Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.2.1.17 (lysozyme)
 21,489 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The electronic-conformational interactions (ECI) of enzyme-substrate complexes are treated with the help of the method of intermolecular orbitals. The applicability of this approach is shown concerning some problems, related to ECI. The activation of N2 in the active site of nitrogenase, the proton transfer in the system, containing hydrogen bonds, and the modelling of the initial state of the reaction of lysozyme with oligosaccharides were examined.
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PMID:[Electronic-conformational interactions of molecular-biological systems. II. Study of the enzyme-substrate complex with the help of qualitative methods of quantum chemistry]. 46 Jan 99

The components of the nitrogenase complex, MoFe-protein and FeMo-cofactor, possessing no ATPase or nitrogen-fixing activity, maintain the 18O-exchange at the level of 1 atom of 18O per molecule of Pi, which is inhibited by ATP. The Fe-protein complex does not catalyze the 18O-exchange. The nitrogenase components do not hydrolyze the substrates for phosphatase (p-nitrophenylphosphate, beta-glycerophosphate, glucose 1-phosphate and ribose 5-phosphate). The artificial albumin-containing MoFe- and Fe-proteins and the carboxyl group-containing proteins (albumin, hemoglobin, lysozyme) as well as sodium molibdate do not catalyze the 18O-exchange. It is assumed that the site of the ATPase center which is subjected to phosphorylation, is located on the MoFe-protein.
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PMID:[Localization of the ATPase site of nitrogenase by isotopic oxygen exchange [180]-Pi in equilibrium with H20]. 621 20

A method of statistical processing of electron micrographs of molecular objects modified by electron-dense labels containing mercury is proposed. The method allows one to study size, degree of modification and heterogeneity of objects. Application of the method for study of modified nitrogenase and its Fe-Mo containing co-factor, lysozyme, myoglobin, sodium thiomolybdate and trichlortriazine has shown the features of chemical modification and electron micrographs of these molecules. The method can be used for processing of data about complex biological objects modified by electron-dense labels.
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PMID:[Statistical analysis of electron microphotographs of bioobjects, labelled by electron-dense mercarbide markers]. 781 10

Five species of filamentous cyanobacteria and two species of Flexibacter were isolated from domestic sewage. Cells and filtrates of F. flexilis and F. sancti lysed the cyanobacterium Oscillatoria williamsii. Inhibition of the photosynthetic electron transport reactions, and glycolate dehydrogenase and nitrogenase activity of O. williamsii due to its incubation with F. flexilis, were observed. Scanning electron micrographs revealed the attachment of F. flexilis to the sheaths of O. williamsii which resulted in the excretion of lysozyme and lysis of the cyanobacterium. Seasonal variations of Flexibacter spp showed that they were more abundant in the aeration tanks during June compared with sewage effluents.
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PMID:Lysis of cyanobacteria with Flexibacter spp isolated from domestic sewage. 815 27

Grau, F. H. (University of Wisconsin, Madison), and P. W. Wilson. Hydrogenase and nitrogenase in cell-free extracts of Bacillus polymyxa. J. Bacteriol. 85:446-450. 1963.-Washed cells of Bacillus polymyxa strain Hino, treated with lysozyme, yield cell-free extracts that rapidly evolve hydrogen from reduced methyl viologen, formate, and pyruvate. Hydrogenase is particulate, 86% being sedimented at 105,000 x g for 60 min. About 65% of the pyruvate metabolized is oxidized to acetyl phosphate, hydrogen, and carbon dioxide; the rest is converted to acetoin. These extracts fix considerable amounts of N(2) (15) when pyruvate is supplied as substrate, but will not fix with formate or mannitol. Centrifugation studies, and the absence of fixation with mannitol, show that this fixation is not caused by residual whole cells or spheroplasts. Cell-free fixation by B. polymyxa is similar to that by Clostridium pasteurianum. A short time lag in fixation occurs, and an optimal concentration of pyruvate is needed for maximal fixation. Arsenate causes a strong inhibition of fixation, presumably because arsenolysis of acetyl phosphate makes high-energy phosphate unavailable for the fixation process.
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PMID:Hydrogenase and nitrogenase in cell-free extracts of Bacillus polymyxa. 1394 23

Heterocysts were isolated from the N(2)-fixing cyanobacterium Anabaena variabilis after vegetative cells were disrupted by treatment with lysozyme and cavitation in a sonic cleaning bath. The acetylene-reducing (nitrogenase) activity of the isolated heterocysts, ca. 5.0 mumol (mg of chlorophyll a)(-1) min(-1) in the presence of H(2) and light, accounted for an average of 60% of the nitrogenase activity of whole filaments, and was relatively insensitive to inactivation by oxygen. Soluble extracts derived from intact filaments grown with (55)Fe, and from their heterocysts and vegetative cells, were subjected to electrophoresis. The nitrogenase and nitrogenase reductase bands (MoFe protein and Fe protein, or component 1 and component 2, respectively) were identified in these nondenaturing gels, and their radioactivities were quantitated. The isolated heterocysts accounted for an average of 91% of the nitrogenase and 69% of the nitrogenase reductase of the original filaments.
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PMID:High recovery of nitrogenase activity and of Fe-labeled nitrogenase in heterocysts isolated from Anabaena variabilis. 1659 99