Abstract
Abstract
The passive transport of molecules through a cell membrane relies on thermal motions of the lipids. However, the nature of transmembrane transport and the precise mechanism remain elusive and call for a comprehensive study of phonon excitations. Here we report a high resolution inelastic X-ray scattering study of the in-plane phonon excitations in 1,2-dipalmitoyl-sn-glycero-3-phosphocholine above and below the main transition temperature. In the gel phase, for the first time, we observe low-frequency transverse modes, which exhibit a phonon gap when the lipid transitions into the fluid phase. We argue that the phonon gap signifies the formation of short-lived nanometre-scale lipid clusters and transient pores, which facilitate the passive molecular transport across the bilayer plane. Our findings suggest that the phononic motion of the hydrocarbon tails provides an effective mechanism of passive transport, and illustrate the importance of the collective dynamics of biomembranes.
Publisher
Springer Science and Business Media LLC
Subject
General Physics and Astronomy,General Biochemistry, Genetics and Molecular Biology,General Chemistry
Reference59 articles.
1. Alberts, B. et al. Molecular Biology of the Cell 4th edn Garland Science (2002).
2. Cooper, G. The Cell: A Molecular Approach. 2nd edn Sinauer Associates (2000).
3. Missner, A. et al. Dioxide transport through membranes. J. Biol. Chem. 283, 25340–25347 (2008).
4. Kleinzeller, A. in Membrane Permeability: 100 Years Since Ernest Overton (eds Deamer D., Kleinzeller A., Fam- brough D. M. 1–18Academic Press (1999).
5. Chen, I. A. et al. RNA catalysis in model protocell vesicles. J. Am. Chem. Soc. 127, 13213–13219 (2005).
Cited by
66 articles.
订阅此论文施引文献
订阅此论文施引文献，注册后可以免费订阅5篇论文的施引文献，订阅后可以查看论文全部施引文献