Exploration of the molecular interactions between angiotensin-I-converting enzyme (ACE) and the inhibitory peptides derived from hazelnut (Corylus heterophylla Fisch.)

• Published in: Food chemistry 2018-04, Vol.245, p.471-480
• Main Authors: Liu, Chunlei, Fang, Li, Min, Weihong, Liu, Jingsheng, Li, Hongmei
• Format: Article
• Language: English
• Subjects: Angiotensin-I-converting enzyme inhibition; Cation–pi interaction; Hazelnut protein; Molecular docking; Purification
• ISSN: 0308-8146; 1873-7072
• DOI: 10.1016/j.foodchem.2017.10.095

•Three novel ACE inhibitory peptides were identified from hazelnut protein.•YLVR had highest ACE inhibitory activity with IC50 value of 15.42 μM.•Cation-pi interaction was crucial to binding affinity between peptide and ACE. The mechanism of action of food-derived angiotensin-I-converting enzyme (ACE) inhibitory peptides has not been completely elucidated. In the present study, ion-exchange chromatography, gel filtration chromatography, reverse phase-high performance liquid chromatography, and liquid chromatography-electrospray ionization–tandem mass (LC-ESI-MS/MS) were employed for purifying and identifying the ACE inhibitory peptides from hazelnut. To understand the mode of action of these peptides, ACE inhibition kinetics, in vitro and in vivo bioavailability assays, active site analysis, and interaction between the inhibitory peptides and ACE were investigated. The results identified novel ACE inhibitory peptides Ala-Val-Lys-Val-Leu (AVKVL), Tyr-Leu-Val-Arg (YLVR), and Thr-Leu-Val-Gly-Arg (TLVGR) with IC50 values of 73.06, 15.42, and 249.3 μM, respectively. All peptides inhibited the ACE activity via a non-competitive mode. The binding free energies of AVKVL, YLVR, and TLVGR for ACE were −3.46, −6.48, and −7.37 kcal/mol, respectively. The strong inhibition of ACE by YLVR may be attributed to the formation of cation–pi interactions.