NEETZoologyBiotechnology and Its Applications
During the development of genetically engineered human insulin, the primary challenge was getting the insulin assembled into its mature form. Why did the American company Eli Lilly choose to synthesize the A and B chains separately in E. coli rather than inserting the complete human pro-insulin gene?
Options
- AE. coli lacks the necessary mechanism to process pro-insulin by removing the C-peptide to form mature insulin.
- BE. coli lacks the enzymes required to transcribe human DNA sequences into mRNA.
- CThe C-peptide sequence is toxic to E. coli and prevents the multiplication of the host cells.
- DE. coli degrades the disulphide bonds immediately after the complete pro-insulin molecule is synthesized.
Correct answer
A. E. coli lacks the necessary mechanism to process pro-insulin by removing the C-peptide to form mature insulin.
Step-by-step solution
The main challenge in producing human insulin using rDNA technology was getting the insulin assembled into its mature form. In humans, insulin is synthesized as a pro-hormone containing an extra stretch called the C-peptide, which is removed during maturation. Bacteria like E. coli lack the eukaryotic post-translational modification machinery required to cleave the C-peptide from pro-insulin. To overcome this, Eli Lilly prepared two separate DNA sequences corresponding to the A and B chains and introduced them into