Based On Transferrin-mediated Targeting Of Fulvic Acid Research Of Drug Carrier

Transferrin(Tf) is a transport protein existed in biological fluids and cells widely. Tf could deliver anticancer drugs into target cells through swallowing function of receptor, and it is widely used to build the targeting delivery of anticancer drugs. Fulvic acid(FA) has wide activities of biology and pharmacology with strong inhibitory effect on the HIV, cervical cancer, ehrlich ascites carcinoma and leukemia. The studies design delivery system of drug molecules by transferrin-mediated, so the mechanism between FA and protein provides a new thought to design delivery system of drug molecule for Tf.The paper investigates the interaction of FA with Tf by using fluorescence quenching, thermodynamics, synchronous fluorescence and circular dichroism(CD) under the pH 7.4 and 4.8 at 15℃,25℃,37℃. The results show that FA has a strong affinity under different pH and temperatures as a static quenching process, it releases FA in tumor cell at low temperature. It is mainly hydrogen bonding and van der Waals force under pH 7.4. FA reduces the Tf of α-helix structure, and make the structure of protein become more loose at pH 7.4. It is mainly hydrophobic forces at pH 4.8. FA increases α-helix structure of Tf, and make the structure of protein become more closely at pH 4.8.The results of study on mechanism of FA with Tf show that the binding of FA with Tf achieves targeted transport process. To further understand the storage and transportation process FA in the body, it investigates the interaction of FA with HSA by using fluorescence quenching, thermodynamics, synchronous fluorescence and CD. The results show that FA had fluorescence quenching as static quenching process for HSA under different pH and temperature, it is difficult to release FA. It is mainly hydrogen bonding and van der Waals force under pH 7.4. FA increases the HSA of α-helix structure, and make the structure of protein become more closely at pH 7.4. It is mainly hydrophobic forces at pH 4.8. FA reduces α-helix structure of Tf, and make the structure of protein become more loose at pH 4.8.