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The binding constant is a special case of the equilibrium constant . It is associated with the binding and unbinding reaction of receptor (R) and ligand (L) molecules, which is formalized as: :. The reaction is characterized by the on-rate constant and the off-rate constant , which have units of 1/(concentration time) and 1/time, respectively. In equilibrium, the forward binding transition should be balanced by the backward unbinding transition . That is, :, An often considered quantity is the dissociation constant , which has the unit of concentration, despite the fact that strictly speaking, all association constants are unitless values. The inclusion of units arises from the simplification that such constants are calculated solely from concentrations, which is not the case. Once chemical activity is factored into the correct form of the equation, a dimensionless value is obtained. For the binding of receptor and ligand molecules in solution, the molar Gibbs free energy , or the binding affinity is related to the dissociation constant via , in which is the ideal gas constant, temperature and the standard reference concentration = 1 mol / L. 抄文引用元・出典: フリー百科事典『 ウィキペディア(Wikipedia)』 ■ウィキペディアで「Binding constant」の詳細全文を読む スポンサード リンク
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