Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:3.1.27.1 (RNase)
16,360 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Cystic fibrosis (CF) is the most common severe, autosomal recessive disease in Caucasians. The main clinical symptoms are all related to exocrine gland disturbances and include obstructive lung disease, pancreatic insufficiency and increased sweat electrolytes. In the present investigation fibroblasts from CF homozygotes were studied by X-ray microanalysis and were shown to have an increased calcium and a decreased sodium content, compared with fibroblasts from controls. The calcium increase was not specific for CF, since it was also found in fibroblasts from trisomy patients. The calcium abnormality could be corrected without any effect on the sodium level by treatment of CF cells with medium conditioned by normal cells. When normal cells were treated with medium conditioned by CF cells, the intracellular sodium level decreased without changes in the calcium level. Acid hydrolases were quantitatively increased in serum from CF patients but no qualitative differences, neither in thermal stability nor in isoelectric focusing patterns were found. Neither was any defect observed in the recognition marker of the hydrolases released from CF fibroblasts. CF homozygotes and heterozygotes had increased concentrations of lactate and electrolytes and increased activities of ribonuclease in their saliva and urine. The salivary concentration of protein was also elevated. When healthy controls were submitted to intensive maximal (anaerobic) exercise on a bicycle ergometer their salivary contents of lactate, ribonuclease, protein and electrolytes increased. Their saliva thus became more like that in CF patients. Indications of abnormal handling of a load dose of sucrose were found in both homozygotes and heterozygotes. Greater increases in the salivary concentrations of both glucose and lactate, but also a more rapid clearance of these metabolites were noted after the sucrose intake. Ingestion of sucrose also caused a normalization (decrease) of the salivary electrolyte content in homozygotes and heterozygotes. Evidence was thus produced to indicate a disturbance in the metabolism of carbohydrates and energy in cystic fibrosis, and it is speculated that such a disturbance might be of importance for the pathogenesis of this disease.
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PMID:Cystic fibrosis. In vitro and in vivo studies on the biochemical background to the pathogenesis. 658 81

Nonenzymatic glucosylation of protein is initiated by the reversible condensation of glucose in its open chain form with the amino groups on the protein. The initial product is an aldimine (Schiff base) which cyclizes to the glycosylamine derivative. The aldimine can undergo a slow Amadori rearrangement to yield the relatively stable ketoamine adduct which is structurally analogous to fructose. 13C NMR has been used to characterize these early products of nonenzymatic glucosylation, using RNase A as a model protein. C-1 of the beta-pyranose anomer of the glycosylamine was identified at 88.8 ppm in the spectrum of RNase glucosylated approximately 1:1 with D-[1-13C]glucose. C-1 of the Amadori product was also apparent in this spectrum, resonating as a pair of intense peaks at 52.7 and 53.1 ppm. The anomeric (C-2) resonances of the Amadori adduct were seen in the spectrum of RNase glucosylated approximately 1:1 with [U-13C]glucose. This spectrum was interpreted by comparison to the spectra of reference compounds: D-fructose, fructose-glycine, N alpha-formyl-N epsilon-fructose-lysine, and glucosylated poly-L-lysine. In the protein spectrum, the most intense of the C-2 resonances was that of the beta-fructopyranose anomer at 95.8 ppm. The alpha- and beta-fructofuranose anomers were also observed at 101.7 and 99.2 ppm, respectively. One unidentified signal in the anomeric region was observed in the spectra of poly-L-lysine and RNase, both glucosylated with [U-13C]glucose; no comparable resonances were observed in the spectra of the model compounds.
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PMID:13C NMR investigation of nonenzymatic glucosylation of protein. Model studies using RNase A. 664 80

Purified and unstained nuclei were isolated from the leaves of several Gossypium species (diploid and tetraploid) by means of a citrate buffer (pH 5.0), Triton X-100 (5%), and a reducing sugar (1M glucose). DNA, previously unobtainable, was then extracted from the nuclei by conventional means. Comparisons of final DNA yield were made between three methods of purification: namely, the standardized ribonuclease procedure, hydroxyapatite chromatography and equilibrium density centrifugation in cesium chloride. The latter method produce the lowest, yet purest, yield of DNA for renaturation studies in Gossypium.
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PMID:An effective method of DNA isolation from the mature leaves of Gossypium species that contain large amounts of phenolic terpenoids and tannins. 664 18

We studied the uptake of D-glucose and L-tryptophan by the small intestine and estimated the activities of the intestinal brush border enzymes (sucrase, lactase, NA+-K+-ATPase and alkaline phosphatase) and lysosomal enzymes in rats receiving T-2 toxin orally. considerable decrease occurred in glucose and tryptophan uptake and in brush border sucrase, lactase and (Na+-K+)-ATPase. Alkaline phosphatase activity and release of lysosomal enzymes (acid phosphatase and acid ribonuclease) was unchanged.
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PMID:Effects of T-2 toxin on glucose and tryptophan uptake and intestinal mucosal enzymes. 671 77

Acholeplasma laidlawii A has been grown in media containing synthetic, long chain C20- and C23-fatty acids possessing a diacetylene group in their acyl chains. Growth on the C23 diacetylenic acid was poor but was good on the C20 acid. Biosynthetic incorporation of the fatty acids occurs; as much as 90% of the membrane lipid fatty acyl chains consisting of the C20-diacetylenic fatty acid, the remainder being shorter chain, saturated fatty acids. The thermal phase transition of this biomembrane has been studied and a differential scanning calorimetry heating curve shows the presence of an endotherm corresponding to a membrane lipid phase transition occurring at about 26 degrees C. The lipid class composition of membranes containing the C20-diacetylene lipids was examined and found to be similar to membranes from cells grown on oleic acid-containing medium. (The ratio of monoglucosyl- to diglucosyldiacylglycerols was the same but the ratio of glycolipid to phosphatidylglycerol was higher in the cells grown with diacetylene fatty acids). Upon irradiation with ultraviolet light the cells and isolated biomembranes become coloured, either red or yellow depending upon their thermal history. The colour change indicates that extensive cross-linking of the lipids of the biomembranes of A. laidlawii has occurred and that a conjugated polymeric structure has been formed. Analysis of the extracted lipids from the biomembranes by GLC indicates that extensive cross-linking of the lipid chains within the biomembrane of a natural cell system has been achieved. The monoglucosyldiacylglycerols cross-link more readily that do the phosphatidylglycerol lipids. The effect of such lipid cross-linking or polymerisation on the activity at 35 degrees C of an intrinsic membrane-bound enzyme, NADH oxidase, and ribonuclease, an extrinsic membrane-bound enzyme, was studied. The NADH oxidase activity decreased rapidly upon cross-linking of the lipid environment whereas ribonuclease activity was unaffected. The potential for future studies of polymerised model and natural biomembranes is discussed.
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PMID:The biosynthetic incorporation of diacetylenic fatty acids into the biomembranes of Acholeplasma laidlawii A cells and polymerisation of the biomembranes by irradiation with ultraviolet light. 683 76

The ribosomal ribonuclease of yeast is induced after a withdrawal of glucose. Cycloheximide inhibits the synthesis of the enzyme under conditions of induction but antimycin shows no effect. Hence, the increase of the ribonuclease activity during growth of yeast is due to newly synthesized enzyme, and the induction does not depend on respiration.
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PMID:The induction of a ribosomal ribonuclease in Saccharomyces cerevisiae. 699 70

There are two latent ribonucleases associated with the 40 S subunits of yeast ribosomes which differ in their digestion products, pH optimum, molecular weight, and in their activity during growth phase. The 3'-nucleotide-producing enzyme is active only in the late logarithmic or stationary growth phase, whereas the ribonuclease which produces 5'-nucleotides is present at all growth phases. The enzymes were separated by affinity chromatography and were partially characterized. By changing growth conditions--i.e. decreasing and increasing the glucose concentration in the medium--the activity of the 3'-ribonuclease could be induced or reduced.
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PMID:The occurrence of two ribosomal ribonucleases depending on growth phase in yeast. Induction of ribonuclease in glucose-starved cells. 701 96

Electrophoretic mobility, glucose metabolism, and oxygen uptake were studied in three leukemic and in four nonleukemic strains of ascites tumor cells. The cells differed markedly in mobility. This variation was related neither to cell growth nor to rates of endogenous respiration and aerobic glycolysis. The nonleukemic tumor cells showed higher mobility than did the leukemic cells. Additional increases in mobility appear to be related to suppressed oxygen uptake, which results from the addition of glucose or 0.05 mM 2,4-dinitrophenol. The augmented negative surface charge does not seem to be related to those ionogenic sites susceptible to neuraminidase. However, RNase treatment of the nonleukemic tumor cell does reveal the presence in their surface membrane of negatively charged sites susceptible to this enzyme. Such RNase-susceptible ionogenic sites presumably redistribute at the cell surface membrane from the inner sites as a response to suppressed oxygen uptake. This results in a higher negative surface charge and increased mobility. The leukemic cells, on the other hand, did not show any change in oxygen uptake or mobility in the presence of glucose. Moreover, the reduced rate of oxygen uptake induced by the addition of 0.05 mM 2,4-dinitrophenol did not result in any significant alterations in mobility. This is consistent with the observation that the ionogenic sites susceptible to RNase do not appear at the surface of the leukemic cells upon suppressed oxygen uptake. The leukemic cells have thus been shown to differ from the nonleukemic tumor cells in certain aspects of their glucose metabolism as well as in the electrophoretic properties of their surface.
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PMID:Mechanism of the linkage between te electrophoretic mobility and oxygen uptake of ascites tumor cells. 743 7

The addition of microelements (Co2+, Cu2+, Zn2+, and Fe2+) to a cultivation medium increased the activity of phosphomonoesterase but not of proteinase and ribonuclease. Glucose and inorganic phosphate (Pi) were the main factors that affected the direction and intensity of the biosynthesis of extracellular enzymes.
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PMID:[Regulation of biosynthesis of intracellular enzymes in Bacillus intermedius 3S-19]. 747 35

We previously isolated a nuclear 5.7 kb genomic fragment carrying the NAM7/UPF1 gene, which is able to suppress mitochondrial splicing deficiency when present in multiple copies. We show here that an immediately adjacent gene ISF1 (Increasing Suppression Factor) increases the efficiency of the NAM7/UPF1 suppressor activity. The ISF1 gene has been independently isolated as the MBR3 gene and comparison of the ISF1 predicted protein sequence with data libraries revealed a significant similarity with the MBR1 yeast protein. The ISF1 and NAM7 genes are transcribed in the same direction, and RNase mapping allowed the precise location of their termini within the intergenic region to be determined. The ISF1 gene is not essential for cell viability or respiratory growth. However as for many mitochondrial genes, ISF1 expression is sensitive to fermentative repression; in contrast expression of the NAM7 gene is unaffected by glucose. We propose that ISF1 could influence the NAM7/UPF1 function, possibly at the level of mRNA turnover, thus modulating the expression of nuclear genes involved in mitochondrial biogenesis.
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PMID:Two adjacent nuclear genes, ISF1 and NAM7/UPF1, cooperatively participate in mitochondrial functions in Saccharomyces cerevisiae. 750 49


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