PuSH - Publication Server of Helmholtz Zentrum München

Different Selectivities of Oxidants During Oxidation of Methionine Residues in the (alpha)-1- proteinase Inhibitor.

FEBS Lett. 250, 221-226 (1989)
Publ. Version/Full Text DOI PMC
Closed
Open Access Green as soon as Postprint is submitted to ZB.
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.
Impact Factor
Scopus SNIP
Scopus
Cited By
Altmetric
0.000
0.000
43
Tags
Annotations
Special Publikation
Hide on homepage

Edit extra information
Edit own tags
Private
Edit own annotation
Private
Hide on publication lists
on hompage
Mark as special
publikation
Publication type Article: Journal article
Document type Scientific Article
Language
Publication Year 1989
HGF-reported in Year 1989
ISSN (print) / ISBN 0014-5793
e-ISSN 1873-3468
Journal FEBS Letters
Quellenangaben Volume: 250, Issue: 2, Pages: 221-226 Article Number: , Supplement: ,
Publisher Elsevier
Reviewing status Peer reviewed
PubMed ID 2546797
Erfassungsdatum 1989-12-31