Chikungunya virus (CHIKV) is an arthropod-born single-stranded RNA virus belonging to the Alphavirus genus of the Togaviridae family. The virion envelope consists of a lipid bilayer derived from the plasma membrane of the host cell, multiple copies of two major virus encoded glycoproteins E1 and E2, and a small 6K peptide.
The E1 and E2 proteins form a heterodimer anchored in the membrane. CHIKV infection causes an illness with symptoms similar to dengue fever. Recent outbreaks of CHIKV provided an opportunity for genetic analysis of patients with the illness, revealing a point mutation at the amino acid 226 (Ala mutated to Val) of the E1 gene. This point mutation was shown to be responsible for an increased capacity of CHIKV strains to infect and replicate in the Aedes albopictus, facilitating virus transmission to a naive human population.
A2323 is composed of the amino acids 67-482 of the chikungunya E1 protein which was cloned into an insect expression vector, however at position 226 the Alanine of the wild-type CHIKV E1 gene was mutated to Valine. The secreted and soluble recombinant protein was purified with affinity chromatography.