Modification of a spectrophotometric method for assessment of monoamine oxidase activity with 2,4-dinitrophenylhydrazine as a derivatizing reagent

The aim of the study was to modify a simple and widely used spectrophotometric assay for MAO activity evaluation with 2,4-dinitrophenylhydrazine. A modified procedure includes molar absorption coefficients of 2,4DNP-hydrazone benzaldehyde and 2,4-DNP-hydrazone 5-hydroxyindolylacetaldehyde as 2.3 x 104mol- 1l cm-1 and 1.0 x 104 mol- 1l cm-1, respectively. Such an approach allows to express specific enzyme activity as nmol product formed/min/mg protein.

Automated summary

The study aimed to modify a spectrophotometric assay for MAO activity evaluation with 2,4-dinitrophenylhydrazine, allowing accurate measurement of specific enzyme activity using different substrates.