Effects of water miscible organic solvents on the activity and conformation of the baeyer–villiger monooxygenases from Thermobifida fusca and Acinetobacter calcoaceticus: A comparative study

• DOI: 10.1002/bit.22963
• Publication Date: 2010-10-11T19:05:19Z
• Authors: Francesco Secundo; Stefano Fialà; Marco W. Fraaije; Gonzalo de Gonzalo; Massimiliano Meli; Francesca Zambianchi; Gianluca Ottolina
• Keywords: Acinetobacter calcoaceticus

A broader exploitation of enzymes in organic synthesis can be achieved by increasing their tolerance toward solvents. In this study, the stability and activity Baeyer-Villiger monooxygenases from Thermobifida fusca (PAMO) Acinetobacter sp. (CHMO) presence water miscible solvents were compared. PAMO was more stable than CHMO. The concentration solvent (v/v) at which it halved its (C(50) ) 4- to 16-fold higher that observed for For PAMO, C(50) varied 16% 55% followed destabilizing order methanol < ethanol 1,4-dioxane acetonitrile trifluoroethanol. case CHMO, maximal 7% with even lower other Therefore, most tolerated solvent. induced a significant increase enzyme (up fivefold), optimal 20% Only minor spectral variations methanol, suggesting condition is not due marked conformational changes. Fluorescence circular dichroism analyses showed CHMO correlates pronounced destructive effect on secondary tertiary structure. possible rationale could inferred inspection (two similar size) structure, revealed twofold) number ionic bridges respect