Nanosecond molecular dynamics trajectories of the protein capsid from the common-cold virus, human rhinovirus (HRV) (bottom left figure), revealed unexpected changes in HRV properties in the presence of the antiviral compound. The asymmetric unit comprising of four viral proteins solvated inside and out (right figure) was simulated using icosahedral symmetry conditions and parallel processing. The antiviral compound increases the compressibility of HRV, thereby stabilizing the capsid against uncoating, and reduces the mobility of loops near the five-fold axes of the capsid.