%0 Journal Article %A CHMARA, HENRYK %T Inhibition of Glucosamine Synthase by Bacilysin and Anticapsin %D 1985 %J Microbiology, %V 131 %N 2 %P 265-271 %@ 1465-2080 %R https://doi.org/10.1099/00221287-131-2-265 %I Microbiology Society, %X l-Glutamine d-fructose-6-phosphate amidotransferase (‘glucosamine synthase’, EC 5.3.1.19) from Escherichia coli MRE 600 was purified at least 75-fold. It catalysed the formation of 21·1 μmol glucosamine 6-phosphate (mg protein)–1 in 30 min at 37 °C. Its molecular weight, estimated by gel filtration, was about 90000 and it was inhibited by thiol group reagents. Anticapsin, the C-terminal amino acid of the dipeptide antibiotic bacilysin, and to a lesser extent bacilysin itself, inhibited glucosamine synthase activity. Kinetic studies indicated that the inhibition was non-competitive with respect to fructose 6-phosphate as substrate but partly competitive with respect to l-glutamine. Incubation of the enzyme with anticapsin brought about a time-dependent and irreversible inhibition. It is suggested that anticapsin behaves as a glutamine analogue and that a reaction of its epoxide group with a thiol group of glucosamine synthase results in its linkage to the enzyme by a covalent bond. %U https://www.microbiologyresearch.org/content/journal/micro/10.1099/00221287-131-2-265