title: Ruthenium(II)-phenanthroline-biotin complexes: synthesis and luminescence enhancement upon binding to avidin.
abstract: We report the synthesis, characterization, and avidin-binding properties of two novel ruthenium complexes, [Ru(bpy)(2)(phen-biotin)][PF(6)](2) 1 and [Ru(phen)(2)(phen-biotin)][PF(6)](2) 2 (bpy = 2,2'-bipyridine; phen = 1,10-phenanthroline, phen-biotin = 5-(10-amidobiotinyl)-1,10-phenanthroline)). We demonstrate that both biotinylated compounds bind to avidin through their biotin moieties with high affinity and in a 4:1 ratio. The binding of compounds 1 and 2 to avidin results in an enhancement in luminescence intensity ( approximately 1.4x, approximately 1.6x, respectively), relative to the unbound biotinylated ruthenium complexes. This behavior is markedly different from biotinylated organic dyes, whose fluorescence is quenched upon binding to avidin. Thus, ruthenium-biotin complexes 1 and 2 can form the basis of new, simplified biotin-avidin assays, which involve luminescence detection of the relevant biotinylated molecule through cross-linking with avidin.
authors.affiliation: Department of Chemistry, McGill University, 801 Sherbrooke Street West, Montreal, QC H3A 2K6 Canada.
authors.forename: Mohamed
authors.initials: M
authors.lastname: Slim
authors.forename: Hanadi F
authors.initials: HF
authors.lastname: Sleiman
mesh_terms: D001360:Avidin / Q000032:analysis* / Q000378:metabolism; D001710:Biotin / Q000032:analysis* / Q000138:chemical synthesis / Q000378:metabolism; D008163:Luminescent Measurements / Q000379:methods*; D010618:Phenanthrolines / Q000032:analysis* / Q000138:chemical synthesis / Q000378:metabolism; D011485:Protein Binding / Q000502:physiology; D012428:Ruthenium / Q000032:analysis* / Q000737:chemistry / Q000378:metabolism
chemical_list: D010618:Phenanthrolines; D001360:Avidin; D001710:Biotin; D012428:Ruthenium