title: Identification of a key structural feature of cobalt(III)-bleomycins: an exogenous ligand (e.g. hydroperoxide) bound to cobalt.
abstract: A series of cobalt(III) complexes of the anticancer antibiotic bleomycin has been prepared. Mass spectrometry and enzymatic analysis show that the green cobalt-bleomycin complex contains a hydroperoxide (-OOH) group bound to cobalt with unusual stability. Under appropriate conditions, cobalt-bleomycins containing other monodentate ligands to cobalt can be formed; fast-atom bombardment mass spectra of such complexes show peaks for cobalt-bleomycin at the expected mass, and also peaks for the intact complexes at the required higher mass.
mesh_terms: D001761:Bleomycin / Q000031:analogs & derivatives; D002851:Chromatography, High Pressure Liquid; D006735:Horseradish Peroxidase / Q000378:metabolism*; D006861:Hydrogen Peroxide / Q000032:analysis*; D007700:Kinetics; D008024:Ligands; D013058:Mass Spectrometry; D010544:Peroxidases / Q000378:metabolism*; D013053:Spectrophotometry
chemical_list: D008024:Ligands; C030187:cobalt bleomycin; D001761:Bleomycin; D006861:Hydrogen Peroxide; D006735:Horseradish Peroxidase; D010544:Peroxidases