Das Lab und seine Wirkung auf das Casein der Milch. XI. Die aminoseitigen Endgruppen des α‐Caseins vor und nach der Labung

Quantitative determinations of the terminal amino groups of α‐casein before and after treatment with crystalline rennin were carried out using Sanger's method of labeling the free amino groups with dinitrophenyl residues. In native α‐casein the terminal amino acids were found to be lysine and arginine. In rennin treated α‐casein the same endgroups can still be detected, though lysine in smaller quantities. In addition a new terminal amino acid namely phenylalanine appears in the α‐paracasein.