Antioxidant and Angiotensin I Converting Enzyme (ACE) Inhibitory Properties of GL-9 Peptide

Abstract

The aim of this study was to examine antioxidant and inhibitory activity of Gly-Ala-Ser-Arg-His-Trp-Tyr-Phe-Leu peptide named GL-9 peptide. The synthetic GL-9 peptide was purified by C8 reveres phase HPLC (RP-HPLC). The antioxidant activity of the GL-9 peptide was investigated based on its scavenging capacity1,1-diphenyl-2-picrylhydrazyl (DPPH) radical, 2,2′-azinobis (3-ethylbenzothiazoline-6-sulphonic acid) diammonium salt (ABTS), superoxide ( ), hydroxyl (OH•−) and lipid peroxidation inhibition. The ACE inhibitory activity and kinetic parameters of the peptide were determined using FAPPG as substrate. GL-9 peptide/ACE complex interaction, position, type and energy was also investigated by using molecular docking. GL-9 peptide displays DPPH (IC50 = 6.5 µg/mL), ABTS•+ (IC50 = 7.2 µg/mL), superoxide (IC50 = 122 µg/mL) and hydroxyl (IC50 = 60.0 µg/mL) radical scavengers. GL-9 peptide showed an IC50 value of 47.8 µg/mL which inhibited ACE activity. The results indicated that the GL-9 peptide has antioxidant and ACE inhibitory capacity. Practical Applications Synthetic GL-9 peptide antioxidant and anti-hypertensive activity were investigated using in vitro assays. Results indicated that this peptide possesses a high potent antioxidant activity as well as ACE-inhibitory activity, demonstrate its potential application as an ingredient in wholesome foodstuffs.