Specific chemical cleavage of asparaginyl and glycyl-glycine bonds in peptides and proteins by anhydrous hydrazine vapor.

Hydrazinolysis of peptide or protein has been used for C-terminal amino acid determination by Akabori et al. (1952). In this study, proteins were reacted with anhydrous hydrazine vapor at 20 degrees C for 16 h. Asparaginyl linkages were cleaved. Asparagine and glutamine were converted to their hydrazides, beta-hydrazidyl aspartic acid and gamma-hydrazidyl glutamic acid, respectively, even under milder conditions. The former hydrazide cyclizes to a 6-membered ring, asparaginyl bond at the carboxyl side. Other cleavages, including the glycyl-glycine bond, were also observed.