Built-In Mechanical Stress in Viral Shells

Author

• C. Carrasco, Consejo Superior de Investigaciones Cientificas
• A. Luque, University of Barcelona
• M. Hernando-Perez, Autonomous University of Madrid
• R. Miranda, Consejo Superior de Investigaciones Cientificas
• J. L. Carrascosa, Consejo Superior de Investigaciones Cientificas
• P. A. Serena, Consejo Superior de Investigaciones Cientificas
• M. de Ridder, Birck Nanotechnology Center, Purdue University
• Arvind Raman, Birck Nanotechnology Center, Purdue UniversityFollow
• J. Gomez-Herrero, Autonomous University of Madrid
• I.A.T. Schaap, University of Gottingen
• D. Reguera, University of Barcelona
• P. J. de Pablo, Autonomous University of Madrid

Abstract

Mechanical properties of biological molecular aggregates are essential to their function. A remarkable example are double-stranded DNA viruses such as the phi 29 bacteriophage, that not only has to withstand pressures of tens of atmospheres exerted by the confined DNA, but also uses this stored elastic energy during DNA translocation into the host. Here we show that empty prolated phi 29 bacteriophage proheads exhibit an intriguing anisotropic stiffness which behaves counterintuitively different from standard continuum elasticity predictions. By using atomic force microscopy, we find that the phi 29 shells are approximately two-times stiffer along the short than along the long axis. This result can be attributed to the existence of a residual stress, a hypothesis that we confirm by coarse-grained simulations. This built-in stress of the virus prohead could be a strategy to provide extra mechanical strength to withstand the DNA compaction during and after packing and a variety of extracellular conditions, such as osmotic shocks or dehydration.

Keywords

ATOMIC-FORCE MICROSCOPY; ICOSAHEDRAL SYMMETRY; BACTERIOPHAGE PHI-29; VIRUS CAPSIDS; DNA; PHAGE; PRESSURE; EJECTION; PROHEAD; MICROTUBULES

DOI

10.1016/j.bpj.2011.01.008

Citation

Biophysical Journal Volume 100, Issue 4, 16 February 2011, Pages 1100-1108

Date of this Version

2-16-2011

Recommended Citation

Carrasco, C.; Luque, A.; Hernando-Perez, M.; Miranda, R.; Carrascosa, J. L.; Serena, P. A.; de Ridder, M.; Raman, Arvind; Gomez-Herrero, J.; Schaap, I.A.T.; Reguera, D.; and de Pablo, P. J., "Built-In Mechanical Stress in Viral Shells" (2011). Birck and NCN Publications. Paper 1054.
http://dx.doi.org/10.1016/j.bpj.2011.01.008