Evidence that the amino acid residue P272 of arginine kinase is involved in its activity, structure and stability

In this research, the role of amino acid residue P272 of arginine kinase (AK) was investigated by site-directed mutagenesis. When the structure of AK was impaired by mutation, AK was in a partially unfolded state with more hydrophobic exposure, which was prone to aggregate under environmental stresses. Mutation at this position influences transition from the molten globule intermediate to the native state in folding process. The results provided herein may suggest that some residues near the active site may play a relatively important role in keeping AK activity and structural stability.