Determination of catechol- O-methyltransferase activity by high-performance liquid chromatography with electrochemical detection

Abstract

A rapid and simple assay for catechol- O-methyltransferase (COMT) activity by high-performance liquid chromatography with electrochemical detection is described. The method is based on the measurement of 3- O- and 4- O-methylated products (3-methoxy-4-hydroxy- and 4-methoxy-3-hydroxybenzylamine, respectively) of the substrate 3,4-dihydroxybenzylamine. These compounds are determined from the incubation mixture after removal of protein injecting aliquot into the liquid chromatograph. The detection limit is 1 pmol of product. This method is very suitable for screening of COMT activity as well as for determining the meta/para product ratios.