title: New fluorescent reagents specific for Ca(2+)-binding proteins.
abstract: Ca(2+) carries information pivotal to cell life and death via its interactions with specific binding sites in a protein. We previously developed a novel photoreactive reagent, azido ruthenium (AzRu), which strongly inhibits Ca(2+)-dependent activities. Here, we synthesized new fluorescent ruthenium-based reagents containing FITC or EITC, FITC-Ru and EITC-Ru. These reagents were purified, characterized and found to specifically interact with and markedly inhibit Ca(2+)-dependent activities but not the activity of Ca(2+)-independent reactions. In contrast to many reagents that serve as probes for Ca(2+), FITC-Ru and EITC-Ru are the first fluorescent divalent cation analogs to be synthesized and characterized that specifically bind to Ca(2+)-binding proteins and inhibit their activity. Such reagents will assist in characterizing Ca(2+)-binding proteins, thereby facilitating better understanding of the function of Ca(2+) as a key bio-regulator.
authors.affiliation: Department of Life Sciences and the NIBN, Ben-Gurion University, Beer-Sheva 84105, Israel.
authors.forename: Danya
authors.initials: D
authors.lastname: Ben-Hail
authors.forename: Daniela
authors.initials: D
authors.lastname: Lemelson
authors.forename: Adrian
authors.initials: A
authors.lastname: Israelson
authors.forename: Varda
authors.initials: V
authors.lastname: Shoshan-Barmatz
mesh_terms: D000818:Animals; D002118:Calcium / Q000378:metabolism; D002135:Calcium-Binding Proteins / Q000037:antagonists & inhibitors*; D002417:Cattle; D002462:Cell Membrane / Q000378:metabolism; D005456:Fluorescent Dyes / Q000138:chemical synthesis / Q000737:chemistry* / Q000302:isolation & purification; D049449:Luminescence; D008297:Male; D011817:Rabbits; D050994:Voltage-Dependent Anion Channels / Q000037:antagonists & inhibitors / Q000378:metabolism
chemical_list: D002135:Calcium-Binding Proteins; D005456:Fluorescent Dyes; D050994:Voltage-Dependent Anion Channels; D002118:Calcium