A method for peptide successive C-terminal degradation using dilute hydrochloric acid.

Dilute hydrochloric acid (10% w/v, 2.74 N) was reacted with peptides and proteins at 25 degrees C for 14 days and 30 days or at 50 degrees C for 1 to 16 hours.These reactions caused successive C-terminal degradation and deamidation of C-terminal alpha-amide and acidic amino acid amides. Under these conditions, the reaction also partially cleaved acid labile peptide bonds, including the C side of aspartic acid and both sides of glycine.