来自伯氏疟原虫的磷酸果糖激酶。Mg2+、ATP及Mg2(+)-复合ATP的影响。
Phosphofructokinase from Plasmodium berghei. Influence of Mg2+, ATP and Mg2(+)-complexed ATP.
作者信息
Buckwitz D, Jacobasch G, Gerth C
机构信息
Institut für Biochemie, Bereich Medizin (Charité), Humboldt-Universität zu Berlin, German Democratic Republic.
出版信息
Biochem J. 1990 Apr 15;267(2):353-7. doi: 10.1042/bj2670353.
The control enzyme phosphofructokinase is of regulatory significance in the metabolism of glucose by the malarial parasite Plasmodium berghei. (1) The enzyme was partially purified from erythrocytic stages of P. berghei by precipitation with poly(ethylene glycol) and chromatography on 2',5'-bisphosphoadenosine-Sepharose 4B. (2) Similarly to various other phosphofructokinases, the enzyme from P. berghei shows an allosteric behaviour. It is activated by fructose 6-phosphate and inhibited by ATP. (3) The effects of Mg2(+)-complexed ATP, free ATP and Mg2+ were studied by keeping constant the concentration of one of these and varying the concentrations of the other two. (4) The enzyme is shown to be allosterically inhibited by free ATP and by higher concentrations of Mg2+. Compared with phosphofructokinase of erythrocytes, inhibition by ATP is weaker by two orders of magnitude. Mg2(+)-complexed ATP has no effect on allosteric regulation. (5) The proposed kinetic model provides an adequate description of the data.
对照酶磷酸果糖激酶在伯氏疟原虫对葡萄糖的代谢中具有调节意义。(1) 该酶通过聚乙二醇沉淀和在2',5'-二磷酸腺苷-琼脂糖4B上进行层析，从伯氏疟原虫的红细胞阶段中部分纯化出来。(2) 与其他各种磷酸果糖激酶类似，来自伯氏疟原虫的该酶表现出别构行为。它被6-磷酸果糖激活并被ATP抑制。(3) 通过保持其中一种的浓度恒定并改变另外两种的浓度，研究了Mg2(+)-络合ATP、游离ATP和Mg2+的作用。(4) 结果表明，该酶受到游离ATP和较高浓度Mg2+的别构抑制。与红细胞的磷酸果糖激酶相比，ATP的抑制作用弱两个数量级。Mg2(+)-络合ATP对别构调节没有影响。(5) 所提出的动力学模型对数据提供了充分的描述。
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