Expression Of Human Basic Fibroblast Growth Factor Mediated By Mini Intein In Bacillus Subtilis

Abstract

Bacillus subtilis (B. subtilis) is an ideal host system in production of homologous proteins. However, the production of heterologous proteins in B. subtilis is rare due to low expression levels encountered in most cases. Inteins, also known as ‘protein intron’, which is capable of excised itself from its fusion partners, have been employed for the expression of recombinant proteins in various host systems especially in Escherichia coli (E. coli) but yet, only few paucity of employment of inteins for protein expression in B. subtilis has been found. In this communication, we demonstrated that B. subtilis was able to facilitate auto-cleavages between intein and C-extein. The construct, pECBS1-H6-DnaE-bFGF, in which a 6x His-tag (H6) and basic fibroblast growth factor (bFGF) were fused at the N- and C-terminus of Asp DnaE (intein) respectively, was shown to be capable of processing intracellular expression and auto-cleavages of bFGF with same primary sequence as Homo Sapiens. Moreover, switching shake of flask cultivation to small fermentative scale yielded 113 mg L-1 of biologically active bFGF. This approach of using intein Asp DnaE for the production of heterologous proteins is highly productive and should be explored further for industrial application.