大鼠肾皮质果糖-1,6-二磷酸酶活性的调节。I. 果糖-2,6-二磷酸和二价阳离子的作用。

Regulation of rat-kidney cortex fructose-1,6-bisphosphatase activity. I. Effects of fructose-2,6-bisphosphate and divalent cations.

Sola M M, Oliver F J, Salto R, Gutiérrez M, Vargas A M

Departamento de Bioquímica y Biología Molecular, Facultad de Ciencias, Universidad de Granada, Spain.

Int J Biochem. 1993 Dec;25(12):1963-8. doi: 10.1016/0020-711x(88)90332-1.

Abstract

The native rat-kidney cortex Fructose-1,6-BPase is differentially regulated by Mg2+ and Mn2+. 2. Mg2+ binding to the enzyme is hyperbolic and large concentrations of the cation are non-inhibitory. 3. Mn2+ produces a 10-fold rise in Vmax higher than Mg2+. [Mn2+]0.5 is much larger than [Mg2+]0.5. At elevated [Mn2+] inhibition is observed. 4. Mg2+ and Mn2+ produce antagonistic effects on the inhibition of the enzyme by high substrate. 5. Fru-2,6-P2 inhibits the enzyme by rising the S0.5 and favouring a sigmoidal kinetics. 6. The inhibition by Fru-2,6-P2 is released by Mg2+ and more powerfully by Mn2+ increasing the I0.5.

摘要

天然大鼠肾皮质果糖-1,6-二磷酸酶受Mg2+和Mn2+的差异调节。2. Mg2+与该酶的结合呈双曲线，高浓度的该阳离子无抑制作用。3. Mn2+使Vmax比Mg2+时升高10倍。[Mn2+]0.5远大于[Mg2+]0.5。在[Mn2+]升高时会观察到抑制作用。4. Mg2+和Mn2+对高底物对该酶的抑制产生拮抗作用。5. Fru-2,6-P2通过提高S0.5并有利于S形动力学来抑制该酶。6. Fru-2,6-P2的抑制作用可被Mg2+解除，被Mn2+更有效地解除，同时提高I0.5。