Afting E G, Lynen A, Hinze H, Holzer H
Hoppe Seylers Z Physiol Chem. 1976 Dec;357(12):1771-7. doi: 10.1515/bchm2.1976.357.2.1771.
Incubation of a crude yeast extract containing phosphofructokinase with proteinase A, proteinase B or carboxypeptidase Y gave the following results: Proteinase B and carboxypeptidase Y did not change the activity of phosphofructokinase during incubation. On the other hand, incubation with proteinase A resulted in a 40-100% activation; continued incubation, however, led to an inactivation of the enzyme. Addition of allosteric effectors did not change the activation or inactivation process. The activated phosphofructokinase was not changed with respect to pH optimum and ATP inhibition. Molecular weight determination of phosphofructokinase in crude extracts in the presence of inhibitors of proteinase A indicated a molecular weight of 700000. Without inhibitors of proteinase A, the molecular weight was determined to be 600 000, while after 40-100% activation by proteinase A, a molecular weight of 500 000 was obtained. The activity profile of proteinase A in density gradients indicated that this enzyme is bound to variety of cellular proteins.
将含有磷酸果糖激酶的粗酵母提取物与蛋白酶A、蛋白酶B或羧肽酶Y一起温育，得到以下结果：在温育过程中，蛋白酶B和羧肽酶Y不会改变磷酸果糖激酶的活性。另一方面，与蛋白酶A一起温育会导致40%-100%的激活；然而，持续温育会导致该酶失活。添加变构效应剂不会改变激活或失活过程。激活后的磷酸果糖激酶在最适pH值和ATP抑制方面没有变化。在存在蛋白酶A抑制剂的情况下，对粗提取物中的磷酸果糖激酶进行分子量测定，结果表明分子量为700000。在没有蛋白酶A抑制剂的情况下，测定的分子量为600000，而在蛋白酶A将其激活40%-100%后，得到的分子量为500000。蛋白酶A在密度梯度中的活性分布表明，这种酶与多种细胞蛋白结合。
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