Kalbitzer H R, Stehlik D, Hasselbach W
Eur J Biochem. 1978 Jan 2;82(1):245-55. doi: 10.1111/j.1432-1033.1978.tb12017.x.
The binding pattern of the biologically relevant ions calcium and magnesium has been investigated via the binding of the ion-analogue manganese. The binding parameters of manganese are obtained conveniently by standard electron paramagnetic resonance techniques, the binding of calcium and magnesium is inferred from competition experiments. The quantitative analysis was carried out with a computer program which was able to treat the competition of three kinds of ions for three classes of independent and one class of cooperative binding sites. It was possible to correlate specific binding classes with biological functions of the sarcoplasmic reticulum membrane. The magnesium and manganese specific binding class of medium affinity is related to the catalytic function of these ions in the ATP-splitting. For the first time a manganese and calcium specific class of cooperative binding sites has been observed and it can be related to the inhibition of the calcium transport at high concentrations of manganese or calcium. From the binding results a model can be developed which allows a full description of the role of the divalent ions and their specific binding sites during calcium transport.
通过离子类似物锰的结合，研究了生物学相关离子钙和镁的结合模式。锰的结合参数可通过标准电子顺磁共振技术方便地获得，钙和镁的结合则通过竞争实验推断得出。使用一个计算机程序进行了定量分析，该程序能够处理三种离子对三类独立结合位点和一类协同结合位点的竞争。将特定的结合类别与肌浆网膜的生物学功能相关联成为可能。中等亲和力的镁和锰特异性结合类别与这些离子在ATP水解中的催化功能有关。首次观察到了一类锰和钙特异性的协同结合位点，它可能与高浓度的锰或钙对钙转运的抑制作用有关。根据结合结果可以建立一个模型，该模型能够全面描述二价离子及其特定结合位点在钙转运过程中的作用。
