N-terminal amino acids, of peptides

This experiment shows that Phe must be the N-terminal amino acid of peptide B because it is labeled with the DNP group. Front hydrolysis of component 1, Val must be attached to Phe from hydrolysis of component 2, Asp must be attached to Val and from hydrolysis of component 3, Glu must be attached to Asp. The sequence of the first four amino acids of peptide B, starting from the N-terminus, is Phe-Val-Asp-Glu. 

Identification of the N-terminal and/or C-terminal amino acid residues The N-terminal amino acids of peptides are determined chemically by one step of Edman degradation or enzymatic removal by the use of an aminopeptidase. Similarly the... 

The Edman degradation uses phenyl isothiocyanate to remove and identify the N-terminal amino acid of peptides or proteins. The Edman degradation can be repeated and automated so that the sequence of up to 20 to 30 N-terminal amino acids can be determined. 

---