Coupling between affinities

The primary function of the pBz receptor is in the regulation of cholesterol uptake and the synthesis of neurosteroids. The latter compounds have an affinity for the GABA-A receptors which provide an indirect coupling between the pBz and the GABA receptors in the brain. 

Synthetic peptides derived from the third intracellular loop of the delta receptor inhibit high-affinity binding of the delta peptide [3H] DSLET and G-protein activation by DSLET by competing with the activated receptor for recognition sites on Ga [11,12]. This is in agreement with studies on a variety of GPCRs that have demonstrated the third intracellular loop of the receptors to mediate much of the coupling between receptor and G protein [13,14]. 

Design considerations in the development of effective chimeric peptides include vector specificity for the brain, vector pharmacokinetics, coupling between vector and drag, and intrinsic receptor affinity for the released drug. 

Illumination of metal-coated semiconductor particles leads to the accumulation of trapped electrons. Islands of noble metals (Pt, Rh, and Pd) on the surface of particles have higher electron affinity and therefore upon charge pair formation electrons are transferred from the semiconductor particle onto the metal islands. Due to the decreased recombination rate and high electron affinity of noble metals, more than one electron can be stored on metallized particles. Therefore, metal-coated particles can be used for subsequent simultaneous injection of multiple charges, and the reduction of compounds that cannot proceed via a one-electron reduction process. In these processes the crucial parameter that governs charge separation processes is the coupling between semiconductor particles and the metal... 

A second method describes intrinsic activity in terms of the GABA shift (338). This method relies on the bidirectional nature of the allosteric coupling between the BZR and the GABA site. Just as the activity of GABA at its receptor site is enhanced by ligands at the BZR, the affinity of BZR ligands for the benzodiazepine site is enhanced in the presence of... 

An alternate strategy was utilized in the synthesis of a potential thyroid receptor ligand [30]. Electrophilic bromination was followed by the Miyaura boronic ester synthesis to yield 49 [31]. Suzuki coupling between 49 and 2-bromothiazole was then accomplished to provide 50, a precursor to the derivative 51. Unfortunately, the presence of the thiazole at C(3), in 51 resulted in a decrease in binding affinity and selectivity as compared to the lead compound. 

Similar to the immunoassay techniques, radioimmunoassay, enzyme immunoassay, and chemiluminescence immunoassay are also applied and have proved useful. All techniques used for immunoassay represent coupling between the specificity of the antibody-antigen reaction and the sensitivity of the radiometric, electrometric, and chemiluminescence techniques. The limit of detection for immunoassay depends on the antibody affinity.128 130 Materials such as silica,131132 latex,133134 and alkylamine films135 are used for antibody absorption. SEM,136 scanning tunneling microscopy,137 and scanning force microscopy138 have been employed as tools for visualization of the immobilized antibodies. 

---