Analysis of the N‑Glycoforms and Immunoactivity of Chinese Yam (Dioscorea opposita Thunb.) Glycoprotein 30CYGP

• Published in: Journal of proteome research 2020-01, Vol.19 (1), p.28-35
• Main Authors: Li, Cheng, Lu, Yu, Chen, Xiaoyi, Yang, Meifang, Zou, Zihua, Han, Jianli, Gao, Xi, Tang, Rui, Wang, Chengjian, Huang, Linjuan, Wang, Zhongfu
• Format: Article
• Language: English
• ISSN: 1535-3893; 1535-3907
• DOI: 10.1021/acs.jproteome.9b00102

The major protein in Chinese yam (Dioscorea opposita Thunb.) glycoprotein, 30CYGP, exhibits strong immunomodulatory activities. Research has identified the sequence and structure of 30CYGP; however, 30CYGP N-glycoform composition and immunoactivity remain unknown. We isolated and purified 30CYGP from Chinese yam and used that material to release the N-glycans contained within. The N-glycans were labeled with 1-phenyl-3-methyl-5-pyrazolone and analyzed via ESI-MS and online LC–MS. Additionally, the immunoactivities of 30CYGP and de-glycosylated 30CYGP in the RAW264.7 cell line were investigated. Six 30CYGP N-glycans were observed in total, in which three were modified with xylose (XM: 40%) and three with xylose and fucose (XFM: 60%). Furthermore, de-glycosylated 30CYGP had significantly weaker immunoactivity than 30CYGP. This study demonstrated that novel N-glycoforms may enhance 30CYGP immunoactivity. Further research on the role of varied glycosylation patterns in immunoactivity is needed.