while two of the three mutant pro-npy molecules were processed to wild-type carboxyl-terminal peptide , the carboxyl-terminal peptide derived from pro-npy ( -arg-lys- ) contained an amino-terminal lysine residue , indicating that biosynthetic endoproteolysis occurred in the middle or at the amino terminus of the pair of basic amino acid residues at the cleavage site .
C0024337
lysine
C0301714
amino