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标题：Nanoindentation studies of full and empty viral capsids and the effects of capsid protein mutations on elasticity and strength
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作者：J. P. Michel ; I. L. Ivanovska ; M. M. Gibbons 等
期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：2006
卷号：103
期号：16
页码：6184-6189
DOI：10.1073/pnas.0601744103
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：The elastic properties of capsids of the cowpea chlorotic mottle virus have been examined at pH 4.8 by nanoindentation measurements with an atomic force microscope. Studies have been carried out on WT capsids, both empty and containing the RNA genome, and on full capsids of a salt-stable mutant and empty capsids of the subE mutant. Full capsids resisted indentation more than empty capsids, but all of the capsids were highly elastic. There was an initial reversible linear regime that persisted up to indentations varying between 20% and 30% of the diameter and applied forces of 0.6-1.0 nN; it was followed by a steep drop in force that is associated with irreversible deformation. A single point mutation in the capsid protein increased the capsid stiffness. The experiments are compared with calculations by finite element analysis of the deformation of a homogeneous elastic thick shell. These calculations capture the features of the reversible indentation region and allow Young's moduli and relative strengths to be estimated for the empty capsids.
关键词：atomic force microscopy ; cowpea chlorotic mottle virus ; finite element analysis ; biomechanics