Component

Phosphopantothenoylcysteine synthetase / PPCS

Human CoA biosynthesis enzyme.

3 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. Under the reported coupled-assay conditions, human PPCS activated substrate with ATP about four times more efficiently than with CTP.

    Phosphopantothenoylcysteine synthetase / PPCS → ATP source_derived_draftungraded
    Experimental context and source evidence
    cross_nutrient
    false
    experimental_model
    Recombinant human PPCS, PPCDC and COASY expressed in Escherichia coli; coupled enzyme assays and HPLC reconstitution
    exposure
    1 mM ATP versus 1 mM CTP, with 1.5 mM phosphopantothenate and 5 mM cysteine; 37°C.
    limitations
    Reported relative assay efficiency, not a universal kinetic constant; the paper contrasts the stronger CTP preference of E. coli PPCS.
    nutrient_topic
    Pantothenic acid (vitamin B5) research collection; topical membership is not evidence of a direct dietary effect. · Pantothenate (vitamin B5)
    organism
    Homo sapiens
    plain_language
    Human PPCS favors ATP; bacterial nucleotide preferences should not be substituted for the human result.
    primary_references
    [b5-bio-daugherty2002] Complete reconstitution of the human coenzyme A biosynthetic pathway via comparative genomics. (2002). https://pubmed.ncbi.nlm.nih.gov/11923312/ DOI: 10.1074/jbc.m201708200
    tissue_or_cell_type
    Purified recombinant protein; no intact tissue

    Pantothenic acid (vitamin B5): coenzyme A, deficiency and nutrient interactions (2026-09-17) · lines 535–546

    AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Recombinant human PPCS, PPCDC and COASY expressed in Escherichia coli; coupled enzyme assays and HPLC reconstitution · source_derived_draft · unverified_draft

    ### b5-bio-ppcs-atp-preference Under the reported coupled-assay conditions, human PPCS activated substrate with ATP about four times more efficiently than with CTP. Condition category: normal nutrient_topic: Pantothenic acid (vitamin B5) research collection; topical membership is not evidence of a direct dietary effect. plain_language: Human PPCS favors ATP; bacterial nucleotide preferences should not be substituted for the human result. organism: Homo sapiens tissue_or_cell_type: Purified recombinant protein; no intact tissue experimental_model: Recombinant human PPCS, PPCDC and COASY expressed in Escherichia coli; coupled enzyme assays and HPLC reconstitution limitations: Reported relative assay efficiency, not a universal kinetic constant; the paper contrasts the stronger CTP preference of E. coli PPCS. exposure: 1 mM ATP versus 1 mM CTP, with 1.5 mM phosphopantothenate and 5 mM cysteine; 37°C. cross_nutrient: false [b5-bio-daugherty2002] Complete reconstitution of the human coenzyme A biosynthetic pathway via comparative genomics. (2002). https://pubmed.ncbi.nlm.nih.gov/11923312/ DOI: 10.1074/jbc.m201708200
    Complete structured claim and evidence

  2. Recombinant human PPCS ligated L-cysteine to 4′-phosphopantothenate in a nucleotide-dependent reaction forming 4′-phosphopantothenoylcysteine.

    Phosphopantothenoylcysteine synthetase / PPCS → 4-Phosphopantothenate source_derived_draftungraded
    Experimental context and source evidence
    cross_nutrient
    true
    experimental_model
    Recombinant human PPCS, PPCDC and COASY expressed in Escherichia coli; coupled enzyme assays and HPLC reconstitution
    exposure
    Coupled PPCS assay: 1.5 mM phosphopantothenate, 5 mM cysteine and 1 mM ATP or CTP; 2 mM MgCl2, pH 8.0, 37°C.
    limitations
    Human enzyme expressed in E. coli; assay substrate supply is not evidence that oral cysteine raises human CoA or that low blood cysteine gates B5 repletion.
    nutrient_topic
    Pantothenic acid (vitamin B5) research collection; topical membership is not evidence of a direct dietary effect. · Pantothenate (vitamin B5)
    organism
    Homo sapiens
    plain_language
    Cysteine supplies the sulfur-containing portion of the developing CoA molecule.
    primary_references
    [b5-bio-daugherty2002] Complete reconstitution of the human coenzyme A biosynthetic pathway via comparative genomics. (2002). https://pubmed.ncbi.nlm.nih.gov/11923312/ DOI: 10.1074/jbc.m201708200
    tissue_or_cell_type
    Purified recombinant protein; no intact tissue

    Pantothenic acid (vitamin B5): coenzyme A, deficiency and nutrient interactions (2026-09-17) · lines 522–533

    AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Recombinant human PPCS, PPCDC and COASY expressed in Escherichia coli; coupled enzyme assays and HPLC reconstitution · source_derived_draft · unverified_draft

    ### b5-bio-ppcs-ligation Recombinant human PPCS ligated L-cysteine to 4′-phosphopantothenate in a nucleotide-dependent reaction forming 4′-phosphopantothenoylcysteine. Condition category: normal nutrient_topic: Pantothenic acid (vitamin B5) research collection; topical membership is not evidence of a direct dietary effect. plain_language: Cysteine supplies the sulfur-containing portion of the developing CoA molecule. organism: Homo sapiens tissue_or_cell_type: Purified recombinant protein; no intact tissue experimental_model: Recombinant human PPCS, PPCDC and COASY expressed in Escherichia coli; coupled enzyme assays and HPLC reconstitution limitations: Human enzyme expressed in E. coli; assay substrate supply is not evidence that oral cysteine raises human CoA or that low blood cysteine gates B5 repletion. exposure: Coupled PPCS assay: 1.5 mM phosphopantothenate, 5 mM cysteine and 1 mM ATP or CTP; 2 mM MgCl2, pH 8.0, 37°C. cross_nutrient: true [b5-bio-daugherty2002] Complete reconstitution of the human coenzyme A biosynthetic pathway via comparative genomics. (2002). https://pubmed.ncbi.nlm.nih.gov/11923312/ DOI: 10.1074/jbc.m201708200
    Complete structured claim and evidence

Where it participates (unsigned role)

  1. Purified human PPCS, PPCDC and bifunctional CoA synthase reconstituted CoA synthesis from phosphopantothenate in vitro.

    4-Phosphopantothenate → Coenzyme A source_derived_draftungraded
    Experimental context and source evidence
    cross_nutrient
    Provides the B5-derived CoA partner required by PDH, OGDH, BCKDH and OADH; simultaneous B1/B5 depletion was not tested.
    evidence
    [{"paper_key": "daugherty-2002-coa", "source_bundle": "artifacts/thiamine_metabolism_sources.json", "passage_ids": ["abstract"], "locator": "Primary publication abstract", "preservation": "Exact text retained in the source bundle; full source document retained when openly retrievable."}]
    experimental_model
    Reconstituted human enzyme pathway.
    limitations
    Cross-pathway connection is biochemical integration, not a tested clinical supplementation interaction.
    nutrient
    Thiamine (vitamin B1) · Thiamine (vitamin B1)
    nutrient_topic
    Thiamine research collection; topical membership is not evidence of a direct dietary effect. · Thiamine (vitamin B1)
    organism
    Homo sapiens
    plain_language
    Vitamin B5 supplies a separate carrier used after B1-dependent decarboxylation. The experiment starts with phosphorylated B5, so it does not test absorption or the first phosphorylation step.
    primary_references
    [daugherty-2002-coa] Complete reconstitution of the human coenzyme A biosynthetic pathway via comparative genomics (2002). https://pubmed.ncbi.nlm.nih.gov/11923312/ DOI: 10.1074/jbc.m201708200
    tissue_or_cell_type
    Purified recombinant enzymes

    Thiamine: mechanisms, deficiency and nutrient interactions (2026-09-17) · lines 731–743

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

    ### b1-coa-b5-downstream-biosynthesis Purified human PPCS, PPCDC and bifunctional CoA synthase reconstituted CoA synthesis from phosphopantothenate in vitro. Condition category: normal nutrient_topic: Thiamine research collection; topical membership is not evidence of a direct dietary effect. plain_language: Vitamin B5 supplies a separate carrier used after B1-dependent decarboxylation. The experiment starts with phosphorylated B5, so it does not test absorption or the first phosphorylation step. organism: Homo sapiens tissue_or_cell_type: Purified recombinant enzymes experimental_model: Reconstituted human enzyme pathway. limitations: Cross-pathway connection is biochemical integration, not a tested clinical supplementation interaction. evidence: [{"paper_key": "daugherty-2002-coa", "source_bundle": "artifacts/thiamine_metabolism_sources.json", "passage_ids": ["abstract"], "locator": "Primary publication abstract", "preservation": "Exact text retained in the source bundle; full source document retained when openly retrievable."}] cross_nutrient: Provides the B5-derived CoA partner required by PDH, OGDH, BCKDH and OADH; simultaneous B1/B5 depletion was not tested. nutrient: Thiamine (vitamin B1) [daugherty-2002-coa] Complete reconstitution of the human coenzyme A biosynthetic pathway via comparative genomics (2002). https://pubmed.ncbi.nlm.nih.gov/11923312/ DOI: 10.1074/jbc.m201708200
    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