Biomaterial Database

Estimation of binding constants of receptors and ligands by affinity capillary electrophoresis. 2007

Li-Wei Zhang, and Li Ding, and Xin-Xiang Zhang

Beijing National Laboratory for Molecular Sciences (BNLMS), College of Chemistry, Peking University, Beijing 100871, China.

An estimation method for determination of binding constants of receptors to ligands by affinity capillary electrophoresis was evaluated. On the basis of the theories of pseudostationary phase or so-called dynamic stationary phase, the retention factor (k) was used to represent the interaction between the receptor and ligand. k could be easily deduced from the migration times of the ligand and the receptor. Then, with the linear relationship of k versus the concentration of ligand in the running buffer, the binding constant K(b) was calculated from the slope and intercept. In order to test its feasibility, the calculation method was demonstrated using three model systems: the interactions between vancomycin and N-acetyl-D-Ala-D-Ala, ristocetin and N-acetyl-D-Ala-D-Ala, and carbonic anhydrase B and an arylsulfonamide. Estimated binding constants were compared with those determined by other techniques. The results showed that this estimation method was reliable. This calculation method offers a simple and easy approach to estimating binding constants of ligands to receptors.

UI	MeSH Term	Description	Entries
D008024	Ligands	A molecule that binds to another molecule, used especially to refer to a small molecule that binds specifically to a larger molecule, e.g., an antigen binding to an antibody, a hormone or neurotransmitter binding to a receptor, or a substrate or allosteric effector binding to an enzyme. Ligands are also molecules that donate or accept a pair of electrons to form a coordinate covalent bond with the central metal atom of a coordination complex. (From Dorland, 27th ed)	Ligand
D011485	Protein Binding	The process in which substances, either endogenous or exogenous, bind to proteins, peptides, enzymes, protein precursors, or allied compounds. Specific protein-binding measures are often used as assays in diagnostic assessments.	Plasma Protein Binding Capacity,Binding, Protein
D011956	Receptors, Cell Surface	Cell surface proteins that bind signalling molecules external to the cell with high affinity and convert this extracellular event into one or more intracellular signals that alter the behavior of the target cell (From Alberts, Molecular Biology of the Cell, 2nd ed, pp693-5). Cell surface receptors, unlike enzymes, do not chemically alter their ligands.	Cell Surface Receptor,Cell Surface Receptors,Hormone Receptors, Cell Surface,Receptors, Endogenous Substances,Cell Surface Hormone Receptors,Endogenous Substances Receptors,Receptor, Cell Surface,Surface Receptor, Cell
D019075	Electrophoresis, Capillary	A highly-sensitive (in the picomolar range, which is 10,000-fold more sensitive than conventional electrophoresis) and efficient technique that allows separation of PROTEINS; NUCLEIC ACIDS; and CARBOHYDRATES. (Segen, Dictionary of Modern Medicine, 1992)	Capillary Zone Electrophoresis,Capillary Electrophoreses,Capillary Electrophoresis,Capillary Zone Electrophoreses,Electrophoreses, Capillary,Electrophoreses, Capillary Zone,Electrophoresis, Capillary Zone,Zone Electrophoreses, Capillary,Zone Electrophoresis, Capillary