Abstract

Structural protein VP1 of foot-and-mouth disease virus (FMDV) is the most frequently studied protein due to its significant roles in virus attachment, protective immunity, and serotype specificity. The coding sequence of VP1was amplified and then identified by polymerase chain reaction (PCR) and sequencing. To achieve high-level expression of VP1 protein, we optimized VP1 gene base on Escherichia coli preferred codons and synthesized the optimized gene. The synthetical gene was cloned into the fusion expression vector pET-28a and expressed in E. coli BL21(DE3). After induced with Isopropyl β-D-1-Thiogalactopyranoside (IPTG) and optimized the conditions of expression, the VP1 fusion protein was highly expressed and identified in inclusion bodies by SDS-PAGE and Western blotting. Based on the primary and secondary structure analysis of VP1, Three-dimensional structure of VP1 was developed by homology modeling methods. The validation of 3-D structure was done with the help of PROCHECK encompassing amino acid residues in the most favored region of almost all strains. Potential epitopes of VP1 was predicted with different methods. In this study, the VP1 protein was expressed inE. coli efficiently and highly purified VP1 was obtained, which laid a foundation of refolding and further study on activity of the protein. The VP1 model in the productive conformation can now be used for structure-based design purposes as well as structure-function relation of VP1 protein.

Key words: Foot-and-mouth disease virus, VP1 protein, codon optimization, homology modeling.