Small molecule modulation of DLD diaphorase activity to decrease reactive oxygen species production in the mitochondria (953.1)

Abstract

Oxidative stress and damage is considered to be a significant causative factor in aging and neurodegenerative diseases. Concurrent with the clinical phenotypes associated with these diseases is mitochondrial dysfunction in the form of biochemical malfunctions that create or potentiate reactive oxygen species (ROS) production. Dihydrolipoamide dehydrogenase (DLD) is a mitochondrial multifunctional enzyme with a homodimeric structure, resolved as two monomers bridged by an interface domain. In its dimeric form, DLD plays a critical role in energy metabolism and has been suggested to have a destructive role as a generator of ROS in its monomeric form. The latter activity has been confirmed in prior studies in both mouse and yeast models. Decreased superoxide activity has been measured in DLD knockout (‐/‐) mice vs. WT mice (Starkov et al., 2004) and higher diaphorase activity with increased hydrogen peroxide levels (Vaubel et al., 2011) has been shown in DLD mutants expressed in yeast systems. Our lab using virtual screening and computational docking has designed a small molecule library containing 40 synthetic compounds that putatively bind to a pocket within the interface domain of DLD with the aim of stabilizing the dimer. Primary screening of the compound library using the diaphorase assay is in progress. Validation of hits will be performed using Differential Scanning Fluorimetry (DSF), X‐ray crystallography and other techniques including in‐vivo analyses. We hope that these studies will enhance our understanding of the physiological role of diaphorase activity and facilitate the development of therapeutics for pathologies in which diaphorase activity has a suggested damaging function.