Structure–Activity Studies of 1,2,4-Oxadiazoles for the Inhibition of the NAD<sup>+</sup>-Dependent Lysine Deacylase Sirtuin 2
Arianna Colcerasa, Florian Friedrich, Jelena Melesina, Patrick Moser, Anja Vogelmann, Pavlos Tzortzoglou, Emilia Neuwirt, Manuela Sum, Dina Robaa, Lin Zhang, Elizabeth Ramos‐Morales, Christophe Romier, Oliver Einsle, Eric Metzger, Roland Schüle, Olaf Groß, Wolfgang Sippl, Manfred Jung
Abstract
The NAD + -dependent lysine deacylase sirtuin 2 (Sirt2) is involved in multiple pathological conditions such as cancer. Targeting Sirt2 has thus received an increased interest for therapeutic purposes. Furthermore, the orthologue from Schistosoma mansoni ( Sm Sirt2) has been considered for the potential treatment of the neglected tropical disease schistosomiasis. We previously identified a 1,2,4-oxadiazole-based scaffold from the screening of the “Kinetobox” library as a dual inhibitor of human Sirt2 (hSirt2) and Sm Sirt2. Herein, we describe the structure–activity studies on 1,2,4-oxadiazole-based analogues, which are potent inhibitors of human Sirt2 deacetylation. As proposed by docking studies, a substrate-competitive and cofactor-noncompetitive binding mode of inhibition could be determined in vitro via binding assays and kinetic analysis and further confirmed by a crystal structure of an oxadiazole inhibitor in complex with hSirt2. Optimized analogues reduced cell viability and inhibited prostate cancer cell migration, in correlation with Sirt2 deacetylase inhibition both in vitro and in cells.