Trapping and Stabilization of Integral Membrane Proteins by Hydrophobically Grafted Glucose-Based Telomers
Trapping and Stabilization of Integral Membrane Proteins by Hydrophobically Grafted Glucose-Based Telomers
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DOI：
10.1021/bm900938w
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发表时间：
2009-12-01
影响因子：
6.2
通讯作者：
Pucci, Bernard
中科院分区：
文献类型：
--
作者：
Bazzacco, Paola;Sharma, K. Shivaji;Pucci, Bernard
Amphipols（APols）是一种短的两亲性聚合物，被设计为吸附在膜蛋白的跨膜表面上。使它们在没有洗涤剂的情况下保持水溶性。目前的APOL携带带电基团，这对某些类型的应用是一个限制。这促进了完全非离子两亲性（NAPols）的开发。在先前的工作中，通过亲水性和两亲性单体的自由基共调聚合成的基于葡萄糖的NAPols被证明能够保持膜蛋白可溶（Sharma等人，Langmuir 2008，24. 13581-13590）。这提供了它的原理证明，但繁琐的合成阻碍了大规模生产和任何详细的生物化学研究。在本工作中，我们描述了基于将烷基链接枝到葡萄糖基化的同源调聚物上的NAPols的新合成路线。由此制备的NAPol是高度水溶性的。在水溶液中，它们组装成类似于离子型APOL形成的小而均匀的颗粒。两种模型膜蛋白，细菌视紫红质和OmpA的跨膜结构域，与NAPols形成小的、明确定义的水溶性复合物，其大小与用离子型APols观察到的chat相当。通过NAPols的络合强烈稳定细菌视紫红质以防止变性。因此，葡萄糖基化的NAPols出现作为一个有前途的替代离子APols的应用，如离子交换色谱，等电聚焦，并可能，结构的方法，如NMR和结晶。
Amphipols (APols) are short amphipathic polymers designed to adsorb onto the transmembrane surface of membrane proteins. keeping them water-soluble in the absence of detergent. Current APols carry charged groups, which is a limitation for certain types of applications. This has prompted the development of totally nonionic amphiphols (NAPols) In a previous work, glucose-based NAPols synthesized by free-radical cotelomerization of hydrophilic and amphiphilic monomers proved to be able to keep membrane proteins Soluble (Sharma et al. Langmuir 2008, 24. 13581-13590). This provided it proof of principle, but the cumbersome synthesis prevented large-scale production and any detailed biochemical Studies In the present work, we describe I new synthesis route for NAPols based on grafting alkyl chains onto a glucosylated homotelomer. The NAPols thus prepared are highly water soluble. In aqueous solutions, they assemble into small, homogeneous particles similar to those formed by ionic APols. Two model membrane proteins, bacteriorhodopsin and the transmembrane domain of OmpA, form with NAPols small, well-defined water-soluble complexes whose size is comparable to chat observed with ionic APols. Complexation by NAPols Strongly stabilizes bacteriorhodopsin against denaturation. Glucosylated NAPols thus appear as a promising alternative to ionic APols for such applications as ion-exchange chromatography, isoelectrofocusing, and, possibly, structural approaches such as NMR and crystallography.