試題詳解

3. Emma wants to analyze the sequence of the following peptide "GHYEFLLCRGDENTTCLNKM". She uses several agents to treat the sample. Which of the following description is       correct      ?
(A) If she uses phenylisothiocynate, she can get the information for the first residue only.
(B) If she uses trypsin, she can get the peptide "RGDENTTCLN".
(C) In order to know whether this peptide has disulfide bond, she can treat the sample with or without cyanogen bromide (CNBr) before trypsin digestion and compare the result. If cyanogen bromide makes no difference, it suggests that no disulfide bond formation in this peptide.
(D) If she uses chymotrypsin, she can get the peptide "EFLLCRGDENTTCLNKM".
(E) If she uses pepsin, she can get the peptide "EFLLCRGD".