期刊
BIOCHEMICAL JOURNAL
卷 421, 期 -, 页码 87-96出版社
PORTLAND PRESS LTD
DOI: 10.1042/BJ20082170
关键词
arylphorin; ecdysone; glycosylation; protein stability; protein structure; X-ray crystallography
资金
- Korea Basic Science Institute (KBSI) [T27010]
Although N-glycosylation has been known to increase the stability of glycoproteins, it is difficult to assess the structural importance of glycans in the stabilization of glycoproteins. APA (Antheraea pernyi arylphorin) is an insect hexamerin that has two N-glycosylations at Asn(196) and Asn(344) respectively. The glycosylation of Asn(344) is critical for the folding process; however, glycosylation of Asn(196) is not. Interestingly, the N196-glycan (glycosylation of Asn(196)) remains in an immature form (Glc(1)Man(9)GlcNAc(2)). The mutation of Asn(196) to glutamine does not change the ecdysone-binding activity relative to that of the wild-type. In the present study, we determined the crystal structure of APA, and all sugar moieties of the N196-glycan were clearly observed in the electron-density map. Although the sugar moieties of the glycan generally have high structural flexibility, most sugar moieties of the N196-glycan were well organized in the deep cleft of the subunit interface and mediated many inter- and intra-subunit hydrogen bonds. Analytical ultracentrifugation and GdmCl (guanidinium chloride) unfolding experiments revealed that the presence of the N196-glycan was important for stabilizing the hexameric state and overall stability of APA respectively. Our results could provide a structural basis for studying not only other glycoproteins that carry an immature N-glycan, but also the structural role of N-glycans that are located in the deep cleft of a protein.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据