title: Indicator displacement assays inside live cells.
abstract: The macrocycle p-sulfonatocalix[4]arene (CX4) and the fluorescent dye lucigenin (LCG) form a stable host-guest complex, in which the dye fluorescence is quenched. Incubation of live V79 and CHO cells with the CX4/LCG chemosensing ensemble resulted in its spontaneous uptake. Subsequent addition of choline, acetylcholine, or protamine, which have a high affinity for CX4 and are capable of entering cells, resulted in a fluorescence switch-on response. This can be traced to the displacement of LCG from CX4 by the analytes. The results establish the principal functionality of indicator displacement assays with synthetic receptors for the detection of the uptake of bioorganic analytes by live cells.
authors.affiliation: Department of Life Sciences and Chemistry, Jacobs University Bremen, Campus Ring 1, 28759 Bremen (Germany).
authors.forename: Amir
authors.initials: A
authors.lastname: Norouzy
authors.forename: Zahra
authors.initials: Z
authors.lastname: Azizi
authors.forename: Werner M
authors.initials: WM
authors.lastname: Nau
mesh_terms: D000109:Acetylcholine / Q000032:analysis / Q000378:metabolism; D000166:Acridines / Q000737:chemistry* / Q000378:metabolism; D000818:Animals; D016466:CHO Cells; D047250:Calixarenes / Q000737:chemistry* / Q000378:metabolism; D002460:Cell Line; D002794:Choline / Q000032:analysis / Q000378:metabolism; D006224:Cricetinae; D003412:Cricetulus; D005456:Fluorescent Dyes / Q000737:chemistry* / Q000378:metabolism; D008856:Microscopy, Fluorescence; D010636:Phenols / Q000737:chemistry* / Q000378:metabolism; D011479:Protamines / Q000032:analysis / Q000378:metabolism
chemical_list: D000166:Acridines; D005456:Fluorescent Dyes; D010636:Phenols; D011479:Protamines; C121325:calix(4)arene; D047250:Calixarenes; C033472:10,10'-dimethyl-9,9'-biacridinium; D002794:Choline; D000109:Acetylcholine
keywords: bioanalytical chemistry; fluorescence; host-guest complexes; macrocycles; supramolecular chemistry