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 inactivation of lysozyme caused by the radicals produced by thermolysis of 2,2'-azo-bis-2-amidinopropane can be prevented by the addition of different compounds that can react with the damaging free radicals. Compounds of high reactivity (propyl gallate, Trolox, cysteine, albumin, ascorbate, and NADH) afford almost total protection until their consumption, resulting in well-defined induction times. The number of radicals trapped by each additive molecule consumed ranges from 3 (propyl gallate) to 0.12 (cysteine). This last value is indicative of chain oxidation of the inhibitor. Uric acid is able to trap nearly 2.2 radicals per added molecule, but even at large (200 microM) concentrations, a residual inactivation of the enzyme is observed, which may be caused by urate-derived radicals. Compounds of lower reactivity (tryptophan, Tempol, hydroquinone, desferrioxamine, diethylhydroxylamine, methionine, histidine, NAD+ and tyrosine) only partially decrease the lysozyme inactivation rates. For these compounds, we calculated the concentration necessary to reduce the enzyme inactivation rate to one half of that observed in the absence of additives. These concentrations range from 9 microM (tryptophan and Tempol) to 5 mM (NAD+).
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PMID:Effect of additives on the inactivation of lysozyme mediated by free radicals produced in the thermolysis of 2,2'-azo-bis-(2-amidinopropane). 177 8

Partially purified enzymatic fractions from extracts of Escherichia coli B/r catalyse transfer of the isotope label from [adenine-2,8-(3)H]NAD+ to some bacterial proteins, as well as to hen egg-white lysozyme. The radioactive group in the modified lysozyme was identified as mono(ADP-ribose). Several bacterial proteins were labelled in vivo with 32P; the presence of the label in the form of an ADP-ribosyl group was shown in one of them.
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PMID:ADP-ribosylation of proteins in non-infected Escherichia coli cells. 626 16

Purified recombinant poly(hydroxyalkanoic acid) (PHA) synthase from Chromatium vinosum (PhaECCv) was used to examine in vitro the specific synthase activity, turnover of R-(-)-3-hydroxybutyryl coenzyme A (3HB-CoA) and poly(3-hydroxybutyric acid) formation under various conditions. The 3HB-CoA consumption was terminated by a reaction-dependent inactivation of the PHA synthase. Salts (MgCl2, CaCl2, NaCl), proteins (bovine serum albumin, lysozyme, phasine) or detergent (Tween 20) increased the 3HB-CoA turnover to 2.5-fold. Specific PHA synthase activity was only partially affected by the added components. In general, a higher concentration of salt often inhibited the activity of PhaECCv without affecting the yield according to 3HB-CoA turnover. NAD+ and NADP+ (2 mM) inhibited PhaECCv completely, whereas NADH and NADPH did not. Macroscopic poly(3HB) granules were formed in vitro if PhaECCv was incubated in the presence of sufficient amounts of 3HB-CoA and if MgCl2 was present. The form and size of the granules synthesized in vitro were affected by the concentration of the PHA synthase protein as well as by bovine serum albumin and the GA24 protein, a poly(3HB)-granule-associated protein of Alcaligenes eutrophus. Scanning electron micrographs from the synthesized granules were obtained. The granules consisted of poly(3HB) that had a molar mass in the range (1-2) x 10(6) g/mol.
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PMID:In vitro biosynthesis of poly(3-hydroxybutyric acid) by using purified poly(hydroxyalkanoic acid) synthase of Chromatium vinosum. 958 Dec 89