ACE-Inhibitory and Antioxidant Activity of Temporin-Ra Peptide: Biochemical Characterization and Molecular Modeling Study

Abstract

In this study, the inhibitory effect of Temporin-Ra (FP-14 peptide) on angiotensin converting enzyme (ACE) was evaluated. Inhibition mechanism was investigated by kinetic studies and molecular docking simulation. Lineweaver–Burk plot revealed that Temporin-Ra behaved as a non-competitive ACE inhibitor supported by the docking simulation. The IC50 and Ki values were determined to be 22.19 μM and 36 µg/ml, respectively. Molecular docking simulation showed that Temporin-Ra bound to both of N- and C-domains of ACE by forming hydrogen bonds and electrostatic interactions; Temporin-Ra displayed higher affinity to C-domain than N-domain. Antioxidant activity of Temporin-Ra was examined using different methods. The antioxidant activity of Temporin-Ra (0.2 mg/ml) in the inhibition of linoleic acid autoxidation was evaluated to be 57 %. 1,1-diphenyl-2-picrylhydrazyl and 2, 2-azino-bis (3-ethylbenzothiazoline-6-sulphonicacid) diammonium salt radicals scavenging activities were 60 % at 0.5 mg/ml and 37 % at 0.3 mg/ml, respectively. The hydroxyl radical scavenging of FP-14 peptide at 0.33 mg/ml was 55 %. The results suggest that Temporin-Ra is a multifunctional peptide that could be exploited to develop new anti-hypertension drugs and bio-compatible natural antioxidants.