevisiae and have characterized three different antibodies that recognize a protein with an apparent molecular weight of 38,000, termed p38. subcellular fractionation shows that virtually all of p38 occurs in the nuclear fraction. high concentrations of salt (1 m) or urea (6 m) effectively solubilize p38 from a nuclear envelope fraction prepared by digestion of nuclei with dnase. indirect immunofluoresc ... | 1988 | 3292539 |
| enhancement of dynorphin gene expression in spinal cord following experimental inflammation: stimulus specificity, behavioral parameters and opioid receptor binding. | the stimulus specificity for enhancement of dynorphin gene expression in rat spinal cord was studied by combined measurements of the peptide dynorphin a 1-8 and preprodynorphin mrna levels during peripheral inflammation induced by several agents. the density of kappa receptors, the putative receptor for dynorphin peptides, was examined using receptor binding with autoradiographic visualization. mu and delta receptor classes were also studied. all inflammatory agents tested (carrageenan, phorbol ... | 1988 | 2906426 |
| effect of methotrexate on long-chain fatty acid metabolism in liver of rats fed a standard or a defined, choline-deficient diet. | the effect of methotrexate on lipids in serum and liver and key enzymes involved in esterification and oxidation of long-chain fatty acids were investigated in rats fed a standard diet and a defined choline-deficient diet. hepatic metabolism of long-chain fatty acids were also studied in rats fed the defined diet with or without choline. when methotrexate was administered to the rats fed the standard diet there was a slight increase in hepatic lipids and a moderate reduction in the serum level. ... | 1988 | 2961371 |
| ethionine-induced alterations of enzymes involved in lipid metabolism and their possible relationship to induction of fatty liver. | changes of enzymes involved in the hepatic metabolism of long-chain fatty acids (palmitoyl-coa synthetase (ec 6.2.1.3), carnitine palmitoyltransferase (ec 6.2.1.3), glycerophosphate acyltransferase (ec 2.3.1.15)) in the liver of male rats were examined after ethionine exposure. ethionine administration resulted in a dose- and time-dependent enhancement of the palmitoyl-coa synthetase activity both in the mitochondrial, peroxisomal and microsomal fractions. the total carnitine palmitoyltransferas ... | 1988 | 2973812 |
| acyl-coa ligases from rat brain microsomes: an immunochemical study. | acyl-coa ligase activities, solubilized from rat brain microsomes, were fractionated into three different peaks by hydroxyapatite chromatography. based on physical and chemical properties, we suggested that peak a (pamitoyl-coa ligase) and peak c (lignoceroyl-coa ligase) were two different enzymes (a. bhushan, r. p. singh, and i. singh (1986) arch. biochem. biophys. 246, 374-380). we raised antibodies against purified liver microsomal palmitoyl-coa ligase (ec 6.2.1.3) and examined the effect of ... | 1988 | 2973813 |
| reconstitution of the active rat liver 60 s ribosomal subunit from different preparations of core particles and split proteins. | proteins extracted from the 60 s rat liver ribosomal subunit with 50% ethanol/0.5 m k cl produced only a partial reactivation of the corresponding core particles. in contrast, the same split proteins were able to reactivate the core particles prepared with dimethyl-maleic anhydride (dmma) to the same level as that observed using the dmma-split proteins, i.e. 60-80% of the control according to the catalytic activities tested. comparative analysis of the two split protein fractions showed only fou ... | 1988 | 3044828 |
| isolation of s9 fractions from mouse and rat with increased enzyme activities after repeated administration of cytochrome p-450 and p-448 inducers. | cytochrome p-450 (cyt p-450), nadph cytochrome p-450 reductase and various microsomal monooxygenase activities [e.g. aminopyrine n-demethylase, p-nitroanisole o-demethylase, dinemorphan n-demethylase, ethoxycoumarin o-deethylase and ethoxyresorufin o-deethylase (erd)], were determined in hepatic post-mitochondrial supernatant from mice and rats. experiments were performed on male and female animals treated with a combination of sodium phenobarbital and beta-naphthoflavone according to the standa ... | 1988 | 3045486 |
| cloning and nucleotide sequence of the gene for dihydrolipoamide acetyltransferase from saccharomyces cerevisiae. | a 537-base cdna encoding a portion of saccharomyces cerevisiae dihydrolipoamide acetyltransferase (acetyl-coa:dihydrolipoamide s-acetyltransferase, ec 2.3.1.12) was isolated from a lambda gt11 yeast cdna library by immunoscreening. this cdna was subcloned and used as a probe to screen a lambda gt11 yeast genomic dna library. two overlapping clones were used to determine the complete sequence of the acetyltransferase gene. the composite sequence has an open reading frame of 1446 nucleotides encod ... | 1988 | 3050999 |
| analysis and exploitation of cytochrome p-450 in yeast. | 1988 | 3066665 | |
| interleukin 2 stimulates heart contractility in the presence of exogenous arachidonate or the calcium ionophore a 23187. | an increase in the isometric developed tension (idt) of isolated rat atria was observed shortly after the addition of human interleukin 2 (il-2) to the organ preparation with subthreshold concentrations of either arachidonate (aa, 1.98 x 10(-6)m) or the calcium ionophore a 23187 (1.9 x 10(-6)m). both natural purified il-2 (nil-2) and yeast recombinant il-2 (ril-2) were active in this experimental system. it was determined that this lymphokine was active at 2 x 10(-11)m, considering as a referenc ... | 1988 | 3129371 |
| pharmacology of the dual inhibitor of cyclooxygenase and 5-lipoxygenase 3-hydroxy-5-trifluoromethyl-n-(2-(2-thienyl)-2-phenyl-ethenyl)-benzo (b)thiophene-2-carboxamide. | 3-hydroxy-5-trifluoromethyl-n-(2-(2-thienyl)-2-phenyl-ethenyl)- benzo (b) thiophene-2-carboxamide (l-652,343) is an inhibitor of cyclooxygenase and 5-lipoxygenase in vitro and inhibits the synthesis of the products of both these pathways in whole cells. l-652,343 is an inhibitor of the acute edema induced by carrageenan in vivo and is active topically in suppressing arachidonic acid induced inflammation in the skin. the compound is an effective inhibitor of the chronic inflammation of adjuvant a ... | 1988 | 3132928 |
| fra-1: a serum-inducible, cellular immediate-early gene that encodes a fos-related antigen. | a set of proteins antigenically related to the c-fos protein (fos) are induced by serum in fibroblasts. to isolate cdna clones of genes encoding such proteins, a lambda gt11 expression cdna library constructed from serum-stimulated rat fibroblasts was screened with antibodies raised against a hydrophilic region (amino acids 127 to 152) of fos. one of the positive clones identified, termed fra-1 (fos-related antigen) was characterized. it encoded a protein that shared several regions of extensive ... | 1988 | 3133553 |
| proteasomes (multi-protease complexes) as 20 s ring-shaped particles in a variety of eukaryotic cells. | latent multicatalytic protease complexes, named proteasomes, were purified to apparent homogeneity from various eukaryotic sources, such as human, rat, and chicken liver, xenopus laevis ovary, and yeast (saccharomyces cerevisiae), and their functional and structural properties were compared. they showed latency in breakdown of [methyl-3h]casein, but were greatly activated in various ways, such as by addition of polylysine. they all degraded three types of fluorogenic oligopeptides at the carboxy ... | 1988 | 3141402 |
| the amino acid sequence of rat liver glucokinase deduced from cloned cdna. | rat liver glucokinase (atp:d-hexose 6-phosphotransferase, ec 2.7.1.1) was purified to homogeneity, cleaved, and subjected to amino acid sequence analysis. forty-five percent of the protein sequence was obtained, and this information was used to design oligonucleotide probes to screen a rat liver cdna library. a 1601-base pair cdna (gk1) contained an open reading frame that encoded the amino acid sequences found in the peptides used to generate the oligonucleotide probes. a second cdna was subseq ... | 1989 | 2909525 |
| mouse primase p49 subunit molecular cloning indicates conserved and divergent regions. | primase is a specialized rna polymerase that synthesizes rna primers for initiation of dna synthesis. a full cdna clone of the p49 subunit of mouse primase, a heterodimeric enzyme, has been isolated using a primase p49-specific polyclonal antibody to screen a lambda gt11 mouse cdna expression library. the cdna indicated the subunit is a 417-amino acid polypeptide with a calculated molecular mass of 49,295 daltons. the p49 mrna is approximately 1500 nucleotides long with a 5'-untranslated region ... | 1989 | 2925677 |
| extremely rapid endocytosis mediated by the mannose receptor of sinusoidal endothelial rat liver cells. | isolated sinusoidal endothelial rat liver cells (ec) in suspension bound and internalized ovalbumin, a mannose-terminated glycoprotein, in a saturable manner. the binding and uptake were ca2+-dependent and were effectively inhibited by alpha-methyl mannoside and yeast mannan, but not by galactose or asialoglycoproteins. this corresponds to the binding specificity described for the mannose receptor of macrophages and non-parenchymal liver cells. binding studies indicated a surface pool of 20,000- ... | 1989 | 2930475 |
| proliferating cell nuclear antigen/cyclin in the ciliate euplotes eurystomus: localization in the replication band and in micronuclei. | human autoimmune sera specific for proliferating cell nuclear antigen (pcna)/cyclin (auxiliary protein for dna polymerase delta) demonstrated the presence of epitopes within the macro- and micronuclei of the hypotrichous ciliated protozoa euplotes eurystomus. tightly bound pcna/cyclin was localized at the site of dna synthesis in macronuclei, the rear zone of the replication band. starvation or heat shock, conditions that reduce macronuclear replication, resulted in a decrease of pcna/cyclin in ... | 1989 | 2477376 |
| effects of neonatal monosodium-l-glutamate treatment on rat alveolar macrophages. | treatment of neonatal rats with repeated doses of monosodium-l-glutamate resulted in changes of morphology and function of alveolar macrophages recovered from adult female rats. numerous cellular lipid vacuoles and lamellar structures were observed in these alveolar macrophages under transmission electron microscopy. there was approximately 50% increase of cellular total lipid content measured by oil-red-o staining and colorimetric method. the yeast phagocytosis and intracellular killing ability ... | 1989 | 2495191 |
| characterization and expression of the human rhoh12 gene product. | the rho genes constitute an evolutionarily conserved family having significant homology to the ras oncogene family. these genes have been found in saccharomyces cerevisiae, drosophila melanogaster, rat, and human; their 21,000-dalton products show strong conservation of structure. in humans, three classes of rho cdna clones have been identified which differ by virtue of the presence of variable c-terminal domains: rhoh12, rhoh6, and rhoh9. the predicted 193 amino acids of human rhoh12 protein sh ... | 1989 | 2501657 |
| altered hepatic fatty acid metabolism in endotoxicosis: effect of l-carnitine on survival. | the activities of palmitoyl-coenzyme a (coa) synthetase, carnitine acetyltransferase (cat), and carnitine palmitoyltransferase (cpt) and the levels of ketone bodies, reduced coenzyme a (coash), carnitine, and their esters, which are involved in fatty acid metabolism, in rat liver and plasma were measured after the administration of escherichia coli lipopolysaccharide (lps). we also studied the effect of l-carnitine treatment before lps administration on survival and on hepatic fatty acid metabol ... | 1989 | 2521428 |
| the cdc2 kinase is a nuclear protein that is essential for mitosis in mammalian cells. | a homolog of the fission yeast cdc2-encoded protein kinase (p34) is a component of m phase promoting factor in xenopus oocytes. the homologous kinase in human hela cells is maximally active during mitosis, suggesting a mitotic role in mammalian somatic cells. this has been directly investigated by microinjection of anti-p34 antibodies into serum-stimulated rat fibroblasts. dna synthesis was unaffected but cell division was quantitatively blocked in injected cells. injection of antibodies against ... | 1989 | 2541912 |
| [response to cholera toxin of 2 epithelial intestinal cell lines. effect of saccharomyces boulardii]. | cholera toxin acts in vivo by activating intestinal adenylate cyclase. this study was designed to determine (1) whether normal rat epithelial intestinal cell lines (ird 98 and iec 17) respond to cholera toxin (ct) by an increased concentration of cyclic amp and (2) whether the yeast saccharomyces boulardii, which reduced ct-induced secretion of water and electrolytes using the isolated jejunal loop technique, has an effect on these models. the camp concentration evaluated in cells exposed to sac ... | 1989 | 2544474 |
| lamin a, lamin b, and lamin b receptor analogues in yeast. | previous studies have shown that turkey erythrocyte lamin b is anchored to the nuclear envelope via a 58-kd integral membrane protein termed p58 or lamin b receptor (worman h. j., j. yuan, g. blobel, and s. d. georgatos. 1988. proc. natl. acad. sci. usa. 85:8531-8534). we now identify a p58 analogue in the yeast saccharomyces cerevisiae. turkey erythrocyte lamin b binds to yeast urea-extracted nuclear envelopes with high affinity, associating predominantly with a 58-kd polypeptide. this yeast po ... | 1989 | 2544600 |
| inhibition of the phosphate-stimulated cytochrome c oxidase activity by thiophosphate. | yeast and mammalian cytochrome c oxidase activity is inhibited by thiophosphate. this inhibition was observed when using either whole mitochondria or the isolated or reconstituted enzyme. the kinetics of the reduction reaction enabled us to demonstrate that thiophosphate acted on the electron transfer between hemes a and a3. with whole mitochondria, phosphate alone stimulated respiration. the inhibition induced by thiophosphate was suppressed by phosphate only in mitochondria, but not when the i ... | 1989 | 2545671 |
| effects of inadequate vitamin e and/or selenium nutrition on the release of arachidonic acid metabolites in rat alveolar macrophages. | effects of vitamin e and/or selenium (se) deficiency on the secretion of arachidonic acid metabolites by zymosan-stimulated pulmonary alveolar macrophages (am) were examined using cells from male long-evans hooded rats fed torula-yeast based diets with or without the supplementation of vitamin e (150 iu/kg) or se (0.5 mg/kg). alveolar macrophages obtained by lavage were purified by adherence and cultured for 4 h in hank's balanced salt solution containing bovine serum albumin (0.1%) and zymosan ... | 1989 | 2546191 |
| remarkable similarities between yeast and mammalian protein phosphatases. | protein phosphatase activities in extracts of the yeast saccharomyces cerevisiae showed remarkable similarities to the mammalian type 1, type 2a and type 2c enzymes. similarities included their substrate specificities, including selectivity for the alpha-and beta-subunits of muscle phosphorylase kinase, sensitivity to okadaic acid and to mammalian inhibitor 1 and inhibitor 2, and requirement for divalent cations. the results suggest that the function and regulation of these enzymes has been high ... | 1989 | 2546813 |
| complementary dna encoding core protein ii of human mitochondrial cytochrome bc1 complex. substantial diversity in deduced primary structure from its yeast counterpart. | core protein ii of mitochondrial cytochrome bc1 complex is the second largest nuclear-encoded subunit that is essential for the assembly of the functional complex. we have isolated, for the first time, a cdna clone for a mammalian core protein ii. immunoscreening of a lambda gt11 rat liver cdna library resulted in isolation of a cdna encoding a partial sequence of rat mitochondrial core protein ii, and this cloned cdna was used as a probe for colony hybridization to screen a human fibroblast cdn ... | 1989 | 2547763 |
| effect of dimethyl sulphoxide on mitochondrial biogenesis in regenerating rat liver and saccharomyces cerevisiae. | effect of dimethyl sulphoxide (dmso) on mitochondrial biogenesis in regenerating rat liver and cells of saccharomyces cerevisiae during aerobiosis has been studied by monitoring the cytochrome oxidase activity. a single dose of dmso (275 mg/100-125 g body wt) to normal rats stimulated cytochrome oxidase activity in liver mitochondria while the same dose to partial hepatectomized rats inhibited the enzyme activity. administration of low dose of dmso (92 mg/100-125 g body wt) to partial hepatectom ... | 1989 | 2550360 |
| cytochrome c methylation. | in this review, protein methylation is outlined in general terms, highlighting the major amino acids that are methylated and some of the proteins in which they are found. the majority of the review examines the methylation of cytochrome c at lys-77 of lower eukaryotes as a possible model for methylation studies. early work involving the purification and characterization of the methyltransferase responsible for this methylation indicated cytochrome c was methylated posttranslationally, yet prior ... | 1989 | 2553076 |
| [identification of human porins. ii. characterization and primary structure of a 31-lda porin from human b lymphocytes (porin 31hl)]. | we characterize and describe for the first time the primary structure of a human porin with the molecular mass of 31 kda derived from the plasmalemm of b-lymphocytes (porin 31hl). porin 31hl is shown to be a basic, channel forming membrane protein. the protein chain is composed of 282 amino acids with a relative molecular mass of 30641 da without derivatisation. it is not a glycoprotein. the n-terminus is acetylated. altogether the amino-acid sequence shows 56% hydrophilic or charged amino acids ... | 1989 | 2559745 |
| a membrane form of guanylate cyclase is an atrial natriuretic peptide receptor. | atrial natriuretic peptide (anp) is a polypeptide hormone whose effects include the induction of diuresis, natriuresis and vasorelaxation. one of the earliest events following binding of anp to receptors on target cells is an increase in cyclic gmp concentration, indicating that this nucleotide might act as a mediator of the physiological effects of the hormone. guanylate cyclase exists in at least two different molecular forms: a soluble haem-containing enzyme consisting of two subunits and a n ... | 1989 | 2563900 |
| cyclase enzymes. deciphering the mosaic. | 1989 | 2570356 | |
| evolutionary relationships among aminotransferases. tyrosine aminotransferase, histidinol-phosphate aminotransferase, and aspartate aminotransferase are homologous proteins. | a data base was compiled containing the amino acid sequences of 12 aspartate aminotransferases and 11 other aminotransferases. a comparison of these sequences by a standard alignment method confirmed the previously reported homology of all aspartate aminotransferases and escherichia coli tyrosine aminotransferase. however, no significant similarity between these proteins and any of the other aminotransferases was detected. a more rigorous analysis, focusing on short sequence segments rather than ... | 1989 | 2574669 |
| [characteristics of dna isolated from a complex form of dna-polymerase alpha from the rat liver]. | a complex from of dna polymerase alpha was isolated from the nuclear membrane of hepatocytes. dna fragments were shown to be among components of the complex under study. in this paper we present evidence that dna from the alpha-polymerase complex from quiescent hepatocytes (dna-g) differs in its nucleotide composition from its counterpart (dna-s) isolated from hepatocytes synthesizing dna. as judged by dot hybridization, dna-g0 does not contain nucleotide sequences which are complementary to rib ... | 1989 | 2586509 |
| developmental expression and 5s rrna-binding activity of xenopus laevis ribosomal protein l5. | ribosomal protein l5 binds specifically to 5s rrna to form a complex that is a precursor to 60s subunit assembly in vivo. analyses in yeast cells, mammalian cells, and xenopus embryos have shown that the accumulation of l5 is not coordinated with the expression of other ribosomal proteins. in this study, the primary structure and developmental expression of xenopus ribosomal protein l5 were examined to determine the basis for its distinct regulation. these analyses showed that l5 expression coul ... | 1989 | 2586520 |
| birch sap and birch leaves extract: screening for antimicrobial, phagocytosis-influencing, antiphlogistic and antipyretic activity. | birch sap and birch leaves extract have been screened for antimicrobial, phagocytosis-influencing, anti-inflammatory and antipyretic activity. no antimicrobial effects could be detected in the agar-diffusion test with staphylococcus as test strain, whereas birch sap exhibited some inhibitory effect on phagocytosis, which exceeded that of the citric acid added to the birch sap as preservative. in rats, only the high doses of 1 and 2 ml/100 g b.m. birch sap had a weak and short-lasting anti-inflam ... | 1989 | 2594828 |
| identification of a noncatalytic domain in amp deaminase that influences binding to myosin. | amp deaminase (amp-d) plays a critical role in energy metabolism in skeletal muscle. prior studies have demonstrated amp-d binds to myosin heavy chain in vitro, and it decorates the end of the a band in the myofibril. the present study presents evidence that proteolytic removal of 14 kilodaltons, presumably from the carboxy terminus, of the native 80k peptide does not eliminate catalytic activity but this deletion has a pronounced influence on binding of amp-d to myosin in the presence of atp. c ... | 1989 | 2605218 |
| [the antipyretic, hypothermal and sedative activities of mieyanling]. | mieyanling has an antipyretic effect on the fever of animals caused by yeast or tab vaccine. the hypothermal effect of mieyanling on the temperature of normal mice and rats was also observed. the ed50 of antipyretic and hypothermal action of this drug in mice was 20g/kg and 50g/kg respectively. there was a cns depressive effect when mieyanling was administered 60g/kg orally to mice. | 1989 | 2635603 |
| peptidyl-prolyl cis-trans isomerase is the cyclosporin a-binding protein cyclophilin. | peptidyl-prolyl cis-trans isomerase (ppiase) catalyses the cis-trans isomerization of proline imidic peptide bonds in oligopeptides and has been shown to accelerate the refolding of several proteins in vitro. its activity has been detected in yeast, insects and escherichia coli as well as in mammals, and it is though to be essential for protein folding during protein synthesis in the cell. we purified ppiase from pig kidney and found that its amino-acid sequence is identical to that reported for ... | 1989 | 2644542 |
| presence of translational inhibitory activity in partially purified extracts from two petrocoptis species. | the presence of translational inhibitory activity in partially purified extracts from several paleoendemisms from spain was investigated. the precipitates from 40-80% (nh4)2so4 fraction from petrocoptis glaucifolia and petrocoptis grandiflora displayed a strong inhibitory activity on the protein synthesis of cell-free extracts from rat liver, rabbit reticulocytes and yeast and to a much lower extent on the protein synthesis in isolated rat liver cells. the inhibitors seem to be proteins since th ... | 1989 | 2650878 |
| vitamin a supplementation improves macrophage function and bacterial clearance during experimental salmonella infection. | the effects of additional but nontoxic amounts of vitamin a on susceptibility to salmonella infection was studied by comparing rates of bacterial clearance and phagocytosis. forty-eight male lewis rats were divided into a treatment group receiving a total of 6000 units of vitamin a palmitate weekly for 5 weeks and a control group was given an equal volume of saline. after completion of the treatment regimen, one-half from each group were infected intraperitoneally with 10(5) salmonella typhimuri ... | 1989 | 2654947 |
| the structure of the escherichia coli hemb gene. | the escherichia coli hemb gene, which encodes 5-aminolevulinic acid dehydratase, and was cloned into ptz18u, a multicopy plasmid, was sequenced. the hemb insert was double-digested with restriction enzymes and recloned back into ptz18u and ptz19u to allow for sequencing in two directions. in a second procedure, used to fill in gaps and to confirm the sequence derived from the first procedure, the whole insert was cloned into m13 phages. a nested set of deletions was constructed and recloned into ... | 1989 | 2656410 |
| the primary structure of rat ribosomal protein s4. | the amino acid sequence of the rat 40 s ribosomal subunit protein s4 was deduced from the sequence of nucleotides in a recombinant cdna and confirmed from the nh2-terminal amino-acid sequence of the protein. ribosomal protein s4 has 282 amino acids (the nh2-terminal methionine is removed after translation of the mrna) and has a molecular weight of 31,841. hybridization of the cdna to digests of nuclear dna suggests that there are 7-11 copies of the s4 gene. the mrna for the protein is about 1 kb ... | 1989 | 2660908 |
| the peptide sequences near the bound pyridoxal phosphate are conserved in serine dehydratase from rat liver, and threonine dehydratases from yeast and escherichia coli. | the blocked amino-terminal residue of rat liver serine dehydratase was shown to be acetylalanine by analysis of an isolated amino-terminal peptide after digestion with acylamino acid-releasing enzyme. digestion of the borohydride-reduced, carboxymethylated enzyme with lysyl endopeptidase yielded a single epsilon-n-pyridoxyllysine-containing peptide, whose sequence is met-asp-ser-ser-gln-pro-ser-gly-ser-phe-lys(pxy)-ile-arg-gly- his-leu-cys(cm)-lys. this peptide comprises residues 30-49 of the cd ... | 1989 | 2660911 |
| kinetic analysis of base substitution mutagenesis by transient misalignment of dna and by miscoding. | we measured the insertion fidelity of dna polymerases alpha and beta and yeast dna polymerase i at a template site that was previously observed to yield a high frequency of t----g transversions when copied by dna polymerase beta but not by the other two polymerases. the results provide direct biochemical evidence that base substitution errors by dna polymerase beta can result from a dislocation mechanism governed by dna template-primer misalignment. in contrast to dna polymerase beta, neither dr ... | 1989 | 2661558 |
| induction of an antioxidant protein of saccharomyces cerevisiae by o2, fe3+, or 2-mercaptoethanol. | a soluble 27-kda protein from saccharomyces cerevisiae specifically prevents the inactivation of various enzymes caused by a nonenzymatic fe3+/o2/thiol mixed-function oxidation system but not by mixed-function oxidation systems in which the thiol component is replaced by another electron donor-e.g., ascorbate. in this report, using a 125i-labeled monospecific antibody against the 27-kda protein, we measured changes in the 27-kda protector protein in response to changes in oxidative stress and he ... | 1989 | 2668950 |
| expression of bovine cytochrome p450c17 cdna in saccharomyces cerevisiae. | we constructed expression plasmids for bovine adrenal cytochrome p450c17 (p450c17) by inserting the corresponding cdna between the yeast alcohol dehydrogenase i promoter and terminator of the expression vector paah5. plasmids pa alpha 1 and pa alpha 2 contained the entire coding region for bovine p450c17, whereas pac alpha 1 included the cdna coding for chimeric p450c alpha consisting of the amino-terminal 45 amino acid residues of rat p450c and the carboxy-terminal 482 amino acid residues of bo ... | 1989 | 2673705 |
| human liver serine dehydratase. cdna cloning and sequence homology with hydroxyamino acid dehydratases from other sources. | rat liver serine dehydratase cdna was used to screen a human liver cdna library in lambda gt11. one positive clone occurred in every 5,000 clones. fifteen positive clones were plaque purified. the largest cdna obtained contained an open reading frame of 987 base pairs, and 5' and 3' noncoding regions of 89 and 317 base pairs, respectively. the deduced amino acid sequence, with a calculated mr of 34,615, was similar to that of rat liver serine dehydratase except for the absence of a segment consi ... | 1989 | 2674117 |
| terconazole. pharmacology of a new antimycotic agent. | terconazole belongs to a new chemical class of antifungal agents, the triazoles. it was designed and synthesized to be more active than the imidazoles. the basic mechanism of action of terconazole, inhibition of fungal cytochrome p-450, is similar to that of the imidazoles. however, because of the additional nitrogen atom in the triazole ring and the lipophilic tail, terconazole establishes a firmer and longer-lasting link with the membrane-bound fungal cytochrome p-450. in addition, terconazole ... | 1989 | 2677363 |
| drug design based on biosynthetic studies: synthesis, biological activity, and kinetics of new inhibitors of 2,3-oxidosqualene cyclase and squalene epoxidase. | various classes of inhibitor of 2,3-oxido squalene cyclase have been synthesized and tested on rat liver and saccharomyces cerevisiae microsomes, 3t3 fibroblast cultures, and various bacteria, fungi, and yeasts. the compounds include azasqualenes, azasqualanes, bis-azasqualenes, bis-azasqualanes, and n-oxide and ammonium derivatives of squalene. in order to better mimic the transition state involved in the sn2-like opening of 2,3-oxidosqualene, we synthesized squalene n-methyloxaziridine. other ... | 1989 | 2678608 |
| acyl carrier protein is present in the mitochondria of plants and eucaryotic micro-organisms. | proteins antigenically similar to the acyl carrier protein (acp) found in the mitochondria of neurospora crassa were detected by immunoblotting and radioimmunoassay techniques in mitochondria isolated from yeast, potatoes, and pea leaves. these mitochondrial proteins were similar to neurospora acp both in their electrophoretic mobility and in their unusual decrease in mobility upon reduction. authentic acp(s) show this type of change upon conversion of the acylated to the unacylated form. purifi ... | 1989 | 2680483 |
| farnesyl diphosphate synthetase. molecular cloning, sequence, and expression of an essential gene from saccharomyces cerevisiae. | farnesyl diphosphate (fpp) synthetase is a key enzyme in isoprenoid biosynthesis which supplies c15 precursors for several classes of essential metabolites including sterols, dolichols, and ubiquinones. the structural gene for fpp synthetase was isolated on a 4.5-kilobase ecori genomic restriction fragment from the yeast saccharomyces cerevisiae. the clone encodes a 40,483-dalton polypeptide of 342 amino acids with a high degree of similarity to the protein encoded by a putative rat liver clone ... | 1989 | 2681213 |
| identification of covalently bound fatty acids on acylated proteins immobilized on nitrocellulose paper. | a general method for identification of fatty acids covalently bound to acylated proteins following their electrophoretic transfer onto nitrocellulose paper is described. as demonstrated for [3h]palmitoylated ras1 protein of saccharomyces cerevisiae and the acylated acyl carrier protein of spirodela oligorrhiza, this procedure alleviates the need for elution of proteins from polyacrylamide gel slices. fatty acid ligands of such proteins are hydrolyzed directly from their immobilized state on the ... | 1989 | 2696384 |
| complete amino acid sequence of rat brain hexokinase, deduced from the cloned cdna, and proposed structure of a mammalian hexokinase. | the complete amino acid sequence for the type i isozyme of hexokinase from rat brain has been deduced from the nucleotide sequence of cloned cdna. the nucleotide sequence of 91 bases in the 5' untranslated region as well as that of the entire 3' untranslated region preceding the poly(a) sequence have also been determined. the n- and c-terminal halves of brain hexokinase show extensive sequence similarity to each other and to yeast hexokinase. these results provide direct support for the proposal ... | 1989 | 2704734 |
| ph and other effects on the antifungal activity of cilofungin (ly121019). | we investigated the effects of various test conditions on broth macro- and microdilution susceptibility test results for several species of yeasts with a new antifungal agent, cilofungin. as the ph decreased from 7.4 to 3.0, 50% inhibitory concentrations (ic1/2) increased up to 64-fold. this effect was unrelated to yeast growth rate, solvent concentration, or choice of buffer. broth microdilution results for 42 candida albicans isolates at ph 7.4 in synthetic amino acid medium, fungal (saamf), s ... | 1989 | 2751286 |
| v-cbl, an oncogene from a dual-recombinant murine retrovirus that induces early b-lineage lymphomas. | cas ns-1 is an acutely transforming murine retrovirus that induces pre-b and pro-b cell lymphomas. molecular cloning showed it was generated from the ecotropic cas-br-m virus by sequential recombinations with endogenous retroviral sequences and a cellular oncogene. the oncogene sequence shows no homology with known oncogenes but some similarity to the yeast transcriptional activator gcn4. a 100-kda gag-cbl fusion protein, with no detectable kinase activity, is responsible for the cellular transf ... | 1989 | 2784003 |
| pharmacological studies on eb-382, a new non-steroidal antiinflammatory agents: mode of action of the analgesic effects. | the analgesic mechanism of (+/-)-2-[p-[(2-methylallyl)amino]phenyl]propionic acid (eb-382), a new non-steroidal antiinflammatory agent, was studied. eb-382 exerted a potent analgesic effect on yeast-induced hyperalgesia in rats and bradykinin-induced writhing in mice, and its potency was superior to that of ibuprofen. eb-382 had a comparatively weak inhibitory effect on the prostaglandin e2 production from arachidonic acid in sheep seminal vesicle microsomal fraction in vitro. eb-382 exhibited a ... | 1989 | 2787705 |
| research on heterocyclic compounds. xxv. phenyl derivatives of fused imidazole systems: antiinflammatory activity. | a group of seven acidic phenyl derivatives of some fused imidazole systems were subjected to a series of tests in vivo in order to evaluate their pharmacological activity. antiinflammatory activity was studied by means of the carrageenin-induced rat paw edema. hot plate test and writhing induced by acetic acid in mice were used to evaluate analgesic activity. yeast-induced hyperthermia in rats was employed to study antipyretic action. irritative and ulcerogenic action on the rat gastric mucosa w ... | 1989 | 2789419 |
| arginase of agrobacterium ti plasmid c58. dna sequence, properties, and comparison with eucaryotic enzymes. | agrobacterium nopaline ti plasmids code for three enzymes of nopaline [n2-(1,3-dicarboxypropyl)-l-arginine] degradation: nopaline oxidase, arginase, and ornithine cyclodeaminase. we describe the dna sequence of the arginase gene, a comparison of the deduced protein sequence with eucaryotic arginases, and properties of the procaryotic enzyme. the results show that the agrobacterial arginase is related with arginases from yeast, rat liver, and human liver (28-33% identity). the ti plasmid enzyme r ... | 1989 | 2806247 |
| copolymers of glutamic acid and tyrosine are potent inhibitors of oocyte casein kinase ii. | polypeptides rich in glutamic acid are strong inhibitors purified from isolated nuclei of xenopus laevis oocytes of casein kinase ii. the presence of tyrosine in these peptides greatly enhances their inhibitory capacity. using casein as a substrate, copolyglu:tyr (4:1) has an i50 value of 20 nm, 250 fold lower than that of polyglutamic acid which is 5 microm. a similar large difference is observed when a synthetic peptide is used as substrate. the inhibition of copolyglu:tyr is competitive with ... | 1990 | 1694780 |
| antigenic conservation of primary structural regions of s-adenosylmethionine synthetase. | although the physical and kinetic properties of s-adenosylmethionine (adomet) synthetases from different sources are quite different, it appears that these enzymes have structurally or antigenically conserved regions as demonstrated by studies with adomet synthetase specific antibodies. polyclonal anti-human lymphocyte adomet synthetase crossreacted with enzyme from rat liver (beta isozyme), escherichia coli and yeast. in addition, polyclonal anti-e. coli enzyme and antibodies to synthetic pepti ... | 1990 | 1698095 |
| rhizobium meliloti adenylate cyclase is related to eucaryotic adenylate and guanylate cyclases. | a gene from rhizobium meliloti coding for an adenylate cyclase was sequenced, and the deduced protein sequence was compared with those of other known adenylate cyclases. no similarity could be detected with the procaryotic counterparts. however, striking similarity was found with the catalytic region of saccharomyces cerevisiae adenylate cyclase, the cytoplasmic domains of bovine adenylate cyclase, and two mammalian guanylate cyclases. the gene was fused to the enteric beta-galactosidase, and th ... | 1990 | 1970565 |
| homologous sugar transport proteins in escherichia coli and their relatives in both prokaryotes and eukaryotes. | separate proteins for proton-linked transport of d-xylose, l-arabinose, d-galactose, l-rhamnose and l-fucose into escherichia coli are being studied. by cloning and sequencing the appropriate genes, the amino acid sequences of proteins for d-xylose/h+ symport (xyle), l-arabinose/h+ symport (arae), and part of the protein for d-galactose/h+ symport (galp) have been determined. these are homologous, with at least 28% identical amino acid residues conserved in the aligned sequences, although their ... | 1990 | 1970645 |
| yeast acetyl-coa carboxylase: in vitro phosphorylation by mammalian and yeast protein kinases. | acetyl-coa carboxylase (acc) is regulated in mammalian tissues, in part, by multisite enzyme phosphorylation. yeast acc (y-acc) has been highly purified from s. cerevisiae by monomeric avidin-sepharose chromatography, revealing an enzyme subunit species of molecular mass 265,000 da. unlike mammalian enzyme, y-acc is citrate-independent, and reacts weakly or not at all with a panel of anti-rat liver acc antibodies. like rat acc, y-acc is rapidly phosphorylated and inactivated by two mammalian car ... | 1990 | 1972618 |
| regulation of the pituitary-specific homeobox gene ghf1 by cell-autonomous and environmental cues. | homeodomain proteins function in determination of mating type in yeast, segmentation in fruit flies and cell-type specific gene expression in mammals. in drosophila, expression of homeobox genes is controlled by cell-autonomous interactions between regulatory proteins and environmental clues. similar controls may operate during mammalian limb development and frog embryogenesis. but, the exact way in which expression of homeodomain proteins is regulated in these systems is not clear and requires ... | 1990 | 1972784 |
| the ole1 gene of saccharomyces cerevisiae encodes the delta 9 fatty acid desaturase and can be functionally replaced by the rat stearoyl-coa desaturase gene. | strains of saccharomyces cerevisiae bearing the ole1 mutation are defective in unsaturated fatty acid (ufa) synthesis and require ufas for growth. a previously isolated yeast genomic fragment complementing the ole1 mutation has been sequenced and determined to encode the delta 9 fatty acid desaturase enzyme by comparison of primary amino acid sequence to the rat liver stearoyl-coa desaturase. the ole1 structural gene encodes a protein of 510 amino acids (251 hydrophobic) having an approximate mo ... | 1990 | 1978720 |
| thalidomide induced alteration in secondary structure of rat embryonic dna in vivo. | teratogenicity of thalidomide was demonstrated in wistar rats following a single maternal intravenous injection during the embryonic organogenetic period. when compared to day 13 embryonic dna isolated from untreated control mothers, differences were observed in the mean wet weights of day 13 embryos from rats treated with thalidomide during days 10 or 11 of gestation, and significantly less amounts of embryonic dna were recovered from mothers similarly treated on days 10 or 12 of their respecti ... | 1990 | 1980031 |
| molecular cloning of aldolases for synthetic applications. | 1990 | 2076016 | |
| influence of the presence of a methyl group on the myocardial metabolism of 15-(paraiodophenyl)-3 methyl pentadecanoic acid (imppa). | the objective of the present study was to determine the mechanism of accumulation of myocardial activity following i.v. injection of 15-(paraiodophenyl)-3 methyl pentadecanoic acid (imppa). imppa and 15 phenyl-3 methyl pentadecanoic acid (mppa) were labeled with 14c at position 1 and used to perfuse isolated rat hearts in a closed system. after 5 min of perfusion, imppa reached 2/3 of its value at 45 min. 14co2 production was low. most of the myocardial activity was in the form of free imppa. an ... | 1990 | 2079420 |
| [low-molecular peptides in food as factors altering the resistance of rats to emotional stress]. | the authors studied the resistance of animals to emotional stress when they were given in the diet, as a source of protein, casein and a protein fraction composed of a mixture of amino acids and low-molecular peptides (18 and 2.7%) obtained by reprocessing saccharomyces cerevisiae yeasts, biomass. the ecg, rheovasogram, systolic arterial pressure, and respiratory rate were studied in rats given a diet containing 18 and 2.7% low-molecular peptides (controls) and in the same animals after 24-hour ... | 1990 | 2080075 |
| [analgesic and antipyretic effects of cyproheptadine]. | cyproheptadine-hcl raised the pain thresholds during hot plat test and writhing test in mice and tail flick test in rats, strengthened the hypnotic action by subthreshold dosage of sodium pentobarbital and chloral hydrate. the ed50 were 4.4 (3.2-5.7) and 12.4 (8.4-18.2) mg/kg 30 min after ip cyproheptadine in mice and rats, respectively. the ed50 was 0.14 (0.12-0.18) mg/kg 90 min after icv cyproheptadine in mice. cyproheptadine po 20, 40 mg/kg and ip 10, 20 mg/kg showed significant antipyretic e ... | 1990 | 2087993 |
| genotoxic risk associated with pesticides: evidences on short-term tests. | 1990 | 2097665 | |
| simultaneous determination of pantothenic acid and hopantenic acid in biological samples and natural products by gas chromatography-mass fragmentography. | a method for the simultaneous determination of pantothenic acid and hopantenic acid in plasma samples was developed using gas chromatography-mass spectrometry with multiple ion detection. plasma samples were directly purified without deproteinization on an ion-exchange resin, and the eluate was extracted with ethyl acetate under acidic conditions. the organic layer was evaporated to dryness under a stream of nitrogen, and the residue was dissolved in an internal standard solution. pantothenic an ... | 1990 | 2109760 |
| effects of expression of mammalian g alpha and hybrid mammalian-yeast g alpha proteins on the yeast pheromone response signal transduction pathway. | scg1, the product of the saccharomyces cerevisiae scg1 (also called gpa1) gene, is homologous to the alpha subunits of g proteins involved in signal transduction in mammalian cells. scg1 negatively controls the pheromone response pathway in haploid cells. either pheromonal activation or an scg1 null mutation relieves the negative control and leads to an arrest of cell growth in the g1 phase of the cell cycle. expression of rat g alpha s was previously shown to complement the growth defect of scg ... | 1990 | 2111439 |
| cloning and expression of rat histidase. homology to two bacterial histidases and four phenylalanine ammonia-lyases. | histidase (histidine ammonia-lyase, ec 4.3.1.3) catalyzes the deamination of histidine to urocanic acid. apart from phenylalanine ammonia-lyase, which is not expressed in animals, histidase is the only enzyme known to have a dehydroalanine residue in its active site. the amino site precursor and the mechanism of formation of dehydroalanine are not known. as an initial step to determining the precursor of dehydroalanine in histidase, we have isolated a functional cdna clone for histidase from a r ... | 1990 | 2120224 |
| identification of a putative yeast homolog of the mammalian beta chains of the clathrin-associated protein complexes. | the clathrin-associated protein complexes are heterotetrameric structures believed to interact with clathrin and with membrane components of mammalian coated pits and coated vesicles. i have identified a yeast homolog of the mammalian beta-type large chains, suggesting the existence in yeast cells of clathrin-associated protein complexes. a sequence comparison between the putative yeast beta-type chain and its mammalian counterparts shows that their amino-terminal domains are related over their ... | 1990 | 2122239 |
| inactivity of terbinafine in a rat model of pulmonary aspergillosis. | in a model of bronchopulmonary aspergillosis terbinafine did not improve survival of experimental animals in doses up to 80 mg/kg/day despite adequate lung concentrations. pretreatment and aerosolization of the compound were also ineffective. terbinafine was markedly less active in vitro when serum was used instead of yeast-nitrogen-glucose-broth. it is concluded that a lack of bioavailability in the presence of serum may explain the lack of activity of terbinafine in experimental aspergillosis. | 1990 | 2128278 |
| rat homologs of the drosophila dunce gene code for cyclic amp phosphodiesterases sensitive to rolipram and ro 20-1724. | the dunce locus of drosophila melanogaster codes for a low km, camp phosphodiesterase. the correct function of this gene is required for normal learning and memory activity in flies, because dunce mutants fail in tests of behavioral conditioning. these observations have indicated that camp regulation is an important aspect of the biochemistry underlying learning and memory processes in insects. to determine whether the locus is functionally conserved in mammals, we have expressed dunce gene homo ... | 1990 | 2153912 |
| characteristics of l-alanine:4,5-dioxovaleric acid transaminase: an alternate pathway of heme biosynthesis in yeast. | the present study reports for the first time the presence of the enzyme l-alanine:4,5-dioxovaleric acid transaminase (ec 2.6.1.43), which catalyzes the irreversible synthesis of 5-aminolevulinic acid in three strains of yeast: candida albicans 3100, saccharomyces cerevisiae 3059, and s. cerevisiae s288c. the enzyme was predominantly present in the cytosol and was purified from c. albicans 3100 by about 200-fold with an overall yield of 23% to apparent homogeneity. the purification procedure invo ... | 1990 | 2154954 |
| molecular cloning of mevalonate kinase and regulation of its mrna levels in rat liver. | mevalonate kinase [atp:(r)-mevalonate 5-phosphotransferase, ec 2.7.1.36] may be a regulatory site in the cholesterol biosynthetic pathway, and a mutation in the gene coding for this enzyme is thought to cause the genetic disease mevalonic aciduria. to characterize this enzyme, a rat liver cdna library was screened with a monospecific antibody, and a 1.7-kilobase cdna clone coding for mevalonate kinase was isolated. the complete dna sequence was determined, and the longest open reading frame code ... | 1990 | 2158094 |
| tissue and species distribution of liver type and tumor type nuclear poly(a) polymerases. | previous studies in this laboratory have identified two distinct nuclear poly(a) polymerases, a 48 kda tumor type enzyme and a 36-38 kda liver type enzyme. to investigate the tissue and species specificity of these enzymes, nuclear extracts were prepared from various rat tissues, pig brain and two human cell lines. these as well as whole cell extract from yeast were probed for the two enzymes by immunoblot analysis using polyclonal anti-tumor poly(a) polymerase antibodies or autoimmune sera whic ... | 1990 | 2162661 |
| protein kinase c in saccharomyces cerevisiae: comparison with the mammalian enzyme. | protein kinase c (pkc) was detected in the yeast saccharomyces cerevisiae with bovine myelin basic protein as the phosphate acceptor. the enzyme was purified at least 500-fold by a four-step column chromatographic procedure (phenyl-sepharose cl-4b, mono q, heparin-5pw, and hydroxyapatite). the molecular mass was approximately 90 kda, as estimated by gel-filtration analysis. yeast pkc was activated by the simultaneous addition of ca2+, diacylglycerol, and phosphatidylserine. free arachidonic acid ... | 1990 | 2164217 |
| proton-linked sugar transport systems in bacteria. | the cell membranes of various bacteria contain proton-linked transport systems for d-xylose, l-arabinose, d-galactose, d-glucose, l-rhamnose, l-fucose, lactose, and melibiose. the melibiose transporter of e. coli is linked to both na+ and h+ translocation. the substrate and inhibitor specificities of the monosaccharide transporters are described. by locating, cloning, and sequencing the genes encoding the sugar/h+ transporters in e. coli, the primary sequences of the transport proteins have been ... | 1990 | 2172229 |
| changing the invariant proline-30 of rat and drosophila melanogaster cytochromes c to alanine or valine destabilizes the heme crevice more than the overall conformation. | drosophila melanogaster and rat cytochromes c in which proline-30 was converted to alanine or valine were expressed in a strain of baker's yeast, saccharomyces cerevisiae, where they sustained aerobic growth. the mutations had no significant effect on the spectra or redox potentials but altered drastically the stability of the bond between the methionine-80 sulfur and the heme iron, as judged by four criteria: (i) the alkaline pka values of the 695-nm band of the ferric form of the mutant protei ... | 1990 | 2174161 |
| rous sarcoma virus enhancer factor i is a ubiquitous ccaat transcription factor highly related to cbf and nf-y. | we have characterized enhancer factor i (efi), a trans-acting factor present in avian nuclear extracts which binds to the rous sarcoma virus long terminal repeat enhancer and promoter. through deletion and point mutagenesis, we show that efi is a member of the ccaat family of transcription factors. although the ccaat motif is essential for protein-dna recognition, efi shows surprising latitude in the nucleotide sequences flanking the ccaat motif to which it will bind with high affinity. efi will ... | 1990 | 2176209 |
| 31p nmr measurements of the adp concentration in yeast cells genetically modified to express creatine kinase. | rabbit muscle creatine kinase has been introduced into the yeast saccharomyces cerevisiae by transforming cells with a multicopy plasmid containing the coding sequence for the enzyme under the control of the yeast phosphoglycerate kinase promoter. the transformed cells showed creatine kinase activities similar to those found in mammalian heart muscle. 31p nmr measurements of the near-equilibrium concentrations of phosphocreatine and cellular ph together with measurements of the total extractable ... | 1990 | 2185836 |
| how different eukaryotic transcriptional activators can cooperate promiscuously. | a striking characteristic of many different eukaryotic transcriptional activators is their ability to activate gene expression synergistically. thus, for example, the rat glucocorticoid receptor and the yeast activator gal4 cooperatively activate transcription of a mammalian gene bearing binding sites for each of the proteins: activation by both activators is greater than the sum of the effects of each working alone. it would seem unlikely that these two proteins from such different organisms di ... | 1990 | 2188137 |
| cytoplasmic components of natural killer cells limit the growth of cryptococcus neoformans. | murine natural killer (nk) cell-mediated inhibition of growth of a yeast-like target cell, cryptococcus neoformans, was completely abrogated by blocking the effector cell secretory process with monensin. therefore, further studies were performed to determine the ability of various cytoplasmic fractions of nk cells to mediate inhibition of cryptococcal growth. percoll-fractionated homogenates of rat lgl tumor cells demonstrated that the granule-containing fractions plus three additional sets of l ... | 1990 | 2193078 |
| a candidate protein kinase c gene, pkc1, is required for the s. cerevisiae cell cycle. | probes derived from cdnas encoding isozymes of rat protein kinase c (pkc) were used to screen the genome of the budding yeast s. cerevisiae. a single gene (pkc1) was isolated that encodes a putative protein kinase closely related to the alpha, beta, and gamma subspecies of mammalian pkc. deletion of pkc1 resulted in recessive lethality. cells depleted of the pkc1 gene product displayed a uniform phenotype, a characteristic of cell division cycle (cdc) mutants, and arrested cell division at a poi ... | 1990 | 2196995 |
| elucidation of the deficiency in two yeast coenzyme q mutants. characterization of the structural gene encoding hexaprenyl pyrophosphate synthetase. | the assembly of a polyisoprenoid side chain and its transfer to para-hydroxybenzoate are the first two steps of coenzyme q biosynthesis. in yeast these reactions are catalyzed by hexaprenyl pyrophosphate synthetase and phb:polyprenyltransferase, respectively. we have screened nine complementation groups of yeast coenzyme q mutants for the activities of these two enzymes and found two strains deficient in either activity. the strain deficient in hexaprenyl pyrophosphate synthetase activity, c296- ... | 1990 | 2198286 |
| metabolic stability of 3-o-methyl-d-glucose in brain and other tissues. | 3-o-methyl-d-glucose (methylglucose) is often used to study blood-brain barrier transport and the distribution spaces of hexoses in brain. a critical requirement of this application is that it not be chemically converted in the tissues. recent reports of phosphorylation of methylglucose by yeast and heart hexokinase have raised questions about its metabolic stability in brain. therefore, we have re-examined this question by studying the metabolism of methylglucose by yeast hexokinase and rat bra ... | 1990 | 2200849 |
| in vivo expression of rat liver c-erba beta thyroid hormone receptor in yeast (saccharomyces cerevisiae). | to study thyroid hormone receptor (tr), we developed an in vivo expression system in yeast by using a copper-responsive yeast metallothionein promoter and ubiquitin-fusion protein technology. the cdna encoding full-length rat liver tr beta was expressed under the control of copper. the [125i]t3 binding activities to yeast extracts were significantly correlated with the added copper sulfate into the medium. partially purified tr from the transformed yeast had a high hormone binding affinity (kd = ... | 1990 | 2203342 |
| ligand-specific transactivation of gene expression by a derivative of the human glucocorticoid receptor expressed in yeast. | in this study we have reconstituted transactivation of gene expression by the human glucocorticoid receptor in the yeast, saccharomyces cerevisiae. we have expressed the c-terminal half of the human glucocorticoid receptor (residues 415-777), the smallest derivative that can be expected to function as a ligand-dependent activator of transcription, in yeast cells. the function of the expressed protein has been assayed using a reporter gene consisting of the beta-galactosidase gene from escherichi ... | 1990 | 2203760 |
| purified presequence binding factor (pbf) forms an import-competent complex with a purified mitochondrial precursor protein. | in vitro mitochondrial import of the purified precursor form (potc) of rat ornithine carbamoyltransferase (otc) is stimulated by a cytosolic factor(s) contained in rabbit reticulocyte lysate. a protein factor that binds to potc but not to mature otc and was named presequence binding factor or pbf, was purified 91,000-fold from the lysate by affinity chromatography using potc-bound sepharose, deae-5pw hplc and sucrose gradient centrifugation. the purified pbf migrated as a single polypeptide of 5 ... | 1990 | 2209543 |
| immunoreactivity of neoglycolipids constructed from oligomannosidic residues of the candida albicans cell wall. | to establish a model to study the immunoreactivity of oligosaccharidic structures from the candida albicans cell wall, we attempted to construct neoglycolipids with these residues by using oligomannosides released after mild acid hydrolysis of the phosphopeptidomannans isolated from yeast forms. from a mixture of manno-oligosaccharides ranging from mannobiose to mannononaose, the structure of a quantitatively major component (mannotriose) was determined to be man (beta 1-2) man (beta 1-2) man al ... | 1990 | 2228224 |
| an amino-terminal c-myc domain required for neoplastic transformation activates transcription. | the product of the c-myc proto-oncogene is a nuclear phosphoprotein whose normal cellular function has not yet been defined. c-myc has a number of biochemical properties, however, that suggest that it may function as a potential regulator of gene transcription. specifically, it is a nuclear dna-binding protein with a short half-life, a high proline content, segments that are rich in glutamine and acidic residues, and a carboxyl-terminal oligomerization domain containing the leucine zipper and he ... | 1990 | 2233723 |
| the general mitochondrial matrix processing protease from rat liver: structural characterization of the catalytic subunit. | a critical step in the import of nuclear-encoded precursor proteins into mitochondria involves proteolytic cleavage of their amino-terminal leader peptides by processing proteases found in the mitochondrial matrix. we report here the characterization of the general matrix processing protease from rat liver mitochondria. the final enzyme preparation consisted of two polypeptides, a catalytically active 55-kda subunit and a 52-kda one. to deduce the complete primary structure of the 55-kda subunit ... | 1990 | 2236012 |
| sorting of peroxisomal membrane protein pmp47 from candida boidinii into peroxisomal membranes of saccharomyces cerevisiae. | a gene encoding pmp47, a peroxisomal integral membrane protein of the methylotrophic yeast candida boidinii, was isolated from a genomic library. dna sequencing of pmp47 revealed an open reading frame of 1269 base pairs capable of encoding a protein of 46,873 da. at least two membrane-spanning regions in the protein are predicted from the sequence. since the 3 amino acids at the carboxyl terminus are -ake, pmp47 lacks a typical peroxisomal sorting signal. no significant similarities in primary s ... | 1990 | 2243083 |
| inhibitory effect of transfer rna on protein kinases from baker's yeast and rat skeletal muscle. | sephadex g-200 gel filtration of dna cellulose-treated crude extracts of rat skeletal muscle, revealed a broad peak-fraction of trna-inhibitory protein kinases (pk) coeluted endogenous substrates. in comparison, the elution profile of baker's yeast exhibited multiple peak-fractions of trna-inhibiting pk. various trna all showed inhibition to pk. in the presence of regulatory subunit of cyclic amp-dependent protein kinase, trna did not exert synergetic inhibition on pk. moreover, the interaction ... | 1990 | 2257756 |