Vesicles surfing on a lipid bilayer: Self-induced haptotactic motion
Vesicles surfing on a lipid bilayer: Self-induced haptotactic motion
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DOI：
10.1073/pnas.0601400103
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发表时间：
2006-08-15
影响因子：
11.1
通讯作者：
Bassereau, Patricia
中科院分区：
文献类型：
--
作者：
Solon, Jerome;Streicher, Pia;Bassereau, Patricia
趋触性是20世纪60年代末提出的一种解释细胞运动的机制。它描述了由粘附梯度诱导的细胞运动。在这项工作中，我们提出的证据selfinduced haptotaxis使用带负电荷的巨囊泡相互作用，带正电荷的支持脂质双层，这是以前没有描述。根据囊泡的电荷，我们观察到不同的行为。在低电荷下，不发生粘附。在高电荷下，囊泡粘附但不移动。在一个有限的范围内的中间电荷密度，我们发现，囊泡自发移动的速度为每秒几微米的顺序超过100 μ m的距离。我们发现，巨囊泡和支持的脂质双层之间的局部脂质转移发生在粘附，打破对称性，并诱导横向电荷梯度。这种电荷梯度使巨囊泡极化并诱导其运动。为了解释我们的观察结果，我们提出了一个缩放模型，涉及的粘附能的速度囊泡运动和特征脂质转移时间。我们的测量结果表明，有效的粘附能强烈减少的抗衡离子，这是动态捕获之间的囊泡和支持的双层。
Haptotaxis is a mechanism proposed at the end of the 1960s to explain cell motility. It describes cell movement induced by an adhesion gradient. In this work, we present evidence for selfinduced haptotaxis using negatively charged giant vesicles interacting with positively charged supported lipid bilayers, which has not been previously described. Depending on the charge of the vesicle, we observed different behaviors. At low charge, no adhesion occurs. At high charge, the vesicle adheres but does not move. In a restricted range of intermediate charge densities, we found that the vesicle moves spontaneously with velocities of the order of a few micrometers per second over distances of > 100 mu m. We show that a local lipid transfer between the giant vesicle and the supported lipid bilayer takes place during the adhesion, breaking the symmetry and inducing a lateral charge gradient. This charge gradient polarizes the giant vesicle and induces its motion. To explain our observations, we propose a scaling model that relates the adhesion energy to the velocity of vesicle motion and to the characteristic lipid transfer time. Our measurements indicate that the effective adhesion energy is strongly reduced by counterions, which are dynamically trapped between the vesicle and the supported bilayer.