Mechanics of membrane bulging during cell-wall disruption in Gram-negative bacteria
Mechanics of membrane bulging during cell-wall disruption in Gram-negative bacteria
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DOI：
10.1103/physreve.83.041922
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发表时间：
2011-04-25
影响因子：
2.4
通讯作者：
Mukhopadhyay, Ranjan
中科院分区：
文献类型：
--
作者：
Daly, Kristopher E.;Huang, Kerwyn Casey;Mukhopadhyay, Ranjan
细菌细胞壁是一个由多肽交联的糖链网络，是承受渗透胁迫的主要结构。尽管它在细胞存活中很重要，但细胞壁对网络缺陷的鲁棒性一直相对未被探索。用抗生素万古霉素治疗革兰氏阴性细菌大肠杆菌，会破坏生长过程中新物质的交联，导致明显的凸起，最终导致细胞裂解。在这里，我们模拟了细胞质膜通过细胞壁上的孔膨胀的机制。我们发现膜在接近20 nm的临界孔半径处经历了近乎扁平状态和球形凸起之间的过渡。与邻近肽和聚糖链之间的典型距离相比，这个临界孔径较大，因此孔径大小对网络完整性起着约束作用。我们还讨论了我们的模型的一般含义膜变形真核泡和囊泡在红细胞。
The bacterial cell wall is a network of sugar strands crosslinked by peptides that serve as the primary structure for bearing osmotic stress. Despite its importance in cellular survival, the robustness of the cell wall to network defects has been relatively unexplored. Treatment of the Gram-negative bacterium Escherichia coli with the antibiotic vancomycin, which disrupts the crosslinking of new material during growth, leads to the development of pronounced bulges and eventually of cell lysis. Here, we model the mechanics of the bulging of the cytoplasmic membrane through pores in the cell wall. We find that the membrane undergoes a transition between a nearly flat state and a spherical bulge at a critical pore radius of similar to 20 nm. This critical pore size is large compared to the typical distance between neighboring peptides and glycan strands, and hence pore size acts as a constraint on network integrity. We also discuss the general implications of our model to membrane deformations in eukaryotic blebbing and vesiculation in red blood cells.