The effect of hydrostatic pressure on model membrane domain composition and lateral compressibility. Issue 1 (25th November 2015)

• Record Type: Journal Article
• Authors: Barriga, H. M. G.; Law, R. V.; Seddon, J. M.; Ces, O.; Brooks, N. J.
• Is Part Of: Physical chemistry chemical physics. Volume 18:Issue 1(2016)
• Page Start: 149
• Page End: 155
• Publication Date: 2015-11-25
• Subjects: Chemistry, Physical and theoretical -- Periodicals; 541.3
• DOI: 10.1039/c5cp04239a
• Languages: English
• ISSNs: 1463-9076

Abstract

Abstract : We distinguish the liquid ordered and liquid disordered phases in diffraction patterns of biphasic mixtures, comparing their lateral compressibility and report the variations in the two phase region with increasing hydrostatic pressure. Abstract : Phase separation in ternary model membranes is known to occur over a range of temperatures and compositions and can be induced by increasing hydrostatic pressure. We have used small angle X-ray scattering (SAXS) to study phase separation along pre-determined tie lines in dioleoylphosphatidylcholine (DOPC), dipalmitoylphosphatidylcholine (DPPC) and cholesterol (CHOL) mixtures. We can unequivocally distinguish the liquid ordered (Lo ) and liquid disordered (Ld ) phases in diffraction patterns from biphasic mixtures and compare their lateral compressibility. The variation of tie line endpoints with increasing hydrostatic pressure was determined, at atmospheric pressure and up to 100 MPa. We find an extension and shift of the tie lines towards the DOPC rich region of the phase diagram at increased pressure, this behaviour differs slightly from that reported for decreasing temperature.