Component
Branched-chain ketoacid dehydrogenase E1 beta / BCKDHB
Human beta subunit of BCKDH E1.
2 recorded relationships. Experimental role, claim status and evidence remain attached to each record.
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.
Other things that act on it
Enzymes, hormones, genes, and other components with a recorded effect. These are not nutrients, so they do not count toward the arrows above. Each finding names the chapter that recorded it.
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.
Where it participates (unsigned role)
The isoleucine pathway in the primary biochemical study places BCKDH-mediated oxidative decarboxylation of the branched ketoacid upstream of 2-methylbutyryl-CoA.
Experimental context and source evidence
- evidence_access
- Primary full text, pathway background
- experimental_model
- Established pathway shown in a human ECHS1 disease/biochemistry study; not a new BCKDH assay in that paper.
- limitations
- Cofactor and catalytic evidence is separately linked from existing ThDP/DLD records.
- nutrient_topic
- L-Isoleucine collection; species, compartment, exposure, co-substrates and manipulation remain explicit. · L-Isoleucine
- plain_language
- A shared BCAA enzyme commits the carbon skeleton to further breakdown.
- primary_references
- Clinical and biochemical characterization of four patients with mutations in ECHS1. · 2015 · https://pubmed.ncbi.nlm.nih.gov/26081110/ · DOI 10.1186/s13023-015-0290-1
L-Isoleucine: transport, translation, catabolism and cross-nutrient mechanisms (2026-09-19) · lines 170–176
AI-assisted research curation; primary references, access levels and experimental limitations individually identified. Not publisher full text. · supports · Established pathway shown in a human ECHS1 disease/biochemistry study; not a new BCKDH assay in that paper. · source_derived_draft · unverified_draft
## isoleucine-bckdh-carbon-step A shared BCAA enzyme commits the carbon skeleton to further breakdown. The isoleucine pathway in the primary biochemical study places BCKDH-mediated oxidative decarboxylation of the branched ketoacid upstream of 2-methylbutyryl-CoA. Model: Established pathway shown in a human ECHS1 disease/biochemistry study; not a new BCKDH assay in that paper. Limitations: Cofactor and catalytic evidence is separately linked from existing ThDP/DLD records. Evidence access: Primary full text, pathway background Clinical and biochemical characterization of four patients with mutations in ECHS1. · 2015 · https://pubmed.ncbi.nlm.nih.gov/26081110/ · DOI 10.1186/s13023-015-0290-1
Complete structured claim and evidenceHuman BCKDH E1 decarboxylates a branched-chain alpha-ketoacid using ThDP and reductively acylates the lipoylated DBT domain.
Experimental context and source evidence
- cross_nutrient
- Thiamine and protein-bound lipoate connect branched-chain amino-acid catabolism; CoA and DLD act later.
- evidence
- [{"paper_key": "li-2004-bckdh", "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
- Recombinant human E1b and E2b lipoyl domain assays.
- limitations
- Purified-system evidence; nutritional response was not tested.
- 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
- B1 helps process ketoacids formed from branched-chain amino acids; the acyl fragment then moves to a lipoyl carrier on E2.
- primary_references
- [li-2004-bckdh] Cross-talk between thiamin diphosphate binding and phosphorylation loop conformation in human branched-chain alpha-keto acid decarboxylase/dehydrogenase (2004). https://pubmed.ncbi.nlm.nih.gov/15166214/ DOI: 10.1074/jbc.m403611200
- tissue_or_cell_type
- Purified proteins
Thiamine: mechanisms, deficiency and nutrient interactions (2026-09-17) · lines 773–785
AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Recombinant human E1b and E2b lipoyl domain assays. · source_derived_draft · unverified_draft
### b1-bckdh-ketoacid-acylation Human BCKDH E1 decarboxylates a branched-chain alpha-ketoacid using ThDP and reductively acylates the lipoylated DBT domain. Condition category: normal nutrient_topic: Thiamine research collection; topical membership is not evidence of a direct dietary effect. plain_language: B1 helps process ketoacids formed from branched-chain amino acids; the acyl fragment then moves to a lipoyl carrier on E2. organism: Homo sapiens tissue_or_cell_type: Purified proteins experimental_model: Recombinant human E1b and E2b lipoyl domain assays. limitations: Purified-system evidence; nutritional response was not tested. evidence: [{"paper_key": "li-2004-bckdh", "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: Thiamine and protein-bound lipoate connect branched-chain amino-acid catabolism; CoA and DLD act later. nutrient: Thiamine (vitamin B1) [li-2004-bckdh] Cross-talk between thiamin diphosphate binding and phosphorylation loop conformation in human branched-chain alpha-keto acid decarboxylase/dehydrogenase (2004). https://pubmed.ncbi.nlm.nih.gov/15166214/ DOI: 10.1074/jbc.m403611200
Complete structured claim and evidence
The events it takes part in
A mechanism often involves more than two components. These are the full events, with every participant and its role.
Situations it appears in
Low-supply and faulty-machinery situations recorded in the chapters where this component plays a part.
In the sources
Preserved passages that mention this component, quoted exactly. Open one to read it in context.
Open hypotheses
Proposed ideas that involve this component. They are labeled as hypotheses and do not change any recorded statement.
This is a research prototype built from draft material. It is not medical advice, and its statements still await verification against the original studies.