title: Improvement of a stereoselective biocatalytic synthesis by substrate and enzyme engineering: 2-hydroxy-(4'-oxocyclohexyl)acetonitrile as the model.
abstract: Even if biocatalysis is finding increasing application, it still has to gain widespread use in synthetic chemistry. Reasons for this are limitations that enzymes have with regard to substrate range, reaction scope, and insufficient selectivity with unnatural compounds. These shortcomings can be challenged by enzyme and/or substrate engineering, which are employed to alter substrate specificity and enhance the enzyme selectivity toward unnatural substrates. Herein, these two approaches are coupled to improve the hydroxynitrile lyase catalyzed synthesis of 2-hydroxy-(4'-oxocyclohexyl)acetonitrile (4). The ketone functionality is masked as an enol ether, and the oxynitrilase of Hevea brasiliensis is engineered towards this masked substrate to give the product with a high optical purity and to drastically lower the amount of enzyme needed.
authors.affiliation: Institute of Organic Chemistry, Graz University of Technology, Austria.
authors.forename: Manuela
authors.initials: M
authors.lastname: Avi
authors.forename: Romana M
authors.initials: RM
authors.lastname: Wiedner
authors.forename: Herfried
authors.initials: H
authors.lastname: Griengl
authors.forename: Helmut
authors.initials: H
authors.lastname: Schwab
mesh_terms: D000097:Acetonitriles / Q000138:chemical synthesis* / Q000737:chemistry; D000446:Aldehyde-Lyases / Q000737:chemistry* / Q000378:metabolism; D019943:Amino Acid Substitution; D001483:Base Sequence; D055162:Biocatalysis; D003198:Computer Simulation; D028482:Hevea / Q000201:enzymology; D009154:Mutation; D017434:Protein Structure, Tertiary; D013237:Stereoisomerism; D013329:Structure-Activity Relationship; D013379:Substrate Specificity
chemical_list: C535009:2-hydroxy-(4'-oxocyclohexyl)acetonitrile; D000097:Acetonitriles; D000446:Aldehyde-Lyases; C496044:S-hydroxynitrile lyase, Hevea brasiliensis