Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.1.26.9 (ribonuclease)
 6,589 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Lambda coli phage is not inactivated by chymotrypsin, trypsin, or ficin. T(2) phage is slowly inactivated by high concentrations of (alpha-, beta-, gamma-, or Delta-chymotrypsin, but not by trypsin or ficin. P(1) phage is slowly inactivated by alpha-, beta-, or gamma-chymotrypsin, or ficin, more rapidly by Delta-chymotrypsin, and much more rapidly by trypsin. Crystalline egg albumin, crystalline serum albumin, E. coli nucleoprotein, and yeast nucleoprotein are hydrolyzed slowly by alpha-chymotrypsin. Yeast nucleoprotein, like P(1) phage, is hydrolyzed more rapidly by Delta-chymotrypsin than by alpha-chymotrypsin, but not by trypsin or ficin. Neither phages nor native proteins were attacked by papain, carboxypeptidase, deoxyribonuclease, or ribonuclease.
J Gen Physiol 1964 Sep
PMID:THE EFFECT OF PROTEOLYTIC ENZYMES ON E. COLI PHAGES AND ON NATIVE PROTEINS. 1421 51

The pif gene (per os infectivity factor) of Spodoptera littoralis nucleopolyhedrovirus (SpliNPV) encodes a structural protein essential for oral infection. This protein is expressed in very low quantities. In this study, transcription and promoter analysis of SpliNPV pif were carried out to understand more fully the regulation of pif gene expression. Transcription in the pif gene region was examined using RT-PCR, Northern blot, primer extension, ribonuclease protection and 3' RACE. The pif gene was encoded by a late bicistronic messenger, which was characterized. This 1.9 kb messenger was present in very small amounts. In addition, this messenger was part of a set of six late mRNAs overlapping the pif sequence. A functional complementation assay was used to analyse the pif promoter. This assay allowed the detection of amounts of PIF which were sufficient for the production of orally infectious virions. The 13 bp region upstream from the initial ATG of pif was required and sufficient for the production of orally infectious virions. This promoter region was much shorter than the studied baculovirus promoters. A late promoter motif (TTAAG) is situated at the 5' end of this region. This motif was shown to be the promoter core by using single mutations of the motif in the complementation assay. These results suggest that the low expression of the pif gene is regulated chiefly at the transcriptional level.
J Gen Virol 2004 Feb
PMID:Transcription and promoter analysis of pif, an essential but low-expressed baculovirus gene. 1476 90

The proteasome is a multicatalytic complex involved in many cellular processes in eukaryotes, such as protein and RNA turnover, cell division, signal transduction, transcription and translation. Intracellular pathogens are targets of its enzymic activities, and a number of animal viruses are known to interfere with these activities. The first evidence that a plant virus protein, the helper component-proteinase (HcPro) of Lettuce mosaic virus (LMV; genus Potyvirus), interferes with the 20S proteasome ribonuclease is reported here. LMV infection caused an aggregation of the 20S proteasome to high-molecular mass structures in vivo, and specific binding of HcPro to the proteasome was confirmed in vitro using two different approaches. HcPro inhibited the 20S endonuclease activity in vitro, while its proteolytic activities were unchanged or slightly stimulated. This ability of HcPro, a pathogenicity regulator of potyviruses, to interfere with some of the catalytic functions of the 20S proteasome suggests the existence of a novel type of defence and counter-defence interplay in the course of interaction between potyviruses and their hosts.
J Gen Virol 2005 Sep
PMID:HcPro, a multifunctional protein encoded by a plant RNA virus, targets the 20S proteasome and affects its enzymic activities. 1609 19

It is shown that in the medium rich with inorganic phosphate there is a stimulation of biosynthesis of ribonuclease from B. amyloliquefaciens (barnase) by actinomycin D, while biosynthesis of ribonucleases from B. intermedius (binase) and B. pumilus (KNase Bpu) in these conditions was suppressed. Features of biosynthesis of binase and RNase Bpu, directed by the barnase promoter, and also expression of chimeric gene of RNase Bpu with leader peptide of barnase were investigated. It was established that stimulation of synthesis of extracellular ribonuclease from B. amyloliquefaciens in the presence of actinomycin D was defined by structure of leader sequences.
Mol Gen Mikrobiol Virusol 2005
PMID:[The role of the promoter and leader sequences of extracellular ribonuclease from Bacillus amyloliquefaciens in regulation of enzyme biosynthesis]. 1617 98

Dilute solutions of sulfhydryl enzymes (phosphoglyceraldehyde dehydrogenase, adenosinetriphosphatase, succinoxidase) showed reduced activity on irradiation by small amounts of x-rays. When the inhibition was partial the enzyme was reactivated on addition of glutathione. When the inhibition was more complete, reactivation was only partial. These observations are interpreted as being due to oxidation of the -SH groups of the protein by the products of water irradiation, the radicals OH and O(2)H, and H(2)O(2) and atomic oxygen. The irreversible inhibition which occurs when the dose of x-rays is increased is attributed to protein denaturation. Inhibition of the non-sulfhydryl enzymes trypsin, catalase, and ribonuclease, which required larger amounts of x-rays, is attributed to protein denaturation. These experiments are further evidence that inhibition of enzymes by ionizing radiations is due to the indirect action of the products of irradiated water rather than to direct ionization of the enzyme through collision with the ionizing radiation.
J Gen Physiol 1949 Mar 20
PMID:Studies on the mechanism of action of ionizing radiations; inhibition of enzymes by X-rays. 1811 65

1. The ability of crystalline ribonuclease to hydrolyze proteins is due to impurities present in the preparations and not to an intrinsic property of the ribonuclease molecule. The amounts of these impurities vary enormously with different preparations. 2. The dangers inherent in the use of crystalline enzymes as specific tools, without assaying them for all possible interfering impurities, are emphasized.
J Gen Physiol 1948 Sep 10
PMID:Proteolytic contaminants of crystalline ribonuclease. 1888 74

A method is described for the preparation of crystalline ribonuclease free from all measurable traces of proteolytic enzymes.
J Gen Physiol 1948 Sep 10
PMID:A method for the preparation of protease-free crystalline ribonuclease. 1888 75

1. A crystalline enzyme capable of digesting yeast nucleic acid has been isolated from fresh beef pancreas. 2. The enzyme called "ribonuclease" is a soluble protein of albumin type. Its molecular weight is about 15,000. Its isoelectric point is in the region of pH 8.0. 3. Ribonuclease splits yeast nucleic acid into fragments small enough to diffuse readily through collodion or cellophane membranes. 4. The split products of digestion, unlike the undigested yeast nucleic acid, are not precipitable with glacial acetic acid or dilute hydrochloric acid. 5. The digestion of yeast nucleic acid is accompanied by a gradual formation of free acid groups without any significant liberation of free phosphoric acid. 6. Ribonuclease is stable over a wide range of pH even when heated for a short time at 100 degrees C. Its maximum stability is in the range of pH 2.0 to 4.5. 7. Denaturation of the protein of ribonuclease by heat or alkali, or digestion of the protein by pepsin, causes a corresponding percentage loss in the enzymatic activity of the material.
J Gen Physiol 1940 Sep 20
PMID:CRYSTALLINE RIBONUCLEASE. 1987 97

Electrophoretic studies on purified crystalline ribonuclease showed the absence of any impurities differing in mobility from the bulk of material. The isoelectric point of ribonuclease was found by electrophoresis to be at about pH 7.8. Ultracentrifuge studies indicated fair homogeneity of ribonuclease in solution. Only one moving component has been observed. The molecular weight of ribonuclease was found to be 12,700 from rate of sedimentation (S(25) = 1.85 x 10(-13) in 0.5 M (NH(4))(2)SO(4)) and diffusion measurement (D = 1.36 x 10(-6) in 0.5 M (NH(4))(2)SO(4)), in good agreement with the average value of 13,000 found from equilibrium measurements. This low value for the molecular weight of a protein would seem to discredit the value 17,600 as representing a universal unit weight for proteins in general.
J Gen Physiol 1940 Nov 20
PMID:MOLECULAR WEIGHT AND ELECTROPHORESIS OF CRYSTALLINE RIBONUCLEASE. 1987 9

The reversible inactivation of tobacco mosaic virus by crystalline ribonuclease is reported. Studies on the effect of time of standing on the amount of inactivation, and on the effect of dilution and repeated high speed centrifugation on the recovery of virus activity, and the preparation of an insoluble virus-enzyme complex show that the inactivation is brought about at least in part by a combination between virus and enzyme. The significance of the fact that ribonuclease has no detectable effect on the virus nucleic acid when the latter is in combination with protein in the form of virus is discussed with respect to the structure of the virus.
J Gen Physiol 1942 Jan 20
PMID:THE REVERSIBLE INACTIVATION OF TOBACCO MOSAIC VIRUS BY CRYSTALLINE RIBONUCLEASE. 1987 89


<< Previous 1 2 3 4 5 6 7 Next >>