title: Removing the Active-Site Flap in Lipase A from Candida antarctica Produces a Functional Enzyme without Interfacial Activation.
abstract: A mobile region is proposed to be a flap that covers the active site of Candida antarctica lipase A. Removal of the mobile region retains the functional properties of the enzyme. Interestingly interfacial activation, required for the wild-type enzyme, was not observed for the truncated variant, although stability, activity, and stereoselectivity were very similar for the wild-type and variant enzymes. The variant followed classical Michaelis-Menten kinetics, unlike the wild type. Both gave the same relative specificity in the transacylation of a primary and a secondary alcohol in organic solvent. Furthermore, both showed the same enantioselectivity in transacylation of alcohols and the hydrolysis of alcohol esters, as well as in the hydrolysis of esters chiral at the acid part.
authors.affiliation: Department of Organic Chemistry, Arrhenius Laboratory, Stockholm University, 106 91, Stockholm, Sweden.
authors.forename: Ylva
authors.initials: Y
authors.lastname: Wikmark
authors.affiliation: Department of Organic Chemistry, Arrhenius Laboratory, Stockholm University, 106 91, Stockholm, Sweden.
authors.forename: Karim
authors.initials: K
authors.lastname: Engelmark Cassimjee
authors.affiliation: Department of Organic Chemistry, Arrhenius Laboratory, Stockholm University, 106 91, Stockholm, Sweden.
authors.forename: Richard
authors.initials: R
authors.lastname: Lihammar
authors.affiliation: Department of Organic Chemistry, Arrhenius Laboratory, Stockholm University, 106 91, Stockholm, Sweden. jeb@organ.su.se.
authors.forename: Jan-E
authors.initials: JE
authors.lastname: Bäckvall
mesh_terms: D002175:Candida / Q000201:enzymology*; D020134:Catalytic Domain; D014644:Genetic Variation; D057927:Hydrophobic and Hydrophilic Interactions; D007700:Kinetics; D008049:Lipase / Q000737:chemistry* / Q000235:genetics; D008958:Models, Molecular; D015394:Molecular Structure; D013237:Stereoisomerism
chemical_list: D008049:Lipase
keywords: Candida antarctia lipase A; enzyme catalysis; flap; interfacial activation; lid; protein engineering