{"title":"Changes in free energy barrier for water permeation by stretch-induced phase transitions in phospholipid/cholesterol bilayers.","authors":"Taiki Shigematsu, Kenichiro Koshiyama","doi":"10.1080/07391102.2023.2250447","DOIUrl":null,"url":null,"abstract":"<p><p>Water permeation through phospholipid/cholesterol bilayers is the key to understanding tension-induced rupture of biological cell membranes. We performed molecular dynamics simulations of stretched phospholipid/cholesterol bilayers to investigate changes in the free energy profile of water molecules across the bilayer and the lipid structure responsible for water permeation. We modeled stretching of the bilayer by applying areal strain. In stretched phospholipid/cholesterol bilayers, the hydrophobic tail of the phospholipids became disordered and the free energy barrier to water permeation decreased. Upon exceeding the critical areal strain, a phase transition to an interdigitated gel phase occurred before rupture, and the hydrophobic tail ordering as well as the free energy barrier were restored. In pure phospholipid bilayers, we did not observe such recoveries. These transient recoveries in the phospholipid/cholesterol bilayer suppressed water permeation and membrane rupture, followed by an increase in the critical areal strain at which the bilayer ruptured. This result agrees with experimental results and provides a reasonable molecular mechanism for the toughness of phospholipid/cholesterol bilayers under tension.Communicated by Ramaswamy H. Sarma.</p>","PeriodicalId":15272,"journal":{"name":"Journal of Biomolecular Structure & Dynamics","volume":null,"pages":null},"PeriodicalIF":2.7000,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Biomolecular Structure & Dynamics","FirstCategoryId":"99","ListUrlMain":"https://doi.org/10.1080/07391102.2023.2250447","RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"2023/9/1 0:00:00","PubModel":"Epub","JCR":"Q3","JCRName":"BIOCHEMISTRY & MOLECULAR BIOLOGY","Score":null,"Total":0}
引用次数: 0
Abstract
Water permeation through phospholipid/cholesterol bilayers is the key to understanding tension-induced rupture of biological cell membranes. We performed molecular dynamics simulations of stretched phospholipid/cholesterol bilayers to investigate changes in the free energy profile of water molecules across the bilayer and the lipid structure responsible for water permeation. We modeled stretching of the bilayer by applying areal strain. In stretched phospholipid/cholesterol bilayers, the hydrophobic tail of the phospholipids became disordered and the free energy barrier to water permeation decreased. Upon exceeding the critical areal strain, a phase transition to an interdigitated gel phase occurred before rupture, and the hydrophobic tail ordering as well as the free energy barrier were restored. In pure phospholipid bilayers, we did not observe such recoveries. These transient recoveries in the phospholipid/cholesterol bilayer suppressed water permeation and membrane rupture, followed by an increase in the critical areal strain at which the bilayer ruptured. This result agrees with experimental results and provides a reasonable molecular mechanism for the toughness of phospholipid/cholesterol bilayers under tension.Communicated by Ramaswamy H. Sarma.
期刊介绍:
The Journal of Biomolecular Structure and Dynamics welcomes manuscripts on biological structure, dynamics, interactions and expression. The Journal is one of the leading publications in high end computational science, atomic structural biology, bioinformatics, virtual drug design, genomics and biological networks.