Butt H J, Downing K H, Hansma P K
Department of Physics, University of California, Santa Barbara 93106.
Biophys J. 1990 Dec;58(6):1473-80. doi: 10.1016/S0006-3495(90)82492-9.
The membrane protein bacteriorhodopsin was imaged in buffer solution at room temperature with the atomic force microscope. Three different substrates were used: mica, silanized glass and lipid bilayers. Single bacteriorhodopsin molecules could be imaged in purple membranes adsorbed to mica. A depression was observed between the bacteriorhodopsin molecules. The two dimensional Fourier transform showed the hexagonal lattice with a lattice constant of 6.21 +/- 0.20 nm which is in agreement with results of electron diffraction experiments. Spots at a resolution of approximately 1.1 nm could be resolved. A protein, cationic ferritin, could be imaged bound to the purple membranes on glass which was silanized with aminopropyltriethoxysilane. This opens the possibility of studying receptor/ligand binding under native conditions. In addition, purple membranes bound to a lipid bilayer were imaged. These images may help in interpreting results of functional studies done with purple membranes adsorbed to black lipid membranes.
利用原子力显微镜在室温下的缓冲溶液中对膜蛋白细菌视紫红质进行了成像。使用了三种不同的底物：云母、硅烷化玻璃和脂质双层。吸附在云母上的紫色膜中的单个细菌视紫红质分子能够被成像。在细菌视紫红质分子之间观察到一个凹陷。二维傅里叶变换显示出晶格常数为6.21±0.20 nm的六边形晶格，这与电子衍射实验结果一致。分辨率约为1.1 nm的斑点能够被分辨出来。一种蛋白质，阳离子铁蛋白，能够被成像显示结合在用氨丙基三乙氧基硅烷硅烷化的玻璃上的紫色膜上。这开启了在天然条件下研究受体/配体结合的可能性。此外，对结合到脂质双层上的紫色膜进行了成像。这些图像可能有助于解释用吸附在黑色脂质膜上的紫色膜所做的功能研究结果。
