Thermal and Mechanical Stability of Immobilized Candida antarctica Lipase B: an Approximation to Mechanochemical Energetics in Enzyme Catalysis.

Very recently, several successful enzymatic processes performed with mechanical activation have been disclosed; that is, despite the mechanical stress caused by High-Speed Ball-Milling, immobilized enzymes can retain activity. In the present study, the effect of thermal and mechanical stress was examined as potential inducers of enzymatic denaturation, when using either free, immobilized, or ground immobilized enzyme. The recorded observations show a remarkable stability of ground immobilized enzyme. Moreover, ground biocatalyst turns out to exhibit an increase of one order of magnitude in the efficiency of the catalytic process, maintaining excellent enantiodiscrimination, without significant activity loss even after four milling cycles. These observations rule out enzyme inactivation as direct consequence of the milling process. Additionally, boosted enzyme efficiency was used to optimize a relatively inefficient chiral amine resolution reaction, achieving a 25 % faster biotransformation (in 45 min) and yielding essentially enantiopure products (ee>99%, E>500).