A detailed analysis of partial molecular volumes in DPPC/cholesterol binary bilayers
Autor: | J. Peter Slotte, Satoru Kato, Tsubasa Miyoshi, Max Lönnfors |
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Jazyk: | angličtina |
Předmět: |
Buoyant density measurement
Cholesterol Liquid ordered phase Bilayer Biophysics Analytical chemistry Liquid-ordered phase DPPC/cholesterol binary bilayer Partial molecular volume Ld/Lo phase coexistence Cell Biology Biochemistry Fluorescence chemistry.chemical_compound Fluorescence decay Volume (thermodynamics) chemistry Dipalmitoylphosphatidylcholine Phase (matter) Molecule lipids (amino acids peptides and proteins) |
Zdroj: | Biochimica et Biophysica Acta (BBA) - Biomembranes. (12):3069-3077 |
ISSN: | 0005-2736 |
DOI: | 10.1016/j.bbamem.2014.07.004 |
Popis: | We examined the volumetric behavior of the dipalmitoylphosphatidylcholine (DPPC)/cholesterol binary bilayer system with high accuracy and more cholesterol concentrations to reveal the detailed molecular states in the liquid-disordered (Ld) phase, the liquid-ordered (Lo) phase and the gel phase. We measured the average specific volume of the binary bilayer at several temperatures by the neutral flotation method and calculated the average volume per molecule to estimate the partial molecular volumes of DPPC and cholesterol in each phase. As a result, we found that the region with intermediate cholesterol concentrations showed a more complicated behavior than expected from simple coexistence of Ld and Lo domains. We also measured fluorescence decay of trans-parinaric acid (tPA) added into the binary bilayer with more cholesterol concentrations to get further insight into the cholesterol-induced formation of the Lo phase. On the basis of these results we discuss the molecular interaction between DPPC and cholesterol molecule in the Lo phase and the manner of Ld/Lo phase coexistence. |
Databáze: | OpenAIRE |
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