Which of the following protein is produced by genetic engineering as a cure for diseases like emphysema?

Options

A. a - 1 antitrypsin
B. Trypsin
C. Chymotrypsin
D. All of the above

Answer

### Step-by-Step Solution:

1. **Understanding the Question**: The question asks for a specific protein produced by genetic engineering that serves as a cure for diseases like emphysema.

2. **Identifying the Disease**: Emphysema is a lung disease that involves damage to the alveoli (air sacs in the lungs), leading to breathing difficulties. It is often associated with a deficiency of a specific protein.

3. **Researching the Relevant Protein**: The protein that is crucial for lung protection and is often deficient in individuals with emphysema is called Alpha-1 Antitrypsin (AAT).

4. **Role of Alpha-1 Antitrypsin**: AAT is produced in the liver and helps protect the lungs from damage caused by enzymes such as elastase. In emphysema, the deficiency of AAT means that the lungs are not adequately protected.

5. **Genetic Engineering Context**: In cases where individuals have a deficiency of AAT, genetic engineering techniques can be used to produce this protein artificially, allowing it to be administered to patients to help manage or treat emphysema.

6. **Conclusion**: Therefore, the protein produced by genetic engineering as a cure for diseases like emphysema is Alpha-1 Antitrypsin.

### Final Answer:
The protein produced by genetic engineering as a cure for diseases like emphysema is **Alpha-1 Antitrypsin (AAT)**.