Interaction forces and adhesion of supported myelin lipid bilayers modulated by myelin basic protein
Force-distance measurements between supported lipid bilayers mimicking the cytoplasmic surface of myelin at various surface coverages of myelin basic protein (MBP) indicate that maximum adhesion and minimum cytoplasmic spacing occur when each negative lipid in the membrane can bind to a positive arg...
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Published in | Proceedings of the National Academy of Sciences - PNAS Vol. 106; no. 9; pp. 3154 - 3159 |
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Main Authors | , , , , , |
Format | Journal Article |
Language | English |
Published |
United States
National Academy of Sciences
03.03.2009
National Acad Sciences |
Subjects | |
Online Access | Get full text |
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Summary: | Force-distance measurements between supported lipid bilayers mimicking the cytoplasmic surface of myelin at various surface coverages of myelin basic protein (MBP) indicate that maximum adhesion and minimum cytoplasmic spacing occur when each negative lipid in the membrane can bind to a positive arginine or lysine group on MBP. At the optimal lipid/protein ratio, additional attractive forces are provided by hydrophobic, van der Waals, and weak dipolar interactions between zwitterionic groups on the lipids and MBP. When MBP is depleted, the adhesion decreases and the cytoplasmic space swells; when MBP is in excess, the bilayers swell even more. Excess MBP forms a weak gel between the surfaces, which collapses on compression. The organization and proper functioning of myelin can be understood in terms of physical noncovalent forces that are optimized at a particular combination of both the amounts of and ratio between the charged lipids and MBP. Thus loss of adhesion, possibly contributing to demyelination, can be brought about by either an excess or deficit of MBP or anionic lipids. |
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Bibliography: | ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 Author contributions: Y.M., K.K., J.A.Z., and J.I. designed research; Y.M. and K.K. performed research; J.M.B. and C.H. contributed new reagents/analytic tools; Y.M., K.K., and J.I. analyzed data; and Y.M., K.K., J.M.B., C.H., J.A.Z., and J.I. wrote the paper. Contributed by Jacob Israelachvili, December 23, 2008 |
ISSN: | 0027-8424 1091-6490 |
DOI: | 10.1073/pnas.0813110106 |