amino acid analysis of the peptide revealed that it is a tridecapeptide composed of aspartic acid ( asp ) , glutamic acid ( glu ) , proline ( pro ) , alanine ( ala ) , valine ( val ) , isoleucine ( ile ) , two residues of leucine ( leu ) , tyrosine ( tyr ) , histidine ( his ) , lysine ( lys ) and two residues of arginine ( arg ) .
C0002520
amino acid
C0001898
alanine