Physical virology: From virus self‐assembly to particle mechanics

Abstract

Viruses are highly ordered supramolecular complexes that have evolved to propagate by hijacking the host cell's machinery. Although viruses are very diverse, spreading through cells of all kingdoms of life, they share common functions and properties. Next to the general interest in virology, fundamental viral mechanisms are of growing importance in other disciplines such as biomedicine and (bio)nanotechnology. However, in order to optimally make use of viruses and virus‐like particles, for instance as vehicle for targeted drug delivery or as building blocks in electronics, it is essential to understand their basic chemical and physical properties and characteristics. In this context, the number of studies addressing the mechanisms governing viral properties and processes has recently grown drastically. This review summarizes a specific part of these scientific achievements, particularly addressing physical virology approaches aimed to understand the self‐assembly of viruses and the mechanical properties of viral particles. Using a physicochemical perspective, we have focused on fundamental studies providing an overview of the molecular basis governing these key aspects of viral systems. This article is categorized under: Biology‐Inspired Nanomaterials > Protein and Virus‐Based Structures Nanotechnology Approaches to Biology > Nanoscale Systems in Biology

Relative humidity in droplet and airborne transmission of disease

“…Salt ions are a ubiquitous component in physiological fluids, and when their concentration changes, the viability of enveloped and non-enveloped viruses exhibits different responses. Adding salt to a droplet medium has been shown to improve rather than reduce the viability of some non-enveloped viruses [ 155 , 157 ], which is potentially related to the observations that screening of electrosatic interactions due to salt ions is in general beneficial to the stability of (often highly charged [ 158 , 159 ]) non-enveloped viruses [ 160 – 166 ]. On the other hand, salt ions usually have a toxic effect on enveloped viruses, but the precise mechanisms remain unclear [ 146 ].…”

Physics of viral dynamics

“…Approaches focusing on the mechanical properties of retroviral capsids using AFM nanoindentation [102][103][104][105][106] have further elucidated the physics of maturation. The retrovirus Moloney murine leukaemia virus undergoes a marked softening of the shell during maturation 107 , as expected in view of the proteolytic cleavage of the capsid proteins.…”

Soft matter science and the COVID-19 pandemic

“…132 However, the results may not be directly applicable to understanding real enveloped viruses, because proteins expressed in the lipid bilayer envelope play vital roles in determining membrane mechanics. 128 Such 'mechanical virology' is a very active area of research 133,134 in which soft matter scientists should be able to make a strong contribution. Progress in viral mechanics, coupled with an understanding of what forces operate on viruses, especially at interfaces, should suggest strategies by which virions may be mechanically inactivated.…”