title: A photoactivable probe for calcium binding proteins.
abstract: Ca2+ as a signaling molecule carries information pivotal to cell life and death via its reversible interaction with a specific site in a protein. Although numerous Ca2+-dependent activities are known, the proteins responsible for some of these activities remain unidentified. We synthesized and characterized a photoreactive reagent, azido ruthenium (AzRu), which interacts specifically with Ca2+ binding proteins and strongly inhibits their Ca2+-dependent activities, regardless of their catalytic mechanisms or functional state as purified proteins, embedded in the membrane or in intact cells. As expected from a Ca2+ binding protein-specific reagent, AzRu had no effect on Ca2+-independent and Mg2+-dependent activities. Az103Ru covalently bound, and specifically labeled, known Ca2+ binding proteins. AzRu is a photoreactive reagent that provides an approach for identification of Ca2+ binding proteins, characterization of their binding sites, and exploration of new Ca2+-dependent processes.
authors.affiliation: Department of Life Sciences and The Zlotowski Center for Neuroscience, Ben-Gurion University of the Negev, Beer-Sheva 84713, Israel.
authors.forename: Adrian
authors.initials: A
authors.lastname: Israelson
authors.forename: Laetitia
authors.initials: L
authors.lastname: Arzoine
authors.forename: Salah
authors.initials: S
authors.lastname: Abu-hamad
authors.forename: Vladimir
authors.initials: V
authors.lastname: Khodorkovsky
authors.forename: Varda
authors.initials: V
authors.lastname: Shoshan-Barmatz
mesh_terms: D017209:Apoptosis / Q000187:drug effects; D001386:Azides / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology; D002118:Calcium / Q000737:chemistry / Q000378:metabolism; D002135:Calcium-Binding Proteins / Q000032:analysis* / Q000037:antagonists & inhibitors / Q000737:chemistry* / Q000378:metabolism; D017871:Calcium-Calmodulin-Dependent Protein Kinases / Q000378:metabolism; D000252:Calcium-Transporting ATPases / Q000378:metabolism; D002413:Cations, Divalent; D002460:Cell Line; D005987:Glyceraldehyde-3-Phosphate Dehydrogenases / Q000378:metabolism; D006801:Humans; D008928:Mitochondria / Q000737:chemistry / Q000378:metabolism; D015335:Molecular Probes / Q000032:analysis* / Q000737:chemistry*; D009154:Mutation / Q000235:genetics; D009942:Organometallic Compounds / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology; D017319:Photosensitizing Agents / Q000737:chemistry; D012433:Ryanodine / Q000494:pharmacology; D019837:Ryanodine Receptor Calcium Release Channel / Q000378:metabolism; D012519:Sarcoplasmic Reticulum / Q000187:drug effects / Q000378:metabolism / Q000528:radiation effects; D019311:Staurosporine / Q000494:pharmacology; D050994:Voltage-Dependent Anion Channels / Q000235:genetics / Q000378:metabolism
chemical_list: D001386:Azides; D002135:Calcium-Binding Proteins; D002413:Cations, Divalent; D015335:Molecular Probes; D009942:Organometallic Compounds; D017319:Photosensitizing Agents; D019837:Ryanodine Receptor Calcium Release Channel; D050994:Voltage-Dependent Anion Channels; C508266:azido ruthenium; D012433:Ryanodine; D005987:Glyceraldehyde-3-Phosphate Dehydrogenases; D017871:Calcium-Calmodulin-Dependent Protein Kinases; D000252:Calcium-Transporting ATPases; D019311:Staurosporine; D002118:Calcium