Perturbation-HDX reveals glycosylation sites as weakest links in dengue capsid quaternary structure.

Abstract

Dengue virus (DENV) is a mosquito-borne, icosahedral flavivirus that represents a significant threat to human health worldwide. Vaccine development for dengue has long eluded scientists due to serotype and strain diversity associated with altered viral capsid dynamics. Despite being largely conserved, dengue strains show distinctive reversible fluctuations referred to as ‘breathing’. DENV capsids have T=3 icosahedral symmetry, consisting of 180 copies of out envelope (E) protein. E-protein dimer contacts confer stability of the native virus particle. To localize and rank the strengths of E-protein interfaces on the surface, we carried out urea and temperature perturbation of DENV particles analyzed using amide hydrogen-deuterium exchange mass spectrometry. Our results highlight the weakest links on the virion surface. These sites are spanning the glycosylation sites of dengue. We have isolated and characterized the viable deglycosylated mutant which shows a different temperature stability profile. These sensitive sites are prime targets for drug development and predict sites that may change due to the selective pressure that impact viral evolution.