Ligand binding radiolabeled

The principle of equilibrium fluorescence measurements is identical to that of radiolabelled ligand binding experiments, i.e., the ligand (L) binds to its receptor (R) and the formation of the complex (RL) is... 

The above discussion provides only a brief overview of how fluorescence techniques can be used to study the interactions of ligands with their receptors. We have focused on the quantitation of the binding parameters and compared the data with that which may be obtained with those from radiolabelled ligand binding studies. The number of applications of fluorescence in the study of neurochemistry and molecular biology is ever increasing. Outside the scope of this review is, for example, the use of fluorescence microscopy to monitor cell surface expression and targeting of receptors or the use of fluorescence probes to monitor ion transport into and out of cells. 

Characterization of receptors by radiolabelled ligand binding techniques... 

Further radiolabeled ligand-binding assays have been reported for a wide variety of analytes, namely morphine and leu-enkephaline [30], (S )-propanolol [33], atra-zine [47], 17-jS-estradiol [59], 2,4-dichlorophenoxyacetic acid (2,4-D) [32], yohimbine and corynanthine [60], and corticosterone/cortisol [29]. Other assays are summarized in Table 3. 

Fig. 2.4. Reactions of radicals generated from a ligand bound to a receptor. X-Y or X = Y is the photoactivatable ligand Y is radiolabeled but X is not Z is an atom in the ligand binding site (e.g. H) S represents termination of the reaction by H, by another radical from the buffer, or by X. Elimination of a radical from the receptor could also terminate the reaction. If termination occurred at stage c, a covalent adduct with a radiolabeled fragment of XY would not be formed but the receptor might be inactivated (see e.g. Ogez et al., 1977 Smith...

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