Selective oxidative destruction of iron-sulfur clusters. Ferricyanide oxidation of Azotobacter vinelandii ferredoxin I.
The destructive oxidation of aerobically isolated 7Fe Azotobacter vinelandii ferredoxin I [(7Fe)FdI] by Fe(CN)3-6 is examined using low-temperature magnetic circular dichroism (MCD) and EPR. The results demonstrate that oxidation of the [3Fe-3S] cluster occurs only after essentially complete destruction of the [4Fe-4S] cluster. It is therefore feasible by controlled Fe(CN)3-6 oxidation to obtain a partially metallated form of FdI, (3Fe)FdI, containing only a [3Fe-3S] cluster. The MCD and EPR data demonstrate that the [3Fe-3S] cluster in (3Fe)FdI is essentially identical in structure to that in the native protein.
Morgan
T V
TV
Stephens
P J
PJ
Devlin
F
F
Burgess
B K
BK
Stout
C D
CD
D001395:Azotobacter / Q000378:metabolism*; D002942:Circular Dichroism; D004578:Electron Spin Resonance Spectroscopy; D005288:Ferredoxins / Q000378:metabolism*; D005292:Ferricyanides / Q000378:metabolism*; D010084:Oxidation-Reduction
D005288:Ferredoxins; D005292:Ferricyanides; C007931:hexacyanoferrate III