CUTINASE ACTIVITY AND ENANTIOSELECTIVITY IN SUPERCRITICAL FLUIDS

We studied the performance of Fusarium solani pisi cutinase, immobiliz ed on a zeolite, in supercritical fluids. The catalytic activity of th e enzyme was strongly dependent on water activity, was unaffected by p ressure up to 300 bar, and was higher in supercritical ethylene than i n supercritical carbon dioxide. The enzyme was very selective toward o ne of the isomers of 1-phenylethanol, with an enantiomeric excess of v irtually 100%, regardless of water activity, pressure, solvent, and te mperature. We used the X-ray crystal structure of the enzyme and did a computer modeling of the structures of the transition states formed b y the two enantiomers. The differences between these structures helped elucidate the preference for the (R)-enantiomer.