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Iron binding and autoreduction by citrate: are these involved in signalling by iron regulatory protein-1?
J M Gutteridge1, S Mumby, N J Lamb
1Oxygen Chemistry Laboratory, Royal Brompton Hospital, London.
Abstract:
Ferric ions bind to citrate and undergo an autoreduction to form a ferrous-citrate complex, greatly increasing the redox activity of the iron complex. Ferrous ions and citrate are also essential for the enzymic activity of aconitase. Aconitase, with its iron-sulphur cluster has a versatile structure which allows it to act as an iron regulatory protein (IRP-1). The purpose of this study was to see whether iron binding, and its autoreduction by citrate, could play a physiological signalling role in iron regulation. Significant amounts of ferrous ions were associated with citrate, when measured using ferrozine, however, these did not appear to activate iron-requiring aconitase.
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