Extracellular domain of myelin oligodendrocyte glycoprotein (MOG) exhibits solvent-dependent conformational
Maria Ngu-Schwemlein1, Michele Corzett, Kevin H Thornton
1Department of Chemistry, University of South Alabama, Mobile, AL 36688, USA.
Protein and Peptide Letters
|October 17, 2003
Abstract:
The conformation of the non-glycosylated recombinant form of the extracellar domain of rat MOG (rMOG(1-125)) dissolved in different solvent conditions was studied by CD spectroscopy. The results show that rMOG(1-125) exhibits a predominantly beta sheet conformation in aqueous buffer solution at pH 7.5 and that this 'beta-form' is stabilized by zwitterionic phospholipids, DPC and LPCP. The alpha helical content of the protein can increase from 9% to up to 20% when TFE or anionic detergent LPAP and SDS are added.
Insights
The extracellular domain of rat myelin oligodendrocyte glycoprotein (rMOG) adopts a beta sheet structure in solution, stabilized by phospholipids. Detergents and TFE can increase its alpha-helical content.
Area of Science:
- Biochemistry
- Structural Biology
- Neuroscience
Background:
- Myelin oligodendrocyte glycoprotein (MOG) is a key component of the myelin sheath in the central nervous system.
- Understanding MOG's structure is crucial for deciphering its role in myelin formation and autoimmune diseases like multiple sclerosis.
Purpose of the Study:
- To investigate the conformational properties of the non-glycosylated extracellular domain of rat MOG (rMOG(1-125)).
- To determine how different solvent conditions affect the secondary structure of rMOG(1-125).
Main Methods:
- Circular Dichroism (CD) spectroscopy was employed to analyze protein conformation.
- rMOG(1-125) was studied in various solvent conditions, including aqueous buffers, zwitterionic phospholipids (DPC, LPCP), and anionic detergents (LPAP, SDS), with and without TFE.
Main Results:
- rMOG(1-125) predominantly adopts a beta sheet conformation in aqueous buffer at pH 7.5.
- Zwitterionic phospholipids (DPC, LPCP) stabilize this beta-sheet 'beta-form'.
- Addition of TFE or anionic detergents (LPAP, SDS) increased the alpha-helical content from 9% to up to 20%.
Conclusions:
- The conformation of rMOG(1-125) is sensitive to its surrounding environment.
- Phospholipids play a role in stabilizing the beta-sheet structure of MOG.
- Solvent conditions can induce significant conformational changes, favoring alpha-helical structures.
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