Premium
Oxygenated complex of cytochrome bd from Escherichia coli : Stability and photolability
Author(s) -
Belevich Ilya,
Borisov Vitaliy B.,
Konstantinov Alexander A.,
Verkhovsky Michael I.
Publication year - 2005
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/j.febslet.2005.07.011
Subject(s) - escherichia coli , chemistry , cytochrome , biochemistry , microbiology and biotechnology , biology , enzyme , gene
Cytochrome bd is one of the two terminal ubiquinol oxidases in the respiratory chain of Escherichia coli catalyzing reduction of O 2 to H 2 O. The enzyme is expressed under low oxygen tension; due to high affinity for O 2 it is isolated mainly as a stable oxygenated complex. Direct measurement of O 2 binding to heme d in the one‐electron reduced isolated enzyme gives K d (O 2 ) of ∼280 nM. It is possible to photolyse the heme d oxy‐complex by illumination of the enzyme for several minutes under microaerobic conditions; the light‐induced difference absorption spectrum is virtually identical to the inverted spectrum of O 2 binding to heme d .