TY - JOUR AU - Losasso, Valeria AU - Schiffer, Sonja AU - Barth, Stefan AU - Carloni, Paolo TI - Design of human granzyme B variants resistant to serpin B9 JO - Proteins VL - 80 IS - 11 SN - 0887-3585 CY - New York, NY PB - Wiley-Liss M1 - FZJ-2015-03596 SP - 2514 - 2522 PY - 2012 AB - Human granzyme B (hGB) is a serine protease involved in immune-mediated apoptosis. Its cytotoxicity makes it potentially applicable in cancer therapy. However, the effectiveness of hGB can be hampered by the cytosolic expression of a natural protein inhibitor, human Serpin B9 (hSB9). Here, we used computational approaches to identify hGB mutations that can affect its binding to hSB9 without significantly decreasing its catalytic efficiency. Alanine-scanning calculations allowed us to identify residues of hGB important for the interaction with hSB9. Some variants were selected, and molecular dynamic simulations on the mutated hGB in complex with hSB9 in aqueous solution were carried out to investigate the effect of these variants on the stability of the complex. The R28K, R201A, and R201K mutants significantly destabilized the interaction of the protein with hSB9. Consistently, all of these variants also retained their activity in the presence of the Serpin B9 inhibitor in subsequent in vitro assays of wild-type and mutated hGB. In particular, the activity of R201K hGB with and without Serpin B9 is very similar to that of the wild-type protein. Hence, R201K hGB emerges as a promising species for antitumoral therapy applications LB - PUB:(DE-HGF)16 UR - <Go to ISI:>//WOS:000309456500003 C6 - pmid:22733450 DO - DOI:10.1002/prot.24133 UR - https://juser.fz-juelich.de/record/201291 ER -