Tryptophyl bonds, selective cleavage

Patchornik A, Lawson WB, Witkop B. Selective cleavage of peptide bonds.2. The tryptophyl peptide bond and the cleavage of glucagon. J. Am. Chem. Soc. 1958 80 4747-4748. 

B. Selective Cleavage of Tryptophyl Peptide Bonds in Serum Albumins... 284... 

Bromosuccinimide and N-Bromoacetamide for the Selective Cleavage of C-Tryptophyl Peptide Bonds in Model Peptides and Glucagon. J. Amer. Chem. Soc. 82, 5923-5927 (1960). 

---