Competitive inhibition and substrate activity of uridine diphosphate 6-deoxygalactose for Escherichia coli uridine diphosphate galactose 4-epimerase (Short Communication)

UDP-6-deoxygalactose inhibits the UDP-galactose 4-epimerase (EC 5.1.3.2) from Escherichia coli in a competitive manner with respect to the substrate UDP-galactose, giving K i 1.3×10 -3 m. As a substrate for the enzyme, it is transformed into UDP-6-deoxyglucose, although the reaction stops before equilibrium is attained. Possible causes of this behaviour are discussed.