Insulin Production Process

Human insulin is a small protein consisting of 51 amino acids with a molecular weight of 5734 and an isoelectric point (pi) of 5.4. Insulin is made up of two peptide chains connected by 2 disulfide bonds the A chain with 21 amino acids and the B chain with 30 amino acids. This small recombinant protein has been produced on very large scales for over two decades. The various commercial processes in production have been improved over the years but are still very complex [18-21]. 

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Insulin production process A small protein with very complex and extensive purification/reaction processing. 

Recovery nd Purifica.tion. The production of EH Lilly s human insulin requires 31 principal processing steps of which 27 are associated with product recovery and purification (13). The production process for human insulin, based on a fermentation which yields proinsulin, provides an instmctive case study on the range of unit operations which must be considered in the recovery and purification of a recombinant product from a bacterial fermentation. Whereas the exact sequence has not been pubUshed, the principle steps in the purification scheme are outlined in Figure la. 

Fig. 1. (a) Process flow sheet for human insulin production, recovery, and purification (12) (b) corresponding steps in recovery of biosynthetic human... 

Generai This human insulin product differs from animal-source insulins because it is structurally identical to the insulin produced by the body s pancreas and because of its unique manufacturing process. 

Typically, 7.0 g of human insulin can be prepared from 10 g of purified porcine insulin. The process allows large-scale production of human insulin simply and inexpensively. The complete de novo synthesis of human insulin, while technically possible, is economically unattractive. 

Petrides, D., Sapidov, E., and Calandranis, J. (1995). Computer-aided process analysis and economic evaluation for biosynthetic human insulin production—A case study. Biotechnol. Bioeng. 48, 529-541. 

The next two examples pursue this line of thought further wherein we analyze a computer-aided process of human insulin production.15 This is then followed by an analysis of process simulation of heparinase I production from E. coli.5... 

Here, we review the possibilities for optimization of the production process for human insulin and its analogues in a specific S. cerevisiae host system described below and used by Novo Nordisk A/S. 

Since the first product, the recombinant kallilcrein inhibitor ecallantide (KALBITOR , Dyax, USA), was approved by the FDA in 2009, several more followed, mainly being peptides and small proteins. Antibodies and fragments thereof are currently in clinical trials awaiting approval [154]. Several more biopharmaceutical products such as insulin, interferon-alpha 2b, and hepatitis B vaccine are on the market in India and other Asian countries [155]. Apart from biopharmaceuticals, a range of industrial enzymes, among them phytase, nitrate reductase, or lipase, are commercially available. Direct information on the production process is mostly not available, but it can be concluded from journal and patent literature that mostly the AOXl promoter is used in these cases, and other expression systems like the GAP promoter are applied as well. In total, approximately 70 products are on the market, and a list can be found at http // www.pichia.com/science-center/commercialized-products/ [156]. 

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