Over-Stabilization of Chemically Modified and Cross-Linked Candida antarctica Lipase B Using Various Epoxides and Diepoxides

Candida antarctica lipase B, Cal-B, was (i) chemically modified with various epoxides, or (ii) cross-linked with various diepoxides in order to improve enzyme activity and thermal stability. Changed enzyme structure was confirmed by kinetic resolution of p-nitrophenol acetate with methanol and deter...

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Bibliographic Details
Published in:Australian Journal of Chemistry
Main Authors: Miletic, Nemanja, Loos, Katja
Format: Article in Journal/Newspaper
Language:English
Published: CSIRO PUBLISHING 2009
Subjects:
Online Access:https://scidar.kg.ac.rs/handle/123456789/19835
https://doi.org/10.1071/CH09033
Description
Summary:Candida antarctica lipase B, Cal-B, was (i) chemically modified with various epoxides, or (ii) cross-linked with various diepoxides in order to improve enzyme activity and thermal stability. Changed enzyme structure was confirmed by kinetic resolution of p-nitrophenol acetate with methanol and determination of the kinetic parameters. Thermal stability measurements were carried out for each Cal-B derivative, proving that Cal-B modified with 1,2-epoxypropane and 1,2-epoxypentane, and cross-linked with 1,2,7,8-diepoxyoctane and 1,2,9,10-diepoxydecane showed higher stability than soluble enzyme. The influence of the length of the epoxide arm in the modification process, as well as the length of the spacer arm in the cross-linking process, on the final enzyme preparation properties was investigated. The amount of epoxides and diepoxides used for structural rearrangement played an important role in the derivatives’ characteristics. The influence of the precipitant used and the presence of additives, such as surfactant or crown-ether, during modification and cross-linking processes was also revealed. Published