In vitro assembly of nucleocapsid-like particles from purified recombinant capsid protein of dengue-2 virus.

The capsid protein is one of the three structural proteins of flaviviruses and is the building block of the nucleocapsid. It has also a predominant role in the replication of dengue virus. To obtain nucleocapsid-like particles from recombinant dengue-2 capsid protein produced in E. coli, a purification process using cation exchange chromatography was established. The purified protein exhibited a molecular mass corresponding to a dimer; therefore, similar to that reported for alphaviruses, an in vitro assembly reaction using single-stranded DNA was performed. In all cases, particles were obtained independently of the specificity and the length of the oligonucleotides used. The present work is the first report of in vitro assembly of the recombinant dengue capsid protein, which could constitute a powerful tool in the development of vaccine candidates.