Research on the Stability and Activity of Two ACE Inhibitory Peptides from Volutharpa ampullaceal perryi

In this paper,the thermal stability,the ability of anti-gastrointestinal absorption,resistance to metal ions,high salt and high sugar of two ACE inhibitory peptides IVTNWDDMEK(Ile-Val-Thr-Asn-Trp-Asp-Asp-Met-Glu-Lys)and VGPAGPRG(Val-Gly-Pro-Ala-Gly-Pro-Arg-Gly)separated from Volutharpa ampullacea perryi were measured using a method of reversed phase high performance liquid chromatography. The results showed that peptide retention rate decreased by 75% after heating at 100℃ for 6 h. The reason may be that the peptide bond was broken due to prolonged high temperature heating,which affected its physiological activity. In vitro simulated gastrointestinal digestion studies have shown that after IVTNWDDMEK and VGPAGPRG were separately treated with gastric juice for 2 h and intestinal fluid for 6 h,the ACE inhibition rates were 30.47%,15.74%,28.01%,12.33%,respectively. The polypeptide is decomposed to small molecular peptides to some extent,but it still has ACE inhibitory activity after decomposition. The addition of metal ions(Fe³⁺),high salt and high sugar can reduce ACE inhibitory activity. Therefore,in the daily production and storage process,we should avoid high temperature heating for a long time,avoid the addition of metal ions(Fe³⁺)and reduce the intake of salt and sugar to keep the stability of ACE inhibitory peptides better.