An EPR investigation of non-haem iron sites in Escherichia coli bacterioferritin and their interaction with phosphate. A study using nitric oxide as a spin probe.
EPR studies of bacterioferritin (BFR), an iron-storage protein of Escherichia coli [1993, Biochem. J. 292, 47-56], have revealed the presence of non-haem iron (III) (NHI) sites within the protein coat which may be involved in iron uptake and release. When nitric oxide was used as an EPR spin probe of the Fe(II) state of the NHI sites, two distinct mononuclear NHI species were found. Under certain conditions, an iron dimer was also observed. The reaction of phosphate with NHI species has been investigated. Results point to a function for this anion in core nucleation.
Centre for Metalloprotein Spectroscopy and Biology, School of Chemical Sciences, University of East Anglia, Norwich, UK.
N E
NE
Le Brun
M R
MR
Cheesman
A J
AJ
Thomson
G R
GR
Moore
S C
SC
Andrews
J R
JR
Guest
P M
PM
Harrison
D001426:Bacterial Proteins; D001665:Binding Sites; D003573:Cytochrome b Group / Q000737:chemistry* / Q000378:metabolism*; D004578:Electron Spin Resonance Spectroscopy / Q000379:methods; D004926:Escherichia coli / Q000378:metabolism*; D005293:Ferritins / Q000737:chemistry* / Q000378:metabolism*; D006418:Heme; D007501:Iron / Q000378:metabolism*; D009569:Nitric Oxide; D011487:Protein Conformation; D013113:Spin Labels
D001426:Bacterial Proteins; D003573:Cytochrome b Group; D013113:Spin Labels; D009569:Nitric Oxide; D006418:Heme; D005293:Ferritins; C018032:bacterioferritin; D007501:Iron