Concentration dependent aggregation of purified recombinant VP2 protein of foot-and-mouth disease virus serotype O/IND/R2/75

The VP2 capsid protein of the Foot-and-mouth disease virus (FMDV) is important for viral assembly, inducing host autophagy to enhance replication, and serving as an important target for broad-spectrum diagnostic tests and engineered vaccines. It is considerably conserved among different FMDV serotypes; hence, often targeted in serotype independent diagnosticassay for FMDV. In this study, the VP2 protein of the FMDV O/IND/R2/75 was expressed in Escherichia coliBL21 cells in Luria broth. The VP2 proteinwas produced at 2 mg L^-1. The protein was predominantly expressed in the soluble fraction, with only a minimal amount detected in the insoluble fraction of the bacterial lysate. On concentrating rVP2 protein to concentration exceeding 50–70 μM, the protein tends to aggregate. This aggregation and amino acid sequence of rVP2 protein responsible for aggregation can be predicted using tools like TANGO and PASTA 2.0. The aggregated protein was successfully solubilised and refolded using slow dialysis protocol. The expressed rVP2 capsid protein can be utilised for further characterisation of protein, for the serotype independent diagnostic assay development and structural studies of the protein.