Mass spectrometry study of the adduct formed by F-ALDH with thiram

F-ALDH is a recently characterized psychrophilic aldehyde dehydrogenase from Flavobacterium PL002. Thiram was shown to inhibit its enzymatic activity, yet the mechanism of inhibition is unknown. We have used low flow liquid chromatography (nanoLC) coupled to tandem mass spectrometry (MS/MS) to study the mechanism behind thiram inhibition, as we assumed a Cys-covalent adduct could be formed between F-ALDH and thiram. For this, purified F-ALDH was incubated with thiram and the sample was subjected to Cys reduction or not along a control sample of non-treated F-ALDH.