Escherichia coli dihydrodipicolinate synthase: characterization of the imine intermediate and the product of bromopyruvate treatment by electrospray mass spectrometry.

Simplified procedures for assaying and purifying dihydrodipicolinate synthase (EC 4.2.1.52), the first enzyme of the lysine biosynthetic pathway, have been developed and electrospray ionization m.s. has been used to observe the imine intermediate with pyruvate and to investigate the reaction of the enzyme with bromopyruvate and fluoropyruvate.