Component

Human quinoid dihydropteridine reductase / QDPR

Homo sapiens protein; gene perturbations are separate gene entities.

2 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. A catalytically characterized recombinant human dihydropteridine reductase was crystallized in complex with NADH at 2.5-angstrom resolution.

    Human quinoid dihydropteridine reductase / QDPR → NADH source_derived_draftungraded
    Experimental context and source evidence
    evidence_access
    Primary abstract
    experimental_model
    Human QDPR expressed in E. coli; enzyme purification, kinetic characterization and structure.
    limitations
    This binary structure alone does not show that niacin supplementation changes phenylalanine clearance.
    nutrient_topic
    L-Phenylalanine collection; species, compartment, exposure, co-substrates and manipulation remain explicit. · L-Phenylalanine
    plain_language
    The cofactor-recycling network includes an NADH-binding enzyme.
    primary_references
    The crystallographic structure of a human dihydropteridine reductase NADH binary complex expressed in Escherichia coli by a cDNA constructed from its rat homologue. · 1993 · https://pubmed.ncbi.nlm.nih.gov/8262916/

    L-Phenylalanine: transport, protein synthesis, cofactor recycling and cross-nutrient mechanisms (2026-09-19) · lines 70–76

    AI-assisted research curation; primary references, access levels and experimental limitations individually identified. Not publisher full text. · supports · Human QDPR expressed in E. coli; enzyme purification, kinetic characterization and structure. · source_derived_draft · unverified_draft

    ## l-phenylalanine-qdpr-nadh The cofactor-recycling network includes an NADH-binding enzyme. A catalytically characterized recombinant human dihydropteridine reductase was crystallized in complex with NADH at 2.5-angstrom resolution. Model: Human QDPR expressed in E. coli; enzyme purification, kinetic characterization and structure. Limitations: This binary structure alone does not show that niacin supplementation changes phenylalanine clearance. Evidence access: Primary abstract The crystallographic structure of a human dihydropteridine reductase NADH binary complex expressed in Escherichia coli by a cDNA constructed from its rat homologue. · 1993 · https://pubmed.ncbi.nlm.nih.gov/8262916/
    Complete structured claim and evidence

  2. Biochemical experiments identified QDPR activity that repairs oxidatively damaged tetrahydrofolate.

    Human quinoid dihydropteridine reductase / QDPR → Oxidative degradation of reduced folates source_derived_draftungraded
    Experimental context and source evidence
    cross_nutrient
    Shared QDPR machinery connects biopterin and folate redox maintenance.
    experimental_model
    Biochemical enzyme experiments
    exposure
    Assay conditions described in the linked primary study.
    limitations
    Repair capacity is finite; no human dietary requirement was determined.
    nutrient_topic
    Folate and folic acid research collection; topical membership is not evidence of a direct dietary effect. · Folate (vitamin B9)
    organism
    Homo sapiens
    plain_language
    An enzyme also used in biopterin metabolism helps preserve reduced folate.
    primary_references
    [zheng-2018] Mitochondrial One-Carbon Pathway Supports Cytosolic Folate Integrity in Cancer Cells (2018). https://pubmed.ncbi.nlm.nih.gov/30500537/ DOI: 10.1016/j.cell.2018.09.041
    tissue_or_cell_type
    Cell-free and cancer-cell experiments

    Folate and folic acid: mechanisms, deficiency and nutrient interactions (2026-09-17) · lines 1230–1241

    AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Biochemical enzyme experiments · source_derived_draft · unverified_draft

    ### qdpr-folate-repair Biochemical experiments identified QDPR activity that repairs oxidatively damaged tetrahydrofolate. Condition category: normal nutrient_topic: Folate and folic acid research collection; topical membership is not evidence of a direct dietary effect. plain_language: An enzyme also used in biopterin metabolism helps preserve reduced folate. organism: Homo sapiens tissue_or_cell_type: Cell-free and cancer-cell experiments experimental_model: Biochemical enzyme experiments limitations: Repair capacity is finite; no human dietary requirement was determined. exposure: Assay conditions described in the linked primary study. cross_nutrient: Shared QDPR machinery connects biopterin and folate redox maintenance. [zheng-2018] Mitochondrial One-Carbon Pathway Supports Cytosolic Folate Integrity in Cancer Cells (2018). https://pubmed.ncbi.nlm.nih.gov/30500537/ DOI: 10.1016/j.cell.2018.09.041
    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.

    Evidence, AI assistance and curation standards