BIOL 300 Lecture Notes - Gtpase, Bound 2, Guanine

• School: McGill University
• Department: Biology (Sci)
• Course: BIOL 300
• Professor: Siegfried Hekimi

Document Summary

Now, we have isolated the ligand and the receptor, but we want to know how well they are able to bind to one another, i. e. the affinity. A ligand-receptor association is normally a non-covalent interaction (through h bonds, ionic, etc. Nonetheless, it can be treated as an equilibrium reaction with the receptor and ligand as the reactants, and the receptor-ligand complex as the product. How do we measure the dissociation constant experimentally upon isolation of a receptor and its ligand: you don"t necessarily have all of the concentrations needed to calculate it. You usually start out with the concentration of the ligand, which you purified; in this example, we"ll talk about insulin, which binds to an insulin receptor: you can vary this concentration to your liking. You can then add this insulin to cells; you know the number of cells in your colony by counting them.