Question

Which of the following is the correct sequence to artificially synthesise human insulin in E.coli?

A. Creation of disulfide bonds between A and B chains
B. Ligation of A and B genes with plasmid vector
C. Extraction of product from the bacteria
D. Transformation of E.coli with the recombinant vector
E. Culture of bacterial cells having recombinant DNA in the bioreactors
F. Synthesis of DNA sequences coding for A and B insulin peptide chains

• A. B→F→D→A→C→E
• B. F→B→D→A→E→C
• C. A→B→D→E→C→F
• D. F→B→D→E→C→A

Answer 1

The correct option is D F→B→D→E→C→A

In 1983, Eli Lilly, an American company, prepared human insulin.

The procedure is as follows.

1. Artificial synthesis of DNA sequences, each coding for A and B peptide chains of mature insulin. (F)

2. Plasmid DNA extracted from E.coli is cut with a restriction enzyme. Each of the artificially synthesised insulin-producing genes are inserted into separate bacterial plasmid vectors to form the recombinant DNA using DNA ligase. (B)

3. Transformation of bacteria with recombinant DNA to form the recombinant bacterium. (D)

4. The recombinant bacteria cultured in the bioreactor produce A and B chains of insulin separately. (E)

5. Extraction of the product from the bacteria is done. (C)

6. This is followed by the creation of disulfide bonds between A and B chains to get the matured form of human insulin. (A)