title: Application of fluorescence resonance energy transfer techniques to establish ligand-receptor orientation.
abstract: Fluorescence resonance energy transfer (FRET) has been utilized to determine distances between a fluorescence donor and a fluorescence acceptor having appropriately overlapping spectra. In this chapter, we utilize this approach to establish distances between a fluorescence donor situated in a distinct position within a docked ligand and a fluorescence acceptor situated in a distinct position within its receptor. This technique is applicable to receptor expressed in the environment of an intact cell containing the full complement of signaling and regulatory proteins. A number of controls are necessary, including those establishing the normal function of the modified ligand and receptor, the absence of energy transfer to non-receptor proteins, and the specificity of transfer between the donor of interest and the acceptor of interest. We have utilized the example of FRET between a secretin peptide incorporating Alexa(488) and a secretin receptor construct derivatized with Alexa(568). The latter was prepared by the derivatization of a mono-cysteine-reactive receptor construct with a fluorescent methanethiosulfonate reagent. This approach can provide important spatial information that can be useful in the meaningful docking of a ligand at its receptor.
authors.affiliation: Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic, Scottsdale, AZ, USA.
authors.forename: Kaleeckal G
authors.initials: KG
authors.lastname: Harikumar
authors.forename: Laurence J
authors.initials: LJ
authors.lastname: Miller
mesh_terms: D000818:Animals; D016466:CHO Cells; D006224:Cricetinae; D003412:Cricetulus; D031541:Fluorescence Resonance Energy Transfer / Q000379:methods*; D008024:Ligands; D011956:Receptors, Cell Surface / Q000737:chemistry* / Q000378:metabolism*
chemical_list: D008024:Ligands; D011956:Receptors, Cell Surface