Pathway switching in templated virus-like particle assembly

Assembly pathways of virus-like particles formed from a virus coat protein cage encapsulating a metal nanoparticle were studied by intrinsic fluorescence quenching. Depending on buffer conditions, the in vitro formation of a virus-like particle can take place through cooperative or non-cooperative adsorption of protein subunits on the nanoparticle template. Simple equilibrium models provided estimates for the thermodynamic forces driving the assembly as well as the size of the critical nucleus in the case of cooperative growth.