Arabinose dehydrogenase (AraDH) reporter enzyme assay for Haloferax volcanii

Abstract In H. volcanii the arabinose dehydrogenase is routinely used as a reporter enzyme. The AraDH (XacB) enzyme catalyzes the oxidation of L-arabinose to L-arabino-1,4-lactone while reducing the cofactor NAD+ or NADP+ [1]. Reduction of the preferred cofactor NADP+ to NADPH or NAD+ to NADH can be measured and quantified via increase of the extinction at 340 nm. To enable the parallel handling of multiple samples the assay was adapted to the microtiter plate format. The “procedure” (see below) describes an application with the araDH ( xacB ) gene in a translational fusion with the gene of interest.