Ligand-ligate interaction

These various contributions to the overall free-energy change for the ligand-ligate interaction, given by AG°SS0C, in all modes of HPLC of polypeptides and proteins can thus be expressed in terms of the relevant solvophobic considerations29,30,42,47,53,62,215,216 such that... 

Quaternary structures or ligand-ligate (receptor) interactions may be partially conserved during electrophoresis. Identification of a distinct protein is possible only by biochemical or immunochemical reactions or by comparison with an authentic sample. 

In the context here, there is nothing special about H+, and in principle, Scheme 2.1 and Equation 2.2 can be applied to any fast ligation interaction by making the appropriate changes to reflect a ligand, L, rather than H+, i.e., -log [L] for pH and -log K for pKa, thereby leading to Equation 2.3. 

Fig. 28.12 The receptor—G-protein complex. An activated receptor interacts with the trimeric GDP-ligated complex to produce an interchange of GDP with GTP and dissociation into the activated GoGTP and Gp. subunits these subunits then interact with a variety of effectors. The activated receptor thus acts as a switch for the G-protein complex. Constitutively active receptors do not require a ligand to interact with the G-protein.

Fig. 9.1. Schematic illustration of the elements involved in bio-affinity chromatography. The solute (Lt) is retained on the stationary phase (S) by specific interaction with the ligand (Ln). The ligand is covalently attached to a spacer arm (SP) which is in turn attached to the stationary phase. Elution as shown here is achieved by specific ligand competition by another solute (Lt ). Alternatively the ligand-ligate complex can be disrupted by reversible denaturation using low pH solvent or mild chaotropic salts, e.g.

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