Identification of a novel ACE-inhibitory peptide from casein and evaluation of the inhibitory mechanisms

Maolin Tu; Cong Wang; Cheng Chen; Ruyi Zhang; Hanxiong Liu; Weihong Lu; Lianzhou Jiang; Ming Du

doi:10.1016/j.foodchem.2018.02.107

Identification of a novel ACE-inhibitory peptide from casein and evaluation of the inhibitory mechanisms

Food Chem. 2018 Aug 1:256:98-104. doi: 10.1016/j.foodchem.2018.02.107. Epub 2018 Feb 21.

Authors

Maolin Tu¹, Cong Wang², Cheng Chen³, Ruyi Zhang³, Hanxiong Liu³, Weihong Lu⁴, Lianzhou Jiang², Ming Du⁵

Affiliations

¹ School of Food Science and Technology, National Engineering Research Center of Seafood, Dalian Polytechnic University, Dalian 116034, China; Department of Food Science and Engineering, School of Chemistry and Chemical Engineering, Harbin Institute of Technology, Harbin 150001, China.
² College of Food Science, Northeast Agricultural University, Harbin 150030, China.
³ School of Food Science and Technology, National Engineering Research Center of Seafood, Dalian Polytechnic University, Dalian 116034, China.
⁴ Department of Food Science and Engineering, School of Chemistry and Chemical Engineering, Harbin Institute of Technology, Harbin 150001, China. Electronic address: lwh@hit.edu.cn.
⁵ School of Food Science and Technology, National Engineering Research Center of Seafood, Dalian Polytechnic University, Dalian 116034, China. Electronic address: duming@dlpu.edu.cn.

PMID: 29606478
DOI: 10.1016/j.foodchem.2018.02.107

Abstract

Various bioactive peptides are continuously being identified from casein hydrolysates. In this work, a novel angiotensin I-converting enzyme (ACE)-inhibitory (ACEI) peptide, NMAINPSKENLCSTFCK, derived from the α_s2-casein fragment residues 25-41, was screened and identified by UPLC-ESI-Q-TOF-MS/MS from tryptic casein hydrolysate. The IC₅₀ value of the peptide, determined by an HPLC method, was 129.07 μM. The Lineweaver-Burk plot showed that this peptide acted as a mixed-type inhibitor against ACE, which might be attributed to the peptide being susceptible to degradation by ACE, indicating that the mixed-type inhibition could partly be a result of newly generated peptide fragments. The physicochemical characteristics and the secondary structure were evaluated by circular dichroism analysis and online prediction software (Expasy, PepDraw, and ProtParam) to identify the basic characteristics of this peptide. Moreover, molecular docking was simulated by Discovery Studio 2017 R2 software to provide the potential mechanisms underlying the ACEI activity of the peptides.

Keywords: ACE-inhibitory activity; Casein (PubChem CID: 73995022); Casein peptide; Identification; Molecular docking; UPLC-ESI-Q-TOF-MS/MS.

MeSH terms

Angiotensin-Converting Enzyme Inhibitors / chemistry*
Angiotensin-Converting Enzyme Inhibitors / pharmacology*
Animals
Caseins / chemistry*
Chromatography, High Pressure Liquid
Molecular Docking Simulation
Peptide Fragments / chemistry*
Peptide Fragments / pharmacology*
Peptidyl-Dipeptidase A / chemistry
Peptidyl-Dipeptidase A / metabolism*
Protein Conformation

Substances

Angiotensin-Converting Enzyme Inhibitors
Caseins
Peptide Fragments
Peptidyl-Dipeptidase A