Rationale and objectives: We observed the magnetization transfer rates in a variety of protein solutions at 0.1-T magnetic field and compared our results with previous investigations at high magnetic fields (> 0.5 T). The effects of protein concentration, size, pH, denaturation, cross linking, and fiber formation were investigated.
Methods: We used the saturation transfer technique to determine the transfer of magnetization in gamma globulin, fibronectin, collagen, fibrinogen, and albumin solutions.
Results: The observed transfer rate increased with increasing concentration and size of the protein. Protein degradation decreased the transfer rate. Cross linking and fiber formation each increased the transfer rate, whereas buffer pH had no effect.
Conclusion: Protein denaturation, aggregation, and fiber formation are important determinants of magnetization transfer in vitro. The size, concentration, and cross linking of the proteins contribute strongly to the transfer of magnetization at low fields, and the effect seems to be at least as important as at the higher fields.