SQUID Magnetometry of Concentration Models of Iron-Containing Proteins

Concentration models are used to understand the relationship between the concentration of iron-containing proteins and the magnetization of the examined samples when experimentally measuring iron content using SQUID magnetometry. They were prepared for selected proteins: hemoglobin, myoglobin, and ferritin in such a way that their dimensions and concentration resembled the actual samples as closely as possible, and individual proteins were applied as a solution to a diamagnetic matrix. Magnetization measurements with a SQUID magnetometer showed that heme proteins and ferritin have markedly different profiles. The assumption that magnetization increases with increasing concentration, while coercivity remains unchanged, was confirmed. A model of coupling individual contributions of metalloproteins to the resulting magnetization was demonstrated.