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Updated: Jul 7, 2026
Characterization of Glycoproteins with the Immunoglobulin Fold by X-Ray Crystallography and Biophysical Techniques
Published on: July 5, 2018
Homogeneous sugar modification improves crystallization of measles virus hemagglutinin
Takao Hashiguchi1, Mizuho Kajikawa, Nobuo Maita
1Department of Virology, Faculty of Medicine, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, Fukuoka 812-8582, Japan.
Abstract:
Measles virus (MV) enters cells by binding to the signaling lymphocyte activation molecule (also called CD150) on the cell surface, and thus shows the lymphotropism and immunosuppressive effects. The head domain (residues Asp149 to Arg617) of the MV hemagglutinin (MV-H), the attachment protein, was produced using a transient expression system in HEK293T cells. The purified MV-H protein was heterogeneous because of a variety of complex-sugar modifications. The complex-sugar-type MV-H was crystallized successfully, and the crystals belonged to the space group P41212 with the unit cell dimension of a=b=134 A, c=100 A, but diffracted only to 3.0 A resolution. MV-H was also expressed in HEK293SGnTI(-) cells lacking the N-acetylglucosaminyltransferase I activity, which render N-linked glycans of the proteins restricted and homogeneous, producing the oligomannose, Man5GlcNAc2. The native and selenomethionyl derivative proteins of the oligomannose-type MV-H were crystallized, and the native crystals well diffracted to 2.6A resolution. Thus, homogeneous sugar modification may be useful for improved crystallization of heavily sugar-modified viral envelope proteins.
Insights
Homogeneous glycosylation of measles virus hemagglutinin (MV-H) protein aids crystallization. This finding is crucial for understanding viral entry and developing targeted therapies for measles virus infections.
Area of Science:
- Structural biology
- Virology
- Biochemistry
Background:
- Measles virus (MV) utilizes the signaling lymphocyte activation molecule (CD150) for cell entry, mediating lymphotropism and immunosuppression.
- The MV hemagglutinin (MV-H) protein is the viral attachment protein responsible for cell surface binding.
Purpose of the Study:
- To investigate the role of glycosylation in the crystallization of the MV-H protein.
- To obtain high-resolution structural data of MV-H for understanding measles virus-host interactions.
Main Methods:
- Production of MV-H head domain using transient expression in HEK293T cells.
- Crystallization attempts of both complex-sugar and homogeneous oligomannose-type MV-H.
- X-ray diffraction analysis of the obtained crystals.
Main Results:
- Complex-sugar-type MV-H crystallized but diffracted poorly (3.0 Å resolution).
- Oligomannose-type MV-H, produced in engineered cells, yielded crystals diffracting to 2.6 Å resolution.
- Homogeneous glycosylation significantly improved crystal quality and diffraction.
Conclusions:
- Homogeneous N-linked glycan modification is a viable strategy to enhance the crystallization of heavily glycosylated viral envelope proteins.
- Improved structural data of MV-H can facilitate the development of antiviral strategies.
