Simulation · Biology · Class 12
Human insulin: assembling the mature hormone
From the lesson Genetically engineered insulin in Biotechnology and its Applications. Change the values and watch what happens.
Human insulin: assembling the mature hormoneBiology · Class 12
The idea behind it
NCERT §10.2, §10.2.1
- Recombinant DNA technology allows mass production of safe and more effective therapeutic drugs. Recombinant therapeutics do not provoke the unwanted immune responses common with similar products taken from non-human sources.
- Worldwide, about 30 recombinant therapeutics have approval for use in humans; 12 of these are currently sold in India.
- Adult-onset diabetes can be managed by taking insulin at regular intervals.
- Insulin was earlier extracted from the pancreas of slaughtered cattle and pigs. Being a foreign protein, animal insulin caused allergy or other reactions in some patients.
- Insulin is made of two short polypeptide chains, A and B, linked by disulphide bridges.
- In mammals, humans included, insulin is made as a pro-hormone that must be processed before it works. The pro-hormone carries an extra stretch, the C peptide, which is removed during maturation and is absent from mature insulin.
- The main difficulty in making insulin by rDNA techniques was getting it assembled into the mature form.
- In 1983 the American company Eli Lilly made two DNA sequences, one for the A chain and one for the B chain of human insulin, and placed them in E. coli plasmids.
- The A and B chains were produced separately, extracted, and joined by creating disulphide bonds, giving human insulin.