Prion proteins are known to misfold into a range of different aggregated forms (strains), showing different phenotypic and pathological states, although little is known on which structural properties and molecular mechanisms determine prion replication, disease progression and strain phenotype. The aim of this work is to establish a relationship between the kinetic properties of a prion replication model and the conformational stability of prion aggregated forms. At a qualitative level, the model structure suggests a direct relationship between the stability and the mean size of the fibrils population. In order to explain this relationship, we propose that different prion strains undergoing replication are characterizable by means of different rates of breakage. What we argue is consistent with what has been also observed for yeast prion replication.
