Applicability of the constitutive<i> GAP</i> promoter for recombinant human insulin hormone production in<i> Pichia</i><i> pastoris</i>

Insulin is a hormone regulates glucose homeostasis in the body. In this study, the precursor of the human insulin hormone was expressed under the constitutive Glyceraldehyde-3-phos-phate dehydrogenase (GAP) promoter. The expression vector was transferred into the P. pastoris X33 strain by electroporation. After the protein expression study in 5L scale bioreactor, the samples were analysed by SDS-PAGE and ELISA methods. In this study, 11 mg/ L of protein was produced in the bioreactor at the end of production. The MALDI-TOF analysis confirmed that the protein produced was a precursor of the human insulin hormone. At the end of the study, it can be said that a bioprocess has been developed under bioreactor conditions to produce human insulin precursors by using constitutive GAP promoter of P. pastoris.