Rider M H, Bartrons R, Hue L
Hormone and Metabolic Research Unit, International Institute of Cellular and Molecular Pathology, Brussels, Belgium.
Eur J Biochem. 1990 May 31;190(1):53-6. doi: 10.1111/j.1432-1033.1990.tb15544.x.
Vanadate was found to be a reversible non-competitive inhibitor of chicken liver fructose-2,6-bisphosphatase. The inhibition was best observed in the presence of glycerol 2- or 3-phosphate and half-maximal effect was obtained with about 0.15 mM vanadate. Vanadate decreased the extent of phosphorylation of the enzyme (E-P) by fructose 2,6-[2-32P]bisphosphate. This did not result from an increased rate of E-P breakdown, as is the case with phosphoglycerate mutase, an enzyme which shares structural and functional similarity to fructose-2,6-bisphosphate. The data were consistent with the formation of a dead-end transition state analogue of phosphate in the active site. Inhibition of fructose-2,6-bisphosphatase by vanadate offers a likely explanation for the increase in fructose 2,6-bisphosphate concentration brought about by vanadate in isolated rat hepatocytes.
钒酸盐被发现是鸡肝果糖-2,6-二磷酸酶的一种可逆非竞争性抑制剂。在甘油2-磷酸或3-磷酸存在的情况下，这种抑制作用最为明显，约0.15 mM钒酸盐可产生半数最大效应。钒酸盐降低了果糖2,6-[2-³²P]二磷酸对该酶（E-P）的磷酸化程度。这并非像磷酸甘油酸变位酶那样是由于E-P分解速率增加所致，磷酸甘油酸变位酶与果糖-2,6-二磷酸在结构和功能上具有相似性。这些数据与活性位点中形成磷酸的终态过渡态类似物一致。钒酸盐对果糖-2,6-二磷酸酶的抑制作用可能解释了钒酸盐导致分离的大鼠肝细胞中果糖2,6-二磷酸浓度升高的现象。
