Engineered disulfide bonds restores chaperone like function of DJ-1 mutants linked to familial Parkinson’s disease

Loss-of-function mutations such as L166P, A104T and M26I in the DJ-1 gene (PARK7) have been linked to autosomal-recessive early onset Parkinson’s disease (PD). Cellular and structural studies of the familial mutants suggest that these mutations may destabilize the dimeric structure. In order to look for common dynamical signatures among the DJ-1 mutants, short MD simulations up to 1000ps were carried out to identify the weakest region of the protein (residues 38–70). In an attempt at stabilizing the protein, we mutated residue Val 51 to cysteine (V51C) to make a symmetry-related disulfide bridge with the pre-existing Cys 53 on the opposite subunit. We found that the introduction of this disulfide linkage stabilized the mutants A104T and M26I against thermal denaturation, showed increased ability to scavenge reactive oxygen species (ROS) and restored a chaperone-like function of blocking α-synuclein aggregation. The L166P mutant was far too unstable to be rescued by introduction of V51C. The results presented here points towards the possible development of pharmacological chaperones, which may eventually lead to PD therapeutics.