Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.1.27.5 (RNase)
 17,967 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Newborn rat epidermis was extracted using methods reported to extract keratohyalin granules. All extraction techniques yielded preparations of solubilized proteins with similar sodium dodecyl sulfate-polyacrylamide electrophoretograms. The solubilized proteins were fractionated on a Sephadex G-200 column and six low molecular weight protein fractions (apparent molecular weights between 10000 and 18000) have been identified. Four of these have been isolated and partially characterized. Two of the fractions are characterized by high histidine, arginine, serine and glutamic acid concentrations and have an amino acid composition similar to that of the histidine-rich protein characteristic of keratohyalin granules. One of these histidine-rich fractions (molecular weight 13700) has ribonuclease activity. The other two isolated fractions are basic proteins, one of which (molecular weight 12800) is a basic lysine-rich protein. This protein is not found in any other tissues of the new born or adult rat.
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PMID:Fractionation and characterization of low molecular weight solubilized proteins of newborn rat keratohyalin granules. 99 74

Conformational changes induced in antibody molecules and in their Fab fragments by binding of antigen were investigated by the circular polarization of the fluorescence emitted by the tryptophan residues. This property of the fluorescence is related to the asymmetry, and thus to the conformation and environment, of the emitting chromophore. Changes in the circular polarization of the fluorescence of the antibody were observed upon binding of RNase to anti-RNase, of poly(DL-alanyl)-poly(L-lysine) to antipoly(D-alanine), and of the "loop" of lysozyme, a monovalent antigenic determinant, to anti"loop." The spectral changes were observed at different antigen-antibody ratios, including high antigen excess, indicating that they are due to antigen binding and not to aggregation. The circular polarization of fluorescence also detects changes in conformation of the different Fab fragments upon binding of the corresponding antigens. These changes in conformation were, however, markedly different from those observed for the whole antibody molecules, and indicated an interaction between the Fc and Fab fragments in the antibody molecule, and probably a change in the conformation of Fc upon binding of antigen to the antibody. In contrast, the small hapten, phosphorylcholine, did not induce a change in the circular polarization of the fluorescence of its antibody or corresponding Fab fragments. Reduction of the interchain disulfide bonds of the antibodies abolished the antigen-induced spectral changes due to the presence of the Fc portion in the molecule, but not the changes observed in Fab, suggesting that the disulfide bonds at the hinge region of the antibody are required for the transmission of the conformational change from the Fab to the Fc.
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PMID:Antigen-induced conformational changes in antibodies and their Fab fragments studied by circular polarization of fluorescence. 105 92

(1) By incubation in 0.1 M NaOH for 10 min at room temperature, it is possible to "saponify" some of the methyl carboxylate linkages in bulk yeast tRNA. By incubation with S-adenosyl(Me-14-C)methionine and either homologous (yeast) or heterologous (wheat-embryo) enzymes, it is then possible to "re-esterify" the "saponified" tRNA and thereby effect selective labelling at 5-carboxymethyluridine (Me-14-C)methyl ester residues. (2) There is also selective labelling at 2-thio-5-carboxymethyluridine (Me-14-C)methyl ester residues when "saponified" yeast tRNA is incubated with S-adenosyl(Me-14-C)methionine and homologous (but not heterologous) enzymes. (3) When selectively labelled yeast tRNA is hydrolyzed by RNase T-1, both 5-carboxymethyluridine (Me-14-C)methyl ester and its 2-thio-analogue are released as part of large oligonucleotides, each of which contains roughly 10 nucleotide residues. (4) There are at least three, and possibly four (Me-14-C)methyl ester-containing oligonucleotides released by RNase T-1 digestion of selectively labelled "saponified" yeast tRNA. A comparison of the chromatographic properties of the different (Me-14-C)oligonucleotides suggests that the same 5-carboxymethyluridine residues are probably targets for both homologous and heterologous enzymes. (5) The properties of the selectively labelled oligonucleotides are consistent with the view that some of them probably are derived from yeast tRNA-3-Glu, tRNA-2-Lys, and tRNA-3-Arg, all of which are known to contain 5-carboxymethyl methyl esters as part of their anticodon sequences.
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PMID:Selective labelling ot the methyl carboxylate substituents found in the anticodon sequences of some species of yeast transfer RNA. 109 33

The nucleotide sequences of species I RNA coded for by bacteriophages T2 and T6 have been analyzed using 32-P-labeled material from T2 and T6-infected cultures of Escherichia coli. The T1 and pancreatic ribonuclease digestion products were partially analyzed and the results were compared with nucleotide sequences from T4 species I RNA to obtain a minimum estimate of the number of nucleotide sequence differences among the three species I RNAs. Analysis of fragments obtained by digestion with epsilon-carboxymethyl-lysine-41-pancreatic ribonuclease and with E. coli Q13 S30 crude extract was also performed to provide some additional confirmation for the nucleotide sequences that were derived for the T2 and T6 species I RNAs. T2 species I RNA was found to be different at three positions in the nucleotide sequence, and unlike T4 species I RNA, contained in addition the modified nucleotide, psi, in a region where the proposed secondary structure is identical to the TpsiC-loop of a tRNA. T6 species I RNA was found to contain nucleotide differences from the T4 species I RNA sequence at four positions. The U at position 119 in the sequence appears to be modified to psi only to a small extent. While a biological function for species I RNA is unknown, the fact that there is over 97% homology in the sequences suggests strong evolutionary pressures to retain the nucleotide sequence in the T-even genomes.
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PMID:Nucleotide sequence determination of bacteriophage T2 and T6 species I ribonucleic acids. 109 87

1. RNAase (ribonuclease) U2, a purine-specific RNAase, was reduced, aminoethylated and hydrolysed with trypsin, chymotrypsin and thermolysin. On the basis of the analyses of the resulting peptides, the complete amino acid sequence of RNAase U2 was determined, 2. When the sequence was compared with the amino acid sequence of RNAase T1 (EC 3.1.4.8), the following regions were found to be similar in the two enzymes; Tyr-Pro-His-Gln-Tyr (38-42) in RNAase U2 and Tyr-Pro-His-Lys-Tyr (38-42) in RNAase T1, Glu-Phe-Pro-Leu-Val (61-65) in RNAase U2 and Glu-Trp-Pro-Ile-Leu (58-62) in RNAase T1, Asp-Arg-Val-Ile-Tyr-Gln (83-88) in RNAase U2 and Asp-Arg-Val-Phe-Asn (76-81) in RNAase T1 and Val-Thr-His-Thr-Gly-Ala (98-103) in RNAase U2 and Ile-Thr-His-Thr-Gly-Ala (90-95) in RNAase T1. All of the amino acid residues, histidine-40, glutamate-58, arginine-77 and histidine-92, which were found to play a crucial role in the biological activity of RNAase T1, were included in the regions cited here. 3. Detailed evidence for the amino acid sequence of the sequence of the proteins has been deposited as Supplementary Publication SUP 50041 (33 PAGES) AT THE British Library (Lending Division)(formerly the National Lending Library for Science and Technology), Boston Spa, Yorks. LS23 7BQ, U.K., from whom copies can be obtained on the terms indicated in Biochem. J. (1975), 145, 5.
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PMID:The amino acid sequence of ribonuclease U2 from Ustilago sphaerogena. 115 64

Polycations, including ribonuclease A, ribonuclease S protein and peptide, spermine, spermidine, and polylysines, enhance unstimulated and stimulated adenylate cyclase activity of beef thyroid membranes at low concentrations and inhibit these activities at high concentrations. Peak polylysine stimulation occurs with degrees of polymerization of 6 to 14, and for large polymers a potency limit for this maximum is reached at 4 X 10(-5) M expressed as lysine residues. Both enhancement and inhibition appear to be due to charge-charge interactions and are abolished by KC1. Polyanions are inhibitory only. The biphasic effect of polycations is seen on basal cyclase activity, occurs with prostaglandin E1- and 5'-guanylyl-imidodiphosphate-stimulated cyclase, but is most striking with thyrotropin. There is little enhancement of F--activated cyclase. The enhancement is not sensitive to changes in pH, Mg2+, or regenerating system and does not correlate with the stability constants between polycations and ATP. We suggest that the polycation effect is a general, electrostatic effect on membrane conformation and is not restricted to a particular receptor domain.
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PMID:Charge effects in the activation of adenylate cyclase. 115 87

Dromedary (Camelus dromedarius) RNAase (ribonuclease) was isolated from pancreatic tissue by affinity chromatography. Peptides obtained by digestion with different proteolytic enzymes and CNBr were isolated by gel filtration, preparative high-voltage paper electrophoresis and paper chromatography. Peptides were sequenced by the dansyl-Edman method. All peptide bonds were overlapped by one or more peptides. The polypeptide chain consists of 123 amino acids. A deletion (position 39) was observed in an external loop of the polypeptide chain (residues 35-40), as was found earlier to horse RNAase (Scheffer & Beintema, 1974). A heterogeneity was found at position 103 (glutamine and lysine). Dromedary RNAase differs at 23-32% of the positions from all other pancreatic RNAases sequenced to date. In evolutionary terms this indicates that dromedary RNAase has evolved independently during the larger part of the evolution of the mammals. Detailed evidence for the sequence has been deposited as Supplementary Publication SUP 50046 (14 pages) at the British Library (Lending Division), Boston Spa, Wetherby, W. Yorks. LS23 7BQ, U.K., from whom copies may be obtained on the terms given in Biochem. J. (1975) 145, 5.
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PMID:The amino acid sequence of dromedary pancreatic ribonuclease. 116 57

The physico-chemical properties have been studied of RNase A selectively modified at the E-NH2-group of Lys-7 and Lys-41 with pyridoxal-P. Modification did not affect conformational stability of the protein globule, thus all changes in the molecule of the modified RNase A were localised around the alkylated Lys residue. In the both cases pyridoxyl-P. The residue was shown to be localized in the active site region of the (P-Pxy)-Lys-7-RNase A and its chromophore parts was highly exposed to the solvent. (P-Pxy) E-Lys-7-RNase A and its chromophore parts was highly exposed to the solvent. In the Lys-41 derivative, pyridoxamine-P was situated exactly in the active site and is partially hidden in the protein grobule. The pH-dependence of absorption spectra indicates that the chromophore of pyridoxyl-P in modified proteins is quite sensible to the ionic state of its surrounding. The usefulness of pyridoxyl-P as a reporter group was proved in the study with (P-Pxy)-Lys-7-RNase A. Some conformational changes involving His-119 were shown to take place in the course of the enzyme-nucleotide complex formation.
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PMID:[Physico-chemical properties of ribonuclease A modified with pyridoxal-5'-phosphate]. 121 71

Bovine pancreatic ribonuclease A was allowed to react with pyridoxal 5'-phosphate at pH 8 and 4 degrees. After reduction with sodium borohydride, the principal products formed in the initial stages of modification were separated by successive chromatography on CM-cellulose and SP-Sephadex. The isolated derivatives were identified as Nalpha-(P-pyridoxyl)-Lys-1-,Nepsilon-(P-pyridoxyl)-Lys-7-, and Nepsilon-(P-pyridoxyl)-Lys-41-ribonuclease A. These results are interpreted in terms of the specificity of pyridoxal-P as a protein reagent.
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PMID:Modification of bovine pancreatic ribonuclease A with pyridoxal 5'-phosphate. Isolation and identification of derivatives. 123 72

This communication describes a simple method for synthesizing cleavable bifunctional imido esters of different chain lengths. These reagents, which form covalent crosslinks between lysine residues of proteins, contain a disulfide bond which is cleaved under mild conditions by reducing agents such as 2-mercaptoethanol. The reagents are synthesized via the dithiobisnitrile which is prepared in high yield by reacting the appropriate omega-activated nitrile with sodium polysulfide and is then converted quantitatively to the diimidate. Three such reagents were prepared: dimethyl 3.3'-dithiobispropionimidate, dimethyl 4,4'-dithiobisbutyrimidate, and dimethyl 6-6'-dithiobiscaproimidate. The first was synthesized from acrylonitrile, and the others from the appropriate omega-bromonitriles. Experiments with the bispropionimidate and a test protein, pancreatic ribonuclease, have shown the reagent to be effective in producing multimeric crosslinked complexes, from which monomeric proteins can recovered after treatment with 2-mercaptoethanol. The reagents are suitable for studies of ribosomal structure.
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PMID:Synthesis of a cleavable protein-crosslinking reagent for the investigation of ribosome structure. 126 50


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