title: Assay of angiotensin I-converting enzyme-inhibiting activity based on the detection of 3-hydroxybutyrate with water-soluble tetrazolium salt.
abstract: A newly synthesized substrate, 3-hydroxybutyrylglycyl-glycyl-glycine (3HB-GGG), was applied to the assay of ACE-inhibiting activity to overcome the smaller selectivity and sensitivity of the conventional method. In this study, an ACE-inhibiting assay was improved by the use of a water-soluble tetrazolium salt, 4-[3-(4-iodophenyl)-2-(4-nitrophenyl)-2H-5-tetrazolio]-1,3-benzene disulfonate sodium salt (WST-1), for the detection of 3-hydroxybutyrate, derived from 3HB-GGG. The optimized conditions were as follows: 0.333 mM NAD(+), 0.333 mM WST-1, 0.1 mM EDTA, 0.633 U ml(-1) diaphorase, and 0.700 U ml(-1) 3-hydroxybutyrate dehydrogenase. The developed assay was efficiently applicable to evaluate the ACE-inhibiting activity of practical ACE inhibitors.
authors.affiliation: Department of Bioresources Science, Faculty of Agriculture, Kochi University, Monobe B-200, Nankoku 783-8502, Japan.
authors.forename: Le Hoang
authors.initials: le H
authors.lastname: Lam
authors.forename: Tomoko
authors.initials: T
authors.lastname: Shimamura
authors.forename: Sachiyo
authors.initials: S
authors.lastname: Manabe
authors.forename: Munetaka
authors.initials: M
authors.lastname: Ishiyama
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Ukeda
mesh_terms: D020155:3-Hydroxybutyric Acid / Q000032:analysis*; D000806:Angiotensin-Converting Enzyme Inhibitors / Q000032:analysis* / Q000737:chemistry; D001681:Biological Assay / Q000379:methods*; D004492:Edetic Acid / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D006884:Hydroxybutyrate Dehydrogenase / Q000737:chemistry; D006885:Hydroxybutyrates; D009243:NAD / Q000737:chemistry; D009245:NADH Dehydrogenase / Q000737:chemistry; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012995:Solubility; D012997:Solvents / Q000737:chemistry; D013778:Tetrazolium Salts / Q000737:chemistry*; D014867:Water / Q000737:chemistry*
chemical_list: D000806:Angiotensin-Converting Enzyme Inhibitors; D006885:Hydroxybutyrates; D012997:Solvents; D013778:Tetrazolium Salts; D014867:Water; D009243:NAD; D004492:Edetic Acid; D006884:Hydroxybutyrate Dehydrogenase; D009245:NADH Dehydrogenase; D020155:3-Hydroxybutyric Acid