Binding differences

The PAS is located at the rim of the aromatic gorge, on the protein s surface. It spans six AChE residues Tyr 72, Tyr 124, Glu 285 and Tip 286, on one side of the gorge entrance, and Asp 74 and Tyr 341, on its opposite side. Its core is comprised of Tip 286 and Asp 74, which accommodates many distinct ligands. BChE also has a PAS, but its relatively aromatic content and the response upon ligand-binding differ significantly from those of AChE. 

TLRs are transmembrane proteins found on the plasma membrane and on endosomal membranes. The ability of the TLRs to recognise microbial products comes from the 19-25 copies of the LRR motif. The differences in these LRRs are what give the TLRs the ability to bind different components of pathogens. 

A measure of the promiscuity of these diacids was attempted with pyrimidine 26 vs pyrazine 20. The two heterocycles differ in size, shape and also basicity in addition, stacking interactions can be observed in the pyrimidine complex but not with pyrazine. These four variables make interpretation with confidence somewhat futile since it is difficult to attribute the binding differences to any particular feature. 

Mutagenesis studies have shown that morphine and sufentanil bind differently to the jj, receptor [83, 85]. Mutation of an aspartic acid at residue 114 of the // receptor to an asparagine resulted in a mutant that did not bind morphine and morphine was ineffective in inhibiting adenylyl cyclase via that receptor. In contrast, sufentanil bound to the mutant and wild-type receptors equally well and it effectively inhibited cAMP accumulation via the mutant receptor. These findings demonstrate that morphine and sufentanil have different requirements for binding to the // receptor. By binding differentially, these two agonists may induce the ft receptor to interact with different G proteins to induce distinct cellular effects. 

Pyridone HTS hits have been optimized to derivative 29, which has an MIC90 of 0.5 pg/mL against S. aureus [49]. Retention of activity against a triclosan-resistant strain implies that these compounds are binding differently than the preceding 2-pyridones. 

Introduction of chiral centers in the nonleaving groups can achieve interesting binding differences for enantiomers toward DNA. For example, [PtCR-DACH)Cl2] binds to DNA twice as strong as the S-enantiomer (143). Pt(II) complexes containing the meso form of 1,2-bis(2-hydroxyphenyl) ethanediamine exhibit the lowest antitumor activity and reactivity because of the steric hindrance provided by the aromatic rings (144). 

Ammonium cation binding differs from that of alkali metals because the former is a tetrahedral cation and the latter are... 

Antigens can be immobilized on a number of different membranes using one of several methods, and antigens bind differently to different types of membranes. The choice of a membrane is dependent on many factors including the particular antigen to be detected and the requirements of the experiment. To maximize detection sensitivity, it is advisable to use mock samples to test different types of membranes with the particular antigen-antibody combination to be used. 

It was pointed out in Section 6.8 that the term allosteric as coined by MCJ and MWC has been used with three different meanings. In Chapter 6 we discussed the allosteric effect in hemoglobin (Hb). There, the two allosteric sites were identical this has been referred to as the homotropic effect. When the two sites bind different ligands, the heterotropic effect, the induced fit by one ligand can either enhance or diminish the binding affinity of the second ligand (see the example in Section 4.5). 

Staley et al. (2001) 21 Smokers 21 nonsmokers P-CIT SPECT No overall binding difference between smokers and nonsmokers f brainstem 5-HT transporters in male smokers... 

Turcatti, G., Vogel, H., Chollet, A. Probing the binding domain of the NK2 receptor with fluorescent ligands evidence that heptapeptide agonists and antagonists bind differently. Biochemistry 1995, 34, 3972-3980. 

Binds different forms of mercury, including metallic, inorganic, organic, charged, and neutral compounds. 

The BZ binding site of the GABA receptors have been further classified into three types, (Oj.j, based on their location in the CNS and their ability to bind different compounds. A fourth type of BZ receptor, peripheral-type BZ receptors, occurs in the peripheral tissues as well as the CNS. The function of this type of receptor remains unknown (To et ah, 1983 Ballenger, 1995). 

Nevertheless, we know40 that cytochrome c in its two oxidation states has a different solubility, a different rate of movement on columns, and a different pH and temperature stability. It is also known that the protein binds anions (even chloride) or cations, or even other proteins differently on change of redox state. These binding differences would be sufficient to operate a relay. 

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