4. A protein biochemist attempted to determine the amino acid sequence of a deca

Question

4. A protein biochemist attempted to determine the amino acid sequence of a decapeptide. Use the results from chymotrypsin, and cyanogen bromide treatments to suggest the amino acid sequence of this d questions (31-35) based on the results below: the trypsin, ecapeptide. Answer the followir Trypsin digestion gave three fragments containing the following residues (not in order): T1: Pro. Are, Phe, Ala T2:Thr e . Chymotrypsin digestion gave three fragments containing the following residues (not in order): CT1: Trp, Arg CT2: Pro, Phe, Ala CT3: Met, Thr, Val, Met, Lys Treatment with fluorodinitrobenzene, which labels the N-terminal residue, resulted in an Ala derivative. The cyanogen bromide treatment gave three fragments containing the following residues (not in order): CNBr1: Met, Val CNBr2: Ala, Phe, Pro, Trp, Met, Arg CNBr3: Thr, Lys Based on these results, what is the sequence of the decapeptide (4 pts)? d ackhone indicating bond and dihedral angles (including names) (3 pts).

Explanation / Answer

1. N-terminal amino acid = Ala
2. CNBr cleaves at C-terminal of Met. So, CNBr1 = Val-Met
3. Trypsin cleaves at the C-terminal of Arg or Lys.
4. Chymotrypsin cleaves at the C-terminal of Phe, Trp, and Tyr.

a. N-terminal amino acid = Ala
b. CNBr1 = Val-Met
c. CT1 = Arg-Trp
d. CT2 = Ala-Pro-Phe
e. T1 = Ala-Pro-Phe-Arg
f. T1 + CT1 = Ala-Pro-Phe-Arg-Trp
g. T1 + CT1 + CNBr2 = Ala-Pro-Phe-Arg-Trp-Met

Rearranging the remaining sequences will give the actual sequence is
Ala-Pro-Phe-Arg-Trp-Met-Val-Met-Lys-Thr

Related Questions

Navigate

• Browse (All)
• Browse 4
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.