Lipase activity and conformation in neat organic solvents

The methods commonly employed to improve the catalytic efficiency and to determine the conformation of lipases in organic solvents are briefly examined and discussed. Special attention is dedicated to the properties of different formulations of lipase from Pseudomonas cepacia (lipase PC) and lipase B from Candida antarctica (CALB). Non-covalent lipases/PEG complexes are particulary interesting because they are easy to prepare, very active and soluble in suitable organic solvents. This last property makes it possible to carry out conformational studies of lipases by circular dichroism and intrinsic protein fluorescence. Moreover, correlations between enzyme activity and solubility in organic solvents, shed light on the effects of diffusional limitations and lipase conformational changes on the catalytic efficiency of enzymes in organic solvents.