title: Structure of angiotensin I-converting enzyme.
abstract: Angiotensin-converting enzyme (ACE) is a zinc- and chloride-dependent metallopeptidase that plays a vital role in the metabolism of biologically active peptides. Until recently, much of the inhibitor design and mechanism of action of this ubiquitous enzyme was based on the structures of carboxypeptidase A and thermolysin. When compared to the recently solved structures of the testis isoform of ACE (tACE) and its Drosophila homologue (AnCE), carboxypeptidase A showed little structural homology outside of the active site, while thermolysin revealed significant but less marked overall similarity. The ellipsoid-shaped structure of tACE, which has a preponderance of alpha-helices, is characterised by a core channel that has a constriction approximately 10 A from its opening where the zinc-binding active site is located. Comparison of the native protein with the inhibitor-bound form (lisinopril-tACE) does not reveal any striking differences in the conformation of the inhibitor binding site, disfavouring an open and closed configuration. However, the inhibitor complex does provide insights into the network of hydrogen-bonding and ionic interactions in the active site as well as the mechanism of ACE substrate hydrolysis. The three-dimensional structure of ACE now paves the way for the rational design of a new generation of domain-selective ACE inhibitors.
authors.affiliation: Division of Medical Biochemistry, Faculty of Health Sciences, University of Cape Town, 7925, Observatory, Cape Town, South Africa.
authors.forename: E D
authors.initials: ED
authors.lastname: Sturrock
authors.forename: R
authors.initials: R
authors.lastname: Natesh
authors.forename: J M
authors.initials: JM
authors.lastname: van Rooyen
authors.forename: K R
authors.initials: KR
authors.lastname: Acharya
mesh_terms: D000806:Angiotensin-Converting Enzyme Inhibitors / Q000494:pharmacology; D000818:Animals; D018360:Crystallography, X-Ray; D015195:Drug Design; D006801:Humans; D007703:Peptidyl-Dipeptidase A / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D011487:Protein Conformation; D013329:Structure-Activity Relationship
chemical_list: D000806:Angiotensin-Converting Enzyme Inhibitors; D007703:Peptidyl-Dipeptidase A