title: Angiotensin-converting enzyme inhibition and free-radical scavenging properties of cationic peptides derived from soybean protein hydrolysates.
abstract: Soybean protein isolate was hydrolyzed consecutively with pepsin and pancreatin followed by separation of the digest on a SP-Sepharose column to obtain angiotensin-converting enzyme (ACE)-inhibitory fractions. Three of the five fractions obtained inhibited ACE activity, with values of the concentration of hydrolysate fraction that inhibited 50% of ACE activity of 1.09, 0.42, and 0.25 mg/ml for fractions 2, 3, and 4, respectively. Kinetic analysis showed that fractions 2, 3, and 4 are non-competitive, competitive and mixed inhibitors of ACE, respectively. Fluorescence emission of ACE was quenched along with a red shift in wavelength of emission maxima in the presence of the protein hydrolysate fractions. Fraction 3 was the most potent free-radical scavenger, while fraction 4 had almost no scavenging effect. We concluded that fraction 3 had the most potential to be used as a bioactive ingredient because of its strong ACE-inhibitory and free-radical scavenging properties.
authors.affiliation: Department of Human Nutritional Sciences, University of Manitoba, Winnipeg, Manitoba, Canada.
authors.forename: Vahid
authors.initials: V
authors.lastname: Farzamirad
authors.forename: Rotimi E
authors.initials: RE
authors.lastname: Aluko
mesh_terms: D000806:Angiotensin-Converting Enzyme Inhibitors / Q000032:analysis* / Q000494:pharmacology; D002412:Cations; D016166:Free Radical Scavengers / Q000032:analysis* / Q000494:pharmacology; D006801:Humans; D006868:Hydrolysis; D008856:Microscopy, Fluorescence; D010194:Pancreatin / Q000378:metabolism; D010434:Pepsin A / Q000378:metabolism; D011492:Protein Hydrolysates / Q000737:chemistry*; D030262:Soybean Proteins / Q000737:chemistry*; D013053:Spectrophotometry / Q000379:methods
chemical_list: D000806:Angiotensin-Converting Enzyme Inhibitors; D002412:Cations; D016166:Free Radical Scavengers; D011492:Protein Hydrolysates; D030262:Soybean Proteins; D010194:Pancreatin; D010434:Pepsin A