Zakharian E, Reusch R N
Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, MI 48824, USA.
FEBS Lett. 2003 Dec 4;555(2):229-35. doi: 10.1016/s0014-5793(03)01236-5.
The temperature dependence of single-channel conductance and open probability for outer membrane protein A (OmpA) of Escherichia coli were examined in planar lipid bilayers. OmpA formed two interconvertible conductance states, small channels, 36-140 pS, between 15 and 37 degrees C, and large channels, 115-373 pS, between 21 and 39 degrees C. Increasing temperatures had strong effects on open probabilities and on the ratio of large to small channels, particularly between 22 and 34 degrees C, which effected sharp increases in average conductance. The data infer that OmpA is a flexible temperature-sensitive protein that exists as a small pore structure at lower temperatures, but refolds into a large pore at higher temperatures.
在平面脂质双分子层中研究了大肠杆菌外膜蛋白A（OmpA）单通道电导和开放概率的温度依赖性。OmpA形成了两种可相互转换的电导状态，在15至37摄氏度之间为小通道，电导为36 - 140皮西门子，在21至39摄氏度之间为大通道，电导为115 - 373皮西门子。温度升高对开放概率以及大通道与小通道的比例有强烈影响，特别是在22至34摄氏度之间，这导致平均电导急剧增加。数据推断，OmpA是一种灵活的温度敏感蛋白，在较低温度下以小孔结构存在，但在较高温度下会重新折叠成大孔。
