Barcia R, Ramos-Martínez J I
Departamento de Bioquímica e Bioloxia Molecular, Universidade de Santiago de Compostela, Facultade de Veterinaria, Lugo, Spain.
Biochem Int. 1991 Sep;25(1):1-5.
In the absence of AMP and Fru-2,6-P2, several amino-acids such as histidine, lysine, alanine, aspartic acid, and other molecules, as reduced glutathione or citrate, activate FBPase-1 from Mytilus galloprovincialis mantle. AMP decreases Vmax and Km for Fru-1,6-P2 both in the absence and in the presence of activators; but the addition of Fru-2,6-P2 decreases the affinity of the enzyme by its substrate. Na+ acts as a inhibitor reducing both Vmax and Km. The Km value is lower than the physiological level of Fru-1,6-P2, suggesting that the enzyme is operative but its activity is very reduced.
在缺乏AMP和果糖-2,6-二磷酸(Fru-2,6-P2)的情况下,几种氨基酸如组氨酸、赖氨酸、丙氨酸、天冬氨酸以及其他分子如还原型谷胱甘肽或柠檬酸,可激活地中海贻贝外套膜中的果糖-1,6-二磷酸酶-1(FBPase-1)。在不存在和存在激活剂的情况下,AMP均会降低果糖-1,6-二磷酸(Fru-1,6-P2)的最大反应速度(Vmax)和米氏常数(Km);但添加Fru-2,6-P2会降低该酶对其底物的亲和力。钠离子作为抑制剂,会降低Vmax和Km。Km值低于Fru-1,6-P2的生理水平,这表明该酶具有活性但其活性非常低。