title: Examination of the mechanism of human brain aspartoacylase through the binding of an intermediate analogue.
abstract: Canavan disease is a fatal neurological disorder caused by the malfunctioning of a single metabolic enzyme, aspartoacylase, that catalyzes the deacetylation of N-acetyl-L-aspartate to produce L-aspartate and acetate. The structure of human brain aspartoacylase has been determined in complex with a stable tetrahedral intermediate analogue, N-phosphonomethyl-L-aspartate. This potent inhibitor forms multiple interactions between each of its heteroatoms and the substrate binding groups arrayed within the active site. The binding of the catalytic intermediate analogue induces the conformational ordering of several substrate binding groups, thereby setting up the active site for catalysis. The highly ordered binding of this inhibitor has allowed assignments to be made for substrate binding groups and provides strong support for a carboxypeptidase-type mechanism for the hydrolysis of the amide bond of the substrate, N-acetyl- l-aspartate.
authors.affiliation: Department of Chemistry, University of Toledo, Toledo, Ohio 43606, USA.
authors.forename: Johanne
authors.initials: J
authors.lastname: Le Coq
authors.forename: Alexander
authors.initials: A
authors.lastname: Pavlovsky
authors.forename: Radhika
authors.initials: R
authors.lastname: Malik
authors.forename: Ruslan
authors.initials: R
authors.lastname: Sanishvili
authors.forename: Chengfu
authors.initials: C
authors.lastname: Xu
authors.forename: Ronald E
authors.initials: RE
authors.lastname: Viola
mesh_terms: D000581:Amidohydrolases / Q000037:antagonists & inhibitors / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D001051:Apoenzymes / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D001224:Aspartic Acid / Q000031:analogs & derivatives* / Q000737:chemistry / Q000378:metabolism; D001665:Binding Sites / Q000235:genetics; D001921:Brain / Q000201:enzymology*; D002268:Carboxypeptidases / Q000737:chemistry / Q000378:metabolism; D002384:Catalysis; D018360:Crystallography, X-Ray; D004791:Enzyme Inhibitors / Q000378:metabolism; D006031:Glycosylation; D006801:Humans; D016297:Mutagenesis, Site-Directed; D009943:Organophosphorus Compounds / Q000737:chemistry / Q000378:metabolism*; D011485:Protein Binding / Q000235:genetics
chemical_list: D001051:Apoenzymes; D004791:Enzyme Inhibitors; C528693:N-phosphonomethylaspartic acid; D009943:Organophosphorus Compounds; D001224:Aspartic Acid; D002268:Carboxypeptidases; D000581:Amidohydrolases; C019751:aspartoacylase