Improved method for measurement of delta-aminolevulinic acid dehydratase activity of human erythrocytes.

Abstract

We have evaluated and modified a current method for estimating δ-aminolevulinic acid dehydratase (5-aminolaevulinate hydro-lyase, EC 4.2.1.24) activity in blood, so as to adequately control the pH of the enzyme-substrate solution at the optimum throughout the incubation period. This has improved the sensitivity and reliability of the assay. Also, N-ethylmaleimide has been substituted for a potentially hazardous mercury salt, used to remove sulfhydryl groups before color development with a modified Ehrlich’s reagent.