Axial Ligation of Fe(II)−Bleomycin Probed by XANES Spectroscopy
- 26 February 2004
- journal article
- Published by American Chemical Society (ACS) in Inorganic Chemistry
- Vol. 43 (6), 1825-1827
- https://doi.org/10.1021/ic0350537
Abstract
Full multiple scattering calculations of the Fe K-edge X-ray absorption near edge structure of bleomycin have been performed. Structural insight is based on the comparison between experimental and theoretical data calculated for different active site models coming from NMR-informed molecular dynamic simulations. In all models considered, the equatorial ligands (secondary amine in β-aminoalanine, pyrimidine and imidazole rings and the β-hydroxyhistidine) were left unchanged. Seven models with two axial ligands (the primary amine in β-aminoalanine and the carbomoyl group of the mannose or a solvent molecule) were tested. The best agreement between theoretical and experimental spectra is achieved for the model of bleomycin with the primary amine and the oxygen of the mannose sugar occupying the axial positions. The coordination environment is characterized by serious distortions of the Fe octahedron, including the presence of one ligand with a very short bond length and significant angular distortions.Keywords
This publication has 16 references indexed in Scilit:
- Molecular modeling of the three-dimensional structure of Fe(II)-bleomycin: are the Co(II) and Fe(II) adducts isostructural?JBIC Journal of Biological Inorganic Chemistry, 2002
- X-ray absorption spectroscopic investigation of Fe(II)-peplomycin and peplomycin derivatives: the effect of axial ligation on Fe-pyrimidine back-bondingJBIC Journal of Biological Inorganic Chemistry, 2001
- Coordination Chemistry of Co(II)-Bleomycin: Its Investigation through NMR and Molecular Dynamics,Biochemistry, 2000
- Spectroscopic Investigation of the Metal Ligation and Reactivity of the Ferrous Active Sites of Bleomycin and Bleomycin DerivativesJournal of the American Chemical Society, 1998
- Structures of Cobalt(III)‐Pepleomycin and Cobalt(III)‐Deglycopepleomycin (green forms) Determined by NMR StudiesEuropean Journal of Biochemistry, 1997
- Atomic and electronic structure probed by X-ray absorption spectroscopy: Full multiple scattering analysis with the G4XANES packageComputational Materials Science, 1995
- Determination of the Geometric and Electronic Structure of Activated Bleomycin Using X-ray Absorption SpectroscopyJournal of the American Chemical Society, 1995
- NMR Determination of the Structures of Peroxycobalt(III) Bleomycin and Cobalt(III) Bleomycin, Products of the Aerobic Oxidation of Cobalt(II) Bleomycin by DioxygenBiochemistry, 1994
- A designed synthetic analog of cobalt(III)-bleomycin with enhanced DNA-binding and photocleaving activityJournal of the American Chemical Society, 1993
- Characterization of a crystalline synthetic analog of copper(II)-bleomycinJournal of the American Chemical Society, 1988