Simonson L P, Bär H P, Jastorff B, Hitkari R
Biochim Biophys Acta. 1975 Jan 30;379(1):114-24. doi: 10.1016/0005-2795(75)90013-6.
A method for determining the dissociation constants of ligands and ligand analogs is described. It is based on competition binding studies in the presence of an isotope-labeled, or otherwise measurable, ligand and suitable analog concentrations. The steps used are determination of (1) the maximal amount of radioactive ligand that can be bound, (2) the slopes and intercepts from Scatchard plots at different analog concentrations and (3) the values for the dissociation constants of radioactive ligand and ligand analog from replots of the reciprocals of the slopes and intercepts obtained from the Scatchard plots. Application of the method to a cyclic AMP-binding protein from beef muscle is demonstrated, yielding dissociation constants of 2.10-9 M for cyclic (3H) AMP and cyclic AMP, and 3.10-5 M for cyclic 5'-amido-5'-deoxyadenosine-3', 5'-monophosphate.
本文描述了一种测定配体及其类似物解离常数的方法。该方法基于在存在同位素标记的或其他可测量的配体以及合适的类似物浓度的情况下进行的竞争结合研究。所使用的步骤包括：（1）测定可结合的放射性配体的最大量；（2）在不同类似物浓度下从Scatchard图中确定斜率和截距；（3）从Scatchard图获得的斜率和截距的倒数的重新绘图中确定放射性配体和配体类似物的解离常数。文中展示了该方法在牛肉肌肉中环磷酸腺苷结合蛋白上的应用，得出环（3H）腺苷酸和环磷酸腺苷的解离常数为2.10-9 M，环5'-氨基-5'-脱氧腺苷-3'，5'-单磷酸的解离常数为3.10-5 M。
