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)

The hydroxyl groups of poly(ethyleneglycol) have been esterified (partly) with a number of carboxylic acids. When these esters are included in dextranpoly(ethyleneglycol)-water biphasic systems the partitions of proteins and membranes between the two phases (and the interface) are in some cases strongly affected. The affinity of serum albumin for the poly(ethyleneglycol)-rich phase is strongly increased when the fatty acid group consists of more than 10 carbon atoms. The partition also depends on the number of double bonds in the fatty acid. A corresponding relationship is found for membranes from spinach chloroplasts. The partitions of ovalbumin, lysozyme (EC 3.2.1.17) and ribonuclease (EC 3.1.4.22) are not influenced by the fatty acid esters. Esters of dibasic carboxylic acids show a minute but marked effect on the partition of proteins in general while malate and tartrate esters affect strongly the partition of chloroplast membranes. The partitions of both proteins and membranes are influenced by poly(ethyleneglycol) deoxycholate. Experiments with malate dehydrogenase (EC 1.1.1.37), lactate dehydrogenase (EC 1.1.1.27), fumarase (EC 4.2.1.2), enolase (EC 4.2.1.11) and glutamate-ocaloacetate transaminase (EC 2.6.1.1) show that their partitions, measured on enzymic activity basis, is changed when esters of benzoic, linolenic, tartaric or deoxycholic acid are included in the biphasic system. The mechanism behind the effect of the esterified poly (ethyleneglycol) on the partition of biomaterial, in this type of aqueous biphasic systems, is discussed in terms of a direct binding of the esters to the partitioned material.
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PMID:The effect of poly(ethyleneglycol) esters on the partition of proteins and fragmented membranes in aqueous biphasic systems. 99 68

1. Homogenates of bovine splenic nerves were subjected to differential and sucrose density gradient centrifugation. From the low-speed supernatant a high-speed sediment (mitochondria, lysosomes, microsomes and noradrenaline (NA) vesicles) was obtained. By density gradient centrifugation of this sediment it was shown that NA vesicles are slightly less dense than mitochondria, but denser than microsomes.2. In further experiments a mitochondrial and a microsomal sediment were obtained. The mitochondrial sediment was fractionated with a short centrifugation time over a density gradient ranging from 0.6 to 1.2 M sucrose. Mitochondria (fumarase and succinate-dehydrogenase) and lysosomes (acid ribonuclease and deoxyribonuclease) sedimented to the bottom of the tube. The highest concentration of NA vesicles was found in a medium position. There was only a small amount of microsomes (glucose-6-phosphatase) present.3. The microsomal sediment was centrifuged for 150 min over a density gradient ranging from 0.8 to 1.4 M sucrose. The microsomes remained on the top of the gradient. There were also some mitochondria and lysosomes present. The NA vesicles were found in highest concentration in the middle of the gradient (at about 1.2 M sucrose).4. With the use of these two density gradients, the subcellular distribution of dopamine-beta-hydroxylase, monoamine oxidase and ATPase was studied. Dopamine-beta-hydroxylase was found to be localized in the NA vesicles. Monoamine oxidase was mainly recovered in mitochondria; a small part of the enzyme appeared to be microsomal. ATPase was present in microsomal elements.
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PMID:Bovine splenic nerve: characterization of noradrenaline-containing vesicles and other cell organelles by density gradient centrifugation. 431 May 9

Fumarase (EC 4.2.1.2) and mitochondrial L-malate dehydrogenase (EC 1.1.1.37) were both inhibited by NaAuCl4 and KAuBr4. The inhibition for both was measured as a function of gold complex concentration and aquation time, and the NaAuCl4 inhibition was also measured in the presence of 0.15 M NaCl. Regeneration of the enzyme activity after NaAuCl4 inhibition using L-cysteine, L-methionine and NaCN was also investigated. Sodium dodecyl sulfate (SDS) acrylamide gel electrophoresis and amino acid analysis was performed on the NaAuCl4 inhibited enzymes as well as on ribonuclease A (EC 3.1.26.2), lysozyme (EC 3.2.1.17) and liver alcohol dehydrogenase (EC 1.1.1.1). It was observed that the inhibition was proportional to the gold complex concentration but decreased markedly after aquation of the complex. In the presence of NaCl the initial rate of inactivation is essentially unaffected unless the complex has been aquated and then the initial rate is increased. Gel electrophoresis on gold complex-enzyme mixtures show polymerization for ribonuclease and lysozyme and amino acid analysis indicates that no oxidation has taken place. From these results, a binding mechanism is postulated for the inhibition of the dehydrogenases by direct displacement of a halide ligand, probably by two groups on the enzyme, at least one of which may be a sulfur containing acid.
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PMID:Inhibition of two mitochondrial enzymes by gold (III) halo complexes. Evidence for a binding mechanism. 715 Dec 34

The activities of fumarase- and manganese-cofactored superoxide dismutase (SOD), encoded by the fumC and sodA genes in Pseudomonas aeruginosa, are elevated in mucoid, alginate-producing bacteria and in response to iron deprivation (D. J. Hassett, M. L. Howell, P. A. Sokol, M. L. Vasil, and G. E. Dean, J. Bacteriol. 179:1442-1451, 1997). In this study, a 393-bp open reading frame, fagA (Fur-associated gene), was identified immediately upstream of fumC, in an operon with orfX and sodA. Two iron boxes or Fur (ferric uptake regulatory protein) binding sites were discovered just upstream of fagA. Purified P. aeruginosa Fur caused a gel mobility shift of a PCR product containing these iron box regions. DNA footprinting analysis revealed a 37-bp region that included the Fur binding sites and was protected by Fur. Primer extension analysis and RNase protection assays revealed that the operon is composed of at least three major iron-regulated transcripts. Four mucoid fur mutants produced 1.7- to 2.6-fold-greater fumarase activity and 1.7- to 2.3-greater amounts of alginate than wild-type organisms. A strain devoid of the alternative sigma factor AlgT(U) produced elevated levels of one major transcript and fumarase C and manganase-cofactored SOD activity, suggesting that AlgT(U) may either play a role in regulating this transcript or function in some facet of iron metabolism. These data suggest that the P. aeruginosa fagA, fumC, orfX, and sodA genes reside together on a small operon that is regulated by Fur and is transcribed in response to iron limitation in mucoid, alginate-producing bacteria.
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PMID:An operon containing fumC and sodA encoding fumarase C and manganese superoxide dismutase is controlled by the ferric uptake regulator in Pseudomonas aeruginosa: fur mutants produce elevated alginate levels. 904 99

Seeds of Dixie crimson clover (Trifolium incarnatum cv. Dixie) completed germination in 36 hours at 20 C. At 10 C germination was delayed by 24 hours. At 30 C only 20% germinated and the rest remained viable for a long time but not germinable. Different patterns of adenylate energy state and zymograms of acid phosphatase and esterase were observed from seeds grown under the three temperatures for 24 hours. Varied specific activities of protease, alpha-amylase, ATPase, RNase, acid phosphatase, glutamine synthetase, and fumarase were also found. Protein-synthesizing ability was proportional to temperature. These data indicate that temperature regulates seed germination at multiple sites.
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PMID:Temperature regulation of germination in crimson clover seeds. 1665 91