Angiotensin I-Converting Enzyme (ACE-I) Inhibition and Antioxidant Peptide from a Squilla Species

Background: Oratosquilla woodmasoni is one of the marine squilla species, which is found in the entire Asia-Pacific region. This current study assesses the species as the main basis of both ACEi and antioxidant peptide. Objective: To isolate the ACEi peptide derived from O. woodmasoni and examine its ACE inhibition along with antioxidant potential. Materials and Methods: The squilla muscle protein was hydrolysed using alcalase and trypsin enzymes for 12 hours and tested for DH. The hydrolysates were examined for their ACEi activity and then the best hydrolysate was sequentially purified in various chromatographical methods. The purified peptide was studied for anti-oxidant and functional properties, followed by amino acid sequencing. The purified peptide was also evaluated for its toxicity by in vitro cell viability assay. Results: The DH% was found to be 47.13 +/- 0.72% and 89.43 +/- 2.06% for alcalase and trypsin, respectively. The alcalase 5th-hour hydrolysate was detected with potent activity (65.97 +/- 0.56%) using ACEi assay and was primarily fractionated using ultrafiltration; the maximum inhibitory activity was found with 77.04 +/- 0.52% in 3-10 kDa fraction. Subsequently, the fraction was purified using IEC and GFC, in which the AC1-A2 fraction had higher antihypertensive activity (70.85 +/- 0.78%). The non-toxic fraction showed hexapeptide HVGGCG with molecular weight 529 Da with great potential of antioxidant activity along with functional property. Conclusion: This peptide could be developed as a potential ACE-inhibitory and antioxidant agent.