Different selectivities of oxidants during oxidation of methionine residues in the alpha-1-proteinase inhibitor.

Détails

ID Serval
serval:BIB_6A055E8D1898
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Titre
Different selectivities of oxidants during oxidation of methionine residues in the alpha-1-proteinase inhibitor.
Périodique
Febs Letters
Auteur(s)
Maier K.L., Matejkova E., Hinze H., Leuschel L., Weber H., Beck-Speier I.
ISSN
0014-5793 (Print)
ISSN-L
0014-5793
Statut éditorial
Publié
Date de publication
1989
Volume
250
Numéro
2
Pages
221-226
Langue
anglais
Notes
Publication types: Journal Article
Publication Status: ppublish
Résumé
Oxidation of the reactive site methionine (Met) in alpha-1-proteinase inhibitor (alpha-1-PI) to methionine sulfoxide (Met(O] is known to cause depletion of its elastase inhibitory activity. To estimate the selectivity of different oxidants in converting Met to Met(O) in alpha-1-PI, we measured the molar ratio Met(O)/alpha-1-PI at total inactivation. This ratio was determined to be 1.2 for both the myeloperoxidase/H2O2/chloride system and the related compound NH2Cl. With taurine monochloramine, another myeloperoxidase-related oxidant, 1.05 mol Met(O) were generated per mol alpha-1-PI during inactivation. These oxidants attack preferentially one Met residue in alpha-1-PI, which is identical with Met 358, as concluded from the parallelism of loss of elastase inhibitory activity and oxidation of Met. A similar high specificity for Met oxidation was determined for the xanthine oxidase-derived oxidants. In contrast, the ratio found for ozone and m-chloroperoxybenzoic acid was 6.0 and 5.0, respectively, indicating oxidation of additional Met residues besides the relative site Met in alpha-1-PI, i.e. unselective action of these oxidants. Further studies were performed on the efficiency of oxidants for total depletion of the elastase inhibitory capacity of alpha-1-PI. Ozone and m-chloroperoxybenzoic acid were 10-fold less effective and the superoxide anion/hydroxyl radicals were 30-50-fold less effective to inactivate the elastase inhibitory activity as compared to the myeloperoxidase-derived oxidants. The myeloperoxidase-related oxidants are discussed as important regulators of alpha-1-PI activity in vivo.
Mots-clé
Animals, Blood Proteins/metabolism, Chlorides/metabolism, Chlorobenzoates/pharmacology, Hydrogen Peroxide/metabolism, Methionine/metabolism, Neutrophils/enzymology, Oxidation-Reduction, Ozone/pharmacology, Pancreatic Elastase/antagonists & inhibitors, Peroxidase/metabolism, Swine, Taurine/analogs & derivatives, Taurine/pharmacology, Xanthine Oxidase/metabolism, alpha 1-Antitrypsin
Pubmed
Création de la notice
03/12/2015 13:33
Dernière modification de la notice
29/01/2020 7:26
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