Tangorra R R, Operamolla A, Milano F, Hassan Omar O, Henrard J, Comparelli R, Italiano F, Agostiano A, De Leo V, Marotta R, Falqui A, Farinola G M, Trotta M
Chemistry Department, Università degli Studi di Bari "Aldo Moro", via Orabona 4, 70125 Bari, Italy.
Photochem Photobiol Sci. 2015 Oct;14(10):1844-52. doi: 10.1039/c5pp00189g.
The reconstitution of the integral membrane protein photosynthetic reaction center (RC) in polymersomes, i.e. artificial closed vesicles, was achieved by the micelle-to-vesicle transition technique, a very mild protocol based on size exclusion chromatography often used to drive the incorporation of proteins contemporarily to liposome formation. An optimized protocol was used to successfully reconstitute the protein in a fully active state in polymersomes formed by the tri-block copolymers PMOXA22-PDMS61-PMOXA22. The RC is very sensitive to its solubilizing environment and was used to probe the positioning of the protein in the vesicles. According to charge-recombination experiments and to the enzymatic activity assay, the RC is found to accommodate in the PMOXA22 region of the polymersome, facing the water bulk solution, rather than in the PDMS61 transmembrane-like region. Furthermore, polymersomes were found to preserve protein integrity efficiently as the biomimetic lipid bilayers but show a much longer temporal stability than lipid based vesicles.
通过胶束-囊泡转变技术，即在人工封闭囊泡（聚合物囊泡）中实现了整合膜蛋白光合反应中心（RC）的重构，这是一种基于尺寸排阻色谱的非常温和的方法，常用于在脂质体形成的同时驱动蛋白质的掺入。采用优化方案成功地在由三嵌段共聚物PMOXA22-PDMS61-PMOXA22形成的聚合物囊泡中重构了处于完全活性状态的蛋白质。RC对其溶解环境非常敏感，被用于探测蛋白质在囊泡中的定位。根据电荷复合实验和酶活性测定，发现RC位于聚合物囊泡的PMOXA22区域，面向大量水溶液，而不是位于PDMS61跨膜样区域。此外，发现聚合物囊泡与仿生脂质双层一样能有效地保持蛋白质完整性，但比基于脂质的囊泡具有更长的时间稳定性。
