Solubilization of lipids and lipid phases by the styrene–maleic acid copolymer

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• 作者：Juan J. Dominguez Pardo ; Jonas M. Dörr ; Aditya Iyer…
• 关键词：Lipid–protein interactions ; Nanodiscs ; Styrene–maleic acid ; SMALP ; SMA ; resistant membrane (SRM) ; Lipid rafts
• 刊名：European Biophysics Journal
• 出版年：2017
• 出版时间：January 2017
• 年：2017
• 卷：46
• 期：1
• 页码：91-101
• 全文大小：1578KB
• 刊物类别：Physics and Astronomy
• 刊物主题：Biochemistry, general; Biological and Medical Physics, Biophysics; Cell Biology; Neurobiology; Membrane Biology; Nanotechnology;
• 出版者：Springer Berlin Heidelberg
• ISSN：1432-1017
• 卷排序：46

文摘

A promising tool in membrane research is the use of the styrene–maleic acid (SMA) copolymer to solubilize membranes in the form of nanodiscs. Since membranes are heterogeneous in composition, it is important to know whether SMA thereby has a preference for solubilization of either specific types of lipids or specific bilayer phases. Here, we investigated this by performing partial solubilization of model membranes and analyzing the lipid composition of the solubilized fraction. We found that SMA displays no significant lipid preference in homogeneous binary lipid mixtures in the fluid phase, even when using lipids that by themselves show very different solubilization kinetics. By contrast, in heterogeneous phase-separated bilayers, SMA was found to have a strong preference for solubilization of lipids in the fluid phase as compared to those in either a gel phase or a liquid-ordered phase. Together the results suggest that (1) SMA is a reliable tool to characterize native interactions between membrane constituents, (2) any solubilization preference of SMA is not due to properties of individual lipids but rather due to properties of the membrane or membrane domains in which these lipids reside and (3) exploiting SMA resistance rather than detergent resistance may be an attractive approach for the isolation of ordered domains from biological membranes.