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

Bacteria were isolated from lake water, and their ability to remain viable in a dilute, nutrient-deficient environment was tested by a method that permits suspension of test bacteria between two appressed microporous membranes in an aqueous environment. This approach permitted separation of the lake isolates into two categories. Members of the tribe Klebsielleae were shown to have a prolonged survival rate of 40% or better after 24 h, whereas nonsurvivors were not viable for much longer than 24 h. These nonsurvivors belonged to the genera Acinetobacter, Aeromonas, Alcaligenes, Erwinia, Escherichia, Flavobacterium, and Pseudomonas. Differences in ribonuclease and adenosine triphosphatase levels between Escherichia coli (nonsurvivor) and Klebsiella (survivor) cells were detected. At pH 7.5, stressed E. coli cells contained 14% of the adenosine triphosphatase activity detected in the control, whereas at pH 5.5, in the presence of calcium ions, these same cells contained 50% of the control adenosine triphosphatase levels. At pH 7.2, E. coli cells were strongly inhibited by an adenosine triphosphatase inhibitor, bathophenanthroline (88%); oligomycin (64%); and the proton ionophore carbonyl- cyanide-m-chlorophenyl hydrazone (67%). Both sodium azide and valinomycin were only moderately inhibitory (15 and 28%, respectively). Although the ability to scavenge internal endogenous reserves seems important, we postulate that certain enteric bacteria are capable of utilizing acidic conditions (pH 5.5) as an electrochemical gradient to generate necessary high-energy intermediates for prolongation of survival beyond that possible in environments of near-neutraL pH.
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PMID:Bacterial survival in a dilute environment. 645 90

The expression of cathepsin B- and L-specific mRNAs as well as active forms of the enzymes was determined in mouse placenta and visceral yolk sac from 7.5 through 17.5 days postconception, a period marked by major anatomic transitions in the mouse conceptus. The level of specific mRNA was determined relative to the 28S ribosomal RNA in a series of multiprobe ribonuclease protection assays using high-specific-activity antisense cathepsin B and L riboprobes. The molecular forms of active cysteine proteases present in the tissues at the time of extraction were detected using a membrane-permeant radiolabeled active site-specific inhibitor, Fmoc-[(125)I(2)]Tyr-Ala-CHN(2). The results of this study show that the expression of active cathepsin L relative to active cathepsin B is significantly higher in visceral yolk sac than in placenta, consistent with a higher proteolytic requirement for the former tissue. Active cathepsin L was highest at Day 9.5 in visceral yolk sac, a stage at which it has been shown that proteolysis in this organ is required for production of amino acids for embryonic protein synthesis. Cathepsin L mRNA was also elevated in the Day 9.5 placenta, but paradoxically this did not result in an increase in cellular active enzyme. An unknown protein, termed p14, highly expressed in placenta, also reacted with the inhibitor. Expression of this protein was highest early during gestation in the ectoplacental cone, suggesting that p14 may be important in the implantation process.
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PMID:Expression of cysteine proteases in extraembryonic tissues during mouse embryogenesis. 1060 Jan 78

Some properties of the cell-free and cell-associated hemolysins of Escherichia coli were studied. Several strains of E. coli that were isolated from intestines of pigs with edema disease produce large quantities of cell-free hemolysin when grown in the presence of an extract of meat. The component of meat that stimulates production of cell-free hemolysin is not extracted by lipid solvents and is not dialyzable. The cell-free hemolysin is an acidic substance that occurs in two forms. It is inactivated by trypsin but not by lecithinase, lysozyme, ribonuclease, or deoxyribonuclease, shows optimum activity between pH 7 and 8, and requires calcium ion for activity. It does not appear to be an enzyme. The kinetics of the lytic reaction are most consistent with the hypothesis that one molecule of cell-free hemolysin is sufficient to lyse one erythrocyte and that it is inactivated in the lytic reaction. The cell-free hemolysin does not sufficiently damage the cell during the prelytic period to cause lysis after the hemolysin-calcium-erythrocyte complex has been disrupted. The cell-associated hemolysin was not separated from the cell by autolysis, freezing, sonic treatment, or treatment with trypsin or lysozyme. It appears to be closely associated with the metabolic status of the cell. Organisms that are highly hemolytic under usual conditions of assay immediately lose most of their hemolytic capability in the presence of sodium cyanide, streptomycin, nalidixic acid, and rifampin.
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PMID:Properties of the Hemolytic Activities of Escherichia coli. 1655 36

The application of boronic acid affinity chromatography to glycoprotein/glycopeptide enrichment is increasingly maturing. The enrichment selectivity, biocompatibility, and facile operation protocol are key aspects in efficient enrichment methods. In this work, a novel triazo-cyanide boronic acid functionalized material (TCNBA) was prepared using triazo-cyanide click chemistry. The TCNBA was proved to be successfully synthesized through infrared ray (IR) characterization. Subsequently, the glycopeptide/glycoprotein enrichment selectivity of the TCNBA was evaluated. Matrix-assisted laser desorption/ionization time-of-flight mass (MALDI-TOF MS) was employed for the glycopeptide enrichment selectivity evaluation. Taking the digestion of horseradish peroxidase (HRP) and immunoglobulin G (IgG) as samples, 13 and 11 glycopeptides could be characterized with improved signals after TCNBA enrichment, respectively. High abundance non-glycopeptides could be removed effectively from the eluting fraction. This result indicates the high glycopeptide enrichment selectivity of TCNBA. In addition, a mixture of HRP and bovine serum albumin (BSA) enzymatic solution (1:10, amount of substance ratio) was utilized as a sample, and five glycopeptide signals could be identified following enrichment. To evaluate the glycoprotein enrichment selectivity, sodium salt-polyacrylamide gel electrophoresis (SDS-PAGE) was adopted as an evaluation method. Mixtures of HRP, IgG, BSA, and ribonuclease B (RNaseB) proteins were employed as samples, and the results demonstrated that TCNBA had a high glycoprotein enrichment selectivity. The application of TCNBA to the analysis of a real biosample was also evaluated using human plasma. The results indicated the TCNBA could be utilized in large-scale glycoprotein analysis.
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PMID:[Preparation of novel phenyl boronic acid functionalized silica gel using triazo-cyanide click chemistry and its application in glycoprotein/glycopeptide selective enrichment]. 3090 Aug 56