Identification and Molecular Docking of ACE Inhibitory Peptides Derived from Sodium Substituted Cheddar Cheese

Present study envisaged the impact of sodium substitution with potassium @ 1:1 and 1:3 on the release of ACE inhibitory peptides in Cheddar cheese during storage (4 ℃/9 months).

Control (NaCl 2.5 g/100gm) and sodium substituted Cheddar cheeses (1NaCl:1KCl and 1NaCl:3KCl) were prepared studied for the in vitro angiotensin converting enzyme (ACE) inhibitory activity during storage period of 9 months. Cheddar Cheeses (5th month) with potent ACE inhibitory activity were further assessed for the peptides identification via RP-HPLC and LC-MS/MS technique. The obtained peptides were screened for bioactivity and potential bioactive peptides were selected for molecular docking for identifying the active sites on ACE enzyme for ACE inhibitory peptides.

Among all identified peptides, 2, 2 and 6 peptides were selected as potentially bioactive via peptide ranker in control, 1NaCl:1KCl and 1NaCl:3KCl Cheddar cheeses respectively. Molecular docking revealed that QEPVLGPVRGPFPI peptide in 1NaCl:3KCl Cheddar cheese showed the highest number of hydrogen bonding (binding energy −10.2) Tyr62, Asn66, Asn70, Arg124, Tyr135, Asn211, Ser219, Ala356, Glu403, Ser516 and Ser517 amino acid residues of ACE.

The salt substitution at higher level (1:3) resulted in the increased number of ACE inhibitory peptides than the control Cheddar cheese during ripening. Therefore salt substitution in cheese can be a healthier approach for minimizing sodium level in the diet.