Moroz J D, Nelson P
Department of Physics and Astronomy, University of Pennsylvania, Philadelphia 19104, USA.
Biophys J. 1997 May;72(5):2211-6. doi: 10.1016/S0006-3495(97)78864-7.
Zhelev and Needham have recently created large, quasistable pores in artificial lipid bilayer vesicles. Initially created by electroporation, the pores remain open for up to several seconds before quickly snapping shut. This result is surprising, in light of the large line tension for holes in bilayer membranes and the rapid time scale for closure of large pores. We show how pores can be dynamically stabilized via a new feedback mechanism. We also explain quantitatively the observed sudden pore closure as a tangent bifurcation. Finally, we show how Zhelev and Needham's experiment can be used to measure accurately the pore line tension, an important material parameter. For their stearoyloleoylphosphatidylcholine/cholesterol mixture we obtain a line tension of 2.6 x 10(-6) dyn.
泽列夫和尼达姆最近在人工脂质双层囊泡中制造出了大的准稳定孔。这些孔最初是通过电穿孔形成的,在迅速关闭之前能保持开放长达数秒。鉴于双层膜中孔的线张力很大以及大孔关闭的时间尺度很快,这个结果令人惊讶。我们展示了如何通过一种新的反馈机制动态稳定孔。我们还定量解释了观察到的突然孔关闭是一种切线分岔。最后,我们展示了泽列夫和尼达姆的实验如何能够精确测量孔线张力,这是一个重要的材料参数。对于他们的硬脂酰油酰磷脂酰胆碱/胆固醇混合物,我们得到的线张力为2.6×10⁻⁶达因。