Ray S, Ali E, Bhaduri A
Indian Institute of Chemical Biology, Calcutta.
Indian J Biochem Biophys. 1992 Apr;29(2):209-13.
A chromophorics and fluorescent analog of uridine 5'-monophosphate (UMP), a known competitive inhibitor of UDPglucose 4-epimerase was synthesised. This analog, namely 2',3'-O-(2,4,6-trinitrocyclohexadienylidene) uridine 5'-monophosphate, was found to be a powerful reversible inhibitor of UDPglucose 4-epimerase indicating its interaction with the substrate binding site of the enzyme. The extreme sensitivity of the fluorescence emission spectrum of this analog to solvent polarity makes it an excellent probe for the study of the environment at the active site of the enzyme. We report here the effective use of this UMP analog to demonstrate that the hydroxyl groups of the ribose moiety of UMP and presumably the substrates (UDPgalactose and UDPglucose) do not reside in a hydrophobic milieu.
合成了尿苷5'-单磷酸（UMP）的一种发色和荧光类似物，它是已知的UDP葡萄糖4-差向异构酶的竞争性抑制剂。这种类似物，即2',3'-O-(2,4,6-三硝基环己二烯叉基)尿苷5'-单磷酸，被发现是UDP葡萄糖4-差向异构酶的一种强效可逆抑制剂，表明它与该酶的底物结合位点相互作用。这种类似物的荧光发射光谱对溶剂极性极其敏感，使其成为研究酶活性位点环境的极佳探针。我们在此报告了这种UMP类似物的有效应用，以证明UMP核糖部分的羟基以及推测的底物（UDP半乳糖和UDP葡萄糖）并不存在于疏水环境中。
