Examining the stability of membrane proteins within SMALPs
Examining the stability of membrane proteins within SMALPs
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DOI：
10.1016/j.eurpolymj.2018.12.008
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发表时间：
2019-03-01
影响因子：
6
通讯作者：
Rothnie, Alice J.
中科院分区：
文献类型：
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作者：
Gulamhussein, Aiman A.;Meah, Danyall;Rothnie, Alice J.
两亲共聚物，如苯乙烯-马来酸（SMA），在过去的几年里越来越受欢迎，因为与传统的提取方法（如洗涤剂）相比，它们在溶解和净化膜蛋白方面的能力和易用性。SMA2000被广泛用于膜蛋白研究，被认为是该技术的最佳聚合物。在本研究中，SMA2000与聚合物SZ30010进行了并排比较，因为这两种聚合物具有相似的苯乙烯：马来酸比和平均分子量。用三种结构不同的膜蛋白对膜蛋白的溶解、纯化和稳定能力进行了测试。我们的研究结果表明，这两种聚合物都可以用于提取膜蛋白，其效率与传统洗涤剂十二烷基麦芽糖苷（DDM）相当。研究发现，SZ30010的蛋白质产量与SMA2000相似，圆盘尺寸较小，与DDM相比，这两种聚合物的纯度和热稳定性都有所提高。进一步研究smallp对二价阳离子的敏感性。结果发现，这种敏感性是聚合物特异性的，而不依赖于被包裹的蛋白质。也不受SMALPs浓度的影响。较大的二价阳离子如Co2+和Zn2+导致灵敏度增加。
Amphipathic co-polymers such as styrene-maleic acid (SMA) have gained popularity over the last few years due to their ability and ease of use in solubilising and purifying membrane proteins in comparison to conventional methods of extraction such as detergents. SMA2000 is widely used for membrane protein studies and is considered as the optimal polymer for this technique. In this study a side-by-side comparison of SMA2000 with the polymer SZ30010 was carried out as both these polymers have similar styrene:maleic acid ratios and average molecular weights. Ability to solubilise, purify and stabilise membrane proteins was tested using three structurally different membrane proteins. Our results show that both polymers can be used to extract membrane proteins at a comparable efficiency to conventional detergent dodecylmaltoside (DDM). SZ30010 was found to give a similar protein yield and, SMALP disc size as SMA2000, and both polymers offered an increased purity and increased thermostability compared to DDM. Further investigation was conducted to investigate SMALP sensitivity to divalent cations. It was found that the sensitivity is polymer specific and not dependent on the protein encapsulated. Neither is it affected by the concentration of SMALPs. Larger divalent cations such as Co2+ and Zn2+ resulted in an increased sensitivity.