La Photooxydation Du Groupe Peptide—i. Protéines Fibreuses*

The determination of the α‐ketoacids, glyoxylic and pyruvic in partial hydrolysates of fibrous proteins (keratin and fibroin) after exposition to u.v. light has allowed us to suggest a photooxydation mechanism for the α‐aminoacid residues of glycine and alanine in proteins. The primary reaction is believed to be the formation of the peptide radical ‐NH‐CR‐CO‐, and the breakdown of polypeptide chains is explained by the formation of α‐ketoacyl peptide linkages.