Chloroperoxidase exhibits a wide variety of enantioselective epoxidation re
actions. Until now, the epoxidation activities have been mainly evaluated u
sing elaborate gas chromatographic methods. This paper reports a rapid and
convenient spectrophotometric assay for CPO. The disappearance of indene by
catalytic epoxidation is monitored at 250 nm and this is used as an index
of enzyme activity. This method will prove to be highly useful in large-sca
le screening of mutants. (C) 1999 Academic Press.