Question
A reagent suitable for the determination of $$N$$ - terminal residue of a peptide is
A.
$$p$$ - toluene sulphonyl chloride
B.
2, 4 - dinitrophenyl hydrazine
C.
Carboxypeptidase
D.
2, 4 - dinitrofluorobenzene
Answer :
2, 4 - dinitrofluorobenzene
Solution :
2,4 - dinitrofluorobenzene is called Sanger's reagent. When this reagent reacts with amino group of peptide chain, it form 2, 4 - dinitrophenyl derivatives which on hydrolysis form $$DNP$$ derivatives of amino acids.