Cavitation in lipid bilayers poses strict negative pressure stability limit in biological liquids
Cavitation in lipid bilayers poses strict negative pressure stability limit in biological liquids
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DOI：
10.1073/pnas.1917195117
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发表时间：
2020-05-19
影响因子：
11.1
通讯作者：
Netz, Roland R.
中科院分区：
文献类型：
--
作者：
Kanduc, Matej;Schneck, Emanuel;Netz, Roland R.
在负压下涉及液体的生物和技术过程很容易形成空洞。在植物中发现的最大负压约为-100巴，即使纯散装水中的空化只在相关时间尺度上的负压大得多的时候发生。在这里，我们调查了所有生物液体的两种成分--小溶质和脂双层对负压下空洞形成的影响。通过将分子动力学模拟与动力学建模相结合，我们在生物相关的长度尺度和时间尺度上量化了空化速率。我们发现，与小的溶质相比，脂双层可以增加空化的速度，而在大多数植物中发现的压力下，空化的速度仍然很低。只有当负压接近-100bar时，空化才会在生物相关的时间尺度上发生。我们的结果表明，基于双层的空化通常限制了含有脂质双层的液体中负压的大小。
Biological and technological processes that involve liquids under negative pressure are vulnerable to the formation of cavities. Maximal negative pressures found in plants are around -100 bar, even though cavitation in pure bulk water only occurs at much more negative pressures on the relevant timescales. Here, we investigate the influence of small solutes and lipid bilayers, both constituents of all biological liquids, on the formation of cavities under negative pressures. By combining molecular dynamics simulations with kinetic modeling, we quantify cavitation rates on biologically relevant length scales and timescales. We find that lipid bilayers, in contrast to small solutes, increase the rate of cavitation, which remains unproblematically low at the pressures found in most plants. Only when the negative pressures approach -100 bar does cavitation occur on biologically relevant timescales. Our results suggest that bilayer-based cavitation is what generally limits the magnitude of negative pressures in liquids that contain lipid bilayers.