The first enzyme of the pathway for uridine diphosphate N-acetyl-D-glucosamine
(UDPAG) biosynthesis i.e. L-glutamine: D-fructose 6-P amidotransferase (E.C.
220.127.116.11) was purified 52-fold from human placenta using methanol fractionation
and column chromatography on DEAE-Sephadex A-50. The enzyme showed
optimal activity in a broad range of pH from 5.8 to 7.8 in both phosphate and
cacodylate buffers. Its K m value for D-fructose 6-P was found to be 2.14 mM. The
enzyme was inhibited up to 76% in the presence of 0.12mM UDPAG. A K value
of 6.6 ?M was obtained for the feedback inhibition of this enzyme by UDPAG