title: Chemical modification of lipases with various hydrophobic groups improves their enantioselectivity in hydrolytic reactions.
abstract: Semi-purified lipases from Candida rugosa, Pseudomonas cepacia and Alcaligenes sp. were chemically modified with a wide range of hydrophobic groups such as benzyloxycarbonyl, p-nitrobenzyloxycarbonyl, p-methoxybenzyloxycarbonyl, t-butoxycarbonyl, lauroyl and acetyl moieties. The Candida rugosa lipase MY modified with the benzyloxycarbonyl group (modification ratio = 84%) brought about a 15-fold increase in enantioselectivity (E value) towards the hydrolysis of racemic butyl 2-(4-ethylphenoxy)propionate in an aqueous buffer solution, although the enzymatic activity was decreased. The origin of the enantioselectivity enhancement by chemical modification of the lipase is attributed to a significant deceleration in the initial reaction rate for the incorrectly binding enantiomer.
authors.affiliation: Division of Natural Environment and Bioorganic Chemistry, Faculty of Human Development and Sciences, Kobe University, Nada, Kobe 657-8501, Japan. ueji@kobe-u.ac.jp
authors.forename: Shin-ichi
authors.initials: S
authors.lastname: Ueji
authors.forename: Ai
authors.initials: A
authors.lastname: Uedal
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Tanaka
authors.forename: Keiichi
authors.initials: K
authors.lastname: Watanabe
authors.forename: Takashi
authors.initials: T
authors.lastname: Okamoto
authors.forename: Yasuhito
authors.initials: Y
authors.lastname: Ebara
mesh_terms: D000421:Alcaligenes / Q000737:chemistry* / Q000201:enzymology; D016956:Burkholderia cepacia / Q000737:chemistry* / Q000201:enzymology; D002175:Candida / Q000737:chemistry* / Q000201:enzymology; D004789:Enzyme Activation; D006868:Hydrolysis; D057927:Hydrophobic and Hydrophilic Interactions; D008049:Lipase / Q000138:chemical synthesis / Q000737:chemistry* / Q000145:classification; D011422:Propionates / Q000737:chemistry*; D011786:Quality Control; D012680:Sensitivity and Specificity; D013045:Species Specificity; D013237:Stereoisomerism
chemical_list: D011422:Propionates; D008049:Lipase