title: Obtaining higher transesterification rates with subtilisin Carlsberg in nonaqueous media.
abstract: Three phase partitioning (protein precipitate obtained as an interfacial layer between lower aqueous and upper t-butanol phases, formed by the addition of ammonium sulphate and t-butanol to the aqueous solution of protein) followed by lyophilization in the presence of two-component excipient resulted in 400-480x increases in transesterification activity of lyophilized powders of subtilisin Carlsberg, depending on the solvent. The three phase partitioned enzyme, 'dried' by washing with butanol, gave 3-4x higher rates (depending on the solvent used) than the enzyme preparation dried by lyophilization in the presence of two-component excipient system.
authors.affiliation: Chemistry Department, Indian Institute of Technology, Delhi, Hauz Khas, New Delhi 110016, India.
authors.forename: Ipsita
authors.initials: I
authors.lastname: Roy
authors.forename: Aparna
authors.initials: A
authors.lastname: Sharma
authors.forename: Munishwar N
authors.initials: MN
authors.lastname: Gupta
mesh_terms: D002384:Catalysis; D004789:Enzyme Activation; D005612:Freeze Drying / Q000379:methods; D007700:Kinetics; D012997:Solvents / Q000494:pharmacology*; D013381:Subtilisins / Q000737:chemistry* / Q000187:drug effects / Q000378:metabolism*
chemical_list: D012997:Solvents; D013381:Subtilisins