STRUCTURE-BASED DRUG DISCOVERY OF SMALL MOLECULE MODULATORS FOR HUMAN SUPEROXIDE DISMUTASE I (HSOD1) ASSOCIATED WITH ALS

B. Padmanabhan

Department of Biophysics, National Institute of Mental Health and Neuro Sciences (NIMHANS), Bangalore – 560029, India

Abstract

Human Superoxide Dismutase I (hSOD1) is an enzyme involved in detoxification by means of removal of superoxide radicals. The mutations in the SOD1 gene have been linked to the neurodegenerative disease, familial amyotrophic lateral sclerosis (fALS). The SOD1 toxic gain-of-function is mainly due to the mutations in SOD1 gene; hence, the protein gets aggregated. The toxic-gain-of-function can be prevented by stabilizing the hSOD1 dimer and/or by protecting the Trp32 residue from oxidation. Hence, identifying and developing potential library compounds to tackle the above mentioned features are in need for the treatment of ALS.

The hSOD1 cDNA was cloned into a pET vector, expressed in the E. coli bacterial system, and the His-tag hSOD1 protein was purified to homogeneity with >95% purity by using multiple chromatography techniques. The purified hSOD1 protein was concentrated and used for protein crystallization. hSOD1 was checked for its intact mass analysis and its purity by Mass spectrometry analysis. The X-ray diffraction data for the apo-form of hSOD1 and hSOD1-ligand complexes were collected on the beamline BM14 at European Synchrotron Radiation Facility (ESRF), Grenoble, France. The structures of an apo-form and protein-ligand complexes of hSOD1 refined to 1.9Å resolution and their binding studies would be discussed.