Imperative role of glycosylation in human MOG-HLA interaction: molecular insights of MOG-Ab associated demyelination

Abstract

Myelin oligodendrocyte glycoprotein is a transmembrane protein found on the outer lamella of the myelin sheath. The autoimmune attack on the MOG leads to demyelination which differs from normal multiple sclerosis. MOG has three epitope regions MOG_1–22, MOG_35–55, and MOG_92–106 in the extracellular region, and the crucial MOG_35–55 epitope and Human Leukocyte Antigen (HLA) interaction is the initial step for autoantibody generation. To study the effective role of glycosylation in MOG-HLA interaction, we performed molecular dynamics simulations of the complex where HLA interacts with three MOG epitopes both in the absence and presence of glycan. The results projected that the epitope MOG_1–22 is decisive for the HLA interaction in the absence of glycan and HLA interacts with the epitope MOG_35–55 irrespective of glycan existence. The residues Arg9, Arg46, and Arg66 were found to interact strongly with HLA even in the presence of glycan. The glycan increased the flexibility of hMOG and enhanced the interaction of MOG with water molecules.

Graphical Abstract

Communicated by Ramaswamy H. Sarma

Keywords:

• Myelin oligodendrocyte glycoprotein
• human leukocyte antigen
• demyelination
• glycosylation
• docking
• Rosetta
• AMBER

Acknowledgements

The authors thank the funding agency for the financial support and also acknowledge the support from SASTRA Deemed to be University for providing the necessary computational facilities.

Disclosure statement

No potential conflict of interest was reported by the authors.

Author’s contribution

LR conceived and designed the study. PJ, RM, and LR performed docking, simulations, and collected data. LR analyzed the data. All authors discussed the results. LR wrote the manuscript and revised it.

Additional information

Funding

This work was supported by the Science and Engineering Research Board (SERB), Government of India (ECR/2017/000192).