1. Key Laboratory of Biomedical Polymers of Ministry of Education & Department of Chemistry; Wuhan University; Wuhan 430072 P. R. China
2. State Key Laboratory of Molecular Vaccinology and Molecular Diagnostics & Center for Molecular Imaging and Translational Medicine; School of Public Health; Xiamen University; Xiamen 361102 P. R. China
3. The Institute for Advanced Studies; Wuhan University; Wuhan 430072 P. R. China
4. Hubei Provincial Cooperative Innovation Center of Industrial Fermentation; Wuhan 430068 P. R. China