Cholesterol modulates the pressure response of DMPC membranes.
Biophys Chem 2019;
252:106210. [PMID:
31265976 DOI:
10.1016/j.bpc.2019.106210]
[Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2019] [Revised: 06/12/2019] [Accepted: 06/19/2019] [Indexed: 11/16/2022]
Abstract
In this work, the effect of cholesterol on the pressure response of solid-supported phospholipid multilayers is analyzed. It is shown that DMPC multilayers become highly pressure-responsive by the incorporation of low amounts of cholesterol, resulting in a strong pressure-induced expansion of the bilayer spacing. This is accompanied by a high tendency of the multilayer system to detach from the substrate. Increasing the cholesterol concentration reduces the pressure-induced expansion and the membrane structure remains largely unchanged upon pressurization, consequently the stability of the multilayers improves. For a determination of the influence of the substrate, the pressure-dependent behavior of multilayers is compared to that of solid-supported bilayers and multi-lamellar vesicles in bulk solution. While single-supported bilayers remain largely unaffected by external pressure independent of their cholesterol content, multi-lamellar vesicles and multilayers behave similarly.
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