Abstract
Ultrasonic and calorimetric studies of small homogenously-sized DMPC unilamellar vesicles showed two thermal transitions at temperatures T c1 and T c2 (T c2 ≥T c1 ); T c2 is close to the phase transition temperature, T c , of large vesicles. The process at T c2 is not a fusion of vesicles and is interpreted as characterizing an order-disorder transition essentially similar to that of large vesicles. The temperatures T c1 and T c2 become increasingly similar as the cholesterol content is increased, while the clusters at T c2 (≅85 lipid molecules in pure DMPC) increase in size up to approximately 180 lipid molecules at 12 mol% cholesterol. Incorporation of cholesterol thus brings about enhanced fluctuations in this model system of a membrane.
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Abbreviations
- DMPC:
-
dimyristoylphosphatidylcholine
- SUV:
-
small unilamellar vesicles
- LUV:
-
large unilamellar vesicles
- MLV:
-
multilamellar vesicles
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Michels, B., Fazel, N. & Cerf, R. Enhanced fluctuations in small phospholipid bilayer vesicles containing cholesterol. Eur Biophys J 17, 187–190 (1989). https://doi.org/10.1007/BF00284724
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DOI: https://doi.org/10.1007/BF00284724