How synthetic Insulin is made using Recombinant DNA Technology From Bacteria

Summary

This script explains the process of creating synthetic human insulin, a milestone in biotechnology. It covers the role of recombinant DNA technology in producing insulin through bacteria and yeast. The script describes the genetic steps involved in getting bacteria to produce insulin, such as inserting DNA fragments into plasmids and using tetracycline to select transformed bacteria. The process also explains how insulin is formed, starting from pre-pro insulin to its mature form, with key steps including protein folding, cleavage, and purification. This process has enabled millions of diabetics worldwide to regulate their blood sugar levels.

Takeaways

• 😀 Synthetic human insulin is the first major product of the biotechnology industry, resulting from recombinant DNA technology.
• 😀 Millions of diabetics globally use synthetic insulin to regulate their blood sugar levels.
• 😀 Synthetic insulin can be made in both bacteria and yeast.
• 😀 Bacteria lack the ability to process introns, so special modifications are required when using bacterial cells to produce insulin.
• 😀 Insulin production in bacteria begins with creating DNA based on the insulin protein sequence for its A and B chains.
• 😀 The DNA for insulin is inserted into plasmids, which also contain a tetracycline resistance gene.
• 😀 The plasmids are introduced into bacteria through transformation, which allows the bacteria to start producing insulin.
• 😀 Tetracycline is used to eliminate non-transformed bacteria from the culture.
• 😀 The transformed bacteria produce a fusion protein containing both insulin and beta-galactosidase, which is harvested and purified.
• 😀 The beta-galactosidase portion of the fusion protein is cleaved off, leaving behind the mature insulin which is then formed by mixing the insulin chains together.

Q & A

What is the significance of synthetic human insulin in the biotech industry?

Synthetic human insulin is considered the 'golden molecule' of the biotech industry as it was the first major product resulting from recombinant DNA technology, impacting millions of diabetics globally who use it to regulate blood sugar levels.

How is synthetic insulin produced?

Synthetic insulin is produced using bacteria and yeast. These organisms are genetically engineered to produce insulin by inserting the insulin gene into their DNA, allowing them to manufacture the hormone.

Why do bacteria need to be modified to produce insulin?

Bacteria lack the biochemical machinery to process certain complex aspects of human insulin production, such as removing introns from genes or folding proteins correctly. Therefore, they are genetically modified to accommodate these processes.

What role do introns play in insulin production?

Introns are non-coding regions of a gene. Bacteria do not have the machinery to remove these introns from the gene sequence, so they need to be engineered with a gene that can produce the correct form of insulin without introns.

What is the process by which insulin is synthesized in bacteria?

First, the DNA sequence for insulin, based on its protein structure, is inserted into plasmids. These plasmids are then introduced into bacteria, where the bacteria use the information to produce a fusion protein. This protein is later purified and processed into insulin.

What is the significance of pre-proinsulin in the insulin production process?

Pre-proinsulin is the initial translated form of insulin, consisting of 108 amino acids. The first 24 amino acids act as a signal peptide that directs the protein out of the cell. It is later cleaved to form proinsulin, which is further processed into active insulin.

What is the role of the sulfide bridges in insulin's structure?

Sulfide bridges, formed between cysteine amino acids, help stabilize insulin's structure by linking different parts of the protein, enabling it to fold into its functional shape.

How are plasmids used in the production of insulin?

Plasmids, which are small circular DNA molecules, are used to carry the insulin gene into bacteria. The plasmids also contain resistance genes, such as the tetracycline resistance gene, to help identify transformed bacteria.

What is the purpose of adding tetracycline to the bacterial culture?

Tetracycline is added to the culture to kill any bacteria that have not been transformed with the plasmid containing the insulin gene. This ensures that only the modified bacteria, which can produce insulin, survive.

What happens to the beta-galactosidase protein in the process of insulin production?

The beta-galactosidase protein is part of the fusion protein produced in the bacteria. After harvesting, the fusion protein is purified, and the beta-galactosidase part is cleaved off and discarded, leaving only the insulin chains to be processed.