Figure 4.
(A) A receptor (orange) and ligand (green) connected by a linker (black), showing the position vector, r, relating the ligand to the receptor, and the orientation of the ligand in space ω. In the bound state r takes the value r0. (B) Binding of a bivalent ligand can be viewed as the sequential binding of the first fragment followed by intramolecular binding of the second.