The development of a new family of intracellular calcium probes.
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.
Iatridou
H
H
Department of Chemistry, University of Crete, Iraklion, Greece.
Foukaraki
E
E
Kuhn
M A
MA
Marcus
E M
EM
Haugland
R P
RP
Katerinopoulos
H E
HE
D000818:Animals; D002118:Calcium / Q000032:analysis*; D003374:Coumarins; D005456:Fluorescent Dyes / Q000138:chemical synthesis / Q000737:chemistry / Q000378:metabolism; D051379:Mice
D003374:Coumarins; D005456:Fluorescent Dyes; C030123:coumarin; D002118:Calcium