INHIBITION OF DOPAMINE β-HYDROXYLASE BY AQUAYAMYCIN

Abstract

Aquayamycin was found to be one of the most potent inhibitors of dopamine β-hydroxylase. Aquayamycin at 4×10-7 M inhibited the enzyme by 50% with a Ki value of 2.1×10-7 M. The inhibitionwas non-competitive with substrate and was not affected by cof actors, i.e. ascorbic acid or fumarate. The inhibitory mechanism is possibly due to chelating action of aquayamycin on protein-bound copper. However, the addition of Cu++ did not reverse the inhibition.