Synthetic insulin, which is essentially a lab-made copy of human insulin, is primarily produced using genetic engineering techniques in microorganisms. Here's a breakdown of the process:
Recombinant DNA Technology
The key to creating synthetic insulin lies in recombinant DNA technology. Here's how it works:
1. Identifying and Isolating the Human Insulin Gene
Scientists first locate and isolate the human gene responsible for insulin production.
2. Inserting the Gene into a Vector
This isolated gene is then inserted into a vector, which acts as a carrier. Common vectors include plasmids – small, circular DNA molecules found in bacteria.
3. Transforming Host Organisms
The engineered vector (plasmid with the insulin gene) is introduced into a host organism, usually bacteria like E. coli or yeast like Saccharomyces cerevisiae. This process is called transformation.
4. Protein Expression
Once inside the host organism, the inserted insulin gene begins to express itself, leading to the production of insulin precursors (IP).
Production in E. coli
As referenced in the provided information, E. coli is a common host for insulin production. Here’s how it works:
- Inclusion Bodies: When E. coli produces insulin precursors, they often form insoluble aggregates called inclusion bodies.
- Solubilization and Refolding: To obtain functional insulin, these inclusion bodies need to be solubilized (dissolved) and refolded into their correct three-dimensional structure. This is a crucial step to ensure the insulin is biologically active.
Production in Saccharomyces cerevisiae
Yeast like Saccharomyces cerevisiae is also used for insulin production, offering an alternative to E. coli production. The process is similar, but it may involve different post-production steps for purification and processing.
Purification and Quality Control
After production, the insulin must undergo several purification steps to separate it from the host cells, including:
- Chromatography: Different forms of chromatography to isolate insulin
- Filtration: Further refining and concentrating the insulin
- Quality Checks: Rigorous quality control measures are used to guarantee the purity, potency, and safety of the final product.
Summary
| Step | Description |
|---|---|
| Gene Isolation | The human insulin gene is isolated. |
| Vector Insertion | The insulin gene is placed into a vector, like a plasmid. |
| Host Transformation | The vector is inserted into a host organism (e.g., E. coli or Saccharomyces cerevisiae). |
| Insulin Production | The host organism expresses the insulin gene, producing insulin precursors. |
| Purification & Refolding | The insulin is extracted, purified, and refolded (if needed), making it usable. |
| Quality Control | The final product is rigorously tested for purity and efficacy. |
In essence, modern synthetic insulin production relies on genetic engineering, where the human insulin gene is transferred into microorganisms that act as miniature factories to produce the insulin. The insulin produced is then purified and processed into a form suitable for use by individuals with diabetes.
