Spontaneous spectral changes of the reduced cytochrome bd

FEBS Letters

Borisov, Vitaliy¹  Konstantinov, Alexander A¹  Azarkina, Natalya¹ 

[1] A.N. Belozerskiy Institute of Physico-Chemical Biology, Moscow State University, Moscow 119899, Russia

关键词: Cytochrome bd;    Heme-ligand interaction;    Absorption spectrum;    Bacillus subtilis;    Escherichia coli;    Azotobacter vinelandii;    CHES;    2-(N-cyclohexylamino)-ethanesulfonic acid;    EDTA;    ethylenediaminetetraacetate;    HEPES;    N-(2-hydroxyethyl)piperazine-N′-(2-ethanesulfonic acid);    MOPS;    3-(N-morpholino)propanesulfonic acid;    NIR;    near infrared;    NSMP;    nutrient broth sporulation medium with phosphate;   

DOI  :  10.1016/S0014-5793(97)01196-4

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Reduction of the membrane-bound cytochrome bd from Bacillus subtilis, Escherichia coli and Azotobacter vinelandii as well as of the purified enzyme from E. coli was followed by secondary absorption changes on a time scale of tens of minutes. The difference absorption spectra of these changes resembled those induced by CO binding with heme d ²⁺ indicating interaction of the heme with an endogenous π-acceptor ligand. The spontaneous spectral changes were prevented and reversed by CO binding with the reduced cytochrome bd. Bonding of heme d iron to an endogenous protein ligand at the sixth axial position upon reduction is proposed and several possible mechanisms of such a process are considered.

【 授权许可】

Unknown