State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, Jilin 130022, PR China.
Ultramicroscopy. 2010 Mar;110(4):305-12. doi: 10.1016/j.ultramic.2009.12.014. Epub 2010 Jan 4.
Studies of cell membrane structure by atomic force microscopy (AFM) have been limited because of the softness of cell membranes. Here, we utilize a new technique of sample preparation to lay red blood cell membranes on the top of a mica surface to obtain high resolution images by in-situ AFM on both sides of cell membranes. Our results indicate that the location of oligosaccharides and proteins in red blood cell membranes might be different from the current membrane model. The inner membrane leaflet is covered by dense proteins with fewer free lipids than expected. In contrast, the outer membrane leaflet is quite smooth; oligosaccharides and peptides supposed to protrude out of the outer membrane leaflet surface might be actually hidden in the middle of hydrophilic lipid heads; transmembrane proteins might form domains in the membranes revealed by PNGase F and trypsin digestion. Our result could be significant to interpret some functions about red blood cell membranes and guide to heal the blood diseases related to cell membranes.
利用原子力显微镜（AFM）研究细胞膜结构受到细胞膜柔软性的限制。本研究利用一种新的样品制备技术，将红细胞膜铺展在云母表面上，通过原位 AFM 在细胞膜两侧获得高分辨率图像。我们的结果表明，红细胞膜中寡糖和蛋白质的位置可能与目前的膜模型不同。内层膜叶由密集的蛋白质覆盖，比预期的游离脂质少。相比之下，外层膜叶非常光滑；推测从外膜叶表面伸出的寡糖和肽可能实际上隐藏在亲水头的中间；通过 PNGase F 和胰蛋白酶消化揭示的跨膜蛋白可能在膜中形成域。我们的结果对于解释红细胞膜的一些功能以及指导治疗与细胞膜相关的血液疾病具有重要意义。
