title: Fluorophore Assisted Photolysis of Thiolato-Cob(III)alamins.
abstract: Cobalamins are known to react with thiols to yield stable β-axial Co(III)-S bonded thiolato-cobalamin complexes. However, in stark contrast to the Co-C bond in alkylcobalamins, the photolability of the Co-S bond in thiolato-cobalamins remains undetermined. We have investigated the photolysis of N-acetylcysteinyl cob(III)alamin at several wavelengths within the ultraviolet and visible spectrum. To aid in photolysis, we show that attaching fluorophore "antennae" to the cobalamin scaffold can improve photolytic efficiency by up to an order of magnitude. Additionally, electron paramagnetic resonance confirms previous conjectures that the photolysis of thiolato-cobalamins at wavelengths as long as 546 nm produces thiyl radicals.
authors: Department of Chemistry, ‡Division of Chemical Biology and Medicinal Chemistry, and §Department of Pharmacology, University of North Carolina , Chapel Hill, North Carolina 27599, United States.
authors: Zachary L
authors: ZL
authors: Rodgers
authors: Department of Chemistry, ‡Division of Chemical Biology and Medicinal Chemistry, and §Department of Pharmacology, University of North Carolina , Chapel Hill, North Carolina 27599, United States.
authors: Thomas A
authors: TA
authors: Shell
authors: Department of Chemistry, ‡Division of Chemical Biology and Medicinal Chemistry, and §Department of Pharmacology, University of North Carolina , Chapel Hill, North Carolina 27599, United States.
authors: Alexander M
authors: AM
authors: Brugh
authors: Department of Chemistry, ‡Division of Chemical Biology and Medicinal Chemistry, and §Department of Pharmacology, University of North Carolina , Chapel Hill, North Carolina 27599, United States.
authors: Hannah L
authors: HL
authors: Nowotarski
authors: Department of Chemistry, ‡Division of Chemical Biology and Medicinal Chemistry, and §Department of Pharmacology, University of North Carolina , Chapel Hill, North Carolina 27599, United States.
authors: Malcolm D E
authors: MD
authors: Forbes
authors: Department of Chemistry, ‡Division of Chemical Biology and Medicinal Chemistry, and §Department of Pharmacology, University of North Carolina , Chapel Hill, North Carolina 27599, United States.
authors: David S
authors: DS
authors: Lawrence
mesh_terms: D002853:Chromatography, Liquid; D004578:Electron Spin Resonance Spectroscopy; D005456:Fluorescent Dyes / Q000737:chemistry*; D010782:Photolysis; D066244:Proton Magnetic Resonance Spectroscopy; D021241:Spectrometry, Mass, Electrospray Ionization; D013438:Sulfhydryl Compounds / Q000737:chemistry; D014805:Vitamin B 12 / Q000737:chemistry*
chemical_list: D005456:Fluorescent Dyes; D013438:Sulfhydryl Compounds; D014805:Vitamin B 12