The case of diabetes increases significantly and has been projected to reach 592 million people in 2035. Consequently, the necessity of insulin will rise manifold and an efficient production system for insulin production is required to meet the market demands. The human insulin precursors that enzymatically converted to human insulin can be produced using Escherichia coli, Saccharomyces cerevisiae, or Pichia pastoris. In this study, Pichia pastoris is used for production human insulin precursor because the resulting recombinant protein can be folded accordingly and secreted to the external environment of the cell that simplifies the purification process. The study was initiated with the insertion of a synthetic gene of human insulin precursor into the pPICZaA to create recombinant pPICZaA-IP plasmid. The recombinant plasmid was transformed into Escherichia coli Top10 which then isolated and digested by the SacI enzyme. The linearize pPICZaA-IP plasmid was transfected into Pichia pastoris X-33 by electroporator. The result of transformation process, a total of 20 colonies of P pastoris X-33 were selected and inoculated in YPD agar medium containing Zeocin. The two colonies of P pastoris were characterized by PCR and sequencing showed that the recombinant pPICZaA-IP plasmid was successfully integrated into selected colonies of P pastoris.

The prevalence of Insulin Dependent Diabetes Mellitus (IDDM) has increased significantly in the last decades, resulting in an increased demand for insulin. In addition, new routes of oral and inhaled insulin require higher doses thus increasing insulin requirements. Insulin is the primary drug in patients with type 1 diabetes mellitus (T1DM). In some cases, type 2 diabetes mellitus (T2DM) requires insulin for treatment. The researchers have widely developed another expression system to meet the ever-increasing demand for insulin with higher production capacities. Human insulin precursor (HIP) production can use several microorganisms such as Escherichia coli, Saccharomyces cerevisiae, and Pichia pastoris. In this study, P. pastoris X-33 was used to produce human insulin precursor. Pichia pastoris becomes the promising yeast host for recombinant protein expression because of its ability to reach high cell densities by its robust methanolinducible alcohol oxidase 1 (AOX1) promoter and simple development process, which provide to high quality and a high percentage of recombinant proteins, both intracellular and secretory. In this study, several zeocin-resistant clones were characterized by PCR and sequencing using a specific human insulin precursor gene to detect plasmid integration into the P. pastoris genome. In addition, a test of the effect of zeocin concentration on the growth of the transformation was carried out. The expression of HIP protein in P. pastoris X-33 was characterized by SDS-PAGE and Elisa. The result of PCR and sequencing showed that the HIP gene was successfully integrated into selected colonies of P. pastoris X-33. All of 20 transformant colonies were able to grow at 100 to 2000 μg per mL and selected colonies of P. pastoris X-33 can produce HIP protein.