Biochemical Characterization of the Envelope Glycoproteins of Chi kungunya Virus

Abstract

Chikungunya (CHIK) virus is a human pathogen classified as an alphavirus. Epizootic in - Southeast Asia and Africa, CHIK virus causes a sylvatic disease in man. Ross River, O'nyong-nyong, and Mayaro alphaviruses are the causative agents of human disease similar to CHIK, and the viruses are closely related based on antigenic cross reactivity. The underlying principle for antigenic relatedness is viral protein structure. Alphaviruses are thought to have evolved from a common ancestor, therefore proteins of related alphaviruses should reflect the degree of evolutionary divergence between viruses in their primary protein structure. Envelope proteins from five geographic strains of CHIK and six other alphaviruses were biochemically characterized by peptide maps. Comparision of peptide maps demonstrated a possible biochemical basis for the serological relationships. Viral envelope proteins have been used as immunogens in mice to determine which protein(s) induced neutralizing and/or hemagglutinin inhibiting antibodies. Alphaviruses have two conserved sequences in the amino-terminus of the envelope polypeptides, and at the 3' terminus of the viral genomic ribonucleic acid. The alphavirus characteristic conserved regions were demonstrated for CHIK virus in this study.