title: Structural effects of amphiphiles on Candida rugosa lipase activation by freeze-drying of aqueous solution of enzyme and amphiphile.
abstract: Lipases co-lyophilized with water-soluble gemini-type amphiphiles were found to have high enzyme activity in nonaqueous media without washing out of the amphiphile with anhydrous organic solvent. In this study, we obtained freeze-dried complexes of Candida rugosa lipase (CRL) with six water-soluble twin glusitol-headed amphiphiles bearing different types of hydrophobic tails, including newly synthesized ones, and their transesterification activity in organic solvent was evaluated. The results indicate that the increased enzyme activity upon CRL modification at 200 molar ratio of amphiphile/CRL, which are restricted to the ester-containing amphiphiles, is probably due to the surface activation by the interaction between ester-carbonyl of the amphiphile and phenyl group of the tyrosine residue situated on the surface of the lid in the CRL.
authors.affiliation: Department of Applied Chemistry and Chemical Engineering, Faculty of Engineering, Yamaguchi University, 2-16-1 Tokiwadai, Ube 755-8611, Japan.
authors.forename: Yurie
authors.initials: Y
authors.lastname: Mine
authors.forename: Kimitoshi
authors.initials: K
authors.lastname: Fukunaga
authors.forename: Ken-Ichi
authors.initials: K
authors.lastname: Samejima
authors.forename: Makoto
authors.initials: M
authors.lastname: Yoshimoto
authors.forename: Katsumi
authors.initials: K
authors.lastname: Nakao
authors.forename: Yoshiaki
authors.initials: Y
authors.lastname: Sugimura