1. School of Food Science and Engineering; South China University of Technology; Guangzhou 510640 China
2. Institute of Structural Biology; Helmholtz Zentrum München; Ingolstädter Landstraße 1 D-85764 Germany
3. State Key Laboratory of Respiratory Disease; Guangzhou Institutes of Biomedicine and Health; Chinese Academy of Sciences; Guangzhou 510530 China
4. Department of Biochemistry; University of Kassel; Heinrich-Plett-Str. 40 34132 Kassel Germany