question_answer

                                                                                                                        Insulin is synthesised by introducing its gene into E. coli which is a bacterium and does not possess enzymes for removing introns, present in mammalian genes. Explain how insulin is obtained from this bacterium?

Answer:

Insulin is produced by the \[\beta \]-cells of islets of Langerhans of the pancreas. In humans, insulin is synthesised as a prohormone which contains an extra stretch called as C-peptide. This C-peptide is not present in the mature insulin and is removed during maturation into insulin. The main challenge for production of insulin using DNA technique was getting insulin assembled into a mature form. To solve this problem, two chains A and B of insulin were synthesised separately by inserting their genes in the E. coli. After extraction, these two chains were combined by creating disulphide bonds to form human insulin.