Analysis of SMALP co-extracted phospholipids shows distinct membrane environments for three classes of bacterial membrane protein.
Analysis of SMALP co-extracted phospholipids shows distinct membrane environments for three classes of bacterial membrane protein.
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SMALP 共提取磷脂的分析显示了三类细菌膜蛋白的不同膜环境。
DOI：
10.1038/s41598-018-37962-0
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发表时间：
2019
影响因子：
4.6
通讯作者：
Teo ACK
中科院分区：
文献类型：
--
作者：
Teo ACK
膜蛋白的生物学特性落后于可溶性蛋白。这反映了传统使用去污剂进行提取的问题，因为周围的脂质通常会丢失，从而产生不利的结构和功能后果。相比之下，苯乙烯马来酸（SMA）共聚物提供了一种无去污剂的方法，用于生物膜增溶，以产生含有膜蛋白及其周围脂质环境的SMA-脂质颗粒（SMALP）。我们报告了细菌磷脂的反相LC-MS/MS方法的发展和SMALP共提取的磷脂的配置文件的第一次比较，从三个示例性的细菌膜蛋白具有不同的地形：FtsA（相关的膜蛋白），ZipA（单跨膜螺旋），和PgpB（整合膜蛋白）。数据显示，虽然SMA处理本身并不优先从膜中提取特定的磷脂，但与大量膜脂质相比，SMALP提取的ZipA显示出磷脂酰乙醇胺的富集和心磷脂的消耗。比较3种SMALP提取蛋白的磷脂谱，发现每种蛋白的脂质组成不同：ZipA和PgpB相似，但在FtsA样品中，长链磷脂酰甘油和磷脂酰乙醇胺更丰富。这种方法提供了新的信息，这些膜蛋白的磷脂相互作用。
Biological characterisation of membrane proteins lags behind that of soluble proteins. This reflects issues with the traditional use of detergents for extraction, as the surrounding lipids are generally lost, with adverse structural and functional consequences. In contrast, styrene maleic acid (SMA) copolymers offer a detergent-free method for biological membrane solubilisation to produce SMA-lipid particles (SMALPs) containing membrane proteins together with their surrounding lipid environment. We report the development of a reverse-phase LC-MS/MS method for bacterial phospholipids and the first comparison of the profiles of SMALP co-extracted phospholipids from three exemplar bacterial membrane proteins with different topographies: FtsA (associated membrane protein), ZipA (single transmembrane helix), and PgpB (integral membrane protein). The data showed that while SMA treatment per se did not preferentially extract specific phospholipids from the membrane, SMALP-extracted ZipA showed an enrichment in phosphatidylethanolamines and depletion in cardiolipins compared to the bulk membrane lipid. Comparison of the phospholipid profiles of the 3 SMALP-extracted proteins revealed distinct lipid compositions for each protein: ZipA and PgpB were similar, but in FtsA samples longer chain phosphatidylglycerols and phosphatidylethanolamines were more abundant. This method offers novel information on the phospholipid interactions of these membrane proteins.