“…It was reported that all amino acids can act as monovalent anions, while glutamic acid and aspartic acid are two important acidic amino acids which can form both monovalent and divalent anions. 18 Amino acids would use the N atom of the amino group and one O atom from the carboxyl group to chelate Ca ions. 19 The effect of amino acid composition on the Ca-binding ability of peptide was reviewed by Choi et al, 20 who concluded that Asp, Glu, Lys, Leu, Arg and Pro played an important role in Ca-binding ability.…”