Studies of enzyme-mediated reactions. Part 14. Stereochemical course of the formation of cadaverine by decarboxylation of (2S)-lysine with lysine decarboxylase (E.C. 4.1.1.18) from Bacillus cadaveris

Abstract

The decarboxylation of (2S)-lysine by lysine decarboxylase (E.C. 4.1.1.18) from B. cadaveris is shown to be stereospecific and to proceed with retention of configuration by incubation of [2-³H,U-¹⁴C]lysine in unlabelled water and [U-¹⁴C]lysine in tritiated water to give labelled samples of [1-³H,U-¹⁴C]cadaverine (1,5-diaminopentane) which are chiral by isotopic substitution. The configuration of each diamine is assayed by deamination with the diamine oxidase from pea seedlings (E.C. 1.4.3.6) which stereospecifically removes the hydrogen from the Si-position of the tritiated methylene group.