PDF(Pubmed)
Abstract：
Topological transitions of lipid membranes are ubiquitous in key biological processes for cell life, like neurotransmission, fertilization, morphogenesis, and viral infections. Despite this, they are not well understood due to their multiscale nature, which limits the use of molecular models and calls for a mesoscopic approach such as the celebrated Canham-Helfrich one. Unfortunately, such a model cannot handle topological transitions, hiding the crucial involved forces and the appearance of the experimentally observed hemifused intermediates. In this work, we describe the membrane as a diffuse interface preserving the Canham-Helfrich elasticity. We show that pivotal features of the hemifusion pathway are captured by this mesoscopic approach, e.g. a (meta)stable hemifusion state and the fusogenic behavior of negative monolayer spontaneous curvatures. The membrane lateral stress profile is calculated as a function of the elastic rigidities, yielding a coarse-grained version of molecular models findings. Insights into the fusogenic mechanism are reported and discussed.
摘要：
脂质膜的拓扑转变在细胞生命的关键生物过程中无处不在，比如神经传递，受精,形态发生,和病毒感染。尽管如此,由于它们的多尺度性质，它们没有被很好地理解，这限制了分子模型的使用，并要求采用介观方法，例如著名的Canham-Helfrich方法。不幸的是,这样的模型不能处理拓扑转换，隐藏了关键的参与力和实验观察到的半折叠中间体的外观。在这项工作中,我们将膜描述为保留Canham-Helfrich弹性的扩散界面。我们表明，半融合通路的关键特征被这种介观方法捕获，例如（元）稳定的半融合状态和负单层自发曲率的融合行为。膜横向应力分布是根据弹性刚度计算的，产生分子模型结果的粗粒度版本。报道和讨论了对融合机制的见解。
