Component

Human chromium(III)-loaded transferrin

Human chromium(III)-loaded transferrin. Species, exposure and limitations are retained in each linked claim.

4 recorded relationships. Experimental role, claim status and evidence remain attached to each record.

Read recorded mechanisms Open recursive mind map

How nutrients influence it

Every nutrient with a recorded effect on this component, credited to the nutrient that acted rather than the chapter that recorded it. Open a nutrient to see the findings and the conditions they were measured under.

How nutrients reach it in more than one step

Chains of two or more recorded steps that end here, grouped by the nutrient they start from. Each step is a separate finding, so a chain is a route a mechanism could take, not proof that it does.

Tracing routes…

What it does

Every recorded relationship this component is part of, grouped by its role. Plain wording comes first; the technical statement follows.

Recorded relationships

What it acts on

  1. Acidic pH promoted rapid Cr(III) release from the weak transferrin site; release from the tighter site was slower and depended on the chelating environment.

    Human chromium(III)-loaded transferrin → Chromium release from transferrin source_derived_draftungraded
    Experimental context and source evidence
    evidence_span
    {"source_cache": "artifacts/chromium-research/31669693.abstract.txt", "locator": "Exact primary indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "bdb962ff7838d36dfbc2cd2df4eed4e07c81ebd824c6e95096c5d7069ec32835", "start_char": 0, "end_char": 1635, "text_sha256": "bdb962ff7838d36dfbc2cd2df4eed4e07c81ebd824c6e95096c5d7069ec32835"}
    experimental_model
    Purified human transferrin release kinetics and soluble receptor interaction
    exposure
    pH 4.5 and 5.5; weak/tight binding sites; biological chelators and soluble transferrin receptor
    limitations
    The study establishes release kinetics, not the entire in-vivo pathway. The molecular route from the endosomal lumen to cytosol remains unresolved.
    nutrient_topic
    Chromium research collection; topical membership is not evidence of a direct dietary effect. · Chromium
    organism
    Human proteins in vitro
    plain_language
    Acidification helps release chromium from its carrier, with different behavior at the two sites.
    primary_references
    [chromium-p31669693] Release of trivalent chromium from serum transferrin is sufficiently rapid to be physiologically relevant. (2020). https://pubmed.ncbi.nlm.nih.gov/31669693/ DOI: 10.1016/j.jinorgbio.2019.110901
    tissue_or_cell_type
    Endosome-mimicking solution

    Chromium: transport, insulin signaling, nutrient interactions and essentiality debate (2026-09-17) · lines 159–170

    AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Purified human transferrin release kinetics and soluble receptor interaction · source_derived_draft · unverified_draft

    ### chromium-acidic-release Acidic pH promoted rapid Cr(III) release from the weak transferrin site; release from the tighter site was slower and depended on the chelating environment. Condition category: normal nutrient_topic: Chromium research collection; topical membership is not evidence of a direct dietary effect. plain_language: Acidification helps release chromium from its carrier, with different behavior at the two sites. organism: Human proteins in vitro tissue_or_cell_type: Endosome-mimicking solution experimental_model: Purified human transferrin release kinetics and soluble receptor interaction limitations: The study establishes release kinetics, not the entire in-vivo pathway. The molecular route from the endosomal lumen to cytosol remains unresolved. exposure: pH 4.5 and 5.5; weak/tight binding sites; biological chelators and soluble transferrin receptor evidence_span: {"source_cache": "artifacts/chromium-research/31669693.abstract.txt", "locator": "Exact primary indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "bdb962ff7838d36dfbc2cd2df4eed4e07c81ebd824c6e95096c5d7069ec32835", "start_char": 0, "end_char": 1635, "text_sha256": "bdb962ff7838d36dfbc2cd2df4eed4e07c81ebd824c6e95096c5d7069ec32835"} [chromium-p31669693] Release of trivalent chromium from serum transferrin is sufficiently rapid to be physiologically relevant. (2020). https://pubmed.ncbi.nlm.nih.gov/31669693/ DOI: 10.1016/j.jinorgbio.2019.110901
    Complete structured claim and evidence

  2. A human chromium-transferrin conformation formed 5–60 minutes after loading released chromium rapidly at endosomal pH, whereas the slowly formed conformation used in many older assays released it slowly.

    Human chromium(III)-loaded transferrin → Chromium release from transferrin source_derived_draftungraded
    Experimental context and source evidence
    evidence_span
    {"source_cache": "artifacts/chromium-research/32088595.abstract.txt", "locator": "Exact primary indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "6fd8562bf1ad589db2876f59b6ecd37beda818b8d349e5a42e50d00bb909de0a", "start_char": 0, "end_char": 1535, "text_sha256": "6fd8562bf1ad589db2876f59b6ecd37beda818b8d349e5a42e50d00bb909de0a"}
    experimental_model
    Time-dependent spectroscopy and release kinetics
    exposure
    Human apo-transferrin loaded at pH 7.4 in 25 mM bicarbonate; conformations followed over time
    limitations
    Preparation time changes the protein-metal state. Kinetics alone do not establish essentiality, nutritional benefit or complete cellular delivery.
    nutrient_topic
    Chromium research collection; topical membership is not evidence of a direct dietary effect. · Chromium
    organism
    Human and bovine serum transferrin; human conformation series
    plain_language
    Different preparation states can explain different release-rate measurements without requiring one universal rate.
    primary_references
    [chromium-p32088595] Significance of conformation changes during the binding and release of chromium(III) from human serum transferrin. (2020). https://pubmed.ncbi.nlm.nih.gov/32088595/ DOI: 10.1016/j.jinorgbio.2020.111040
    tissue_or_cell_type
    Endosome-mimicking in-vitro solution

    Chromium: transport, insulin signaling, nutrient interactions and essentiality debate (2026-09-17) · lines 185–196

    AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Time-dependent spectroscopy and release kinetics · source_derived_draft · unverified_draft

    ### chromium-transferrin-conformation A human chromium-transferrin conformation formed 5–60 minutes after loading released chromium rapidly at endosomal pH, whereas the slowly formed conformation used in many older assays released it slowly. Condition category: normal nutrient_topic: Chromium research collection; topical membership is not evidence of a direct dietary effect. plain_language: Different preparation states can explain different release-rate measurements without requiring one universal rate. organism: Human and bovine serum transferrin; human conformation series tissue_or_cell_type: Endosome-mimicking in-vitro solution experimental_model: Time-dependent spectroscopy and release kinetics limitations: Preparation time changes the protein-metal state. Kinetics alone do not establish essentiality, nutritional benefit or complete cellular delivery. exposure: Human apo-transferrin loaded at pH 7.4 in 25 mM bicarbonate; conformations followed over time evidence_span: {"source_cache": "artifacts/chromium-research/32088595.abstract.txt", "locator": "Exact primary indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "6fd8562bf1ad589db2876f59b6ecd37beda818b8d349e5a42e50d00bb909de0a", "start_char": 0, "end_char": 1535, "text_sha256": "6fd8562bf1ad589db2876f59b6ecd37beda818b8d349e5a42e50d00bb909de0a"} [chromium-p32088595] Significance of conformation changes during the binding and release of chromium(III) from human serum transferrin. (2020). https://pubmed.ncbi.nlm.nih.gov/32088595/ DOI: 10.1016/j.jinorgbio.2020.111040
    Complete structured claim and evidence

Where it participates (unsigned role)

  1. Binding of chromium-loaded transferrin to soluble transferrin receptor accelerated chromium release from both sites at acidic pH.

    Human transferrin receptor 1 / TFRC → Chromium release from transferrin source_derived_draftungraded
    Experimental context and source evidence
    evidence_span
    {"source_cache": "artifacts/chromium-research/31669693.abstract.txt", "locator": "Exact primary indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "bdb962ff7838d36dfbc2cd2df4eed4e07c81ebd824c6e95096c5d7069ec32835", "start_char": 0, "end_char": 1635, "text_sha256": "bdb962ff7838d36dfbc2cd2df4eed4e07c81ebd824c6e95096c5d7069ec32835"}
    experimental_model
    Purified human transferrin release kinetics and soluble receptor interaction
    exposure
    pH 4.5 and 5.5; weak/tight binding sites; biological chelators and soluble transferrin receptor
    limitations
    The study establishes release kinetics, not the entire in-vivo pathway. The molecular route from the endosomal lumen to cytosol remains unresolved.
    nutrient_topic
    Chromium research collection; topical membership is not evidence of a direct dietary effect. · Chromium
    organism
    Human proteins in vitro
    plain_language
    The receptor changed the carrier’s behavior and helped it release chromium in this assay.
    primary_references
    [chromium-p31669693] Release of trivalent chromium from serum transferrin is sufficiently rapid to be physiologically relevant. (2020). https://pubmed.ncbi.nlm.nih.gov/31669693/ DOI: 10.1016/j.jinorgbio.2019.110901
    tissue_or_cell_type
    Endosome-mimicking solution

    Chromium: transport, insulin signaling, nutrient interactions and essentiality debate (2026-09-17) · lines 172–183

    AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Purified human transferrin release kinetics and soluble receptor interaction · source_derived_draft · unverified_draft

    ### chromium-receptor-accelerated-release Binding of chromium-loaded transferrin to soluble transferrin receptor accelerated chromium release from both sites at acidic pH. Condition category: normal nutrient_topic: Chromium research collection; topical membership is not evidence of a direct dietary effect. plain_language: The receptor changed the carrier’s behavior and helped it release chromium in this assay. organism: Human proteins in vitro tissue_or_cell_type: Endosome-mimicking solution experimental_model: Purified human transferrin release kinetics and soluble receptor interaction limitations: The study establishes release kinetics, not the entire in-vivo pathway. The molecular route from the endosomal lumen to cytosol remains unresolved. exposure: pH 4.5 and 5.5; weak/tight binding sites; biological chelators and soluble transferrin receptor evidence_span: {"source_cache": "artifacts/chromium-research/31669693.abstract.txt", "locator": "Exact primary indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "bdb962ff7838d36dfbc2cd2df4eed4e07c81ebd824c6e95096c5d7069ec32835", "start_char": 0, "end_char": 1635, "text_sha256": "bdb962ff7838d36dfbc2cd2df4eed4e07c81ebd824c6e95096c5d7069ec32835"} [chromium-p31669693] Release of trivalent chromium from serum transferrin is sufficiently rapid to be physiologically relevant. (2020). https://pubmed.ncbi.nlm.nih.gov/31669693/ DOI: 10.1016/j.jinorgbio.2019.110901
    Complete structured claim and evidence

  2. Cr(III)-transferrin crystals contained a chromium-loaded closed C-terminal lobe and an open empty N-terminal lobe; two tyrosines, histidine, aspartate and chelating malonate coordinated the metal.

    Human serum transferrin / TF → Trivalent chromium / Cr(III) source_derived_draftungraded
    Experimental context and source evidence
    evidence_span
    {"source_cache": "artifacts/chromium-research/32650146.abstract.txt", "locator": "Exact primary indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "826e2d7f86ec2016d526ca8a8858db0249f4797aad842189d7f0359b6f375f85", "start_char": 0, "end_char": 1004, "text_sha256": "826e2d7f86ec2016d526ca8a8858db0249f4797aad842189d7f0359b6f375f85"}
    experimental_model
    X-ray crystallography of chromium-loaded transferrin
    exposure
    Cr(III)-transferrin crystallized with malonate as the synergistic anion
    limitations
    Crystal ligands and occupancy depend on preparation; malonate is not evidence that every circulating complex has the same coordination environment.
    nutrient_topic
    Chromium research collection; topical membership is not evidence of a direct dietary effect. · Chromium
    organism
    Human serum transferrin
    plain_language
    The iron-carrier protein can bind chromium in a structurally characterized pocket.
    primary_references
    [chromium-p32650146] X-ray structure of chromium(III)-containing transferrin: First structure of a physiological Cr(III)-binding protein. (2020). https://pubmed.ncbi.nlm.nih.gov/32650146/ DOI: 10.1016/j.jinorgbio.2020.111101
    tissue_or_cell_type
    Protein crystals

    Chromium: transport, insulin signaling, nutrient interactions and essentiality debate (2026-09-17) · lines 146–157

    AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · X-ray crystallography of chromium-loaded transferrin · source_derived_draft · unverified_draft

    ### chromium-transferrin-crystal Cr(III)-transferrin crystals contained a chromium-loaded closed C-terminal lobe and an open empty N-terminal lobe; two tyrosines, histidine, aspartate and chelating malonate coordinated the metal. Condition category: normal nutrient_topic: Chromium research collection; topical membership is not evidence of a direct dietary effect. plain_language: The iron-carrier protein can bind chromium in a structurally characterized pocket. organism: Human serum transferrin tissue_or_cell_type: Protein crystals experimental_model: X-ray crystallography of chromium-loaded transferrin limitations: Crystal ligands and occupancy depend on preparation; malonate is not evidence that every circulating complex has the same coordination environment. exposure: Cr(III)-transferrin crystallized with malonate as the synergistic anion evidence_span: {"source_cache": "artifacts/chromium-research/32650146.abstract.txt", "locator": "Exact primary indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "826e2d7f86ec2016d526ca8a8858db0249f4797aad842189d7f0359b6f375f85", "start_char": 0, "end_char": 1004, "text_sha256": "826e2d7f86ec2016d526ca8a8858db0249f4797aad842189d7f0359b6f375f85"} [chromium-p32650146] X-ray structure of chromium(III)-containing transferrin: First structure of a physiological Cr(III)-binding protein. (2020). https://pubmed.ncbi.nlm.nih.gov/32650146/ DOI: 10.1016/j.jinorgbio.2020.111101
    Complete structured claim and evidence

In the sources

Preserved passages that mention this component, quoted exactly. Open one to read it in context.

    This is a research prototype built from draft material. It is not medical advice, and its statements still await verification against the original studies.

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