细胞要进行重要的生理代谢功能,主要的就是得接收与传递细胞内外的讯号,而参与这个过程的重要关键角色,就是位于细胞膜上的蛋白质,科学家虽然知道,膜上蛋白参与的生理机能非常的复杂,但透过新一代计算机技术的帮忙,很可能解开一些目前实验科学所不能回答的疑问。
这次科学家在著名的科学期刊 PLoS计算器生物学 (Computational Biology)上,发表一份最新的研究报告指出,由 Tristan Ursell博士所领导的研究团队,透过计算机程序的模拟,深入的分析膜上蛋白质可能存在的动力学行为,研究人员利用程序仿真膜上蛋白质的行为,发现细胞膜的表面可以非常的具有弹性,并且透过厚薄的改变,来包埋膜上的蛋白质,辅助膜上蛋白质的沟通功能,甚至像是提供离子通透的孔径蛋白,也是透过细胞膜的弹性来辅助变形的过程。
由这次的研究报告,证实了细胞膜脂质双层的弹性结构,确实提供了膜上蛋白质的构成条件,辅助组织生理功能与代谢的过程。
(编译/许仁旗) (资料来源 : biocompare)
英文原文链接:
http://news.biocompare.com/newsstory.asp?id=181263
原始出处:
Cooperative Gating and Spatial Organization of Membrane Proteins through Elastic Interactions
Tristan Ursell1, Kerwyn Casey Huang2, Eric Peterson3, Rob Phillips1,4*
1 Department of Applied Physics, California Institute of Technology, Pasadena, California, United States of America, 2 Department of Molecular Biology, Princeton University, Princeton, New Jersey, United States of America, 3 Department of Physics, California Institute of Technology, Pasadena, California, United States of America, 4 Kavli Nanoscience Institute, Pasadena, California, United States of America
Biological membranes are elastic media in which the presence of a transmembrane protein leads to local bilayer deformation. The energetics of deformation allow two membrane proteins in close proximity to influence each other's equilibrium conformation via their local deformations, and spatially organize the proteins based on their geometry. We use the mechanosensitive channel of large conductance (MscL) as a case study to examine the implications of bilayer-mediated elastic interactions on protein conformational statistics and clustering. The deformations around MscL cost energy on the order of 10 kBT and extend 3 nm from the protein edge, as such elastic forces induce cooperative gating, and we propose experiments to measure these effects. Additionally, since elastic interactions are coupled to protein conformation, we find that conformational changes can severely alter the average separation between two proteins. This has important implications for how conformational changes organize membrane proteins into functional groups within membranes.
Funding. The authors received no specific funding for this study.
Competing interests. The authors have declared that no competing interests exist.
Editor: Andrej Sali, University of California San Francisco, United States of America
Citation: Ursell T, Huang KC, Peterson E, Phillips R (2007) Cooperative Gating and Spatial Organization of Membrane Proteins through Elastic Interactions. PLoS Comput Biol 3(5): e81 doi:10.1371/journal.pcbi.0030081
Received: February 5, 2007; Accepted: March 21, 2007; Published: May 4, 2007
Copyright: © 2007 Ursell et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Abbreviations: MscL, mechanosensitive channel of large conductance
* To whom correspondence should be addressed. E-mail: phillips@pboc.caltech.edu
Author Summary
Membranes form flexible boundaries between the interior of a cell and its surrounding environment. Proteins that reside in the membrane are responsible for transporting materials and transmitting signals across these membranes to regulate processes crucial for cellular survival. These proteins respond to stimuli by altering their shape to perform specific tasks, such as channel proteins, which allow the flow of ions in only one conformation. However, the membrane is not just a substrate for these proteins, rather it is an elastic medium that bends and changes thickness to accommodate the proteins embedded in it. Thus, the membrane plays a role in the function of many proteins by affecting which conformation is energetically favorable. Using a physical model that combines membrane elastic properties with the structure of a typical membrane protein, we show that the membrane can communicate structural and hence conformational information between membrane proteins in close proximity. Hence, proteins can “talk” and “respond” to each other using the membrane as a generic “voice.” We show that these membrane-mediated elastic forces can ultimately drive proteins of the same shape to cluster together, leading to spatial organization of proteins within the membrane.