Mechanical properties of viruses

If a virus releases its genomic content prematurely, it loses its infective capability. Yet, the viral shell does need to open at a specific place and time to ensure genome delivery into a new host. Hence, the chemical and mechanical properties of capsids are carefully tuned to fulfill these constraints. Knowledge of these properties will help to elucidate the viral infectious pathway, to develop virus based therapies and to facilitate the use of viruses in nanotechnology. Here we focus on the material properties of viruses mainly based on data obtained by mechanical manipulation of single viral particles. The main tool for such experiments is the atomic force microscope (AFM) and the experimental basis of these measurements will be explained. Next, aspects of the capsid shell structure, presence of encapsidated material, capsid failure, maturation and capsid protein mutations will be discussed in relation to the viral material properties. By comparing the data of various viruses, similarities and differences in the mechanical properties will be highlighted.