Challenging for Expression Bovine Rotavirus (RF Strain) Full-Length VP7 Protein in Prokaryotic System

Rotavirus enteritis is an acute viral infectious disease among infants. VP7 protein has a key role in attachment and entry virus into the target cell. The VP7 protein is involved in inducing the production of neutralizing antibodies that protect infants against reinfection of the virus. The aim of this study was to heterologous expression of the VP7 gene of bovine rotavirus as a fusion protein of Trx–VP7 in a genetically engineered bacteria.
Total RNA was extracted from MA104 cells infected with bovine rotavirus strain RF. BRV VP7 gene was amplified using polymerase chain reaction. Another gene was the VP7 synthetic that made in the pBSK plasmid. The pBSK-VP7 plasmid was digested using BamHI and SacI restriction endonucleases, then recombined into the prokaryotic expression vector pET32a. The pET32a-VP7 amplified and pET32a-VP7 synthetic were transformed into BL21 (DE3) competent cells of Escherichia coli, respectively, and induced by different concentrations of Isopropyl β-D-1-thiogalactopyranoside at 30°C and 37°C in luria bertani and terrific broth media, then analyzed using SDS-PAGE and western blotting.
SDS-PAGE analysis showed that the both pET32a-VP7 amplified and pET32a-VP7 synthetic were not expressed in the BL21 (DE3) cells, But the expression of pET32a-VP7 synthetic was weak at 30° C in luria bertani media.
This is the first report of the production of bovine rotavirus (RF strain) Full-Length VP7 in prokaryotic system expression. VP7 is a membrane protein and has toxic domains that show high toxicity in this expression system.