Citation

Gladysheva IP, Popykina NA, Zamolodchikova TS, Larionova NI. Biochemistry (Mosc) 2001; 66(6): 682-687.

Copyright

(Copyright © 2001, Holtzbrinck Springer Nature Publishing Group)

DOI

10.1023/a:1010267500296

PMID

11421818

Abstract

The interaction between duodenase, a newly recognized serine proteinase belonging to the small group of Janus-faced proteinases, and alpha1-proteinase inhibitor (alpha1-PI) from human serum was investigated. The stoichiometry of the inhibition was 1.2 mol/mol. The presence of a stable enzyme-inhibitor complex was shown by SDS-PAGE. The mechanism of interaction between duodenase and alpha1-PI was shown to be of the suicide type. The equilibrium and inhibition constants are 13 +/- 3 nM and (1.9 +/- 0.3).105 M-1.sec-1, respectively. Based on the association rate constant of the enzyme-inhibitor complex and localization of duodenase and alpha1-PI in identical compartments, alpha1-PI is suggested to be a duodenase inhibitor in vivo.

Language: en

Keywords

alpha 1-Antitrypsin; Electrophoresis, Polyacrylamide Gel; Humans; Kinetics; Protein Binding; Serine Endopeptidases; Serine Proteinase Inhibitors; Substrate Specificity