Self-assembly of dengue virus empty capsid-like particles in solution
Thais C. Neves-Martins,
Nathane C. Mebus-Antunes,
Carlos H.G. Neto,
Glauce M. Barbosa,
Fabio C.L. Almeida,
Icaro P. Caruso,
Andrea T. Da Poian
Affiliations
Thais C. Neves-Martins
Instituto de Bioquímica Médica Leopoldo de Meis, Universidade Federal do Rio de Janeiro, Rio de Janeiro, 21941-590 Rio de Janeiro, Brazil
Nathane C. Mebus-Antunes
Instituto de Bioquímica Médica Leopoldo de Meis, Universidade Federal do Rio de Janeiro, Rio de Janeiro, 21941-590 Rio de Janeiro, Brazil
Carlos H.G. Neto
Instituto de Bioquímica Médica Leopoldo de Meis, Universidade Federal do Rio de Janeiro, Rio de Janeiro, 21941-590 Rio de Janeiro, Brazil
Glauce M. Barbosa
Instituto de Bioquímica Médica Leopoldo de Meis, Universidade Federal do Rio de Janeiro, Rio de Janeiro, 21941-590 Rio de Janeiro, Brazil
Fabio C.L. Almeida
Instituto de Bioquímica Médica Leopoldo de Meis, Universidade Federal do Rio de Janeiro, Rio de Janeiro, 21941-590 Rio de Janeiro, Brazil; Centro Nacional de Biologia Estrutural e Bioimagem, Universidade Federal do Rio de Janeiro, Rio de Janeiro, 21941-590 Rio de Janeiro, Brazil; Corresponding author
Icaro P. Caruso
Centro Nacional de Biologia Estrutural e Bioimagem, Universidade Federal do Rio de Janeiro, Rio de Janeiro, 21941-590 Rio de Janeiro, Brazil; Centro Multiusuário de Inovação Biomolecular e Departamento de Física, Instituto de Biociências, Letras e Ciências Exatas, Universidade Estadual de São Paulo, São José do Rio Preto, São Paulo 15054-000, Brazil; Corresponding author
Andrea T. Da Poian
Instituto de Bioquímica Médica Leopoldo de Meis, Universidade Federal do Rio de Janeiro, Rio de Janeiro, 21941-590 Rio de Janeiro, Brazil; Corresponding author
Summary: Nucleocapsid (NC) assembly is an essential step of the virus replication cycle. It ensures genome protection and transmission among hosts. Flaviviruses are human viruses for which envelope structure is well known, whereas no information on NC organization is available. Here we designed a dengue virus capsid protein (DENVC) mutant in which a highly positive spot conferred by arginine 85 in α4-helix was replaced by a cysteine residue, simultaneously removing the positive charge and restricting the intermolecular motion through the formation of a disulfide cross-link. We showed that the mutant self-assembles into capsid-like particles (CLP) in solution without nucleic acids. Using biophysical techniques, we investigated capsid assembly thermodynamics, showing that an efficient assembly is related to an increased DENVC stability due to α4/α4′ motion restriction. To our knowledge, this is the first time that flaviviruses’ empty capsid assembly is obtained in solution, revealing the R85C mutant as a powerful tool to understand the NC assembly mechanism.
