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)

Casein kinase II purified from nuclei of Xenopus laevis oocytes is inhibited by several specific nucleic acids. This kinase, the main phosphorylating activity of the oocyte nucleus, is markedly inhibited by poly U at 10 micrograms/ml, and this polymer is a competitive inhibitor of the phosphorylation of the substrate casein (Kiapp 80 nM). M 13 phage ssDNA and unfractionated yeast tRNA also inhibit between 50 and 200 micrograms/ml. Poly C, poly A, poly AG, dsDNA and Escherichia coli rRNA do not alter activity significantly at similar concentrations. Inhibitions are reversed by RNase (poly U, tRNA) or S1 nuclease (ssDNA). Oocyte casein kinase I or rabbit cAMP-dependent protein kinase are not inhibited by poly U at 200 micrograms/ml. The sensitivity of the casein kinase II to these inhibitors suggests a regulatory role for nucleic acids in nuclear phosphorylation reactions.
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PMID:Nucleic acids can regulate the activity of casein kinase II. 279 84

Poly C preferential RNase previously reported by Levy and Karpetsky [J. Biol. Chem. 255, 2153-2159 (1980)] and Miura et al. [Chem. Pharm. Bull. 32, 4053-4060 (1984)] was extensively purified from chicken liver to homogeneity as determined by SDS-PAGE (RNase CL2). The poly C preference over poly U was slightly higher than that of bovine pancreatic RNase A. However, the kinetic constants for 8 dinucleoside phosphates, CpY and UpY (Y = one of A, G, U, and C) as substrates showed that RNase CL2 was preferential for cytidylic acid, but less so than RNase A, and the influence of Y base on the rate of hydrolysis of CpY or UpY was less marked than in the case of RNase A. The primary structure of RNase CL2 was determined. The molecular weight calculated from the sequence was 13,420. Comparison of the amino acid sequence of RNase CL2 with those of other vertebrate RNases showed that RNase CL2 is a member of the RNase A family, but is not a non-secretory RNase. It retains 3 disulfide bridges of RNase A, but Cys65-Cys72 of RNase A is missing. As for the active site, the amino acid residues of the P0 and P1 sites of RNase A are completely conserved. Among the B1 site components, Thr45 (RNase A numbering) is conserved, but Phe120 and Ser123 are substituted by Leu and Thr, respectively. Among the B2 site residues, Gln69, Asn71, and Glu111 are substituted by other amino acids.
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PMID:Characterization of poly C preferential ribonuclease from chicken liver. 840 69

From the fresh sclerotia of the mushroom Pleurotus tuber-regium, a potent homodimeric ribonuclease exhibiting a molecular weight of 29 kDa in FPLC-gel filtration and sodium dodecyl sulfate-polyacrylamide gel electrophoresis was isolated. The protein was unadsorbed on DEAE-cellulose and adsorbed on Affi-gel blue gel, CM-cellulose and Mono S. It manifested strong ribonucleolytic activity toward Poly G, slight activity toward Poly U and Poly A, and minimal activity toward Poly C. Its optimal pH was determined to be 6.5 when yeast transfer RNA was used as substrate. Its ribonucleolytic activity was resistant to heating at 100 degrees C for 30 min but was inhibited by a number of salts. The protein inhibited cell-free translation in a rabbit reticulocyte lysate with an IC50 of 0.09 nM. Three out of the four amino acid residues at the active site (positions 38-41) of P. ostreatus ribonuclease, YNNF, were also found at positions 17-20 in the P. tuber-regum RNase. However, unlike P. ostreatus RNase, no cysteine residues were detected in the N-terminal sequence.
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PMID:Purification and characterization of a potent homodimeric guanine-specific ribonuclease from fresh mushroom (Pleurotus tuber-regium) sclerotia. 1133 Dec 3

Catalytic antibodies (abzymes) which hydrolyze RNA and DNA were isolated from bovine colostrum by sequential chromatography on Protein A Sepharose, denaturated DNA-cellulose, Mono Q, and gel permeation chromatography on Superose 12 at pH 2.3 after acidic shock. Metachromatic agar containing toluidine blue and yeast RNA was used to measure RNase activity. Electrophoresis in agarose showed DNase activity on plasmid DNA from Escherichia coli and DNA from calf thymus in fractions from all 4 purification steps. Gel permeation chromatography showed that the abzymes hydrolysed both a single-stranded polyadenylic acid (Poly A) and single-stranded polycitidylic acid (Poly C), while partially purified RNase from the colostrum hydrolysed Poly (C), but not Poly (A). Electrophoresis of purified abzymes under denaturing conditions showed protein bands of molecular mass corresponding to heavy and light chains of IgG. The abzymes immunoreacted with anti-bovine IgG. The RNase activity of the purified abzymes represented 0.022% of total RNase activity in the colostrum; acid shock and gel filtration at low pH reduced the specific RNase activity of abzymes 3.6-fold. The RNase activity of abzymes at pH 6.6 was reduced by 90% by heat treatment at 75 degrees C for 52 min.
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PMID:Isolation and partial characterization of catalytic antibodies with oligonuclease activity from bovine colostrum. 1193 74