Trigun S K, Singh S N
Biochemistry and Molecular Biology Laboratory, Centre of Advanced Study in Zoology, Banaras Hindu University, Varanasi, India.
Arch Gerontol Geriatr. 1988 Dec;7(4):239-47. doi: 10.1016/0167-4943(88)90007-6.
In vitro studies on various modulations in kinetics and allosteric properties of muscle phosphofructokinase (EC 2.7.1.11) were undertaken, using purified enzyme from young (25-weeks) and old (100-weeks) albino rats. In comparison to normal K0.5 values for fructose-6-phosphate, increase in this value in response to ATP and citrate inhibition, decrease in K0.5 due to AMP activation and extent of ATP inhibition with increase in pH, were observed to be decreased more markedly with the enzyme of old than with that of young rats. Extent of citrate inhibition, reversals of ATP and citrate effects in response to AMP activation, and synergism of citrate and ATP inhibitions were also seen to be decreased considerably with muscle PFK of old in comparison to that of young rats. Such age-related changes in muscle PFK suggest the alterations in allosteric regulation of this enzyme during aging of the animal.
利用从幼年（25周龄）和老年（100周龄）白化大鼠中纯化得到的酶，对肌肉磷酸果糖激酶（EC 2.7.1.11）动力学和别构性质的各种调节进行了体外研究。与果糖-6-磷酸的正常K0.5值相比，观察到老年大鼠酶对ATP和柠檬酸抑制的响应中该值增加、AMP激活导致K0.5降低以及随着pH升高ATP抑制程度，与幼年大鼠酶相比，老年大鼠酶的这些变化更为明显。与幼年大鼠相比，老年大鼠肌肉PFK的柠檬酸抑制程度、AMP激活对ATP和柠檬酸效应的逆转以及柠檬酸和ATP抑制的协同作用也显著降低。肌肉PFK的这种与年龄相关的变化表明，在动物衰老过程中该酶的别构调节发生了改变。
