title: Photoreactivity of lysergic acid diethylamide and its possible utility as a photoaffinity labeling reagent.
abstract: Aqueous solutions of lysergic acid diethylamide (LSD) are extremely sensitive to light in the near-ultraviolet region of the spectrum. This rather efficient photoreaction yields a variety of products which have very low affinity for LSD-binding sites on plasma membranes from Fasciola hepatica. Since this photoreaction may be elicited by normal white fluorescent lighting in the laboratory, it represents a potential source of error in determining the binding affinity of LSD. Utilizing this photoreactivity advantageously, [3H]LSD was used to photolabel membrane proteins. Covalent binding of [3H]LSD was shown to be a function of the duration of illumination and was inhibited by 5-hydroxytryptamine and nonradioactive LSD. Sodium dodecylsulfate (SDS) polyacrylamide gel electrophoresis of [3H]LSD labeled membranes from F. hepatica showed two proteins which were selectively labeled by the photoreactive [3H]LSD. This method of direct photolabeling with non-derivatized [3H]LSD may allow identification of LSD-binding proteins in a variety of systems.
mesh_terms: D000345:Affinity Labels; D002462:Cell Membrane / Q000378:metabolism; D005210:Fasciola hepatica; D008027:Light; D008238:Lysergic Acid Diethylamide / Q000378:metabolism / Q000528:radiation effects*; D008565:Membrane Proteins / Q000378:metabolism; D010777:Photochemistry; D012996:Solutions; D013050:Spectrometry, Fluorescence; D014316:Tritium; D014466:Ultraviolet Rays
chemical_list: D000345:Affinity Labels; D008565:Membrane Proteins; D012996:Solutions; D014316:Tritium; D008238:Lysergic Acid Diethylamide