Selective Monoacylation of Diols by Substrate Assisted Catalysis in T40A Candida antarctica Lipase B

Abstract The selectivity towards diols over monoesters in the esterification of diols catalysed by lipase B from Candida antarctica (CALB) was improved by the single point mutation T40A in the enzyme’s oxyanion hole. Substrate‐assisted catalysis was suggested from molecular modelling of the tetrahed...

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Bibliographic Details
Published in:ChemCatChem
Main Authors: Hamberg, Anders, Magnusson, Anders O., Hu, Francis J., Hult, Karl
Format: Article in Journal/Newspaper
Language:English
Published: Wiley 2013
Subjects:
Online Access:http://dx.doi.org/10.1002/cctc.201200560
https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1002%2Fcctc.201200560
http://onlinelibrary.wiley.com/wol1/doi/10.1002/cctc.201200560/fullpdf
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Summary:Abstract The selectivity towards diols over monoesters in the esterification of diols catalysed by lipase B from Candida antarctica (CALB) was improved by the single point mutation T40A in the enzyme’s oxyanion hole. Substrate‐assisted catalysis was suggested from molecular modelling of the tetrahedral intermediate in esterification of 1,2‐ethanediol catalysed by T40A CALB. The non‐reacting hydroxyl group of the diol forms a hydrogen bond to the oxyanion in the transition state, replacing that deleted in mutation. Monoester yields in transacylation reactions were monitored over time to compare the selectivities for wild‐type and T40A CALB. The results showed increased selectivities towards the diols tested over their corresponding monoesters as a result of the T40A mutation with substrate‐assisted catalysis as a plausible explanation.