ABSTRACT
Objective To investigate the effect of the fusion of leader peptide on the structure of human manganese superoxide dismutase (SOD2) and anti-cisplatin (DDP)-induced renal injury. Methods The effect of mitochondrion targeting sequence (MTS) on the structure and activity of SOD2 was analyzed by structure prediction and superoxide dismutase (SOD) specific-activity determination. The DDP injury model of Kunming (KM) mice was established, and amifostine (AMFT) was set as a positive control. Indicators such as kidney index, renal function, kidney antioxidant capacity, and appearance and pathology changes of mice kidney were used to evaluate the effect of MTS-SOD2 against DDP-induced kidney injury. Results The MTS leader peptide seemed to change the secondary and tertiary structures of SOD2 to some extent, but it also increased the specific activity of the MTS-SOD2 protein. Pre-administration of a medium dose of MTS-SOD2 (0.84 mg/kg) before the use of DDP significantly reduced the level of renal malondialdehyde and increased the SOD activity and total antioxidant capacity (T-AOC) in the kidney, thereby reducing the renal pathological damage and consequently maintaining renal function. The overall protective effect of MTS-SOD2 was comparable to or even better than that of 200 mg/kg AMFT. Conclusion The MTS leader peptide enhances the activity of SOD2 and confers it with an excellent anti-DDP-induced renal-injury effect because of its transmembrane function.