The stoichiometry n and the dissociation constant [Formula: see text] are key binding parameters characterizing the ligand-macromolecule interactions and equilibria. Equilibrium co-sedimentation experiments are performed in varying the concentration of one of the reactant while keeping constant that of the other reactant. The measured observable is the fraction [Formula: see text] of bound ligands when the ligand concentration is kept constant while that of macromolecules is varying whereas it is the macromolecule coverage [Formula: see text] with bound ligands when the ligand concentration is varying while that of macromolecules is kept constant. We have derived general expressions for [Formula: see text] and [Formula: see text] and subsequently showed that those expressions are in perfect agreement with simulations for a system of large ligands binding on macromolecules. Approximations have been developed to derive mathematical simple analytical expressions for [Formula: see text] and [Formula: see text] that can be used to fit the experimental data and thus extract, n and [Formula: see text] within the framework of equilibrium co-sedimentation assays. The method usefulness is illustrated and demonstrated by fitting the data from the literature using the derived formulas to determine the binding parameters.

中文翻译：

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通过共沉淀测定法确定结合参数。

化学计量比n和解离常数[分子式：见正文]是表征配体-大分子相互作用和平衡的关键结合参数。在改变一种反应物的浓度同时保持另一种反应物的浓度不变的情况下进行平衡共沉淀实验。测得的可观测值是当配体浓度保持不变而大分子浓度变化时结合配体的分数[公式：参见文字]，而当配体浓度变化而同时配体浓度不变时结合的配体的大分子覆盖率[公式：参见文字]。大分子的常数保持恒定。我们为[公式：参见文本]和[公式：见正文]，随后表明这些表达与结合大分子的大配体系统的模拟完全吻合。已开发出近似值，以导出[公式：参见文本]和[公式：参见文本]的数学简单解析表达式，可用于拟合实验数据，从而在平衡的框架内提取n和[公式：参见文本]。共同沉淀试验。通过使用衍生公式拟合来自文献的数据来确定结合参数来说明和证明该方法的有效性。在平衡共沉淀试验的框架内。通过使用衍生公式拟合文献中的数据以确定结合参数来说明和证明该方法的有效性。在平衡共沉淀试验的框架内。通过使用衍生公式拟合来自文献的数据来确定结合参数来说明和证明该方法的有效性。