Biomolecules - Result Question 41
####41. A reagent suitable for the determination of $N$-terminal residue of a peptide is
(a) $p$-Toluenesulphonyl chloride
[1996]
(b) 2,4-Dinitrophenylhydrazine
(c) Carboxypeptidase
(d) 2,4-Dinitrofluorobenzene
Show Answer
Solution:
- (d) 2,4-Dinitroflurobenzene, also known as Sanger’s reagent, reacts with the $H_2 N$ - group of the peptide to from 2, 4- dinitrophenyl (DNP) derivative of the peptide. The DNP derivative of the peptide is hydrolysed to give DNP derivative of the single amino acid
CPc1ccc(N+[O-])cc1N+[O-]
2, 4, Dinitrofluoro benzene
(DNP derivative of polypeptide)
(Amino acid mixture)
