Improved triglyceride transesterification by circular permuted Candida antarctica lipase B.

Lipases represent a versatile class of biocatalysts with numerous potential applications in industry including the production of biodiesel via enzyme-catalyzed transesterification. In this article, we have investigated the performance of cp283, a variant of Candida antarctica lipase B (CALB) engineered by circular permutation, with a series of esters, as well as pure and complex triglycerides. In comparison with wild-type CALB, the permutated enzyme showed consistently higher catalytic activity (2.6- to 9-fold) for trans and interesterification of the different substrates with 1-butanol and ethyl acetate as acyl acceptors. Differences in the observed rates for wild-type CALB and cp283 are believe to be related to changes in the rate-determining step of the catalytic cycle as a result of circular permutation.