Tension-induced morphological transition in mixed lipid bilayers(Poster session 1, New Frontiers in Colloidal Physics : A Bridge between Micro- and Macroscopic Concepts in Soft Matter)

Abstract

近年、Rozovskyらは脂質二重膜における、超構造のダイナミクスについて報告した[1]。彼らは固体基板上に吸着したベシクルのドメインが、時間の経過とともにストライプ構造からヘキサゴナル構造へ転移することを蛍光顕微鏡により観察した。我々はこの構造転移がベシクルの吸着に伴う表面張力の増加に起因すると考え、曲率と組成が結合するモデルを提案する。その結果、図2のように張力の増加と転移の順序が対応していることを示す[2]。また張力の増加による転移を数値シミュレーションにより確認する。

Raft domains in biological cell membranes are associated with membrane signaling pathways and have attracted great deal of interest in recent years. Due to the complexity of biological membranes, a minimal model to investigate rafts (or more precisely, domain formation) consists of three-component lipid bilayers containing saturated and unsaturated lipids as well as cholesterol. These three-component systems have been investigated both at the air-water interface and in artificial vesicles. Complex phase separation and appearance of domains have been observed using fluorescence techniques. Such a phase separation occurs between a liquid-disordered phase rich in unsaturated lipid and a liquid-ordered phase rich in saturated lipid and cholesterol.