Identification of axial ligands of cytochrome c 552 from Nitrosomonas europaea

FEBS Letters

Hooper, Alan B.¹  Peterson, Jim²  Arciero, David M.¹  Peng, Qinyun² 

[1] Department of Genetics and Cell Biology, University of Minnesota, St. Paul, MN 55108, USA;Department of Chemistry, University of Alabama, Tuscaloosa, AL 35487-0336, USA

关键词: Cytochrome c 552;    Nitrosomonas europaea;    Axial ligand;    695 nm band;    EPR;    HALS signal;    MCD;    near-infrared;   

DOI  :  10.1016/0014-5793(94)80504-0

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Cytochrome c ₅₅₂ from Nitrosomonas europaea was analyzed by visible, EPR and MCD spectroscopies. The visible and MCD data show that histidine and methionine are the axial ligands to the heme iron of the ferric protein. The EPR spectrum of the cytochrome shows an atypical highly axial low spin (HALS) type signal with g-values that make it difficult to identify the axial ligands. These results reinforce the value of near-infrared MCD spectroscopy for assigning ligands in ferric heme systems and point out the difficulties in using only EPR spectroscopy for the same purpose. The description of another c-cytochrome exhibiting a HALS-type EPR signal will eventually be helpful in explaining the physical basis for this unusual signal.

【 授权许可】

Unknown