Activity assays of methanol dehydrogenases

The field of methanol dehydrogenases (MDHs) has experienced revival in the recent decade due to the observation of lanthanide-dependent MDH, in addition to widely known calcium-MDH. With the advent of lanthanide-dependent alcohol dehydrogenases, the need for reliable assays to evaluate and compare activities between different MDHs is obvious: from extremophilic to neutrophilic organisms, or with different lanthanide ions in the active site. Here we outline four assays that have been reported for Ln-MDH, discussing the advantages and disadvantages of the assays and their components. It should be noted, in 1990Day and Anthony produced a comprehensive summary in Methods in Enzymology on the available methods for Ca-MDH assays at the time (Day & Anthony, 1990). This chapter is an updated appraisal of the most important developments in the last 30 years.