Résumé de : BASAK (A), CHRETIEN (M) & SEIDAH (NG) - 2002 - A rapid fluorometric assay for the proteolytic activity of SKI-1/S1P based on the surface glycoprotein of the hemorrhagic fever Lassa virus. FEBS Letters, 514 (2-3): pp. 333-339.

The subtilase subtilisin kexin isozyme-1 (SKI-1)/site 1 protease (SIP), has been implicated in the processing of Lassa virus glycoprotein C (GP-C) precursor into GP1 and GP2 that are responsible for viral fusion with the host cell membrane. Here, we studied in vitro the kinetics of this cleavage by hSKI-1 using an intramolecularly quenched fluorogenic (IQF) peptide, Q-GPC(251-263) [Abz-(251)Asp-Ile-Tyr-Ile-Ser-Arg-Arg-Leu-Leudown arrowGly-Thr-Phe-Thr(263)-3-NitroTyr-Ala-CONH2], containing the identified site. The measured V-max ((app))/K-m (app) was compared to those for other IQF SKI-substrates. Q-GPC(251-263) is cleaved 10-fold more efficiently than the previously known best SKI-substrate, Q-hproSKI(134-142). This study confirmed the role of SKI-I in GP-C processing and provides a novel, rapid and efficient enzymatic assay of SKI-1. (C) 2002 Federation of European Biochemical Societies. Published by Elsevier Science B.V. All rights reserved.