Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P04040 (Catalase)
 3,577 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The abilities of a number of compounds of biological interest to protect alpha-1-proteinase inhibitor (alPI) against the loss of elastase inhibitory capacity (EIC) resulting from exposure to gas-phase cigarette smoke have been tested. We have identified several species that protect AlPI. Amino acids prevent the loss of EIC in a manner that correlates with their pK alpha-values; only the unprotonated amine provides protection. Catalase partially prevents the loss of EIC, suggesting that hydrogen peroxide produced from the reduction of oxygen in cigarette smoke extracts is responsible for at least some of the smoke-induced inactivation. The best protection against smoke-induced loss of EIC was provided by two biologically important antioxidant species: glutathione and ascorbic acid. Both species provide almost complete protection to alPI under the experimental conditions used. The nature of species that protect AlPI against the inactivation caused by exposure to gas-phase smoke provides clues upon which speculations about the mechanism of this inactivation may be based. The identification of protective species could lead to the development of compounds that smokers could take (for example, vitamin C) that would protect their lung tissue against the oxidative damage caused by cigarette smoke.
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PMID:The inactivation of alpha-1-proteinase inhibitor by gas-phase cigarette smoke: protection by antioxidants and reducing species. 348 47

A procedure for measuring the oxidant content of aqueous condensates of tobacco cigarette smoke is described. The procedure was used in conjunction with analysis of the ability of the smoke solutions to inactivate the elastase inhibitory capacity (EIC) of alpha 1-antitrypsin. The ability of the smoke of a brand to inactivate alpha 1-antitrypsin correlates well with the known tar and nicotine and with the amount of oxidants as measured using o-dianisidine. Filters were found to remove about 73% of the oxidants from smoke. Smoke from a commercial nontobacco cigarette was also found to contain a significant amount of oxidants and to also destroy alpha 1-antitrypsin. Catalase and superoxide dismutase reduce the effect of solutions containing smoke on the EIC of alpha 1-antitrypsin, suggesting that peroxides and superoxide anions in smoke contribute to the oxidant capacity of the smoke. The extent of apparent oxidation by a given quantity of smoke condensate increases for as long as an hour from the time the condensate is collected. The addition of hydrogen peroxide to the smoke solution increases both its oxidant content and its ability to inactivate alpha 1-antitrypsin. These data suggest that occurrence of hydrogen peroxide caused by secretion from macrophages found in the small airways of smokers may contribute to a locally damaging environment for alpha 1-antitrypsin in the presence of cigarette smoke that could promote the development of centrilobular emphysema.
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PMID:Reduction of the elastase inhibitory capacity of alpha 1-antitrypsin by peroxides in cigarette smoke: an analysis of brands and filters. 697 63