A molecular mechanism for how pressure induces interdigitation of phospholipid bilayer membranes.

Autor: Goto M; Department of Bioengineering, Division of Bioscience and Bioindustry, Graduate School of Technology, Industrial and Social Sciences, Tokushima University, 2-1 Minamijosanjima-cho, Tokushima 770-8513, Japan., Yoshida S; Department of Biological Science and Technology, Graduate School of Advanced Technology and Science, Tokushima University, 2-1 Minamijosanjima-cho, Tokushima 770-8506, Japan., Habara S; Department of Biological Science and Technology, Graduate School of Advanced Technology and Science, Tokushima University, 2-1 Minamijosanjima-cho, Tokushima 770-8506, Japan., Wilk-Kohlbrecher A; Laboratory for Neutron Scattering and Imaging, Paul Scherrer Institute, CH-5232, Villigen PSI, Switzerland., Kohlbrecher J; Laboratory for Neutron Scattering and Imaging, Paul Scherrer Institute, CH-5232, Villigen PSI, Switzerland., Tamai N; Department of Bioengineering, Division of Bioscience and Bioindustry, Graduate School of Technology, Industrial and Social Sciences, Tokushima University, 2-1 Minamijosanjima-cho, Tokushima 770-8513, Japan. Electronic address: tamai@tokushima-u.ac.jp., Matsuki H; Department of Bioengineering, Division of Bioscience and Bioindustry, Graduate School of Technology, Industrial and Social Sciences, Tokushima University, 2-1 Minamijosanjima-cho, Tokushima 770-8513, Japan.
Jazyk: angličtina
Zdroj: Biochimica et biophysica acta. Biomembranes [Biochim Biophys Acta Biomembr] 2024 Dec; Vol. 1866 (8), pp. 184385. Date of Electronic Publication: 2024 Sep 28.
DOI: 10.1016/j.bbamem.2024.184385
Abstrakt: The phase transition from the ripple gel phase to the interdigitated gel phase of bilayers of phosphatidylcholines (PCs) with two saturated long-chain fatty acids under high pressure was investigated by pressure-scanning microscopy, fluorometry, and dynamic light scattering (DLS) measurements. Microscopic observation for giant vesicles (GVs) of distearoyl-PC (DSPC) under high pressure showed that spherical GVs transforms significantly into warped and distorted spherical ones instantaneously at the pressure-induced interdigitation. The fluorescence intensities of amphiphilic probe Prodan and hydrophobic probe Laurdan in the dipalmitoyl-PC (DPPC) bilayer steeply decreased and increased, respectively, at the interdigitation, suggesting that the conformational change of the polar head group of DPPC molecule in the bilayer transiently occurred at the interdigitation. Further, it was found from the high-pressure DLS measurements that the size of the vesicle particles of the DPPC and DSPC transiently increases near the interdigitation pressure, whereas the chemically induced interdigitation by adding ethanol to the DSPC bilayer membrane under atmospheric pressure produce no such change in the particle size. Taking account of the critical packing parameter of the PC molecule, the above experimental results would lead us to the conclusion that the pressure-induced interdigitation is attributable to the increase in repulsive interaction between the polar head groups of the PC molecules resulting from the orientational change of the head group from a parallel alignment to a perpendicular one with respect to the bilayer surface by applying pressure, namely the transient state: it occurs when the repulsive interaction exceeds a threshold value for the balance between the repulsive interaction and the attractive interaction among the hydrophobic acyl chains.
Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
(Copyright © 2024 Elsevier B.V. All rights reserved.)
Databáze: MEDLINE
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