Methods of Insulin Production: Method B

The Proinsulin Process:

In 1986, another method to synthesize human insulin using the direct precursor to the insulin gene, proinsulin, was popularized. Many steps are the same as when producing insulin with the A and B chains, except for mostly in the downstream process.

What is proinsulin?
Insulin is naturally synthesized as pre-proinsulin in the pancreas. It is converted to proinsulin with the N-terminal signal peptide enzymatically removed. Proinsulin is composed of the amino acid chains that will form insulin and a connecting 30 residue peptide, that joins one end of chain A to chain B. Enzymatic proteolysis removes the peptide chain to produce insulin.

• The proinsulin coding sequence is inserted into the non-pathogenic E. coli bacteria and the bacteria undergo fermentation where they replicate and produce proinsulin. The connecting sequence between the A and B chains is then spliced away with an enzyme and the resulting insulin is purified.

• At the end of the both manufacturing processes, ingredients are added to insulin to prevent bacteria growth and maintain a neutral pH balance.

There are 3 parts to Process Description:

>Part I of Process Description - Brief Introduction<

>Part II of Process Description - Method A<

>You are Here: Part III of Process Description - Method B<

>Part IV of Process Description - Types of Insulin<