Separation and identification of ACE inhibitory peptides from lizard fish proteins hydrolysates by metal affinity-immobilized magnetic liposome

Purification of peptides responsible for angiotensin I-converting enzyme (ACE) inhibitory activity from highly complex protein hydrolysates is difficult. Affinity chromatography is a powerful method for purification of peptides. In this study, a metal affinity-immobilized magnetic liposome (MA-IML) was prepared using lipid, N-hexadecyl iminodiacetic acid (HIDA) and magnetic nanoparticles made of FeCl3 center dot 6H(2)O and FeCl2 center dot 4H(2)O as main materials. MA-IML was used to adsorb ACE inhibitory peptides from lizard fish proteins hydrolysates. The optimal pH of adsorption solution was 8.5. The peptide sample adsorbed by MA-IML was separated by reverse phase-high performance liquid chromatography (RP-HPLC). Upon amino acid sequence analysis and verification, an ACE inhibitory peptide with IC50 value of 108 mu M was identified to be VYP. Molecular docking results indicated that VYP bound to ACE via multiple binding sites. The present study demonstrated that MA-IML might be a useful tool for separating ACE inhibitory peptides from proteins hydrolysates.

Automated summary

The study successfully purified ACE inhibitory peptides from lizard fish protein hydrolysates using metal affinity-immobilized magnetic liposomes. The identified ACE inhibitory peptide VYP showed high inhibitory activity and multiple binding sites with ACE, demonstrating potential application prospects.