Determination of the orientation of the axial ligands and of the magnetic properties of the haems in the tetrahaem ferricytochrome from Shewanella frigidimarina

FEBS Letters

Louro, Ricardo O³  Pessanha, Miguel³  Reid, Graeme A²  Chapman, Stephen K¹  Turner, David L³  Salgueiro, Carlos A³ 

[1]Department of Chemistry, University of Edinburgh, West Mains Road, Edinburgh EH9 3JJ, UK

[2]Institute of Cell and Molecular Biology, University of Edinburgh, Mayfield Road, Edinburgh EH9 3JR, UK

[3]Instituto de Tecnologia Quı́mica e Biológica, Universidade Nova de Lisboa, Rua da Quinta Grande 6, 2780-156 Oeiras, Portugal

关键词: Heteronuclear nuclear magnetic resonance;    Haem electronic structure;    Paramagnetic shift;    Electron transfer;    Shewanella;    Sfc;    Shewanella frigidimarina NCIMB400 tetrahaem cytochrome;    NOESY;    nuclear Overhauser spectroscopy;    TOCSY;    total correlation spectroscopy;    HMQC;    heteronuclear multiple quantum coherence;    Soc;    Shewanella oneidensis MR-1 tetrahaem cytochrome;   

DOI  :  10.1016/S0014-5793(02)03610-4

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

The unambiguous assignment of the nuclear magnetic resonance (NMR) signals of the α-substituents of the haems in the tetrahaem cytochrome isolated from Shewanella frigidimarina NCIMB400, was made using a combination of homonuclear and heteronuclear experiments. The paramagnetic ¹³C shifts of the nuclei directly bound to the porphyrin of each haem group were analysed in the framework of a model for the haem electronic structure. The analysis yields g-tensors for each haem, which allowed the assignment of some electron paramagnetic resonance (EPR) signals to specific haems, and the orientation of the magnetic axes relative to each haem to be established. The orientation of the axial ligands of the haems was determined semi-empirically from the NMR data, and the structural results were compared with those of the homologous tetrahaem cytochrome from Shewanella oneidensis MR-1 showing significant similarities between the two proteins.

【 授权许可】

Unknown