Lu 2022 — Research progress of metal chelating peptides
Lu and Dong reviewed the preparation, structural characterization, isolation and purification, and physiological activity of metal chelating peptides derived from food proteins. The metals in scope are the nutritionally essential ions Ca²⁺, Fe²⁺, Zn²⁺, and Cu²⁺; the review’s framing is dietary supplementation of essential trace elements through peptide carriers, not contamination by toxic heavy metals. This source is recorded here for its mechanism content on peptide-metal coordination chemistry (binding groups, binding sites, amino acid sequence determinants), which is the same chemistry that governs binding of toxic metals to food protein hydrolysates and therefore provides context for several heavy-metal occurrence and bioavailability questions in the HMI corpus. No occurrence values for HMI’s regulated heavy metals (Pb, Cd, iAs, tAs, MeHg, tHg, Ni, Al, Cr, Cr-VI, Sn, Sb, U) appear in this review.
Key numbers
The review reports preparation conditions, chelation rates, and binding-mode summaries from cited primary studies. Numbers below are copied as the review states them; none are HMI heavy metal occurrence values.
| Cited primary study | Metal | Reported preparation or chelation finding |
|---|---|---|
| Bi et al. (deer bone, pepsin) | Ca²⁺ | Optimum: deer bone peptide concentration 1.535 mg/mL, Ca²⁺ 7.5 mmol/L, pH 7, chelating time 30 min, temperature 37 °C. Deer bone peptide molecular weight < 1000 Da; the chelated product (DBPCC) ranged mainly 2,000–3,000 Da. |
| Fang et al. (Manchurian walnut, alkaline protease) | Ca²⁺ | Optimum by RSM: peptide:calcium mass ratio 3:1, pH 8, time 40 min, temperature 45 °C. Chelation rate 69%. |
| Wang (sesame, trypsin) | Fe²⁺, Zn²⁺ | Optimum trypsin hydrolysis: substrate 5.0%, enzyme 20 U/g, time 5 h. Chelating ability for Fe²⁺ 90.9% and for Zn²⁺ 93.5%. |
| Hao et al. (porcine blood) | Ca²⁺ | Optimum by orthogonal design: peptide:calcium mass ratio 3:1, pH 7.0, time 45 min, temperature 100 °C. Calcium chelate yield 63.8%. |
| Guo et al. (Alaska cod skin) | Fe²⁺ | Iron chelating peptide identified with molecular weight 345 Da. |
| Xia et al. (barley glutelin) | Fe²⁺ | Low molecular weight peptides < 1 kDa showed stronger iron chelating activity than higher molecular weight fractions. |
| Miao et al. (casein hydrolysates) | Fe²⁺ | Four iron chelating peptides isolated: CHP-1 830.6120 Da, CHP-2 1012.5280 Da, CHP-3 873.4440 Da, CHP-4 829.4570 Da. |
| Seth and Mahoney (chicken muscle) | Fe | Most iron bound to macromolecular peptides > 10 kDa; only about 10% bound to small peptides and amino acids. |
| Torres-Fuentes et al. (chickpea protein) | Cu²⁺ | Small peptide fractions with 20–30% histidine content had higher copper chelating activity than fractions with lower histidine content. |
| Zhang et al. (Pacific cod bone) | Ca²⁺ | Optimum: 11 g CaCl₂ : 30 g cod bone hydrolysate, 50 °C, pH 7.0, 60 min. Identified calcium-binding decapeptide KGDPGLSPGK. |
| Cui et al. (sea cucumber ovum) | Ca²⁺ | Optimum: peptide:metal molar ratio 1:6, 50 °C, pH 8.0, 20 min. Identified heptapeptide NDEELNK. |
| Bo et al. (duck egg) | Fe | Optimum: peptide:metal 2:1 w/w, ascorbic acid 0.2 g/g peptide, 40 °C, pH 5.5, 40 min. Iron-binding peptides Pro-Val-Glu-Glu and Arg-Ser-Ser. |
| Eckert et al. (barley protein) | Fe²⁺ | Optimum: peptide:metal 2:1 molar, 25 °C, pH 7.0, 120 min. Iron-binding peptide SVNVPLY; complex Fe-SVNVPLY supported ferritin synthesis above FeSO₄. |
| Zhou et al. (β-lactoglobulin) | Fe³⁺ | Optimum: peptide:metal 40:1 w/w, 25 °C, pH 7.0, 30 min. Binding residues identified as Asp, Glu, and Pro. |
| Wang et al. (sesame, IMAC) | Zn²⁺ | Six zinc-binding peptides identified: Asn-Cys-Ser, Arg-Gln-Arg, Arg-Lys-Arg, Ile-Ala-Asn, Leu-Ala-Asn, Ser-Met. |
| Udechukwu et al. (bovine whey protein) | Zn²⁺ | Conditions 10 mg/mL peptide and 50 µM Zn, pH 7.0, 60 min. Binding groups identified as carboxylate ion and side-chain carbonyl oxygen of Asp/Glu and Ser/Thr. |
| Zhao et al. (whey protein) | Ca²⁺ | Calcium-binding peptide of molecular weight 237.99 Da identified as Gly-Tyr; binding capacity 122% above the whey hydrolysate complex. |
| Yang et al. (low-value fish, antioxidant assay) | Ca²⁺ | Antioxidant activity of non-ethanol-precipitated peptide calcium chelates reported as equivalent to 94.43% of tocopherol; 80%-ethanol-precipitated chelates inhibited Bacillus subtilis and Staphylococcus aureus. |
The review states that chelating peptides containing histidine, cysteine, glutamic acid, and aspartic acid have the strongest binding to Ca²⁺, Fe²⁺, and Zn²⁺ through coordination covalent or adsorption binding, and that the chelation chemistry involves N-terminal amino groups, C-terminal carboxyl groups, side-chain carboxyl and imidazolyl groups, sulfhydryl groups, and amide carbonyl oxygens. Phosphorylation of peptide carriers is reported to increase calcium binding through additional carboxyl and phosphoserine residues that coordinate Ca²⁺.
Methods (brief)
This is a narrative review. Lu and Dong compile findings from primary literature on metal chelating peptides from animal and plant food proteins, organized into preparation (solvent extraction, enzymatic hydrolysis, chemical synthesis, with enzymatic hydrolysis as the dominant route), structural characterization (mass spectrometry, NMR, UV-vis, FTIR, circular dichroism, X-ray diffraction), isolation and purification (ultrafiltration, immobilized metal ion affinity chromatography, hydroxyapatite chromatography, ion exchange chromatography, reversed-phase HPLC, time-of-flight mass spectrometry), and physiological activity (bioavailability assessed in Caco-2 and HT-29 cell models and in rodent models including ovariectomized rats and iron-deficiency anemia mice; antioxidant activity via Fenton-reaction-pathway blocking; antibacterial activity against Bacillus subtilis, Staphylococcus aureus, Escherichia coli, Pseudomonas fluorescens, Candida albicans, Saccharomyces cerevisiae, and Aspergillus niger). The authors do not generate primary analytical data and do not test contamination by Pb, Cd, As, Hg, or other HMI-regulated heavy metals.
Implications
The peptide-metal coordination chemistry described in this review — binding of metal ions to amino groups, carboxyl groups, imidazolyl groups of histidine, sulfhydryl groups of cysteine, and amide carbonyl oxygens — applies in principle to toxic metals such as Pb²⁺, Cd²⁺, and Hg²⁺, which also coordinate to nitrogen-, oxygen-, and sulfur-donor ligands. The review is therefore useful as background context for primary studies on heavy metal binding by food protein hydrolysates and on whether dietary protein matrices alter heavy-metal bioavailability, but the review itself reports no measurements on toxic-metal binding and should not be cited as evidence for any HMI standard.
Verification notes
- PDF read in full (8 pages) via the Read tool; abstract, body sections, Table 1, and references all reviewed.
- DOI
10.53388/FH20221101019, raw handleMFK_47-research-progress-of-metal-chelating-peptides, and cite-keylu2022-metal-chelating-peptides-reviewchecked againstwiki/sources/; no existing page. - The paper is open access under CC-BY 4.0 per the title page; recorded as
license: cc-by-4.0. - Metals discussed are Ca, Fe, Zn, Cu — all essential elements in the paper’s framing. None of HMI’s 10 HMTc analytes (Pb, tAs, Cd, MeHg, tHg, iAs, Ni, Al, Cr-VI, Sn) are measured or reviewed;
metals:is therefore[]. Iron and copper have wiki metal pages but are not the contamination focus here. - The paper reports binding constants, chelation rates, molecular weight ranges, and peptide sequences, not contamination occurrence in food matrices;
ingredients:andproducts:are therefore[]. The protein sources cited (cod bone, deer bone, walnut meal, sesame protein, β-lactoglobulin, etc.) are framed as carrier feedstocks for nutritional supplement manufacture, not as products in which HMI heavy metal contamination is being measured. Routing this source to ingredient or product pages would be misleading. matrices: [protein-hydrolysates, review-context]records what the paper actually concerns at the matrix level.jurisdictions: [GLOBAL]because the review compiles international literature.- Brand firewall: no brand names appear in the review (instrument vendors such as IMAC column types are method components, not brand attributions to contamination values).
- Wiki/HMTc firewall: no synthesis claims about contamination thresholds or HMTc standards were imported from the review.
Page history
The five most recent substantive edits to this page. The full version history lives in git; when DOI minting comes online (see schema docs), each entry below will also link to a version-pinned DataCite DOI.
| Commit | Date | Description |
|---|---|---|
| 1476f44 | 2026-06-09 | ingest: cacic2019-hemp-heavy-metals fresh from MFK/June 9 |