脂質二重層ドメインの質感

Uffe Bernchou¹, Jonathan Brewer, Henrik S Midtiby

¹Department of Physics and Chemistry, MEMPHYS-Center for Biomembrane Physics, University of Southern Denmark, Campusvej 55, DK-5230 Odense M, Denmark.

Journal of the American Chemical Society

|August 26, 2009

まとめ

脂質膜内のゲルドメインは,複雑な内部構造を示し,脂質の傾き方向が異なるサブドメインを明らかにします. これは,二重層の潜在的ヘクサティック・オーダーの持続性を示唆し,膜の組織と機能に影響を与える.

科学分野:

膜バイオフィジックス
脂質二層組織である.
柔らかい物質の物理学

背景:

脂質二重層の横向的な組織化は,生物学的機能にとって極めて重要です.
流体膜ドメインはよく研究されていますが,ゲルドメインの質感は未知のままです.
脂質の詰め込みと順序を理解することは,膜の性質の鍵です.

研究の目的:

バイナリ脂質膜のゲル領域内の内部質感と脂質傾斜の変動を調査する.
脂質二重層におけるヘクサティック・オーダーの存在の可能性を調査する.
ナノスケールでの脂質組織をマッピングするための高度なイメージング技術を適用する.

主な方法:

偏光二フォトン刺激顕微鏡を用いて,光脂質探査機"Laurdan"を使用した.
脂質の傾きをマッピングするために,極化角の関数として放射強度の変動を分析しました.
角強度の変動を定量化し,質感パターンを特定するためにフーリエ分解法を使用した.
汎用ポラライゼーション (GP) 関数を用いて量化された膜相状態.

主要な成果:

ゲルドメインは,異なる脂質の傾き方向を持つサブドメインで構成されており,異質な質感を示していることが発見されました.
ヘクサティック・オーダーされたモノレイヤーで見られるものと類似したテクスチャーパターンを観測した.
支持膜に対するGP分析の実現可能性を実証した.
構造の異質性にもかかわらず,個々のゲル領域内の均一な膜相状態が確認されました.

結論:

バイナリ脂質膜のゲルドメインは,脂質の傾きが異なるサブドメインを持つ異質な内部質感を有する.
観察された質感は,脂質二重層における六次順序の持続性を支持する証拠を提供します.
LaurdanベースのGP分析は,支えられた膜を特徴付けるのに有効な方法です.
膜相状態は,内部の質感に関係なく,ゲル領域内で空間的に均一である.

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