Proteolytic hydrolysis of cowpea proteins is able to release peptides with hypocholesterolemic activity

Author(s)

Marques, Marcelo Rodrigues ; Fontanari, Gustavo Guadagnucci ; Pimenta, Daniel Carvalho ; Soares-Freitas, Rosana Manolio ; Gomes Areas, Jose Alfredo

• Document type: Journal article
• Source: Food Research International; v. 77, p. 6-pg., 2015-11-01.

Abstract

This study aimed to assess the hypocholesterolemic activity of peptides obtained by in vitro simulated human digestion of cowpea bean proteins; moreover, we have screened the bioactive peptides through chromatographic separation by RP-HPLC of the 3 kDa molecular mass cut-off fraction of hydrolyzed isolated cowpea protein. Micellar solubility of cholesterol was measured after adding 35 mu g mL(-1) of each fraction on in vitro prepared intestine-like micelles. The inhibiting activity of each fraction (50 mu g mL(-1)) also was tested on the enzyme 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMG-CoA reductase). The whole hydrolysate was analyzed by 'de novo' mass spectrometry peptide sequencing (RP-HPLC-MS2) and the top score candidate peptide sequences were further analyzed by computational modeling. All collected fractions inhibited the initial HMGCoA reductase activity by 47.8 to 57.1%. They also reduced cholesterol micellar solubilization, with fraction 1 being the most effective (71.7%). The peptide conserved domains may interact with the phosphatidylcholine added in the reaction of the cholesterol micelles. According with a computational prediction, the only peptide able to bind significantly the HMG-CoA reductase was GCTLN. This is the first report of peptide fractions from cowpea bean protein released by human digestion enzymes (pepsin followed by pancreatin) assigned to its cholesterol-lowering effect. These routes may define their action in lipid metabolism. (C) 2015 Elsevier Ltd. All rights reserved. (AU)

• FAPESP's process: 11/04179-0 - Identification of hypocholesterolemic peptides from extruded cowpea beans (Vigna unguiculata L. Walp)
• Grantee: Marcelo Rodrigues Marques
• Support Opportunities: Scholarships in Brazil - Master
• FAPESP's process: 12/15900-4 - Bioavailability of peptides from proteins of lupine, cowpea and amaranth, by permeability through Caco-2 cells and alterations in gene expression of the transporters associated with intestinal cholesterol absorption
• Grantee: José Alfredo Gomes Arêas
• Support Opportunities: Regular Research Grants