On the Morphology of Viral Capsids: Elastic Properties and Buckling Transitions

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• 作者：Eric R. May ; Charles L. Brooks ; III
• 刊名：The Journal of Physical Chemistry B
• 出版年：2012
• 出版时间：July 26, 2012
• 年：2012
• 卷：116
• 期：29
• 页码：8604-8609
• 全文大小：301K
• 年卷期：v.116,no.29(July 26, 2012)
• ISSN：1520-5207

文摘

The morphology of icosahedral viruses ranges from highly spherical to highly faceted, and for some viruses a shape transition occurs during the viral life cycle. This phenomena is predicted from continuum elasticity, via the buckling transition theory by Nelson ( Phys. Rev. E 2003, 68, 051910), in which the shape is dependent on the Foppl鈥搗on K谩rm谩n number (纬), which is a ratio of the two-dimensional Young鈥檚 modulus (Y) and the bending modulus (魏). However, until now, no direct calculations have been performed on atomic-level capsid structures to test the predictions of the theory. In this study, we employ a previously described multiscale method by May and Brooks ( Phys. Rev. Lett. 2011, 106, 188101) to calculate Y and 魏 for the bacteriophage HK97, which undergoes a spherical to faceted transition during its viral life cycle. We observe a change in 纬 consistent with the buckling transition theory and also a significant reduction in 魏, which facilitates formation of the faceted state. We go on to examine many capsids from the T = 3 and 7 classes using only elastic network models, which allows us to calculate the ratio Y/魏, without the expense of all-atom molecular dynamics. We observe for the T = 7 capsids, there is strong correlation between the shape of the capsid and 纬; however, there is no such correlation for the smaller T = 3 viruses.