Related Experiment Videos
X-ray diffraction analysis of myelin lipid/proteolipid protein multilayers
F R Brown1, J Karthigasan, I Singh
1Department of Pediatrics, Medical University of South Carolina, Charleston.
Journal of Neuroscience Research
|October 1, 1989
Summary
Myelin proteolipid protein (PLP) integrates into lipid bilayers, disrupting hydrocarbon chain packing but not mediating membrane adhesion in the central nervous system (CNS). This suggests PLP does not stabilize adjacent myelin membranes.
Area of Science:
- Biophysics
- Neuroscience
- Structural Biology
Background:
- Myelin proteolipid protein (PLP) is a major integral membrane protein in the central nervous system (CNS) myelin.
- Its role in mediating adhesion between apposed myelin membranes is proposed but not fully understood.
Purpose of the Study:
- To investigate the structural role of PLP in myelin membrane interactions.
- To determine if PLP contributes to the adhesion of neighboring CNS myelin membranes.
Main Methods:
- X-ray diffraction studies were performed on model bilayers.
- Model bilayers consisted of total myelin lipids reconstituted with proteolipid apoprotein (PLP).
- Both multilamellar vesicles and oriented multilayers were analyzed.
Main Results:
- Incorporation of PLP into myelin lipid bilayers did not significantly alter the lamellar period (65-71 Å).
- PLP incorporation weakened and disordered the lateral packing of lipid chains within the bilayers.
- No evidence was found for PLP extending into the interbilayer spaces or forming stabilizing contacts between membranes.
Conclusions:
- PLP integrates into the lipid bilayer, affecting lipid chain organization but not mediating intermembrane adhesion.
- The hypothesis that PLP underlies the adhesion of neighboring CNS myelin membranes is not supported by these findings.