Peptide – sequencing via Edman - degradation

 

 

Problems

 

Incomplete cleavage: -Gly-His-, -Pro-His-

Histidine:partial cleavage within peptide chain

Asp-Gly bonds: side-reactions at low pH, Cyclization, Rearrangement of peptide to b-aspartylbond

Glutamine, S-Carboxymethylcysteine: side-reactions at low pH, Cyclization

Tryptophane: side-reaction at low pH and with oxygen

Glycosylated AS