Isolation, characterization, and molecular docking analyses of novel calcium‐chelating peptide from soy yogurt and the study of its calcium chelation mechanism

Abstract

BACKGROUND Calcium is an essential dietary mineral nutrient for humans. Digestive instability limits the bioavailability of calcium ions. Peptide–calcium chelate has been proven to excite higher calcium absorption than amino acid–calcium chelate, organic and inorganic calcium. Soy yogurt, which is produced via liquid‐state fermentation using lactic acid bacteria, has a high amount of bioavailable calcium. In this study, a novel peptide with high calcium binding affinity was purified and identified from soy yogurt. The binding mechanism of peptide and calcium was then analyzed by bioinformatics and spectral analysis. Furthermore, the effect of the novel peptide on gastrointestinal stability by the Caco‐2 cell model and calcium bioavailability in vivo were investigated by the zebrafish model. RESULTS The results showed that a novel peptide was purified and identified as DEDEQIPSHPPR (CBP). Calcium ions probably coordinate with Glu‐2 and Glu‐4 carboxyl groups via salt bridges and interact with Asp‐1, Asp‐3, and Arg‐12 in CBP via charge pairing. The calcium binding activity of the CBP was 36.64 ± 0.04 mg g−1. Fourier transform infrared (FTIR) spectra showed that calcium spontaneously bound to the amino group nitrogen and oxygen atoms of the carboxyl group. The binding mode is either bidentate or unidentate, depending on the circumstances. More importantly, the CBP peptide substantially increased the bone mass in a zebrafish osteoporosis model. CONCLUSION The more glutamic acid and aspartic acid, the high was the calcium affinity with peptide. Soy yogurt‐derived peptides can be used as carriers of calcium ions throughout the gastrointestinal tract, which may be clinically useful for osteoporosis therapy. © 2022 Society of Chemical Industry.

Calcium-binding properties, stability, and osteogenic ability of phosphorylated soy peptide-calcium chelate

“…In our preliminary experiments, DEDEQIPSHPPR dodecapeptide from soy yogurt was confirmed to possess 36.64 ± 0.04 mg/g calcium-chelating capacity (14). Previous studies found that the calcium chelation capacity is closely related to their molecular mass, amino acid compositions, sequences, and spatial conformation (15,16).…”

Structural characterisation of deer sinew peptides as calcium carriers, their promotion of MC3T3-E1 cell proliferation and their effect on bone deposition in mice

“…It has been shown that the molecular weight distribution of peptides is critical for calcium–peptide binding, with fragments with molecular weights below 3000 Da having higher calcium binding capacity. 29 However, more small molecules (<500 Da) in the wheat germ hydrolysis products were detrimental to the calcium-binding capacity. 30 Secondly, on the peptide sequences of the DSPs, a plurality of peptides, such as VPGPMGPSGPR, GDAGPAGPK, GPAGPAGGPR, GPVGPAG, and so on, have triplet repeats of the (Gly-X-Y)n primary structure of the collagen peptide chain.…”

A critical review of a typical research system for food‐derived metal‐chelating peptides: Production, characterization, identification, digestion, and absorption

“…Moreover, pH in the gastric phase is very low, and the hydrolysis of proteins is inefficient. Therefore, in addition to this theory, some types of MCPs or hydrolysates with low molecular weights or synthetic MCPs can remain intact during the whole digestion because these peptides are not sensitive to both pepsin and pancreatic enzymes (Gan, Xiao, et al., 2022). For instance, the molecular weight of a synthetic sea cucumber peptide–zinc complex remained almost unchanged after GI digestion, implying that synthetic MCPs remain stable in GI digestion environments (Wang, Sun, et al., 2022).…”