Probing Dynamics of Transferrin and their Interaction with Metal Ions using High Sensitivity Dielectric Spectroscopy*

Transferrin is a glycoprotein responsible for ferric-ion delivery to various tissues through blood plasma. The saturation level of the protein plays an essential role in iron metabolism and determining certain diseases such as iron deficiency anemia. Transferrin performs its functions by binding two ferric-ions and an anion, while doing so, the conformation of transferrin would change. To probe the conformational dynamics of transferrin and its interaction with ferric-ion in aqueous solutions at molecular level, we have employed a highly sensitive dielectric megahertz-to-terahertz frequency-domain spectroscopy. The dynamics of the protein strongly depend on the temperature, type of metal ions and protein concentrations. The results have revealed the hydration dynamics and transferrin-ion interactions that determine biochemical functions and reactivity of transferrin. Besides, dielectric spectroscopy being a non-invasive and non-destructive method makes it an excellent candidate as a detection method for transferrin in tissues.