Insulin production in bacteria involves genetically engineering bacteria to produce the insulin protein. The insulin chains are made as part of a larger precursor protein inside the bacterial cells.
Steps Involved in Bacterial Insulin Production
The process can be broken down into the following key steps:
- Gene Insertion: The human gene for insulin (or, more accurately, the genes for the A and B chains of insulin) is inserted into a bacterial plasmid. A plasmid is a small, circular DNA molecule that is separate from the bacterial chromosome and can replicate independently.
- Precursor Protein Production: Inside the bacterial cells, the insulin chains are made as tails on a larger precursor protein, specifically the enzyme beta-galactosidase. According to provided references, this method ensures efficient production of the insulin peptide chains.
- Bacterial Growth: The bacteria, now containing the insulin gene, are grown in large fermentation tanks to produce large quantities of the precursor protein.
- Cleavage and Purification:
- The insulin peptide chains are clipped from the precursor protein by treatment, in vitro, with cyanogen bromide.
- The insulin chains are then purified and processed to form the active insulin molecule.
- Assembly: The A and B chains are combined to form the functional insulin molecule.
Summary Table: Insulin Production in Bacteria
| Step | Description |
|---|---|
| Gene Insertion | Human insulin gene inserted into a bacterial plasmid. |
| Precursor Protein Synthesis | Bacteria produce a large precursor protein, where the insulin chains are made as tails of beta-galactosidase. |
| Bacterial Growth | Bacteria are cultivated in large tanks to amplify the insulin production. |
| Cleavage & Purification | Insulin chains are separated from the precursor protein using cyanogen bromide and subsequently purified. |
| Assembly | A and B chains are combined to form active insulin. |
Advantages of Bacterial Insulin Production
- Scalability: Bacteria can be grown quickly and in large quantities, making insulin production cost-effective.
- Purity: Recombinant insulin produced in bacteria is highly pure.
- Ethical Considerations: It avoids the need to extract insulin from animal pancreases.
