Exploring Dynamics of Transferrin in Aqueous Solutions and Interactions with Metal Ions by High Sensitivity Dielectric Spectroscopy

Transferrin (TF) is a glycoprotein responsible for transporting ferric-ions 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. TF performs its functions by binding two ferric-ions and an anion; while doing so, the conformation of TF would change. To elucidate the conformational dynamics of TF and its interactions with water molecules and ferric-ions 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 concentration. Our results uncover the hydration dynamics and TF-ion interactions that determine biochemical functions and reactivity. Moreover, because dielectric spectroscopy is non-invasive and non-destructive, it presents a promising approach for detecting and characterizing TF in biological tissues.