Detection of a near infra-red absorption band of ferrohaem a3 in cytochrome c oxidase.
We have detected weak absorption bands in the near infra-red region of reduced mammalian cytochrome c oxidase, analogous to those that we have recently reported to be present in the bacterial cytochrome o (Ingledew, W.J., Bacon, M. and Rich, P.R. (1992) FEBS Lett. 305, 167-170). The major band is centred at 784 nm and has an sigma mM-1.cm-1 of around 0.1. It is shifted to 760 nm in the carbon monoxide compound and is absent in the reduced cyanide complex. We attribute it to a charge transfer band of ferrohaem a3, equivalent to the 'band III' or 'conformational band' of haemoglobin.
Rich
P R
PR
Glynn Research Institute, Bodmin, Cornwall, UK.
Moody
A J
AJ
Ingledew
W J
WJ
D000818:Animals; D002248:Carbon Monoxide / Q000737:chemistry; D002417:Cattle; D003576:Electron Transport Complex IV / Q000737:chemistry*; D010084:Oxidation-Reduction; D010782:Photolysis; D013053:Spectrophotometry; D013055:Spectrophotometry, Infrared
D002248:Carbon Monoxide; D003576:Electron Transport Complex IV