Abstract: In this paper, alkaline protease was used to hydrolyze goose bone collagen to prepare calcium-chelating peptides, which were separated and purified by Sephadex G-25 column chromatography and reversed-phase high-performance liquid chromatography. The amino acid composition and structure of the purified peptides were identified by automatic amino acid analyzer, liquid chromatography-tandem mass spectrometry, ultraviolet (UV) spectroscopy and Fourier transform infrared spectroscopy. The calcium-chelating peptides were rich in Glu (12.67%) and Asp (7.47%) and were identified as DSYVGDEAQSKR and KLLDEGR, with molecular masses of 1 353.62 and 829.47 u, respectively. It was proved that the calcium chelating capacities of the synthesized peptides were (70.08 ± 2.20) and (68.18 ±1.31) mg/g, respectively. The intensity of UV absorption decreased, the amine I and amide II bands exhibited a red shift and the N-H band showed a blue shift. Accordingly, we speculated that the peptides may chelate calcium ions mainly through the carboxyl and amino groups of amino acid residues.

Key words: goose bone collagen; calcium-chelating peptide; liquid chromatography-tandem mass spectrometry; amino acid composition; ultroviolet spectroscopy; Fourier transform infrared spectroscopy