关键词: 大豆粕, ACE抑制肽, 分离纯化, 分子对接, 活性口袋

Abstract: To establish the ACE inhibitory active peptides sequences quickly and accurately from soybean meal peptides, peptides from soybean meal hydrolysates were purified by ultrafiltration and chromatography. The amino acids sequences of peptides were identified according to the MS/MS spectra. We synthesized the peptide by solid-phase synthesis and determined the ACE inhibitory peptides by high performance liquid chromatography (HPLC). The results showed that after the ultrafiltration，the enzymolysis solution’s molecular weight distribution is mainly under 6000Da. We used AutoDock to compare several peptides’ estimated free energy of binding and we found that GVRP with -8.44 Kcal/mol estimated free energy of binding and IIVTP with -9.04 Kcal/mol estimated free energy of binding， and both of them can inhibit the ACE activity and their 50% inhibitory concentration (IC50) values were 84 ± 0.06 μmol/L and 77 ± 0.08 μmol/L, respectively. The molecular docking results revealed that GVRP and IIVTP were mainly attributed to forming very strong hydrogen bonds with the S1 pocket, S1’ pocket and S2 pocket, respectively. Both of them have the shared ACE amino acid residues that have been in close contact(within 3.5 ?) are His513, Ala354 and Glu384. This study can quickly select identify and evaluate the bioactive peptides while finding potential binding sites between bioactive peptides and ACE via the means of the MS/MS spectra and molecular docking ,which provides the basis and reference for further research.

Key words: soybean meal, ACE inhibitory peptides, isolation and purification, molecular docking, pocket site