Lactokinins: whey protein-derived ACE inhibitory peptides

Area of Science:

• Biochemistry
• Nutritional Science
• Pharmacology

Background:

• Angiotensin-I-converting enzyme (ACE) plays a crucial role in regulating peripheral blood pressure via the renin-angiotensin system.
• Whey proteins, including alpha-lactalbumin (alpha-la), beta-lactoglobulin (beta-lg), and bovine serum albumin (BSA), contain peptides with ACE inhibitory properties.

Purpose of the Study:

• To investigate the ACE inhibitory activity of peptides derived from whey proteins.
• To explore the potential of these natural peptides as nutraceutical or functional food ingredients for hypertension management.

Main Methods:

• Analysis of ACE inhibitory activity of various whey protein-derived peptides.
• Enzymatic digestion of whey proteins using gastric and pancreatic proteases.
• Determination of ACE inhibitory concentration (IC50) values for specific peptides.

Main Results:

• Several peptides derived from alpha-la, beta-lg, and BSA demonstrated ACE inhibition.
• The peptide (beta-lg f(142-148)) showed the most potent ACE inhibition with an IC50 of 42.6 mumol/l.
• Enzyme specificity during whey protein hydrolysis, not the extent, determined the ACE inhibitory potency of hydrolysates.

Conclusions:

• Naturally occurring whey protein peptides possess ACE inhibitory activity.
• These peptides may serve as functional food ingredients for blood pressure management.
• Enzyme specificity is a critical factor in generating potent ACE-inhibiting whey hydrolysates.