title: The development of a new family of intracellular calcium probes.
abstract: Four new potential fluorescent probes for Ca2+ using the coumarin moiety as a fluorophore have been synthesized and their spectral properties and binding affinities for Ca2+ determined. The most promising derivative for intracellular use, BTC, exhibits an excitation wavelength shift from 462 nm to 401 nm on binding Ca2+, with an emission wavelength of 530 nm. The quantum yield of this probe increases from 0.07 as the free indicator to 0.12 on binding Ca2+. BTC, loaded as its tetraacetoxymethyl ester (AM ester) into mouse myeloma P3X cells, responded only when cytoplasmic Ca2+ exceeded typical intracellular calcium concentrations. The dye, therefore, appears to be useful in excitatory cells or extracellular spaces with intracellular calcium concentrations high enough to saturate typical excitation ratio Ca2+ indicators such as Fura-2.
authors.affiliation: Department of Chemistry, University of Crete, Iraklion, Greece.
authors.forename: H
authors.initials: H
authors.lastname: Iatridou
authors.forename: E
authors.initials: E
authors.lastname: Foukaraki
authors.forename: M A
authors.initials: MA
authors.lastname: Kuhn
authors.forename: E M
authors.initials: EM
authors.lastname: Marcus
authors.forename: R P
authors.initials: RP
authors.lastname: Haugland
authors.forename: H E
authors.initials: HE
authors.lastname: Katerinopoulos
mesh_terms: D000818:Animals; D002118:Calcium / Q000032:analysis*; D003374:Coumarins; D005456:Fluorescent Dyes / Q000138:chemical synthesis / Q000737:chemistry / Q000378:metabolism; D051379:Mice
chemical_list: D003374:Coumarins; D005456:Fluorescent Dyes; C030123:coumarin; D002118:Calcium