Bioactive Peptides from Unconventional Food Sources: A Novel Radical Approach in Food Value Addition

Abstract

Introduction: Bioactive peptides are small peptides of 2-20 amino acids encrypted in the proteins of protein-rich unconventional
food sources. Bioactive peptides show therapeutic functions such as antioxidative, immunomodulatory, opioid, anti-hypertensive,
antimicrobial, etc.
Objective: Unconventional protein-rich food sources may be employed to fabricate bioactive peptides using enzyme technology.
Methodology: Protein-rich unconventional food sources such as Bellamya bengalensis Lamellidense marginalis have been used to fabricate
bioactive peptides using different proteases in vitro. The ultrafiltration technique isolated the peptides. Functional properties of protein
isolates from the meat of Bellamya bengalensis were characterized as foaming property, solubility index of protein, and emulsifying
property. The anti-hypertensive property of the bioactive peptides was determined and compared with lisinopril, a standard drug. In
vitro experiments and in silico molecular docking studies were carried out to find the most powerful inhibitory peptide against ACE,
the major enzyme of the Renin-Angiotensin System. Using isothermal titration calorimetry, the results were further authenticated, and
the actual mechanism of action of their anti-hypertensive property was found.
Results: The hydrolysates were ultrafiltered, the smallest fraction was evaluated in MALDI-TOF MS, and five peptides were sequenced
via de novo sequencing. Lisinopril is a synthetic analog of the Angiotensin Converting Enzyme. The BP's binding affinity to ACE's active
site was compared with lisinopril. The thermodynamics of the inhibition was checked by ITC and further validated by in silico molecular
docking study. The ACE-inhibitory potential of the BP positively correlates with the presence of hydrophobic amino acids.
Conclusion: BP from different food sources have been excised and studied for their functional properties. Some have anti-hypertensive
properties and may be of particular interest in the context of hypertension. BP from dietary proteins exposes various biological activities.
These BP with anti-hypertensive effects may serve as a value-added food and pharmaceutical product.