NEETZoologyBiotechnology and Its Applications
In humans, insulin is synthesized as a pro-hormone that contains an extra stretch of C-peptide, which must be removed to form the fully active hormone. Since prokaryotes lack the machinery to process pro-hormones, how did the American company Eli Lilly overcome this structural challenge to produce mature human insulin in 1983?
Options
- ABy introducing the entire human pro-insulin gene into E. coli and allowing the bacteria to naturally process i
- BBy producing pro-insulin in bacteria and using restriction endonucleases to cut out the C-peptide.
- CBy extracting mature insulin from the pancreas of transgenic pigs.
- DBy preparing separate DNA sequences for chains A and B, producing them separately in E. coli, and combining th
Correct answer
D. By preparing separate DNA sequences for chains A and B, producing them separately in E. coli, and combining th
Step-by-step solution
The main challenge for production of insulin using recombinant DNA techniques was getting insulin assembled into a mature form, as bacteria cannot process pro-insulin by removing the C-peptide. In 1983, Eli Lilly prepared two DNA sequences corresponding to A and B chains of human insulin and introduced them in plasmids of E. coli to produce insulin chains. Chains A and B were produced separately, extracted and combined by creating disulphide bonds to form human insulin. Option 1 is incorrect because E. coli lacks t