title: Molecular mechanism investigation of the neutralization of cadmium toxicity by transferrin.
abstract: Cadmium adversely affects the biological function of the liver. Transferrin might be involved in the detoxification system of cadmium. However, owing to the lack of investigation of the molecular mechanism of cadmium conjugating to transferrin, the role of transferrin in cadmium detoxification in the liver and how transferrin undergoes conformational and functional changes upon cadmium binding are not clear. In this article, we demonstrated the potential role of transferrin in the protection of the mouse primary hepatocytes against cadmium toxicity. After the incubation of hepatocytes with 10 and 100 μM CdCl2, pretreatment with transferrin significantly attenuated the reduction of cell viability in comparison with the samples treated with CdCl2 alone. Furthermore, a detailed molecular mechanism investigation of the interaction of CdCl2 with transferrin was reported using biophysical methods. Multi-spectroscopic measurements showed that CdCl2 formed complexes with transferrin and caused structural and conformational changes of transferrin. Isothermal titration calorimetry measurements revealed that transferrin has two classes of binding sites with different binding constants for CdCl2 binding. Hydrophobic forces and electrostatic forces are the major driving forces of the interaction. Preferred specific binding sites on transferrin were identified by dialysis experiments, molecular docking studies and molecular dynamics simulations. Upon low CdCl2 concentration exposure, no content of iron was released from transferrin because CdCl2 preferentially binds to the surface of transferrin molecules. Upon higher CdCl2 concentration exposure, the release of iron content from transferrin was observed due to the interaction of CdCl2 with the key residues around iron binding sites.
authors.affiliation: Shandong Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, China-America CRC for Environment & Health, Shandong Province, 27# Shanda South Road, Jinan 250100, P. R. China. rutaoliu@sdu.edu.cn.
authors.forename: Jing
authors.initials: J
authors.lastname: Wang
authors.affiliation: College of Chemistry Chemical Engineering and Material Science, Zaozhuang University, Zaozhuang, Shandong 277160, China.
authors.forename: Jinhu
authors.initials: J
authors.lastname: Wang
authors.affiliation: Shandong Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, China-America CRC for Environment & Health, Shandong Province, 27# Shanda South Road, Jinan 250100, P. R. China. rutaoliu@sdu.edu.cn.
authors.forename: Wei
authors.initials: W
authors.lastname: Song
authors.affiliation: Shandong Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, China-America CRC for Environment & Health, Shandong Province, 27# Shanda South Road, Jinan 250100, P. R. China. rutaoliu@sdu.edu.cn.
authors.forename: Xinping
authors.initials: X
authors.lastname: Yang
authors.affiliation: College of Population, Resources and Environment, Shandong Normal University, 88# East Wenhua Road, Jinan 250014, P. R. China.
authors.forename: Wansong
authors.initials: W
authors.lastname: Zong
authors.affiliation: Shandong Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, China-America CRC for Environment & Health, Shandong Province, 27# Shanda South Road, Jinan 250100, P. R. China. rutaoliu@sdu.edu.cn.
authors.forename: Rutao
authors.initials: R
authors.lastname: Liu
mesh_terms: D000818:Animals; D019256:Cadmium Chloride / Q000737:chemistry / Q000378:metabolism* / Q000633:toxicity*; D002470:Cell Survival / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D022781:Hepatocytes / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism*; D008658:Inactivation, Metabolic; D051379:Mice; D008810:Mice, Inbred C57BL; D062105:Molecular Docking Simulation; D056004:Molecular Dynamics Simulation; D013329:Structure-Activity Relationship; D013816:Thermodynamics; D014168:Transferrin / Q000737:chemistry / Q000378:metabolism*
chemical_list: D014168:Transferrin; D019256:Cadmium Chloride