Functional and structural implications of variable region immunoglobulin dynamic states.

The consequence of multiple conformational states in the immunoglobulin variable region are considered. Bound ligand is viewed as a stabilizer of one conformer from a series of non-liganded conformers. Kinetic, equilibrium, thermodynamic and crystal formation information are used as supporting evidence for a unique conformer which is the crystallizable liganded state. The multi-state model is discussed in terms of certain biological and biochemical properties exhibited by the immunoglobulin molecule.