Conformation Bound to the Receptor

All these methods have in common that the receptor is not detected so that no size limit applies. Relaxation-based exchange-transferred experiments actually show best performance for longest correlation times, i.e. very large receptors. 

An upper limit for dissociation constants in the rtiQUmolar range is mainly given by the solubility of receptor or ligand and the occurrence of nonspecific binding processes which make the determination of a single bound conformation obsolete. 

For a receptor concentration of approximately the dissociation constant and a 10-fold excess of ligand Pbomid 1. he- essentially all receptor molecules are complexed with maximum intensity of the desired NMR interactions. Lower receptor concentrations relative to Ku can be compensated by a higher ligand excess and might be pushed up to a 1000-fold ligand excess [95], but experiments are easiest appUcable with the mentioned 10-20 fold excess. 

Since the ligand is in fast exchange with respect to its bound and free state, every molecule experiences an averaging over time where the fraction L 

An important aspect of all exchange-transferred experiments is the occurrence of nonspecific binding which contributes equally to the NMR interactions in the bound state and carmot easily be distinguished. Nonspecific interaction is best 

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