1fi7
From Proteopedia
Solution structure of the imidazole complex of cytochrome C
Overview
Although imidazole ligand binding to cytochrome c is not directly related to its physiological function, it has the potential to provide valuable information on the molecular and electronic structure of the protein. The solution structure of the imidazole adduct of oxidized horse heart cytochrome c (Im-cyt c) has been determined through 2D NMR spectroscopy. The Im-cyt c, 8 mM in 1.2 M imidazole solution at pH 5.7 and 313 K, provided altogether 2,542 NOEs (1,901 meaningful NOEs) and 194 pseudocontact shifts. The 35 conformers of the family show the RMSD values to the average structure of 0.063+/-0.007 nm for the backbone and 0.107+/-0.007 nm for all heavy atoms, respectively. The characterization of Im-cyt c is discussed in detail both in terms of structure and electronic properties. The replacement of the axial ligand Met80 with the exogenous imidazole ligand induces significant conformation changes in both backbone and side chains of the residues located in the distal axial ligand regions. The imidazole ligand binds essentially parallel to the imidazole of the proximal histidine, the two planes forming an angle of 8+/-7 degrees. The electron delocalization on the heme moiety and the magnetic susceptibility tensor are consistent with these structural features.
About this Structure
1FI7 is a Single protein structure of sequence from Equus caballus. Full crystallographic information is available from OCA.
Reference
Effects of extrinsic imidazole ligation on the molecular and electronic structure of cytochrome c., Banci L, Bertini I, Liu G, Lu J, Reddig T, Tang W, Wu Y, Yao Y, Zhu D, J Biol Inorg Chem. 2001 Jun;6(5-6):628-37. PMID:11472026 Page seeded by OCA on Fri May 2 16:21:22 2008
Categories: Equus caballus | Single protein | Banci, L. | Bertini, I. | Liu, G. | Lu, J. | Reddig, T. | Tang, W. | Wu, Y. | Zhu, D. | Cytochrome c | Nmr | Solution structure
