The enzymatic synthesis of 5-hydroxy-N-methylpyroglutamic acid.

Cell-free extracts of Pseudomonas M.A., a nonphotosynthetic bacterium which grows on methylamine as its sole source of carbon, nitrogen, and energy, have been shown to catalyze a reaction between methylamine and a-ketoglutaric acid. The product of this reaction has been identified as the cyclic amide, 5-hydroxy-N-methylpyroglutamic acid. This reaction is catalyzed by an enzyme which diEers from the one catalyzing the formation of N-methylglutamic acid, and it appears to be specific for cr-ketoglutarate. The possibility of a two-step reaction is discussed.