title: Enzymatic reduction of oxidized alpha-1-proteinase inhibitor restores biological activity.
abstract: The major serum inhibitor of proteolytic activity, alpha-1-proteinase inhibitor (alpha-1-PI), (or alpha-1-antitrypsin) can be readily inactivated by oxidation [Carp, H. & Janoff, A. (1978) Am. Rev. Resp. Dis. 118, 617-621]. This inactivation appears to be due to the oxidation of a critical methionine(s) in alpha-1-PI that is required for the inhibition of elastase activity. An enzyme from Escherichia coli that reduces methionine sulfoxide residues in protein [Brot, N., Weissbach, L., Werth, J. & Weissbach, H. (1981) Proc. Natl. Acad. Sci. USA 78, 2155-2158] can restore the biological inhibitory activity of canine oxidized alpha-1-PI.
mesh_terms: D000818:Animals; D001665:Binding Sites; D004285:Dogs; D004926:Escherichia coli / Q000201:enzymology; D008715:Methionine / Q000378:metabolism; D051150:Methionine Sulfoxide Reductases; D010084:Oxidation-Reduction; D010088:Oxidoreductases / Q000378:metabolism*; D010196:Pancreatic Elastase / Q000037:antagonists & inhibitors; D013329:Structure-Activity Relationship; D000515:alpha 1-Antitrypsin / Q000378:metabolism*
chemical_list: D000515:alpha 1-Antitrypsin; D008715:Methionine; D010088:Oxidoreductases; D051150:Methionine Sulfoxide Reductases; C027219:methionine sulfoxide reductase; D010196:Pancreatic Elastase