Question

The specific cleavage at Phe, Tyr and Trp amino acids is catalyzed by

• A. chymotrypsin
• B. trypsin
• C. cyanogen bromide
• D. acetylcholinesterase

Hint:

Trypsin = Basic (K, R); Chymotrypsin = Aromatic (F, Y, W).

Answer 1

The Correct Option is A

Step 1: Concept
Proteolytic enzymes (proteases) have specific binding pockets that recognize certain amino acid side chains.

Step 2: Meaning
Phenylalanine (Phe), Tyrosine (Tyr), and Tryptophan (Trp) are large, bulky aromatic amino acids.

Step 3: Analysis
Chymotrypsin has a deep hydrophobic pocket that accommodates these aromatic rings, allowing it to cleave the peptide bond on the carboxyl side of these residues. Trypsin cleaves at basic residues (Lys, Arg), and Cyanogen bromide cleaves at Methionine.

Step 4: Conclusion
Chymotrypsin is the enzyme specific to Phe, Tyr, and Trp. Final Answer: (A)