(Laboratory of Organic Chemistry, the University, PO Box 75, Leiden, The Netherlands) ... Leu-Ser-Phe-Met-Ala-lle-Pro-Pro-Lys-Lys and 14 smaller peptide fragments simulating increasing parts of the sequence around the rennin sensitive Phe-Met bond in r-casein have been synthesized and characterized. ... In a short communication** we reported on the ability of the following peptides corresponding to the sequence around the rennin sensitive Phe-Met bond of K-casein'.' to ...