Preparation Of Recombinant Human Insulin And C Peptide By Transgenic Yeast Pichia Pastoris GS115

Insulin is very well known as the specific medicine for diabetes mellitus treatment for several decades. C peptide, a linking chain with 33 amino acids in length, locates between A and B chain of insulin. In the past, C peptide was considered as a valueless peptide in medicines except its assistant function in formation of disulfide bond of insulin. However, C peptide was proved as a biomedicine helpful to diabetes care at present.In our lab, genetically engineered yeast Pichia Pastoris which boring human proinsulin gene was used to express the protein. Based on comparison of three different kinds of culture media, it was found that heterologous protein could reach a high level with the medium adjusted pH to 5 as well as the inductor methonal concentration could keep with 1%. For cell growth the initial (NH₄)₂SO₄, PTM, glycerol concentrations were 9g/L, 2mL/L and 40g/L, respectively. Based on above, the heterologous protein concentration was increased one time by fermentation in a 10L bioreactor.For the target protein isolation and purification, the supernatant was desalted and concentrated by hollow fiber membrane. The protein could hold...