Dai Xianzhu, Shao Nana, Luo Feng
Wei Sheng Wu Xue Bao. 2014 Nov 4;54(11):1241-7.
A cell of gram-negative bacteria is surrounded by two layers of membrane, the inner membrane and the outer membrane. Proteins are the major composition of outer membrane. Many outer membrane proteins carry a trans-membrane β-barrel structure that formed by multiple anti-parallel β-strands connected with hydrogen bonds. These proteins can act as porins, transporters, enzymes, receptors, virulence factors and structural proteins. Therefore, their correct folding and membrane integration are important for the survival of gram-negative bacteria. Most β-barrel outer membrane proteins could be easily expressed recombinantly and refolded in vitro under certain conditions. The in vitro folding processes could be monitored and investigated through many ways, which makes outer membrane proteins become a model system to study the effects of abiotic and biological factors on the folding of membrane proteins. In this article, the research progress on the in vitro refolding of outer membrane proteins are reviewed from the aspects of refolding methods, the factors that affect folding processes and experimental methods. Finally, the research prospects in this field are discussed.
革兰氏阴性菌的细胞被两层膜包围，即内膜和外膜。蛋白质是外膜的主要组成成分。许多外膜蛋白具有跨膜β桶结构，该结构由多个通过氢键连接的反平行β链形成。这些蛋白质可以充当孔蛋白、转运蛋白、酶、受体、毒力因子和结构蛋白。因此，它们的正确折叠和膜整合对于革兰氏阴性菌的生存至关重要。大多数β桶外膜蛋白可以在特定条件下很容易地在体外进行重组表达和重折叠。体外折叠过程可以通过多种方式进行监测和研究，这使得外膜蛋白成为研究非生物和生物因素对膜蛋白折叠影响的模型系统。本文从重折叠方法、影响折叠过程的因素和实验方法等方面对外膜蛋白体外重折叠的研究进展进行了综述。最后，讨论了该领域的研究前景。
