Biological insights from SMA-extracted proteins.
Biological insights from SMA-extracted proteins.
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DOI：
10.1042/bst20201067
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发表时间：
2021-06-30
影响因子：
3.9
通讯作者：
Rothnie AJ
中科院分区：
文献类型：
--
作者：
Unger L;Ronco-Campaña A;Kitchen P;Bill RM;Rothnie AJ
自苯乙烯马来酸（SMA）首次用于提取和纯化天然脂质双分子层中的膜蛋白以来的12年中，这一技术突破提供了对蛋白质-脂质相互作用的结构和功能细节的深入了解。最近，冷冻电镜技术的进展表明，sma提取的膜蛋白是结构数据的丰富来源。例如，它已经有可能解决环状脂质和复合物内蛋白质-蛋白质相互作用的细节，中心腔和结合袋内脂质的性质，涉及稳定多聚体的区域，否则仍未解决的末端残基的细节以及生理相关状态的识别。在功能上，SMA提取允许分析在洗涤剂中不稳定的膜蛋白，表征在洗涤剂溶解样品中不可能实现的电子转移动力学中的超快组分，以及对低浓度纯化蛋白的结合分析进行定量、实时测量。尽管SMA的使用存在局限性，如对低pH值和二价阳离子的敏感性，但其主要优点是维持了蛋白质的脂质双分子层。这使得研究人员能够在接近蛋白质的环境中观察和分析蛋白质，从而获得新的结构和机制见解。
In the twelve years since styrene maleic acid (SMA) was first used to extract and purify a membrane protein within a native lipid bilayer, this technological breakthrough has provided insight into the structural and functional details of protein–lipid interactions. Most recently, advances in cryo-EM have demonstrated that SMA-extracted membrane proteins are a rich-source of structural data. For example, it has been possible to resolve the details of annular lipids and protein–protein interactions within complexes, the nature of lipids within central cavities and binding pockets, regions involved in stabilising multimers, details of terminal residues that would otherwise remain unresolved and the identification of physiologically relevant states. Functionally, SMA extraction has allowed the analysis of membrane proteins that are unstable in detergents, the characterization of an ultrafast component in the kinetics of electron transfer that was not possible in detergent-solubilised samples and quantitative, real-time measurement of binding assays with low concentrations of purified protein. While the use of SMA comes with limitations such as its sensitivity to low pH and divalent cations, its major advantage is maintenance of a protein's lipid bilayer. This has enabled researchers to view and assay proteins in an environment close to their native ones, leading to new structural and mechanistic insights.