Molecular shape and binding force of Mycoplasma mobile's leg protein Gli349 revealed by an AFM study
Molecular shape and binding force of Mycoplasma mobile's leg protein Gli349 revealed by an AFM study
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DOI：
10.1016/j.bbrc.2009.12.023
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发表时间：
2010-01-15
影响因子：
3.1
通讯作者：
Ikai, Atsushi
中科院分区：
文献类型：
--
作者：
Lesoil, Charles;Nonaka, Takahiro;Ikai, Atsushi
最近对滑行细菌支原体移动的的研究已经鉴定了一个称为Gli家族的蛋白质家族，该家族被认为与这种新颖但相当未知的运动系统有关。Gli349蛋白分子量为349 kDa，经电镜成像和抗体实验证实其为M.移动的，负责附着于基底以及滑动运动。然而，这种蛋白质的分子形状和功能需要更精确的证据来进一步评估这一理论。在这项研究中，原子力显微镜（AFM）被用作成像和力测量设备，以提供有关Gli349及其在滑行运动中的作用的新信息。获得的蛋白质的AFM图像揭示了具有刚性和柔性部分的复杂结构，与之前的蛋白质电子显微照片一致。还进行了单分子力光谱实验，揭示了Gli349能够特异性结合唾液酸乳糖分子，并承受约70 pN的解结合力。这些发现有力地支持了Gli349是M.移动的，负责结合，也很可能在滑动运动期间产生力。(C)2009爱思唯尔公司All rights reserved.
Recent studies of the gliding bacteria Mycoplasma mobile have identified a family of proteins called the Gli family which was considered to be involved in this novel and yet fairly unknown motility system. The 349 kDa protein called Gli349 was successfully isolated and purified from the bacteria, and electron microscopy imaging and antibody experiments led to the hypothesis that it acts as the "leg" of M. mobile, responsible for attachment to the substrate as well as for gliding motility. However, more precise evidence of the molecular shape and function of this protein was required to asses this theory any further. In this study, an atomic force microscope (AFM) was used both as an imaging and a force measurement device to provide new information about Gli349 and its role in gliding motility. AFM images of the protein were obtained revealing a complex structure with both rigid and flexible parts, consistent with previous electron micrographs of the protein. Single-molecular force spectroscopy experiments were also performed, revealing that Gli349 is able to specifically bind to sialyllactose molecules and withstand unbinding forces around 70 pN. These findings strongly support the idea that Gli349 is the "leg" protein of M. mobile, responsible for binding and also most probably force generation during gliding motility. (C) 2009 Elsevier Inc. All rights reserved.