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Phospholipid vesicle aggregation induced by human myelin basic protein
Abstract:
Human myelin basic protein isolated from the brains of individuals who died with multiple sclerosis was more potent in inducing the aggregation of egg phosphatidylcholine vesicles than was the basic protein isolated from the brains of normal individuals. The portion of myelin basic protein which bound to egg phosphatidylcholine vesicles was separated from the free protein by sucrose density gradient centrifugation. Similar amounts of basic protein from normal or from multiple sclerosis brains are bound to the lipid and no consistent differences in the NG, N'G dimethyl-arginine content of the protein fractions have been found.
Insights
Multiple sclerosis (MS) brain protein more effectively clumps lipid vesicles than normal brain protein. This difference in myelin basic protein potency was observed despite similar binding amounts and arginine content.
Area of Science:
- Neuroscience
- Biochemistry
- Lipid Bilayer Interactions
Background:
- Multiple sclerosis (MS) is a demyelinating disease affecting the central nervous system.
- Myelin basic protein (MBP) is a major component of myelin sheath.
- Alterations in MBP may contribute to myelin damage in MS.
Purpose of the Study:
- To investigate the effect of MBP from multiple sclerosis (MS) brains on lipid vesicle aggregation compared to MBP from normal brains.
- To determine if differences in MBP potency correlate with binding affinity or post-translational modifications.
Main Methods:
- Isolation of human myelin basic protein (MBP) from both multiple sclerosis (MS) and normal individuals' brains.
- Incubation of MBP with egg phosphatidylcholine vesicles to assess aggregation.
- Separation of bound and free MBP using sucrose density gradient centrifugation.
- Analysis of NG, N'G dimethyl-arginine content in MBP fractions.
Main Results:
- MBP isolated from MS brains demonstrated higher potency in inducing phosphatidylcholine vesicle aggregation than MBP from normal brains.
- Similar quantities of MBP from both normal and MS brains were found to bind to the lipid vesicles.
- No significant differences in NG, N'G dimethyl-arginine content were detected between the bound MBP fractions.
Conclusions:
- Human myelin basic protein from multiple sclerosis brains exhibits increased potency in aggregating lipid vesicles.
- The enhanced aggregation potency of MS-derived MBP is not explained by differences in lipid binding affinity or NG, N'G dimethyl-arginine modification.