Ligand-receptor interactions, specific sites

Allosteric binding occurs when two molecules bind to different sites on the target. When the two molecules are identical, it is termed homotropic interaction. If the molecules differ from each other, it is termed heterotropic interaction. Binding is competitive when two different ligand molecules compete for the same site. We discuss ligand binding further in Chapter 3. The specificity of ligand-receptor interaction is illustrated in Exhibit 2.9. 

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