A rapid nonchromatographic assay for aminopropyltransferases

Aminopropyltransferases are key enzymes in the biosynthesis of the polyamines spermidine and spermine. A procedure is described for assaying these enzymes by differential charcoal adsorption of 14C-labeled decarboxylated adenosylmethionine substrate from the labeled polyamine product. This assay is linear with time and enzyme concentration, and is suitable for use with a variety of amine acceptors. This procedure has the advantage, over those previously used, that it is extremely rapid yet very sensitive.