Ligand binding selectivity

Xu, H.E. etal. Structural determinants of ligand binding selectivity between the peroxisome proliferator-activated receptors, Proc. Natl Acad. Sci. USA, 24, 13919, 2001. 

Even if conformational selection is more appropriate to explain special binding events, the well-established induced fit concept is not outdated and keeps its legitimation. Each of both pathways may be pursued in case of conformational selection, the ligand binds selectively to one of the macromolecule s low populated conformations while in case of an induced fit, the ligand binds to the predominating conformation of the macromolecule. Which path is chosen mainly depends on ligand and protein concentration [17]. 

Recently, the structure of a dimenc apo-ligand-bmding domain of hRXRa was determined by X-ray crystallography (15). In spite of the difference between RXRa and RARa in their ligand-binding selectivity, the determined... 

Possible applications of MIP membranes are in the field of sensor systems and separation technology. With respect to MIP membrane-based sensors, selective ligand binding to the membrane or selective permeation through the membrane can be used for the generation of a specific signal. Practical chiral separation by MIP membranes still faces reproducibility problems in the preparation methods, as well as mass transfer limitations inside the membrane. To overcome mass transfer limitations, MIP nanoparticles embedded in liquid membranes could be an alternative approach to develop chiral membrane separation by molecular imprinting [44]. 

Equation 1.9 indicates that if the ligand has an equal affinity for both the Ri and Ra states (a = 1) then Poo/po will equal unity and no change in the proportion of Ra will result from maximal ligand binding. However, if a > 1, then the presence of the conformationally selective ligand will cause the ratio Poo/Po to be > 1 and the Ra state will be enriched by presence of the ligand. 

The endothelin receptor subtypes show differences in their signal transduction, ligand binding and tissue distribution. The ETA receptor is isopeptide-selective and binds ET-1 and ET-2 with the same and ET-3 with 70-100-fold lower affinity. The ETB receptor binds all three isoforms with the same affinity. 

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