Isolation of a novel calcium-binding peptide from phosvitin hydrolysates and the study of its calcium chelation mechanism

A new peptide with strong calcium binding capacity was isolated from phosvitin hydrolysates. Taking calcium chelating rate as an indicator, phosvitin hydrolysates were separated gradually by anion-exchange chromatography, gel filtration chromatography and reversed-phase high performance liquid chromatography. A peptide with a molecular weight of 1106.44402 Da was identified by liquid chromatography-electrospray/mass spectrometry (LC-ESI/MS), and its amino acid sequence was DEEENDQVK, the calcium binding capacity reached 151.10 +/- 3.57 mg/g. Its chelating mechanism was investigated. Results showed that, the beta-sheet structure of peptide increased after adding calcium ion, and the main binding sites were carboxyl oxygen atom and amino nitrogen atom. In vitro simulated digestion experiments showed that, the solubility and dialysis rate of calcium in peptide-calcium chelate were higher than those in CaCO3 and D-calcium gluconate. This finding would promote the development of calcium supplements from food resources.

Automated summary

A new peptide with strong calcium binding capacity was isolated and identified, showing potential as a calcium supplement from food resources. The chelating mechanism involves main binding sites and increased beta-sheet structure when interacting with calcium ions. This finding suggests higher solubility and dialysis rate for calcium in the peptide-calcium chelate compared to other calcium sources.