Reaction between Sheep Liver Mitochondrial Aldehyde Dehydrogenase and A Chromogenic ‘Reporter Group’ Reagent

Enzymology and Molecular Biology of Carbonyl Metabolism 7

“…It will be of interest to see if the chemistry investigated here with ALDH-l is also exhibited by ALDH-2, and whether the reactions occur in vivo as well as in vitro (although the latter seems to be already evident in the case of methylene blue; Cronholm, 1993). There may well be naturally occurring a,p-unsaturated compounds that could be endogenous modifiers of ALDH; acrolein (produced during lipid peroxidation and discussed further in the accompanying paper; King et al, 1999) and quinones such as vitamin K and ubiquinone spring to mind. Menadione (vitamin K J ) has been shown to inactivate a phosphatase with an active site thiol group, and exactly the same oxidative addition mechanism as discussed here has been proposed to explain the loss of activity .…”