AN EXACT MATHEMATICAL EXPRESSION FOR DESCRIBING COMPETITIVE-BINDING OF 2 DIFFERENT LIGANDS TO A PROTEIN MOLECULE
AN EXACT MATHEMATICAL EXPRESSION FOR DESCRIBING COMPETITIVE-BINDING OF 2 DIFFERENT LIGANDS TO A PROTEIN MOLECULE
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DOI：
10.1016/0014-5793(95)00062-e
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发表时间：
1995-02-27
期刊：
影响因子：
3.5
通讯作者：
WANG, ZX
中科院分区：
文献类型：
--
作者：
WANG, ZX
在竞争实验中，利用含有报告基团的结构类似物，可以测定光谱上不可见的或非放射性配体与其蛋白质受体结合的解离常数。然而，这些绘图方法的一个共同问题是，方程变换不可避免地导致非标准误差分布，从而不能用简单的线性回归来提取参数的正确值。在数值分析方法的情况下，人们将面临可能存在多解的问题。用于描述两种不同配体与蛋白质分子的竞争性结合的精确数学表达式以系统中物质的总浓度表示。因此，使用可商购的非线性回归程序，用于描述该系统的所有未知参数可以通过将实验数据拟合到代数显式方程而无需任何数据变换来确定。用该方程还可绘制出体系中各组分的分布曲线。它特别适用于系统中所有物质的浓度彼此相当的情况。
The dissociation constant for the binding of a spectroscopically invisible or non-radioactive ligand to its protein receptor can be determined in a competition experiment by using a structural analog that contains a reporter group, Many plotting and numerical analysis methods have been developed to calculate the binding constant of unlabeled ligand from the displacement experiments. However, a common problem with these plotting methods is that the equation transformations inevitably result in non-standard error distribution, and thus simple linear regression can not be used to extract correct values for the parameters, In the case of the numerical analysis methods, one would be faced with the possible existence of multiple solutions, In this paper, the exact mathematical expression for describing competitive binding of two different ligands to a protein molecule is presented in terms of the total concentrations of species in the system, Thus, using a commercially available non-linear regression program, all unknown parameters for describing this system can be determined by fitting the experimental data to the algebraically explicit equation without any data transformations. The distribution curves of ah the species in the system can also be constructed with this equation. It is particularly useful for the cases in which the concentrations of all the species in the system are comparable to each other.