Chapter 24 Practice Questions - CEM252 at MSU Fall 1996

Question 1 - Part A

An octapeptide was divided into three samples and each sample was subjected to cyanogen bromide, chymotrypsin, or trypsin. The fragments obtained in each of the treatments were separated, hydrolyzed and subjected to amino acid analysis with the following results. (Amino acid composition of each fragment is listed in alphabetical rather than sequential order)
Amino acid names, structures, and pKa Values

• Cyanogen bromide fragment 1: cysteine (CYS), lysine (LYS), tryptophan (TRP)
• Cyanogen bromide fragment 2: methionine (MET), tyrosine (TYR), valine (VAL)
• Cyanogen bromide fragment 3: leucine (LEU), methionine (MET)
• Chymotrypsin fragment 1: cysteine, lysine, methionine, tryptophan
• Chymotrypsin fragment 2: leucine, methionine, tyrosine, valine
• Trypsin fragment 1: cysteine, tryptophan
• Trypsin fragment 2: leucine, lysine, methionine (2), tyrosine, valine