title: Caged-Ca2+: a new agent allowing liberation of free Ca2+ in biological systems by photolysis.
abstract: The alkaline earth cation complexes of DM-nitrophen [1-(2-nitro-4,5-dimethoxyphenyl)-N,N,N',N'-tetrakis-[(oxycarbonyl) methyl]- 1,2-ethanediamine)] release the bound cation in the millisecond time range upon irradiation by a short UV-light pulse. This technique allows to generate cation (eg. Ca2+) concentration jumps or pulses in solution or in cellular systems. The physico-chemical properties of DM-nitrophen and its Mg2+, Ca2+ and Ba2+ complexes are investigated by employing spectrophotometric and potentiometric techniques. In case of Ca2+ a stability constant of the complex up to nearly 10(11) M-1 is found. The magnitude of representative Mg2+ and Ca2+ concentration jumps which can be generated under realistic experimental conditions are calculated on the basis of the thermodynamic parameters reported here.
authors.forename: E
authors.initials: E
authors.lastname: Grell
authors.forename: E
authors.initials: E
authors.lastname: Lewitzki
authors.forename: H
authors.initials: H
authors.lastname: Ruf
authors.forename: E
authors.initials: E
authors.lastname: Bamberg
authors.forename: G C
authors.initials: GC
authors.lastname: Ellis-Davies
authors.forename: J H
authors.initials: JH
authors.lastname: Kaplan
authors.forename: P
authors.initials: P
authors.lastname: de Weer
mesh_terms: D000085:Acetates / Q000032:analysis; D001464:Barium / Q000032:analysis; D002118:Calcium / Q000032:analysis; D002614:Chelating Agents / Q000032:analysis; D004492:Edetic Acid; D005029:Ethylenediamines / Q000032:analysis; D006863:Hydrogen-Ion Concentration; D010782:Photolysis
chemical_list: D000085:Acetates; D002614:Chelating Agents; D005029:Ethylenediamines; C057014:DM-nitrophen; D001464:Barium; D004492:Edetic Acid; D002118:Calcium