title: Weighing polyelectrolytes packaged in viruslike particles.
abstract: This Letter reports on the remarkable selectivity of capsid proteins for packaging synthetic polyelectrolytes in viruslike particles. By applying the contrast variation method in small-angle neutron scattering, we accurately estimated the mean mass of packaged polyelectrolytes ⟨Mp⟩ and that of the surrounding capsid ⟨Mcap⟩. Remarkably, the mass ratio ⟨Mp⟩/⟨Mcap⟩ was invariant for polyelectrolyte molecular weights spanning more than 2 orders of magnitude. To do so, capsids either packaged several chains simultaneously or selectively retained the shortest chains that could fit the capsid interior. Our data are in qualitative agreement with theoretical predictions based on free energy minimization and emphasize the importance of protein self-energy. These findings may give new insights into the nonspecific origin of genome selectivity for a number of viral systems.
authors.affiliation: Laboratoire de Physique des Solides, Université Paris-Sud, CNRS, 91400 Orsay, France.
authors.forename: Guillaume
authors.initials: G
authors.lastname: Tresset
authors.affiliation: Laboratoire de Physique des Solides, Université Paris-Sud, CNRS, 91400 Orsay, France.
authors.forename: Mouna
authors.initials: M
authors.lastname: Tatou
authors.affiliation: Laboratoire de Physique des Solides, Université Paris-Sud, CNRS, 91400 Orsay, France.
authors.forename: Clémence
authors.initials: C
authors.lastname: Le Cœur
authors.affiliation: Laboratoire de Physique des Solides, Université Paris-Sud, CNRS, 91400 Orsay, France.
authors.forename: Mehdi
authors.initials: M
authors.lastname: Zeghal
authors.affiliation: Laboratoire de Physique des Solides, Université Paris-Sud, CNRS, 91400 Orsay, France.
authors.forename: Virginie
authors.initials: V
authors.lastname: Bailleux
authors.affiliation: Laboratoire de Physique des Solides, Université Paris-Sud, CNRS, 91400 Orsay, France.
authors.forename: Amélie
authors.initials: A
authors.lastname: Lecchi
authors.affiliation: Institute of Physical and Theoretical Chemistry, Wrocław University of Technology, 27 Wybrzeże Wyspiańskiego, 50-370 Wrocław, Poland.
authors.forename: Katarzyna
authors.initials: K
authors.lastname: Brach
authors.affiliation: Institute of Physical and Theoretical Chemistry, Wrocław University of Technology, 27 Wybrzeże Wyspiańskiego, 50-370 Wrocław, Poland.
authors.forename: Magdalena
authors.initials: M
authors.lastname: Klekotko
authors.affiliation: Institut Laue Langevin, 6 rue Jules Horowitz, 38042 Grenoble Cedex 9, France.
authors.forename: Lionel
authors.initials: L
authors.lastname: Porcar
mesh_terms: D002213:Capsid / Q000737:chemistry; D036022:Capsid Proteins / Q000737:chemistry*; D004573:Electrolytes / Q000737:chemistry*; D008956:Models, Chemical; D008958:Models, Molecular; D033363:Neutron Diffraction; D012367:RNA, Viral / Q000737:chemistry; D053838:Scattering, Small Angle; D014771:Virion / Q000737:chemistry*
chemical_list: D036022:Capsid Proteins; D004573:Electrolytes; D012367:RNA, Viral