title: Inhibition of angiotensin converting enzyme (ACE) activity by flavan-3-ols and procyanidins.
abstract: It was determined that flavan-3-ols and procyanidins have an inhibitory effect on angiotensin I converting enzyme (ACE) activity, and the effect was dependent on the number of epicatechin units forming the procyanidin. The inhibition by flavan-3-ols and procyanidins was competitive with the two substrates assayed: N-hippuryl-L-histidyl-L-leucine (HHL) and N-[3-(2-furyl)acryloyl]-L-phenylalanylglycylglycine (FAPGG). Tetramer and hexamer fractions were the more potent inhibitors, showing Ki of 5.6 and 4.7 microM, respectively. As ACE is a membrane protein, the interaction of flavanols and procyanidins with the enzyme could be related to the number of hydroxyl groups on the procyanidins, which determine their capacity to be adsorbed on the membrane surface.
authors.affiliation: Physical Chemistry-PRALIB, School of Pharmacy and Biochemistry, University of Buenos Aires, Juni;n 956, 1113, Buenos Aires, Argentina.
authors.forename: Lucas
authors.initials: L
authors.lastname: Actis-Goretta
authors.forename: Javier I
authors.initials: JI
authors.lastname: Ottaviani
authors.forename: Carl L
authors.initials: CL
authors.lastname: Keen
authors.forename: Cesar G
authors.initials: CG
authors.lastname: Fraga
mesh_terms: D000806:Angiotensin-Converting Enzyme Inhibitors / Q000494:pharmacology*; D000818:Animals; D044946:Biflavonoids; D001665:Binding Sites; D001667:Binding, Competitive; D002392:Catechin / Q000737:chemistry / Q000494:pharmacology*; D005419:Flavonoids / Q000494:pharmacology*; D020128:Inhibitory Concentration 50; D007700:Kinetics; D008168:Lung / Q000201:enzymology; D007703:Peptidyl-Dipeptidase A / Q000378:metabolism*; D044945:Proanthocyanidins; D011817:Rabbits; D013379:Substrate Specificity; D013816:Thermodynamics
chemical_list: D000806:Angiotensin-Converting Enzyme Inhibitors; D044946:Biflavonoids; D005419:Flavonoids; D044945:Proanthocyanidins; C404987:flavan-3-ol; C017674:procyanidin; D002392:Catechin; D007703:Peptidyl-Dipeptidase A