title: The importance of GLU361 position in the reaction catalyzed by cholesterol oxidase.
abstract: Cholesterol oxidase stereospecifically isomerizes cholest-5-en-3-one to cholest-4-en-3-one. When the base catalyst for isomerization, Glu361, is mutated to Asp, the rate of deprotonation of cholest-5-en-3-one is not affected, but protonation of the dienolic intermediate becomes rate-limiting. This may be a consequence of the large distance between the catalytic base and carbon-6 of the intermediate in the mutant enzyme.
authors.affiliation: Department of Chemistry, State University of New York, Stony Brook, NY 11794-3400, USA.
authors.forename: I J
authors.initials: IJ
authors.lastname: Kass
authors.forename: N S
authors.initials: NS
authors.lastname: Sampson
mesh_terms: D001665:Binding Sites; D002783:Cholestenones / Q000378:metabolism; D002784:Cholesterol / Q000378:metabolism; D002789:Cholesterol Oxidase / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D002942:Circular Dichroism; D018698:Glutamic Acid / Q000737:chemistry* / Q000378:metabolism*; D007536:Isomerism; D007700:Kinetics; D016254:Mutagenesis, Insertional; D010084:Oxidation-Reduction; D017354:Point Mutation; D016133:Polymerase Chain Reaction; D013056:Spectrophotometry, Ultraviolet
chemical_list: D002783:Cholestenones; D018698:Glutamic Acid; C079712:cholest-5-en-3-one; D002784:Cholesterol; D002789:Cholesterol Oxidase