PPIase independent chaperone-like function of recombinant human Cyclophilin A during arginine kinase refolding

► The inactive four variants can suppress aggregation and improve the activation yield during AK refolding. ► The more efficiency of Q63A in chaperoning AK folding may associate with its more solvent-exposed global structures. ► Surface hydrophobicity and hydrophobic active pocket of rhCyPA are two key factors for chaperoning AK folding. ► Another protein is shown to be chaperoned by CyPA, which is essential to understand the general roles of CyPA in the cell.