Dixon H B
Biochem J. 1976 Mar 1;153(3):627-9. doi: 10.1042/bj1530627.
If a molecule contains two groups that bind a common ligand, then to determine their group dissociation constants it is necessary (1) to assume that some property of the molecule is affected by the degree of ligation of only one of the groups, and (2) to determine how this property varies with the concentration of free ligand. When assignment of group dissociation constants made on this basis suggests that the degree of ligation of each group greatly affects the dissociation constant of the other, then the original assumption that the chosen property is completely unaffected by ligation of the second group is rendered doubtful. Dissociation constants of interacting groups can therefore not be reliably determined.
如果一个分子含有两个结合共同配体的基团,那么要确定它们的基团解离常数,就有必要:(1)假设分子的某些性质仅受其中一个基团的结合程度影响;(2)确定该性质如何随游离配体浓度变化。当基于此确定的基团解离常数表明每个基团的结合程度对另一个基团的解离常数有很大影响时,那么最初认为所选性质完全不受第二个基团结合影响的假设就值得怀疑了。因此,相互作用基团的解离常数无法可靠地确定。