PMID: 17502107 , Related PDB id: 2P2C

Authors:

Schweizer A, Roschitzki-Voser H, Amstutz P, Briand C, Gulotti-Georgieva M, Prenosil E, Binz HK, Capitani G, Baici A, Pluckthun A, Grutter MG

Title:

Inhibition of caspase-2 by a designed ankyrin repeat protein: specificity, structure, and inhibition mechanism.

Journal:

Structure. 2007 May;15(5):625-36.

Abstract:

Specific and potent caspase inhibitors are indispensable for the dissection of the intricate pathways leading to apoptosis. We selected a designed ankyrin repeat protein (DARPin) from a combinatorial library that inhibits caspase-2 in vitro with a subnanomolar inhibition constant and, in contrast to the peptidic caspase inhibitors, with very high specificity for this particular caspase. The crystal structure of this inhibitor (AR_F8) in complex with caspase-2 reveals the molecular basis for the specificity and, together with kinetic analyses, the allosteric mechanism of inhibition. The structure also shows a conformation of the active site that can be exploited for the design of inhibitory compounds. AR_F8 is a specific inhibitor of an initiator caspase and has the potential to help identify the function of caspase-2 in the complex biological apoptotic signaling network.