ISSN:
1573-6881
Keywords:
Escherichia coli
;
Quinol oxidase
;
cytochrome bo3
;
cytochrome c oxidase
;
nitric oxide reductase
;
EPR spectroscopy
;
MCD spectroscopy
;
oxyferryl heme
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Chemistry and Pharmacology
,
Physics
Notes:
Abstract For the study of the dinuclear center of heme-copper oxidases cytochrome bo 3 from Escherichia coli offers several advantages over the extensively charactererized bovine cytochrome c oxidase. The availability of strains with enhanced levels of expression allows purification of the significant amounts of enzyme required for detailed spectroscopic studies. Cytochrome bo 3 is readily prepared as the fast form, with a homogeneous dinuclear center which gives rise to characteristic broad EPR signals not seen in CcO. The absence of CuA and the incorporation of protohemes allows for a detailed interpretation of the MCD spectra arising from the dinuclear center heme o 3. Careful analysis allows us to distinguish between small molecules that bind to heme o 3, those which are ligands of CuB, and those which react to yield higher oxidation states of heme o 3. Here we review results from our studies of the reactions of fast cytochrome bo 3 with formate, fluoride, chloride, azide, cyanide, NO, and H2O2.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1023/A:1020507511285
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