title: A deeply recessed active site in angiotensin-converting enzyme is indicated from the binding characteristics of biotin-spacer-inhibitor reagents.
abstract: Two biotinylated derivatives of the angiotensin-converting enzyme (ACE) inhibitor, lisinopril, were synthesized. Compounds BL11 (epsilon-biotinamidocaproyl-lisinopril) and BL19 (epsilon-biotinamidocaproyl-beta-alanyl-beta-alanyl-lisinopril) have, respectively, 11 and 19 atoms of spacing structure between the biotin and the inhibitor moieties. Both compounds were found to be potent inhibitors of mouse kidney ACE, but they lost this ability in the presence of streptavidin in free solution. However, BL19 (but not BL11), when complexed to ACE, retained enough residual binding strength for streptavidin to allow the complex to be specifically removed from solution by streptavidin-agarose beads. It was thus possible to employ BL19 for the affinity isolation of ACE from crude mixtures. These results indicate that the bound determinant of lisinopril must lie at least 11 A below the outer surface of the ACE molecule.
authors.affiliation: Department of Pathology, Emory University, Atlanta, GA 30322.
authors.forename: K E
authors.initials: KE
authors.lastname: Bernstein
authors.forename: S L
authors.initials: SL
authors.lastname: Welsh
authors.forename: J K
authors.initials: JK
authors.lastname: Inman
mesh_terms: D000806:Angiotensin-Converting Enzyme Inhibitors / Q000138:chemical synthesis / Q000494:pharmacology*; D000818:Animals; D001665:Binding Sites; D001710:Biotin / Q000031:analogs & derivatives / Q000138:chemical synthesis / Q000494:pharmacology; D002848:Chromatography, DEAE-Cellulose; D003432:Cross-Linking Reagents; D004656:Enalapril / Q000031:analogs & derivatives / Q000138:chemical synthesis / Q000494:pharmacology; D007668:Kidney / Q000201:enzymology; D017706:Lisinopril / Q000031:analogs & derivatives; D051379:Mice; D007703:Peptidyl-Dipeptidase A / Q000302:isolation & purification
chemical_list: D000806:Angiotensin-Converting Enzyme Inhibitors; D003432:Cross-Linking Reagents; C063195:BL 19; C063194:BL 11; D004656:Enalapril; D001710:Biotin; D017706:Lisinopril; D007703:Peptidyl-Dipeptidase A