Enzymic Reduction of α-Aminoadipic Acid by Yeast Enzyme

Abstract

RECENT work in this laboratory demonstrated that, with the whole cells of Torulopsis utilis and baker's yeast, α-aminoadipic acid is converted to lysine to an appreciable extent¹ and that it has a primary role for lysine biosynthesis in this organism, as inferred earlier by Strassman and Weinhouse². Enzymic conversion of α-aminoadipic acid to lysine has so far been supposed to occur via α-aminoadipic acid-δ-semialdehyde, which actually has been shown to be an oxidation product of hexahomoserine catalysed by mould enzyme³; but no evidence for the enzymic reduction of α-aminoadipic acid to its semialdehyde has hitherto been presented. The present communication reports the enzymic reduction of α-aminoadipic acid to an intermediary substance which is easily converted to dehydropiperidine-2-carboxylic acid, a cyclized form of α-aminoadipic acid-δ-semialdehyde.