3-Methyl-2-oxobutanoate / alpha-ketoisovalerate: molecular mechanisms & dependencies

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.

Human evidence only

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

Where it participates (unsigned role)

Human BCKDH E1 decarboxylates a branched-chain alpha-ketoacid using ThDP and reductively acylates the lipoylated DBT domain.
Human branched-chain ketoacid dehydrogenase E1 → Dihydrolipoyl branched-chain transacylase / DBT source_derived_draftungraded
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
Total plasma branched-chain alpha-ketoacids were 2.7 times control after thiamine deprivation, without a significant reported correlation to liver thiamine.
Thiamine (vitamin B1) → Plasma total branched-chain alpha-ketoacid concentration source_derived_draftungraded
Experimental context and source evidence
availability_state
nutrient_deficiency Imported condition classification; unverified.
cross_nutrient
B1 deprivation changes metabolites of three essential amino acids.
evidence
[{"paper_key": "shigematsu-1989-bcaa", "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
Four-week dietary depletion.
limitations
Do not infer a linear liver-thiamine/ketoacid relationship or human MSUD equivalence.
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
Rattus norvegicus
plain_language
Ketoacid accumulation is compatible with impaired disposal, but this pool measurement is not a direct flux assay.
primary_references
[shigematsu-1989-bcaa] Branched-chain alpha-ketoacids and related acids in thiamin-deprived rats (1989). https://pubmed.ncbi.nlm.nih.gov/2760689/ DOI: 10.3177/jnsv.35.163
tissue_or_cell_type
Plasma; liver thiamine measured
trigger_kind
nutrient_deficiency Imported condition classification; unverified.
Thiamine: mechanisms, deficiency and nutrient interactions (2026-09-17) · lines 828–840
AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Four-week dietary depletion. · source_derived_draft · unverified_draft
### b1-deficiency-plasma-bcka-rise Total plasma branched-chain alpha-ketoacids were 2.7 times control after thiamine deprivation, without a significant reported correlation to liver thiamine. Condition category: nutrient_deficiency nutrient_topic: Thiamine research collection; topical membership is not evidence of a direct dietary effect. plain_language: Ketoacid accumulation is compatible with impaired disposal, but this pool measurement is not a direct flux assay. organism: Rattus norvegicus tissue_or_cell_type: Plasma; liver thiamine measured experimental_model: Four-week dietary depletion. limitations: Do not infer a linear liver-thiamine/ketoacid relationship or human MSUD equivalence. evidence: [{"paper_key": "shigematsu-1989-bcaa", "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: B1 deprivation changes metabolites of three essential amino acids. nutrient: Thiamine (vitamin B1) [shigematsu-1989-bcaa] Branched-chain alpha-ketoacids and related acids in thiamin-deprived rats (1989). https://pubmed.ncbi.nlm.nih.gov/2760689/ DOI: 10.3177/jnsv.35.163
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.

3-Methyl-2-oxobutanoate / alpha-ketoisovalerate