Mutation of residue arginine 330 of arginine kinase results in the generation of the oxidized form more susceptible

► Arginine kinase (AK) and mutant R330K existed in two forms, the reduced form and the oxidized form. ► The oxidized form of R330K (O-R330K) generated more susceptible than that of AK (O-AK). ► O-R330K contained an intramolecular disulfide bond. ► The intramolecular disulfide bond was demonstrated to be formed between Cys201 and Cys271. ► Conserved residue R330 plays an important role in the structural stability and activity of AK.