1. Key Laboratory of Intelligent Information Processing, Institute of Computing Technology, Chinese Academy of Sciences, 6 Kexueyuan South Road, Beijing 100080, China
2. University of Chinese Academy of Sciences, 19 Yuquan Road, Beijing 100049, China
3. Institute of Biophysics, Chinese Academy of Sciences, 15 Datun Road, Beijing 100101, China
4. Glycosciences Laboratory, Faculty of Medicine, Imperial College London, London W12 0NN, United Kingdom