Mossbauer spectra of bicarbonate-free ferric-transferrin complex

The bicarbonate-free ferric-transferrin complex was investigated by Mossbauer Spectroscopy under anaerobic conditions. No evidence of specific binding was found. The spectral results indicates that the apparent binding is due to the formation of antiferromagnetic ferric hydroxide polymers which are firmly attached to the transferrin molecule. Specific binding would only occur in the presence of bicarbonate or other low molecular weight chelators.