Inhibition of glucosamine-6-phosphate synthetase from bacteria by anticapsin.

Abstract

On the basis of kinetic studies on glucosamine-6-phosphate synthetase (EC 5.3.1.19) from 6 bacteria sources, it was shown that the epoxyamino acid anticapsin, a glutamine analog, is a competitive inhibitor of the enzyme in regard to glutamine with Km value of 10-4 M and Ki varying from 10-7 to 10-6 M. Unlike other glutamine analogs like 6-diazo-5-oxo-L-norleucine, chloropentanoic acid, L-.alpha.-amino-3-chloro-4,5-dihydro-5-isoxazole acetic acid or albizziin, anticapsin is not generally inhibitory to various amidotransferases. It does not inhibit xanthosine 5''-monophosphate amidotransferase, glutaminase or .gamma.-glutamyltranspeptidase.