title: Assessment of the spectrophotometric method for determination of angiotensin-converting-enzyme activity: influence of the inhibition type.
abstract: A set of in vitro assay conditions were selected for the determination of ACE-inhibitory activity, and the need was demonstrated to standardize this assay so that the results obtained by different authors may be comparable. The conditions selected were as follows: 10 mM HHL concentration in 0.2 M potassium phosphate buffer and 0.3 M NaCl and 26 mU of ACE/mL as reaction medium; incubation time, 80 min at 37 degrees C. The method was applied to the study of ACE-inhibitory activity of dairy product and wine samples. Of the samples assayed, it was infant formulae whey that produces the greatest ACE inhibition. Red wine also presents a high inhibition percentage. This latter sample has an important matrix effect that must be corrected in the calculation. ACE-inhibition type was also studied, using a yogurt whey and a Captropil solution as substrates. The whey produced noncompetitive inhibition and the Captropil competitive inhibition.
authors.affiliation: Instituto de Fermentaciones Industriales, C.S.I.C., C/Juan de la Cierva, 3, 28006 Madrid, Spain.
authors.forename: Blanca
authors.initials: B
authors.lastname: Hernández-Ledesma
authors.forename: Pedro J
authors.initials: PJ
authors.lastname: Martín-Alvarez
authors.forename: Encarnación
authors.initials: E
authors.lastname: Pueyo
mesh_terms: D000806:Angiotensin-Converting Enzyme Inhibitors / Q000032:analysis*; D000818:Animals; D002216:Captopril / Q000494:pharmacology; D006801:Humans; D007223:Infant; D007225:Infant Food / Q000032:analysis; D008168:Lung / Q000201:enzymology; D008894:Milk Proteins / Q000032:analysis; D009842:Oligopeptides / Q000494:pharmacology; D007703:Peptidyl-Dipeptidase A / Q000378:metabolism*; D011817:Rabbits; D013053:Spectrophotometry / Q000379:methods*; D000067816:Whey Proteins; D014920:Wine / Q000032:analysis; D015014:Yogurt / Q000032:analysis
chemical_list: D000806:Angiotensin-Converting Enzyme Inhibitors; D008894:Milk Proteins; D009842:Oligopeptides; D000067816:Whey Proteins; C010980:hippuryl-histidyl-leucine; D002216:Captopril; D007703:Peptidyl-Dipeptidase A