Easy expression of the C-terminal heavy chain domain of botulinum neurotoxin serotype A as a vaccine candidate using a bi-cistronic baculovirus system

► Botulinum toxin C-terminal heavy chain in a bi-cistronic baculovirus vector. ► One-step chromatographic purification was used to purify the recombinant protein. ► Enhanced green fluorescent protein was used to facilitate virus selection. ► Vaccination of the mice with recombinant protein induces protective immunogenicity.