Talk:Structural Biochemistry/Proteins/Protein sequence determination techniques

A peptide A was analyzed and contained the following amino acids: aspartic acid, glycine, serine, tyrosine and valine. Analysis gave the following results : The N-terminus was shown to be serine. On the reaction with a special reagent which digests at the carboxyl group of valine, two peptides were obtained. One of these two was a dipeptide of sequence glycine-serine. The enzyme chymotrypsin, which hydrolyzed at the carboxyl group of tyrosine gave two tripeptides. Use these results to deduce the amino acid sequence of peptide A and explain your reasoning