title: Synthesis and spectral characterization of a thiol-reactive long-lifetime Ru(II) complex.
abstract: We report the synthesis and spectral properties of a long-lifetime luminescent Ru complex containing a sulfhydryl-reactive maleimide group, [Ru (2,2'-bipyridine)2(1, 10-phenanthroline-5-maleimide)](PF6)2. [Ru(bpy)2(phen-mi)]2+ was covalently linked to human serum albumin, immunoglobulin G, and beta-galactosidase. The lifetimes for probe bound to proteins were near 1.1 micros. In the absence of rotational motions, the probe displayed an anisotropy near 0.17 for excitation near 475 nm. Anisotropy decay data were used to determine rotational correlation times of the proteins, which showed local probe motions in addition to overall rotational diffusion. This long-lifetime sulfhydryl-reactive probe can be used to recover microsecond rotational motions and/or domain motions of proteins and/or macromolecular complexes.
authors.affiliation: Department of Biochemistry and Molecular Biology, University of Maryland School of Medicine, 725 West Lombard Street, Baltimore, Maryland 21201, USA.
authors.forename: E
authors.initials: E
authors.lastname: Terpetschnig
authors.forename: J D
authors.initials: JD
authors.lastname: Dattelbaum
authors.forename: H
authors.initials: H
authors.lastname: Szmacinski
authors.forename: J R
authors.initials: JR
authors.lastname: Lakowicz
mesh_terms: D016231:Fluorescence Polarization Immunoassay; D006801:Humans; D007074:Immunoglobulin G; D008024:Ligands; D008163:Luminescent Measurements; D046911:Macromolecular Substances; D015335:Molecular Probes / Q000138:chemical synthesis* / Q000737:chemistry; D009942:Organometallic Compounds / Q000138:chemical synthesis* / Q000737:chemistry; D010618:Phenanthrolines / Q000138:chemical synthesis* / Q000737:chemistry; D011487:Protein Conformation; D012709:Serum Albumin; D013438:Sulfhydryl Compounds; D001616:beta-Galactosidase
chemical_list: C108535:(ruthenium (2,2'-bipyridine)2(1,10-phenanthroline-5-maleimide))(PF6)2; D007074:Immunoglobulin G; D008024:Ligands; D046911:Macromolecular Substances; D015335:Molecular Probes; D009942:Organometallic Compounds; D010618:Phenanthrolines; D012709:Serum Albumin; D013438:Sulfhydryl Compounds; D001616:beta-Galactosidase