(714c) Structure Based Drug Design for Insulin Degrading Enzyme

Insulin degrading enzyme (IDE) is a zinc-binding protease mediates cleavage of multiple short polypeptides including the degradation of insulin and amyloid-β (Aβ) which are the key substrates of type 2 diabetes mellitus (T2DM) and Alzheimer's disease (AD), respectively. The regulation of IDE activity is considered as a potential approach for the treatment of these diseases. In this study, our objective is to design novel activators of IDE by using structure-based drug design approach, and to test the effect of these compounds on the proteolytic activity of IDE in a fluorogenic assay. First we have performed molecular dynamics on IDE and followed by virtual screening using chemical compound databases with 1,000,000 numbers of molecules to identify compounds that bind to the exosite region of IDE. After initial screening, binding energies of hit compounds were calculated using the molecular docking. Molecules that have binding Gibbs free energy with value between -11 kcal/mol and -13 kcal/mol were picked for the experimental test to see their effect on enzyme using fluorogenic assay. To test effect of these candidate molecules, the human cDNA IDE were cloned into pET17 expression plasmid. IDE cDNA were expressed and purified using nickel resin from E.coli BL21. Currently we are experimentally testing the effect of candidate drug molecules. Small molecules discovered in this study might be significant for the discovery of new drugs that might facilitate the clearance of Aβ and other pathologically relevant IDE substrates.