Which of the following characteristics about the peptide Val-Asp-Trp-Asn-Ser is correct?
A)It would show a strong absorption band at 280 nm.
B)Reaction with clostripain would yield 2 peptides.
C)After the second round of Edman degradation using the reagent PITC,the PTH-amino acid residue released would be PTH-Asn.
D)It is resistant to trypsin.

Question

Quizplus · Accepted Answer

The peptide contains tryptophan, which absorbs strongly at 280 nm.

Answer: B 
 The peptide contains the amino acid sequence Asp-Trp, which is a known cleavage site for clostripain. Therefore, reaction with clostripain would yield two peptides.

Answer: C 
 In the second round of Edman degradation, the N-terminal residue would be Asn, which would be converted to PTH-Asn upon reaction with PITC.

Answer: D 
 The question does not provide any information to suggest that the peptide is resistant to trypsin, so this statement is incorrect.

Which of the Following Characteristics About the Peptide Val-Asp-Trp-Asn-Ser Is