Component
Human methylcrotonyl-CoA carboxylase beta subunit / MCCC2
Human methylcrotonyl-CoA carboxylase beta subunit / MCCC2. Species, exposure and limitations are retained in each linked claim.
3 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.
What acts on it
Active recombinant human MCC contained alpha and beta subunits at a one-to-one ratio.
Experimental context and source evidence
- evidence_span
- {"source_cache": "artifacts/biotin-research/17360195.abstract.txt", "locator": "Exact primary indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "3ae046490d9657d005d5c39efb1f7439bc015d0cb2190834e3e868de70eaf985", "start_char": 0, "end_char": 1067, "text_sha256": "3ae046490d9657d005d5c39efb1f7439bc015d0cb2190834e3e868de70eaf985"}
- experimental_model
- Purified recombinant human MCC produced by baculovirus expression
- exposure
- ATP and methylcrotonyl-CoA kinetics
- limitations
- Recombinant-enzyme kinetics do not determine human dietary requirements.
- nutrient_topic
- Biotin research collection; topical membership is not evidence of a direct dietary effect. · Biotin
- organism
- Homo sapiens
- plain_language
- MCC needs both subunits; biotin cannot replace a missing protein partner.
- primary_references
- [b7-p17360195] Expression, purification, characterization of human 3-methylcrotonyl-CoA carboxylase (MCCC). (2007). https://pubmed.ncbi.nlm.nih.gov/17360195/ DOI: 10.1016/j.pep.2007.01.012
- tissue_or_cell_type
- Purified human MCC complex
Biotin: carboxylases, recycling, deficiency and nutrient interactions (2026-09-17) · lines 767–778
AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Purified recombinant human MCC produced by baculovirus expression · source_derived_draft · unverified_draft
### b7-mcc-complex Active recombinant human MCC contained alpha and beta subunits at a one-to-one ratio. Condition category: normal nutrient_topic: Biotin research collection; topical membership is not evidence of a direct dietary effect. plain_language: MCC needs both subunits; biotin cannot replace a missing protein partner. organism: Homo sapiens tissue_or_cell_type: Purified human MCC complex experimental_model: Purified recombinant human MCC produced by baculovirus expression limitations: Recombinant-enzyme kinetics do not determine human dietary requirements. exposure: ATP and methylcrotonyl-CoA kinetics evidence_span: {"source_cache": "artifacts/biotin-research/17360195.abstract.txt", "locator": "Exact primary indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "3ae046490d9657d005d5c39efb1f7439bc015d0cb2190834e3e868de70eaf985", "start_char": 0, "end_char": 1067, "text_sha256": "3ae046490d9657d005d5c39efb1f7439bc015d0cb2190834e3e868de70eaf985"} [b7-p17360195] Expression, purification, characterization of human 3-methylcrotonyl-CoA carboxylase (MCCC). (2007). https://pubmed.ncbi.nlm.nih.gov/17360195/ DOI: 10.1016/j.pep.2007.01.012
Complete structured claim and evidence
Where it participates (unsigned role)
In the 88-person MCC-deficiency series, 57% were asymptomatic; 12 had acute metabolic decompensations, and genotype or biochemical phenotype did not reliably predict the course.
Experimental context and source evidence
- availability_state
- machinery_impairment Imported condition classification; unverified.
- evidence_span
- {"source_cache": "artifacts/biotin-research/22642865.abstract.txt", "locator": "Exact primary indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "f0c40118afe81e9b597d2d2cbe6a785c2b96a4dbd7f4dcb634230070c61865ee", "start_char": 0, "end_char": 1384, "text_sha256": "f0c40118afe81e9b597d2d2cbe6a785c2b96a4dbd7f4dcb634230070c61865ee"}
- experimental_model
- Retrospective clinical, biochemical and molecular study of 88 MCC-deficient individuals
- exposure
- MCCC1/MCCC2 defects; mixed newborn screening and clinical ascertainment
- limitations
- Ascertainment bias and incomplete penetrance limit predictions. This is an isolated inherited enzyme defect, not biotin intake deficiency.
- nutrient_topic
- Biotin research collection; topical membership is not evidence of a direct dietary effect. · Biotin
- organism
- Homo sapiens
- plain_language
- A striking biochemical marker does not determine how ill a person will be.
- primary_references
- [b7-p22642865] 3-methylcrotonyl-CoA carboxylase deficiency: clinical, biochemical, enzymatic and molecular studies in 88 individuals. (2012). https://pubmed.ncbi.nlm.nih.gov/22642865/ DOI: 10.1186/1750-1172-7-31
- tissue_or_cell_type
- Clinical and biochemical phenotype
- trigger_kind
- machinery_impairment Imported condition classification; unverified.
Biotin: carboxylases, recycling, deficiency and nutrient interactions (2026-09-17) · lines 1027–1038
AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Retrospective clinical, biochemical and molecular study of 88 MCC-deficient individuals · source_derived_draft · unverified_draft
### b7-mcc-genetic-variability In the 88-person MCC-deficiency series, 57% were asymptomatic; 12 had acute metabolic decompensations, and genotype or biochemical phenotype did not reliably predict the course. Condition category: machinery_impairment nutrient_topic: Biotin research collection; topical membership is not evidence of a direct dietary effect. plain_language: A striking biochemical marker does not determine how ill a person will be. organism: Homo sapiens tissue_or_cell_type: Clinical and biochemical phenotype experimental_model: Retrospective clinical, biochemical and molecular study of 88 MCC-deficient individuals limitations: Ascertainment bias and incomplete penetrance limit predictions. This is an isolated inherited enzyme defect, not biotin intake deficiency. exposure: MCCC1/MCCC2 defects; mixed newborn screening and clinical ascertainment evidence_span: {"source_cache": "artifacts/biotin-research/22642865.abstract.txt", "locator": "Exact primary indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "f0c40118afe81e9b597d2d2cbe6a785c2b96a4dbd7f4dcb634230070c61865ee", "start_char": 0, "end_char": 1384, "text_sha256": "f0c40118afe81e9b597d2d2cbe6a785c2b96a4dbd7f4dcb634230070c61865ee"} [b7-p22642865] 3-methylcrotonyl-CoA carboxylase deficiency: clinical, biochemical, enzymatic and molecular studies in 88 individuals. (2012). https://pubmed.ncbi.nlm.nih.gov/22642865/ DOI: 10.1186/1750-1172-7-31
Complete structured claim and evidenceStructural comparisons supported substrate-dependent, coordinated activation of human MCC.
Experimental context and source evidence
- evidence_span
- {"source_cache": "artifacts/biotin-research/39223421.abstract.txt", "locator": "Exact primary indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "221115ee36b8452b3915e000ae5f363f8f771705dcbb17570343b8f536b7c87a", "start_char": 0, "end_char": 1050, "text_sha256": "221115ee36b8452b3915e000ae5f363f8f771705dcbb17570343b8f536b7c87a"}
- experimental_model
- Structures of purified endogenous human MCC, PCC and PC; substrate-bound MCC conformations
- exposure
- Cryo-EM and substrate-bound structural analysis
- limitations
- Indexed abstract and publisher preview inspected; detailed residue-level claims require full-paper review. Published online 2024, journal issue 2025.
- nutrient_topic
- Biotin research collection; topical membership is not evidence of a direct dietary effect. · Biotin
- organism
- Homo sapiens
- plain_language
- Adding substrate reorganizes the working enzyme; the word synergy here refers to enzyme parts, not proven synergy between supplements.
- primary_references
- [b7-p39223421] Structural insight into synergistic activation of human 3-methylcrotonyl-CoA carboxylase. (2025). https://pubmed.ncbi.nlm.nih.gov/39223421/ DOI: 10.1038/s41594-024-01379-3
- tissue_or_cell_type
- Purified endogenous mitochondrial carboxylases
Biotin: carboxylases, recycling, deficiency and nutrient interactions (2026-09-17) · lines 806–817
AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Structures of purified endogenous human MCC, PCC and PC; substrate-bound MCC conformations · source_derived_draft · unverified_draft
### b7-mcc-substrate-conformations Structural comparisons supported substrate-dependent, coordinated activation of human MCC. Condition category: normal nutrient_topic: Biotin research collection; topical membership is not evidence of a direct dietary effect. plain_language: Adding substrate reorganizes the working enzyme; the word synergy here refers to enzyme parts, not proven synergy between supplements. organism: Homo sapiens tissue_or_cell_type: Purified endogenous mitochondrial carboxylases experimental_model: Structures of purified endogenous human MCC, PCC and PC; substrate-bound MCC conformations limitations: Indexed abstract and publisher preview inspected; detailed residue-level claims require full-paper review. Published online 2024, journal issue 2025. exposure: Cryo-EM and substrate-bound structural analysis evidence_span: {"source_cache": "artifacts/biotin-research/39223421.abstract.txt", "locator": "Exact primary indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "221115ee36b8452b3915e000ae5f363f8f771705dcbb17570343b8f536b7c87a", "start_char": 0, "end_char": 1050, "text_sha256": "221115ee36b8452b3915e000ae5f363f8f771705dcbb17570343b8f536b7c87a"} [b7-p39223421] Structural insight into synergistic activation of human 3-methylcrotonyl-CoA carboxylase. (2025). https://pubmed.ncbi.nlm.nih.gov/39223421/ DOI: 10.1038/s41594-024-01379-3
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.