Dhingra Shruti, Morita Masamune, Yoda Tsuyoshi, Vestergaard Mun'delanji C, Hamada Tsutomu, Takagi Masahiro
School of Material Science, Japan Advanced Institute of Science and Technology, Asahidai Nomi Ishikawa 923-1292, Japan.
Materials (Basel). 2013 Jun 19;6(6):2522-2533. doi: 10.3390/ma6062522.
It is important to understand the physicochemical mechanisms that are responsible for the morphological changes in the cell membrane in the presence of various stimuli such as osmotic pressure. Lipid rafts are believed to play a crucial role in various cellular processes. It is well established that Ctb (Cholera toxin B subunit) recognizes and binds to GM1 (monosialotetrahexosylganglioside) on the cell surface with high specificity and affinity. Taking advantage of Ctb-GM1 interaction, we examined how Ctb and GM1 molecules affect the dynamic movement of liposomes. GM1 a natural ligand for cholera toxin, was incorporated into liposome and the interaction between fluorescent Ctb and the liposome was analyzed. The interaction plays an important role in determining the various surface interaction phenomena. Incorporation of GM1 into membrane leads to an increase of the line tension leading to either rupture of liposome membrane or change in the morphology of the membrane. This change in morphology was found to be GM1 concentration specific. The interaction between Ctb-GM1 leads to fast and easy rupture or to morphological changes of the liposome. The interactions of Ctb and the glycosyl chain are believed to affect the surface and the curvature of the membrane. Thus, the results are highly beneficial in the study of signal transduction processes.
了解在诸如渗透压等各种刺激存在下导致细胞膜形态变化的物理化学机制非常重要。脂筏被认为在各种细胞过程中起着关键作用。众所周知，霍乱毒素B亚基（Ctb）能以高特异性和亲和力识别并结合细胞表面的GM1（单唾液酸四己糖神经节苷脂）。利用Ctb与GM1的相互作用，我们研究了Ctb和GM1分子如何影响脂质体的动态运动。GM1是霍乱毒素的天然配体，被整合到脂质体中，并分析了荧光Ctb与脂质体之间的相互作用。这种相互作用在确定各种表面相互作用现象中起着重要作用。将GM1整合到膜中会导致线张力增加，从而导致脂质体膜破裂或膜形态改变。发现这种形态变化具有GM1浓度特异性。Ctb与GM1之间的相互作用导致脂质体快速且容易破裂或形态改变。Ctb与糖基链的相互作用被认为会影响膜的表面和曲率。因此，这些结果对信号转导过程的研究非常有益。
