Understanding and mimicking virus self-assembly
Viruses are ubiquitous pathogens in all kingdoms of life and are major public health issues. Despite a huge body of work dedicated to the molecular biology of viral life cycles, there are currently no physical models accounting for the mechanisms by which the hundreds of molecular building blocks making up a virus fit into the final structure with a pinpoint accuracy. I will present first the assembly and disassembly pathways of empty icosahedral capsids. Kinetic models inferred from time-resolved small-angle X-ray scattering (TR-SAXS) data revealed cooperative mechanisms involving unexpected long-lived intermediate species. I will give some insights into the packaging of synthetic polyelectrolytes studied by neutron scattering at equilibrium and demonstrate a nonspecific electrostatic selectivity that may play a crucial role for genome packaging in host cells. The nonequilibrium dynamics of genome packaging was investigated as well by TR-SAXS and I will show that both cooperative and nucleation-growth pathways can be followed depending on ionic conditions. At last, I will review the recent strategies we developed to direct the self-assembly of virus-mimicking, DNA-surfactant nanoparticles by using microfluidic devices. The approach might open attractive opportunities for the formulation of efficient gene delivery vectors.
Laboratoire de Physique des Solides (Paris-Sud)