title: New fluorescent calcium indicators designed for cytosolic retention or measuring calcium near membranes.
abstract: A new family of fluorescent calcium indicators has been developed based on a new analog of BAPTA called FF6. This new BAPTA analog serves as a versatile synthetic intermediate for developing Ca2+ indicators targeted to specific intracellular environments. Two of these new Ca2+ indicators, fura-PE3 and fura-FFP18, are described in this report. Fura-PE3 is a zwitterionic indicator that resists the rapid leakage and compartmentalization seen with fura-2 and other polycarboxylate calcium indicators. In contrast to results obtained with fura-2, cells loaded with PE3 remain brightly loaded and responsive to changes in concentration of cytosolic free calcium for hours. Fura-FFP18 is an amphipathic indicator that to binds to liposomes and to cell membranes. Studies to be detailed later indicate that FFP18 functions as a near-membrane Ca2+ indicator and that calcium levels near the plasma membrane rise faster and higher than in the cytosol.
authors.affiliation: Department of Zoology, University of Texas at Austin 78712-1064, USA.
authors.forename: C
authors.initials: C
authors.lastname: Vorndran
authors.forename: A
authors.initials: A
authors.lastname: Minta
authors.forename: M
authors.initials: M
authors.lastname: Poenie
mesh_terms: D000818:Animals; D055592:Biophysical Phenomena; D001703:Biophysics; D002118:Calcium / Q000032:analysis / Q000378:metabolism; D002460:Cell Line; D002462:Cell Membrane / Q000378:metabolism; D002614:Chelating Agents / Q000138:chemical synthesis / Q000737:chemistry; D003600:Cytosol / Q000378:metabolism; D004533:Egtazic Acid / Q000031:analogs & derivatives / Q000138:chemical synthesis / Q000737:chemistry; D005456:Fluorescent Dyes / Q000138:chemical synthesis / Q000737:chemistry; D016257:Fura-2 / Q000031:analogs & derivatives / Q000138:chemical synthesis / Q000737:chemistry; D051379:Mice; D015394:Molecular Structure; D013050:Spectrometry, Fluorescence
chemical_list: D002614:Chelating Agents; D005456:Fluorescent Dyes; C098105:fura-FFP18; C098106:fura-PE3; D004533:Egtazic Acid; C025603:1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid; D002118:Calcium; D016257:Fura-2