Nature of papain products resulting from inactivation by a peptidyl O-acyl hydroxamate.
Mass spectrometry has been used to provide insights into the mechanism of inhibition of cysteine proteases by a hydroxylamine derivative, CBZ-Phe-Gly-NH-O-CO-(2,4,6-Me3)Ph. An oxidized form of papain resulting from the incubation of the enzyme with the peptidyl hydroxamate in the absence of a reducing agent has been identified as a sulfinic acid. The presence of a covalent enzyme-inhibitor complex of molecular mass consistent with a sulfenamide adduct of papain could also be detected by this method. Implications on the mechanism of inactivation of cysteine proteases by peptidyl hydroxamates are discussed.
Ménard
R
R
Biotechnology Research Institute, National Research Council of Canada, Montréal, Québec.
Feng
R
R
Storer
A C
AC
Robinson
V J
VJ
Smith
R A
RA
Krantz
A
A
D004229:Dithiothreitol / Q000494:pharmacology; D006877:Hydroxamic Acids / Q000138:chemical synthesis / Q000494:pharmacology*; D013058:Mass Spectrometry; D010206:Papain / Q000037:antagonists & inhibitors / Q000378:metabolism*; D011480:Protease Inhibitors / Q000494:pharmacology*; D011485:Protein Binding; D013379:Substrate Specificity
D006877:Hydroxamic Acids; D011480:Protease Inhibitors; C072330:O-mesitoyl N-benzyloxycarbonylphenylalanyl-glycine hydroxamate; D010206:Papain; D004229:Dithiothreitol