A Simplified and Efficient Process for Insulin Production in Pichia pastoris

PLoS One. 2016 Dec 1;11(12):e0167207. doi: 10.1371/journal.pone.0167207. eCollection 2016.

Abstract

A significant barrier to insulin is affordability. In this manuscript we describe improvements to key steps in the insulin production process in Pichia pastoris that reduce cost and time. The strategy for recovery and processing of human insulin precursor has been streamlined to two steps from bioreactor to the transpeptidation reaction. In the first step the insulin precursor secreted during the methanol induction phase is recovered directly from the culture broth using Tangential Flow Filtration with a Prostak™ module eliminating the laborious and time-consuming multi-step clarification, including centrifugation. In the second step the protein is applied at very high loadings on a cation exchange resin and eluted in a mixture of water and ethanol to obtain a concentrated insulin precursor, suitable for use directly in the transpeptidation reaction. Overall the yield from insulin precursor to human insulin was 51% and consisted of three purification chromatography steps. In addition we describe a method for recovery of the excess of H-Thr(tBu)-OtBu from the transpeptidation reaction mixture, one of the more costly reagents in the process, along with its successful reuse.

MeSH terms

  • Batch Cell Culture Techniques
  • Bioreactors*
  • Chromatography / methods
  • Fermentation*
  • Humans
  • Insulin / biosynthesis*
  • Insulin / isolation & purification
  • Pichia / metabolism*
  • Proteolysis
  • Recombinant Proteins / biosynthesis*
  • Recombinant Proteins / isolation & purification

Substances

  • Insulin
  • Recombinant Proteins

Grants and funding

The authors received no specific funding for this work. Origi Domenico is employed by Merck, manufacturer of the Prostack module used in this study. Merck provided support in the form of salary for author OD, but did not have any additional role in the study design, data collection and analysis, decision to publish, or preparation of the manuscript.