Quantifying Growth of Symmetric and Asymmetric Lipid Bilayer Domains
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- 作者：Craig D. Blanchette ; Christine A. Orme ; Timothy V. Ratto ; Marjorie L. Longo
- 刊名：Langmuir
- 出版年：2008
- 出版时间：February 19, 2008
- 年：2008
- 卷：24
- 期：4
- 页码：1219 - 1224
- 全文大小：282K
- 年卷期：v.24,no.4(February 19, 2008)
- ISSN：1520-5827
文摘
Here, we examine by atomic force microscopy (AFM) the kinetics and morphology of lipid domain growth duringlipid phase separation by rapid thermal cooling of fully mixed two-component supported lipid bilayers. At the undercooledtemperatures chosen, symmetric 1,2-distearoyl-sn-glycero-3-phosphocholine (DSPC)-rich domains favored slowerreaction-limited growth whereas asymmetric galactosylceramide (GalCer)-rich domains favored faster diffusion-limited growth, indicated by shape factors and kinetic exponents. Because kinetically limited conditions could beaccessed, we were able to estimate the activation energy barrier (~16kT) and lateral diffusion coefficient (~0.20 
m2/s)of lipid molecular addition to a growing domain. We discuss these results with respect to transition states, obstructeddiffusion, and the necessity for coordinating growth in both leaflets in a symmetric lipid domain.
m2/s)of lipid molecular addition to a growing domain. We discuss these results with respect to transition states, obstructeddiffusion, and the necessity for coordinating growth in both leaflets in a symmetric lipid domain.