Premium
A substrate‐based approach to convert serpinB1 into a specific inhibitor of proteinase 3, the Wegener granulomatosis autoantigen
Author(s) -
Korkmaz Brice,
Jégot Gwenhael,
Derache Chrystelle,
RemoldO'Donnell Eileen,
Kellenberger Christine,
Gauthier Francis
Publication year - 2011
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.25.1_supplement.623.4
The pathophysiological function of proteinase 3 (PR3) is not well understood mainly because of its close structural and functional resemblance with neutrophil elastase and the absence of a specific inhibitor able to target its active site in vivo. Based on the structural analysis of the active sites of human neutrophil elastase (HNE) and PR3, we have raised recombinant serpins derived from the polyvalent inhibitor serpinB1 (monocyte, neutrophil elastase inhibitor), that specifically inhibit PR3. The rate constant of association between the best serpinB1 mutant and purified PR3 was 1.4×107 M‐1s‐1 which is about 100‐fold higher than that observed with wild‐type serpinB1, and compares with that of alpha‐1‐protease inhibitor towards HNE. Proteolytic cleavage of the mutant serpinB1 by HNE does not impair the formation of the SDS stable, irreversible complex with PR3 when a molar excess of HNE is present in the reactional mixture. Mutant serpinB1inhibits soluble PR3 as well as membrane‐bound PR3 at the surface of activated neutrophils and clears induced PR3, but not constitutive PR3, from the cell surface. Such a specific inhibitor should help investigating the biological function of this protease and possibly serve as a therapeutic agent in PR3‐related inflammatory diseases such as Wegener granulomatosis. This work is supported by “Region Centre” (Projet INFINHI)