The CNS Myelin Proteome: Deep Profile and Persistence After Post-mortem Delay.

Area of Science:

• Neuroscience
• Proteomics
• Biochemistry

Background:

• Myelin membranes are primarily lipid-rich, with historically underestimated protein complexity.
• Recent discoveries indicate a broader spectrum of myelin-associated proteins beyond the major components.

Purpose of the Study:

• To conduct a deep qualitative and quantitative proteomic analysis of purified CNS myelin from healthy mice.
• To establish a comprehensive proteome resource for CNS myelin.
• To investigate the correlation between myelin proteome, mRNA, and oligodendrocyte protein abundance.

Main Methods:

• Biochemical purification of myelin from healthy c56Bl/6N mouse brains.
• Gel-free, label-free mass spectrometry for deep proteomic coverage.
• Comparison with existing datasets on mRNA and protein abundance.

Main Results:

• Identified major myelin proteins: Proteolipid protein (PLP) (38%), Myelin basic protein (MBP) (30%), 2',3'-cyclic nucleotide 3'-phosphodiesterase (CNP) (5%), and Myelin oligodendrocyte glycoprotein (MOG) (1%).
• Revealed a dynamic range of protein abundance exceeding four orders of magnitude.
• Demonstrated minimal changes in myelin proteome even after a 6-hour post-mortem delay.

Conclusions:

• The study presents the most extensive proteome resource of CNS myelin to date.
• Findings highlight the significant underrepresentation of less abundant myelin proteins in previous studies.
• This resource serves as a foundation for studying myelin heterogeneity in neurological disorders.