Intein-mediated high-yield expression of recombinant teriparatide

Teriparatide, a recombinant fragment of parathyroid hormone (rPTH), is employed in the treatment of osteoporosis. However, its biosynthesis is hampered by several challenges, including host-mediated degradation, low expression levels, and the high costs associated with affinity tag removal. In this study, a gp41-1 mutant with demonstrated high traceless cleavage activity was fused to teriparatide to address these issues and develop an intein-mediated high-yield expression system. D107Ggp41-1 presented relatively low unexpected cleavage in vivo (30%-40%, over 50% for other inteins) and a great cleavage efficiency in vitro, reaching 90% completion within 4 h. An optimized fed-batch fermentation process, incorporating refined induction conditions and carbon source selection, was developed to enhance teriparatide production, resulting in a final yield of 1.3 g/L. Following secondary purification, the purity of recombinant teriparatide (rTeriparatide) exceeded 98%. This scalable fermentation process for high teriparatide production that utilizes gp41-1-mediated expression system, presenting a promising foundation for efficient industrial manufacturing.