Which of the following peptide chain is removed during maturation of pro-insulin into insulin ?

Options

A. A peptide
B. B peptide
C. C peptide
D. Both A & C peptide

Answer

To answer the question about which peptide chain is removed during the maturation of pro-insulin into insulin, we can follow these steps:

### Step-by-Step Solution:

1. **Understand Pro-insulin Structure**: Pro-insulin is a precursor to insulin and consists of three polypeptide chains: A-chain, B-chain, and C-chain.

2. **Identify the Chains**:
- A-chain: Contains 21 amino acids.
- B-chain: Contains 30 amino acids.
- C-chain: This is the chain that is not part of the final insulin structure.

3. **Maturation Process**: During the maturation of pro-insulin into insulin, the C-chain is cleaved off. This process is essential for the formation of active insulin.

4. **Final Insulin Structure**: After the removal of the C-chain, the remaining A-chain and B-chain are linked together by disulfide bonds to form the functional insulin molecule, which consists of 51 amino acids in total.

5. **Conclusion**: Therefore, the peptide chain that is removed during the maturation of pro-insulin into insulin is the C-peptide.

### Answer:
The C-peptide is removed during the maturation of pro-insulin into insulin.

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