Obtaining high transesterification activity for subtilisin in ionic liquids

• Published in: Biochimica et biophysica acta Vol. 1770; no. 1; pp. 94 - 98
• Main Authors: Shah, Shweta, Gupta, Munishwar N.
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 2007
• Subjects: Chromatography, High Pressure Liquid; Cryoprotectant; Esterification; Ionic liquids; Ions; Lyoprotectant; Propanol rinsed enzyme preparation; Subtilisin; Subtilisins - metabolism; Three phase partitioning; Lyoprotectant; Cryoprotectant; PREP; EPRP; Subtilisin; [Bmim][PF 6]; ILs; PEG; Propanol rinsed enzyme preparation; TPP; [Omim][PF 6]; Ionic liquids; [Bmim][BF 4]; Three phase partitioning; Cal-B
• ISSN: 0304-4165; 0006-3002; 1872-8006
• DOI: 10.1016/j.bbagen.2006.10.004

It is known that subtilisin shows poor transesterification activity in ionic liquids (ILs). The present work, taking subtilisin as the system, explores approaches for biocatalyst preparations, which are capable of yielding higher/adequate transesterification activity in these solvents. Of all the approaches tried, enzyme precipitated and rinsed with n-propanol (EPRP) gave the best results (about 10,000 times increase in initial rates in 1-butyl-3-methylimidazolium hexafluorophosphate ([Bmim][PF 6]) over what is obtained with pH tuned lyophilized powders). In case of water soluble ionic liquid 1-butyl-3-methylimidazolium tetrafluoroborate ([Bmim][BF 4]), pH tuned lyophilized subtilisin did not show any transesterification activity. EPRP, however, gave an initial rate (for transesterification) of 2.78 mmol mg − 1 h − 1 .