Component

5'-Deoxyadenosylcobalamin

5'-Deoxyadenosylcobalamin; distinguish intact cobalamin-bound cobalt from free cobalt ion. 5-prime-Deoxyadenosylcobalamin

15 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. Bovine aortic endothelial cells converted cobalt-57-labeled adenosylcobalamin into labeled methylcobalamin during metabolic labeling.

    5'-Deoxyadenosylcobalamin → Methylcobalamin source_derived_draftungraded
    Experimental context and source evidence
    cross_nutrient
    false
    evidence_location
    Abstract; indexed Methods: Assessment of dealkylation; Discussion
    experimental_model
    Bovine aortic endothelial cell metabolic labeling
    exposure
    0.125 nM labeled alkylcobalamin; 48-hour processing assay protected from light
    limitations
    Cellular conversion supports processing but does not by itself identify every enzyme or establish a human supplement hierarchy.
    nutrient_topic
    Vitamin B12 research collection; topical membership is not evidence of a direct dietary effect. · Vitamin B12 (cobalamins)
    organism
    Bos taurus
    plain_language
    These bovine cells could rework one active B12 form into the other.
    primary_references
    [hannibal-2009-cell-processing] Processing of alkylcobalamins in mammalian cells: A role for the MMACHC (cblC) gene product (2009). https://pubmed.ncbi.nlm.nih.gov/19447654/ DOI: 10.1016/j.ymgme.2009.04.005
    tissue_or_cell_type
    Aortic endothelium

    Vitamin B12: mechanisms, deficiency and nutrient interactions (2026-09-17) · lines 795–807

    AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Bovine aortic endothelial cell metabolic labeling · source_derived_draft · unverified_draft

    ### b12-bovine-ado-to-methyl Bovine aortic endothelial cells converted cobalt-57-labeled adenosylcobalamin into labeled methylcobalamin during metabolic labeling. Condition category: normal nutrient_topic: Vitamin B12 research collection; topical membership is not evidence of a direct dietary effect. plain_language: These bovine cells could rework one active B12 form into the other. organism: Bos taurus tissue_or_cell_type: Aortic endothelium experimental_model: Bovine aortic endothelial cell metabolic labeling limitations: Cellular conversion supports processing but does not by itself identify every enzyme or establish a human supplement hierarchy. exposure: 0.125 nM labeled alkylcobalamin; 48-hour processing assay protected from light cross_nutrient: false evidence_location: Abstract; indexed Methods: Assessment of dealkylation; Discussion [hannibal-2009-cell-processing] Processing of alkylcobalamins in mammalian cells: A role for the MMACHC (cblC) gene product (2009). https://pubmed.ncbi.nlm.nih.gov/19447654/ DOI: 10.1016/j.ymgme.2009.04.005
    Complete structured claim and evidence

What acts on it

  1. Human MMACHC transfers the 5′-deoxyadenosyl group from adenosylcobalamin to glutathione, yielding cob(I)alamin and the corresponding glutathione thioether; reported turnover was 0.174 +/- 0.006 per hour at 20 C.

    Human MMACHC / cobalamin-processing protein CblC → 5'-Deoxyadenosylcobalamin source_derived_draftungraded
    Experimental context and source evidence
    cross_nutrient
    true
    evidence_location
    Primary abstract; indexed article Introduction/Figure 1
    experimental_model
    Purified human MMACHC substrate chemistry
    exposure
    Specified alkylcobalamin plus GSH; kinetic temperature 20 C
    limitations
    Reconstituted biochemical system; establishes reaction capability rather than the quantitatively dominant pathway in living humans.
    nutrient_topic
    Vitamin B12 research collection; topical membership is not evidence of a direct dietary effect. · Vitamin B12 (cobalamins)
    organism
    Homo sapiens
    plain_language
    Glutathione receives the side group removed from this B12 form.
    primary_references
    [kim-2009-gsh-dealkylation] A human vitamin B12 trafficking protein uses glutathione transferase activity for processing alkylcobalamins (2009). https://pubmed.ncbi.nlm.nih.gov/19801555/ DOI: 10.1074/jbc.M109.057877
    tissue_or_cell_type
    Cell-free assay

    Vitamin B12: mechanisms, deficiency and nutrient interactions (2026-09-17) · lines 725–737

    AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Purified human MMACHC substrate chemistry · source_derived_draft · unverified_draft

    ### b12-mmachc-adenosyl-dealkylation Human MMACHC transfers the 5′-deoxyadenosyl group from adenosylcobalamin to glutathione, yielding cob(I)alamin and the corresponding glutathione thioether; reported turnover was 0.174 +/- 0.006 per hour at 20 C. Condition category: normal nutrient_topic: Vitamin B12 research collection; topical membership is not evidence of a direct dietary effect. plain_language: Glutathione receives the side group removed from this B12 form. organism: Homo sapiens tissue_or_cell_type: Cell-free assay experimental_model: Purified human MMACHC substrate chemistry limitations: Reconstituted biochemical system; establishes reaction capability rather than the quantitatively dominant pathway in living humans. exposure: Specified alkylcobalamin plus GSH; kinetic temperature 20 C cross_nutrient: true evidence_location: Primary abstract; indexed article Introduction/Figure 1 [kim-2009-gsh-dealkylation] A human vitamin B12 trafficking protein uses glutathione transferase activity for processing alkylcobalamins (2009). https://pubmed.ncbi.nlm.nih.gov/19801555/ DOI: 10.1074/jbc.M109.057877
    Complete structured claim and evidence

  2. In cblD-MMA/HC fibroblasts, an MMADHC construct with improved mitochondrial targeting increased adenosylcobalamin formation relative to the targeting comparator.

    MMADHC with enhanced mitochondrial targeting sequence → 5'-Deoxyadenosylcobalamin source_derived_draftungraded
    Experimental context and source evidence
    availability_state
    machinery_impairment Imported condition classification; unverified.
    cross_nutrient
    false
    evidence_location
    Abstract
    experimental_model
    Human cblD-MMA/HC fibroblast transfection
    exposure
    Engineered mitochondrial leader sequence
    limitations
    Abstract-level construct experiment; effect in isolated cblD-MMA lines depended on mutation and endogenous expression.
    nutrient_topic
    Vitamin B12 research collection; topical membership is not evidence of a direct dietary effect. · Vitamin B12 (cobalamins)
    organism
    Homo sapiens
    plain_language
    Redirecting MMADHC toward mitochondria increased production of this B12 cofactor.
    primary_references
    [stucki-2012-mmad-routing] Molecular mechanisms leading to three different phenotypes in the cblD defect of intracellular cobalamin metabolism (2012). https://pubmed.ncbi.nlm.nih.gov/22156578/ DOI: 10.1093/hmg/ddr579
    tissue_or_cell_type
    Patient fibroblasts
    trigger_kind
    machinery_impairment Imported condition classification; unverified.

    Vitamin B12: mechanisms, deficiency and nutrient interactions (2026-09-17) · lines 823–835

    AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Human cblD-MMA/HC fibroblast transfection · source_derived_draft · unverified_draft

    ### b12-mmad-mito-target-adenosylcobalamin In cblD-MMA/HC fibroblasts, an MMADHC construct with improved mitochondrial targeting increased adenosylcobalamin formation relative to the targeting comparator. Condition category: machinery_impairment nutrient_topic: Vitamin B12 research collection; topical membership is not evidence of a direct dietary effect. plain_language: Redirecting MMADHC toward mitochondria increased production of this B12 cofactor. organism: Homo sapiens tissue_or_cell_type: Patient fibroblasts experimental_model: Human cblD-MMA/HC fibroblast transfection limitations: Abstract-level construct experiment; effect in isolated cblD-MMA lines depended on mutation and endogenous expression. exposure: Engineered mitochondrial leader sequence cross_nutrient: false evidence_location: Abstract [stucki-2012-mmad-routing] Molecular mechanisms leading to three different phenotypes in the cblD defect of intracellular cobalamin metabolism (2012). https://pubmed.ncbi.nlm.nih.gov/22156578/ DOI: 10.1093/hmg/ddr579
    Complete structured claim and evidence

Where it participates (unsigned role)

  1. Fibroblasts from three cblC patients had little or no conversion of cobalt-57-labeled propylcobalamin into adenosylcobalamin and methylcobalamin, whereas control skin fibroblasts converted the probe.

    Human MMACHC gene → Propylcobalamin source_derived_draftungraded
    Experimental context and source evidence
    availability_state
    machinery_impairment Imported condition classification; unverified.
    cross_nutrient
    false
    evidence_location
    Abstract; indexed Methods: Assessment of dealkylation; Discussion
    experimental_model
    Human control and cblC patient fibroblast labeling
    exposure
    0.125 nM cobalt-57 propylcobalamin for 48 hours
    limitations
    Propylcobalamin is a synthetic C3 probe; patients and genotypes differ and this comparison does not quantify every natural vitamer response.
    nutrient_topic
    Vitamin B12 research collection; topical membership is not evidence of a direct dietary effect. · Vitamin B12 (cobalamins)
    organism
    Homo sapiens
    plain_language
    A synthetic B12 probe exposed the processing defect in patient cells.
    primary_references
    [hannibal-2009-cell-processing] Processing of alkylcobalamins in mammalian cells: A role for the MMACHC (cblC) gene product (2009). https://pubmed.ncbi.nlm.nih.gov/19447654/ DOI: 10.1016/j.ymgme.2009.04.005
    tissue_or_cell_type
    Skin fibroblasts
    trigger_kind
    machinery_impairment Imported condition classification; unverified.

    Vitamin B12: mechanisms, deficiency and nutrient interactions (2026-09-17) · lines 809–821

    AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Human control and cblC patient fibroblast labeling · source_derived_draft · unverified_draft

    ### b12-cblc-propyl-probe Fibroblasts from three cblC patients had little or no conversion of cobalt-57-labeled propylcobalamin into adenosylcobalamin and methylcobalamin, whereas control skin fibroblasts converted the probe. Condition category: machinery_impairment nutrient_topic: Vitamin B12 research collection; topical membership is not evidence of a direct dietary effect. plain_language: A synthetic B12 probe exposed the processing defect in patient cells. organism: Homo sapiens tissue_or_cell_type: Skin fibroblasts experimental_model: Human control and cblC patient fibroblast labeling limitations: Propylcobalamin is a synthetic C3 probe; patients and genotypes differ and this comparison does not quantify every natural vitamer response. exposure: 0.125 nM cobalt-57 propylcobalamin for 48 hours cross_nutrient: false evidence_location: Abstract; indexed Methods: Assessment of dealkylation; Discussion [hannibal-2009-cell-processing] Processing of alkylcobalamins in mammalian cells: A role for the MMACHC (cblC) gene product (2009). https://pubmed.ncbi.nlm.nih.gov/19447654/ DOI: 10.1016/j.ymgme.2009.04.005
    Complete structured claim and evidence

  2. Human [2Fe-2S] ferredoxin FDX1 supplied electrons for MMAB-dependent adenosylcobalamin synthesis in the FDXR/NADPH reconstitution.

    Human adrenodoxin / FDX1 → Human ATP:cob(I)alamin adenosyltransferase / MMAB source_derived_draftungraded
    Experimental context and source evidence
    cross_nutrient
    true
    evidence_location
    Abstract and indexed primary Results, Figure 3
    experimental_model
    Purified human proteins
    exposure
    FDX1, FDXR and NADPH with MMAB, cob(II)alamin and ATP
    limitations
    Biochemically competent donor; exclusivity or necessity in living humans was not tested.
    nutrient_topic
    Vitamin B12 research collection; topical membership is not evidence of a direct dietary effect. · Vitamin B12 (cobalamins)
    organism
    Homo sapiens
    plain_language
    In the purified human system, an iron-sulfur electron carrier supported B12 activation.
    primary_references
    [gouda-2023-mmab-redox] Coordination Chemistry Controls Coenzyme B12 Synthesis by Human Adenosine Triphosphate:Cob(I)alamin Adenosyltransferase. (2023). https://pubmed.ncbi.nlm.nih.gov/37526260/ DOI: 10.1021/acs.inorgchem.3c02163
    tissue_or_cell_type
    Purified protein assay

    Vitamin B12: mechanisms, deficiency and nutrient interactions (2026-09-17) · lines 1005–1017

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

    ### fdx1-supports-mmab Human [2Fe-2S] ferredoxin FDX1 supplied electrons for MMAB-dependent adenosylcobalamin synthesis in the FDXR/NADPH reconstitution. Condition category: normal nutrient_topic: Vitamin B12 research collection; topical membership is not evidence of a direct dietary effect. plain_language: In the purified human system, an iron-sulfur electron carrier supported B12 activation. organism: Homo sapiens tissue_or_cell_type: Purified protein assay experimental_model: Purified human proteins limitations: Biochemically competent donor; exclusivity or necessity in living humans was not tested. exposure: FDX1, FDXR and NADPH with MMAB, cob(II)alamin and ATP cross_nutrient: true evidence_location: Abstract and indexed primary Results, Figure 3 [gouda-2023-mmab-redox] Coordination Chemistry Controls Coenzyme B12 Synthesis by Human Adenosine Triphosphate:Cob(I)alamin Adenosyltransferase. (2023). https://pubmed.ncbi.nlm.nih.gov/37526260/ DOI: 10.1021/acs.inorgchem.3c02163
    Complete structured claim and evidence

  3. Itaconyl-CoA inactivated purified human MMUT by forming a stable adduct with the B12-derived deoxyadenosyl moiety.

    Itaconyl-CoA → Human methylmalonyl-CoA mutase / MMUT source_derived_draftungraded
    Experimental context and source evidence
    cross_nutrient
    false
    evidence_location
    Primary abstract; indexed Results and Figure 3E
    experimental_model
    Purified human MMUT; inhibitor-product spectroscopy and analysis
    exposure
    Itaconyl-CoA exposure in the purified-enzyme assay
    limitations
    Mechanism-based inhibitor is distinct from physiological methylmalonyl-CoA; no human dietary effect inferred.
    nutrient_topic
    Vitamin B12 research collection; topical membership is not evidence of a direct dietary effect. · Vitamin B12 (cobalamins)
    organism
    Homo sapiens
    plain_language
    The itaconyl-CoA experiment trapped B12 radical chemistry and stopped the purified human enzyme.
    primary_references
    [ruetz-2019-itaconyl-radical] Itaconyl-CoA forms a stable biradical in methylmalonyl-CoA mutase and derails its activity and repair. (2019). https://pubmed.ncbi.nlm.nih.gov/31672889/ DOI: 10.1126/science.aay0934
    tissue_or_cell_type
    Purified protein assay

    Vitamin B12: mechanisms, deficiency and nutrient interactions (2026-09-17) · lines 1384–1396

    AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Purified human MMUT; inhibitor-product spectroscopy and analysis · source_derived_draft · unverified_draft

    ### itaconyl-coa-inactivates-human-mmut Itaconyl-CoA inactivated purified human MMUT by forming a stable adduct with the B12-derived deoxyadenosyl moiety. Condition category: normal nutrient_topic: Vitamin B12 research collection; topical membership is not evidence of a direct dietary effect. plain_language: The itaconyl-CoA experiment trapped B12 radical chemistry and stopped the purified human enzyme. organism: Homo sapiens tissue_or_cell_type: Purified protein assay experimental_model: Purified human MMUT; inhibitor-product spectroscopy and analysis limitations: Mechanism-based inhibitor is distinct from physiological methylmalonyl-CoA; no human dietary effect inferred. exposure: Itaconyl-CoA exposure in the purified-enzyme assay cross_nutrient: false evidence_location: Primary abstract; indexed Results and Figure 3E [ruetz-2019-itaconyl-radical] Itaconyl-CoA forms a stable biradical in methylmalonyl-CoA mutase and derails its activity and repair. (2019). https://pubmed.ncbi.nlm.nih.gov/31672889/ DOI: 10.1126/science.aay0934
    Complete structured claim and evidence

  4. Human MCEE interconverts methylmalonyl-CoA epimers, supplying the (R) form for MMUT; MCEE expression increased coupled succinate production.

    Human methylmalonyl-CoA epimerase / MCEE → (S)-Methylmalonyl-CoA source_derived_draftungraded
    Experimental context and source evidence
    cross_nutrient
    false
    evidence_location
    Full text Methods 2.6 and Results 3.6; Figure 5
    experimental_model
    Human fibroblast lysates overexpressing MCEE and/or MMUT
    exposure
    Radiolabeled propionyl-CoA; MCEE/MMUT expression and AdoCbl
    limitations
    Coupled labeled hydrolysis-product assay; MCEE being limiting here is not a universal in-vivo rate limitation.
    nutrient_topic
    Vitamin B12 research collection; topical membership is not evidence of a direct dietary effect. · Vitamin B12 (cobalamins)
    organism
    Homo sapiens
    plain_language
    Human fibroblast assays showed why the epimerase step matters before the B12 enzyme.
    primary_references
    [heuberger-2019-mcee] Genetic, structural, and functional analysis of pathogenic variations causing methylmalonyl-CoA epimerase deficiency. (2019). https://pubmed.ncbi.nlm.nih.gov/30682498/ DOI: 10.1016/j.bbadis.2019.01.021
    tissue_or_cell_type
    Fibroblasts

    Vitamin B12: mechanisms, deficiency and nutrient interactions (2026-09-17) · lines 1174–1186

    AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Human fibroblast lysates overexpressing MCEE and/or MMUT · source_derived_draft · unverified_draft

    ### mcee-epimerizes-methylmalonyl-coa Human MCEE interconverts methylmalonyl-CoA epimers, supplying the (R) form for MMUT; MCEE expression increased coupled succinate production. Condition category: normal nutrient_topic: Vitamin B12 research collection; topical membership is not evidence of a direct dietary effect. plain_language: Human fibroblast assays showed why the epimerase step matters before the B12 enzyme. organism: Homo sapiens tissue_or_cell_type: Fibroblasts experimental_model: Human fibroblast lysates overexpressing MCEE and/or MMUT limitations: Coupled labeled hydrolysis-product assay; MCEE being limiting here is not a universal in-vivo rate limitation. exposure: Radiolabeled propionyl-CoA; MCEE/MMUT expression and AdoCbl cross_nutrient: false evidence_location: Full text Methods 2.6 and Results 3.6; Figure 5 [heuberger-2019-mcee] Genetic, structural, and functional analysis of pathogenic variations causing methylmalonyl-CoA epimerase deficiency. (2019). https://pubmed.ncbi.nlm.nih.gov/30682498/ DOI: 10.1016/j.bbadis.2019.01.021
    Complete structured claim and evidence

  5. Human MCEE I53R lacked measured activity in the coupled patient-fibroblast assay with overexpressed MMUT and added adenosylcobalamin.

    Human MCEE p.Ile53Arg → Human MCEE-dependent coupled propionyl-CoA pathway activity source_derived_draftungraded
    Experimental context and source evidence
    availability_state
    machinery_impairment Imported condition classification; unverified.
    cross_nutrient
    false
    evidence_location
    Full text Methods 2.6 and Results 3.6; Figure 5
    experimental_model
    MCEE-null human fibroblasts expressing MCEE I53R
    exposure
    I53R expression; MMUT coexpression; 50 micromolar AdoCbl
    limitations
    Overexpression assay; not a clinical test of B12 treatment.
    nutrient_topic
    Vitamin B12 research collection; topical membership is not evidence of a direct dietary effect. · Vitamin B12 (cobalamins)
    organism
    Homo sapiens
    plain_language
    Adding activated B12 did not make this defective epimerase work in the human-cell assay.
    primary_references
    [heuberger-2019-mcee] Genetic, structural, and functional analysis of pathogenic variations causing methylmalonyl-CoA epimerase deficiency. (2019). https://pubmed.ncbi.nlm.nih.gov/30682498/ DOI: 10.1016/j.bbadis.2019.01.021
    tissue_or_cell_type
    Fibroblasts
    trigger_kind
    machinery_impairment Imported condition classification; unverified.

    Vitamin B12: mechanisms, deficiency and nutrient interactions (2026-09-17) · lines 1188–1200

    AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · MCEE-null human fibroblasts expressing MCEE I53R · source_derived_draft · unverified_draft

    ### mcee-i53r-reduces-coupled-activity Human MCEE I53R lacked measured activity in the coupled patient-fibroblast assay with overexpressed MMUT and added adenosylcobalamin. Condition category: machinery_impairment nutrient_topic: Vitamin B12 research collection; topical membership is not evidence of a direct dietary effect. plain_language: Adding activated B12 did not make this defective epimerase work in the human-cell assay. organism: Homo sapiens tissue_or_cell_type: Fibroblasts experimental_model: MCEE-null human fibroblasts expressing MCEE I53R limitations: Overexpression assay; not a clinical test of B12 treatment. exposure: I53R expression; MMUT coexpression; 50 micromolar AdoCbl cross_nutrient: false evidence_location: Full text Methods 2.6 and Results 3.6; Figure 5 [heuberger-2019-mcee] Genetic, structural, and functional analysis of pathogenic variations causing methylmalonyl-CoA epimerase deficiency. (2019). https://pubmed.ncbi.nlm.nih.gov/30682498/ DOI: 10.1016/j.bbadis.2019.01.021
    Complete structured claim and evidence

  6. Human MMAA formed a stable complex preferentially with apo-MMUT and with GMPPNP rather than GDP.

    Human MMAA GTPase → Human methylmalonyl-CoA mutase / MMUT source_derived_draftungraded
    Experimental context and source evidence
    cross_nutrient
    false
    evidence_location
    Indexed primary abstract; indexed Results
    experimental_model
    Purified human proteins
    exposure
    Apo versus holo-MMUT; GMPPNP versus GDP
    limitations
    GMPPNP is a GTP analogue; stable-complex abundance is not cofactor transfer rate.
    nutrient_topic
    Vitamin B12 research collection; topical membership is not evidence of a direct dietary effect. · Vitamin B12 (cobalamins)
    organism
    Homo sapiens
    plain_language
    The purified human proteins assembled differently depending on MMUT cofactor occupancy and nucleotide state.
    primary_references
    [froese-2010-human-mmaa] Structures of the human GTPase MMAA and vitamin B12-dependent methylmalonyl-CoA mutase and insight into their complex formation. (2010). https://pubmed.ncbi.nlm.nih.gov/20876572/ DOI: 10.1074/jbc.m110.177717
    tissue_or_cell_type
    Purified protein assay

    Vitamin B12: mechanisms, deficiency and nutrient interactions (2026-09-17) · lines 1047–1059

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

    ### mmaa-prefers-apo-mmut-complex Human MMAA formed a stable complex preferentially with apo-MMUT and with GMPPNP rather than GDP. Condition category: normal nutrient_topic: Vitamin B12 research collection; topical membership is not evidence of a direct dietary effect. plain_language: The purified human proteins assembled differently depending on MMUT cofactor occupancy and nucleotide state. organism: Homo sapiens tissue_or_cell_type: Purified protein assay experimental_model: Purified human proteins limitations: GMPPNP is a GTP analogue; stable-complex abundance is not cofactor transfer rate. exposure: Apo versus holo-MMUT; GMPPNP versus GDP cross_nutrient: false evidence_location: Indexed primary abstract; indexed Results [froese-2010-human-mmaa] Structures of the human GTPase MMAA and vitamin B12-dependent methylmalonyl-CoA mutase and insight into their complex formation. (2010). https://pubmed.ncbi.nlm.nih.gov/20876572/ DOI: 10.1074/jbc.m110.177717
    Complete structured claim and evidence

  7. Adding human MMAA at reaction initiation protected recombinant human MMUT against catalytic inactivation.

    Human MMAA GTPase → Human methylmalonyl-CoA mutase / MMUT source_derived_draftungraded
    Experimental context and source evidence
    cross_nutrient
    false
    evidence_location
    Indexed primary abstract
    experimental_model
    Purified human proteins
    exposure
    MMAA added at reaction initiation
    limitations
    Biochemical reconstitution; does not determine cellular rate or dietary requirement.
    nutrient_topic
    Vitamin B12 research collection; topical membership is not evidence of a direct dietary effect. · Vitamin B12 (cobalamins)
    organism
    Homo sapiens
    plain_language
    MMAA helped purified human MMUT remain active during the tested reaction.
    primary_references
    [takahashi-2010-mmaa-repair] Protection and reactivation of human methylmalonyl-CoA mutase by MMAA protein. (2011). https://pubmed.ncbi.nlm.nih.gov/21138732/ DOI: 10.1016/j.bbrc.2010.11.141
    tissue_or_cell_type
    Purified protein assay

    Vitamin B12: mechanisms, deficiency and nutrient interactions (2026-09-17) · lines 1075–1087

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

    ### mmaa-protects-mmut-activity Adding human MMAA at reaction initiation protected recombinant human MMUT against catalytic inactivation. Condition category: normal nutrient_topic: Vitamin B12 research collection; topical membership is not evidence of a direct dietary effect. plain_language: MMAA helped purified human MMUT remain active during the tested reaction. organism: Homo sapiens tissue_or_cell_type: Purified protein assay experimental_model: Purified human proteins limitations: Biochemical reconstitution; does not determine cellular rate or dietary requirement. exposure: MMAA added at reaction initiation cross_nutrient: false evidence_location: Indexed primary abstract [takahashi-2010-mmaa-repair] Protection and reactivation of human methylmalonyl-CoA mutase by MMAA protein. (2011). https://pubmed.ncbi.nlm.nih.gov/21138732/ DOI: 10.1016/j.bbrc.2010.11.141
    Complete structured claim and evidence

  8. Adding MMAA after 60 minutes restored activity in an inactivated human MMUT reaction through GTP hydrolysis.

    Human MMAA GTPase → Human methylmalonyl-CoA mutase / MMUT source_derived_draftungraded
    Experimental context and source evidence
    cross_nutrient
    false
    evidence_location
    Indexed primary abstract
    experimental_model
    Purified human proteins
    exposure
    MMAA added after 60-minute catalytic inactivation
    limitations
    In-vitro reactivation; abstract interprets damaged-cofactor exchange rather than measuring every intermediate.
    nutrient_topic
    Vitamin B12 research collection; topical membership is not evidence of a direct dietary effect. · Vitamin B12 (cobalamins)
    organism
    Homo sapiens
    plain_language
    MMAA restarted an inactive purified human MMUT reaction in a GTP-dependent assay.
    primary_references
    [takahashi-2010-mmaa-repair] Protection and reactivation of human methylmalonyl-CoA mutase by MMAA protein. (2011). https://pubmed.ncbi.nlm.nih.gov/21138732/ DOI: 10.1016/j.bbrc.2010.11.141
    tissue_or_cell_type
    Purified protein assay

    Vitamin B12: mechanisms, deficiency and nutrient interactions (2026-09-17) · lines 1089–1101

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

    ### mmaa-reactivates-mmut Adding MMAA after 60 minutes restored activity in an inactivated human MMUT reaction through GTP hydrolysis. Condition category: normal nutrient_topic: Vitamin B12 research collection; topical membership is not evidence of a direct dietary effect. plain_language: MMAA restarted an inactive purified human MMUT reaction in a GTP-dependent assay. organism: Homo sapiens tissue_or_cell_type: Purified protein assay experimental_model: Purified human proteins limitations: In-vitro reactivation; abstract interprets damaged-cofactor exchange rather than measuring every intermediate. exposure: MMAA added after 60-minute catalytic inactivation cross_nutrient: false evidence_location: Indexed primary abstract [takahashi-2010-mmaa-repair] Protection and reactivation of human methylmalonyl-CoA mutase by MMAA protein. (2011). https://pubmed.ncbi.nlm.nih.gov/21138732/ DOI: 10.1016/j.bbrc.2010.11.141
    Complete structured claim and evidence

  9. Purified human MMAB uses ATP to adenosylate cob(I)alamin to adenosylcobalamin.

    Human ATP:cob(I)alamin adenosyltransferase / MMAB → Cob(I)alamin source_derived_draftungraded
    Experimental context and source evidence
    cross_nutrient
    false
    evidence_location
    Indexed primary abstract
    experimental_model
    Purified human proteins
    exposure
    Cob(I)alamin and ATP
    limitations
    Biochemical reconstitution; does not determine cellular rate or dietary requirement.
    nutrient_topic
    Vitamin B12 research collection; topical membership is not evidence of a direct dietary effect. · Vitamin B12 (cobalamins)
    organism
    Homo sapiens
    plain_language
    In a purified human-protein assay, MMAB made the B12 cofactor used by MMUT.
    primary_references
    [leal-2004-human-mmab] Human ATP:Cob(I)alamin adenosyltransferase and its interaction with methionine synthase reductase. (2004). https://pubmed.ncbi.nlm.nih.gov/15347655/ DOI: 10.1074/jbc.m405449200
    tissue_or_cell_type
    Purified protein assay

    Vitamin B12: mechanisms, deficiency and nutrient interactions (2026-09-17) · lines 977–989

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

    ### mmab-adenosylates-cob-i Purified human MMAB uses ATP to adenosylate cob(I)alamin to adenosylcobalamin. Condition category: normal nutrient_topic: Vitamin B12 research collection; topical membership is not evidence of a direct dietary effect. plain_language: In a purified human-protein assay, MMAB made the B12 cofactor used by MMUT. organism: Homo sapiens tissue_or_cell_type: Purified protein assay experimental_model: Purified human proteins limitations: Biochemical reconstitution; does not determine cellular rate or dietary requirement. exposure: Cob(I)alamin and ATP cross_nutrient: false evidence_location: Indexed primary abstract [leal-2004-human-mmab] Human ATP:Cob(I)alamin adenosyltransferase and its interaction with methionine synthase reductase. (2004). https://pubmed.ncbi.nlm.nih.gov/15347655/ DOI: 10.1074/jbc.m405449200
    Complete structured claim and evidence

  10. R186Q human MMAB showed no detectable adenosylcobalamin synthesis with FDX1/FDXR/NADPH, although a strong chemical reductant supported activity.

    Human MMAB p.Arg186Gln → Human MMAB adenosylcobalamin synthesis source_derived_draftungraded
    Experimental context and source evidence
    availability_state
    machinery_impairment Imported condition classification; unverified.
    cross_nutrient
    true
    evidence_location
    Abstract and indexed primary Results, Figure 3
    experimental_model
    Purified human MMAB R186Q
    exposure
    R186Q variant; FDX1/FDXR/NADPH versus titanium(III)citrate
    limitations
    Detection-limited in-vitro activity; not proof of zero activity in every tissue.
    nutrient_topic
    Vitamin B12 research collection; topical membership is not evidence of a direct dietary effect. · Vitamin B12 (cobalamins)
    organism
    Homo sapiens
    plain_language
    This MMAB variant failed in the ferredoxin assay; the result depended on the electron donor.
    primary_references
    [gouda-2023-mmab-redox] Coordination Chemistry Controls Coenzyme B12 Synthesis by Human Adenosine Triphosphate:Cob(I)alamin Adenosyltransferase. (2023). https://pubmed.ncbi.nlm.nih.gov/37526260/ DOI: 10.1021/acs.inorgchem.3c02163
    tissue_or_cell_type
    Purified protein assay
    trigger_kind
    machinery_impairment Imported condition classification; unverified.

    Vitamin B12: mechanisms, deficiency and nutrient interactions (2026-09-17) · lines 1019–1031

    AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Purified human MMAB R186Q · source_derived_draft · unverified_draft

    ### mmab-r186q-fdx-system-fails R186Q human MMAB showed no detectable adenosylcobalamin synthesis with FDX1/FDXR/NADPH, although a strong chemical reductant supported activity. Condition category: machinery_impairment nutrient_topic: Vitamin B12 research collection; topical membership is not evidence of a direct dietary effect. plain_language: This MMAB variant failed in the ferredoxin assay; the result depended on the electron donor. organism: Homo sapiens tissue_or_cell_type: Purified protein assay experimental_model: Purified human MMAB R186Q limitations: Detection-limited in-vitro activity; not proof of zero activity in every tissue. exposure: R186Q variant; FDX1/FDXR/NADPH versus titanium(III)citrate cross_nutrient: true evidence_location: Abstract and indexed primary Results, Figure 3 [gouda-2023-mmab-redox] Coordination Chemistry Controls Coenzyme B12 Synthesis by Human Adenosine Triphosphate:Cob(I)alamin Adenosyltransferase. (2023). https://pubmed.ncbi.nlm.nih.gov/37526260/ DOI: 10.1021/acs.inorgchem.3c02163
    Complete structured claim and evidence

  11. Adenosylcobalamin-loaded human MMUT converts (R)-methylmalonyl-CoA to succinyl-CoA in the coupled enzyme assay.

    Human methylmalonyl-CoA mutase / MMUT → (R)-Methylmalonyl-CoA source_derived_draftungraded
    Experimental context and source evidence
    cross_nutrient
    false
    evidence_location
    Full text Results; Figures 2-4; cofactor off-loading and MMUT activity Methods
    experimental_model
    Purified human proteins
    exposure
    AdoCbl-loaded MMUT and methylmalonyl-CoA; thiokinase-coupled readout
    limitations
    Product formation is a coupled assay; cellular net flux was not measured.
    nutrient_topic
    Vitamin B12 research collection; topical membership is not evidence of a direct dietary effect. · Vitamin B12 (cobalamins)
    organism
    Homo sapiens
    plain_language
    Purified human MMUT used activated B12 to make succinyl-CoA from the matching methylmalonyl-CoA epimer.
    primary_references
    [mascarenhas-2023-nanoassembly] Architecture of the human G-protein-methylmalonyl-CoA mutase nanoassembly for B12 delivery and repair. (2023). https://pubmed.ncbi.nlm.nih.gov/37468522/ DOI: 10.1038/s41467-023-40077-4
    tissue_or_cell_type
    Purified protein assay

    Vitamin B12: mechanisms, deficiency and nutrient interactions (2026-09-17) · lines 1103–1115

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

    ### mmut-isomerizes-r-methylmalonyl-coa Adenosylcobalamin-loaded human MMUT converts (R)-methylmalonyl-CoA to succinyl-CoA in the coupled enzyme assay. Condition category: normal nutrient_topic: Vitamin B12 research collection; topical membership is not evidence of a direct dietary effect. plain_language: Purified human MMUT used activated B12 to make succinyl-CoA from the matching methylmalonyl-CoA epimer. organism: Homo sapiens tissue_or_cell_type: Purified protein assay experimental_model: Purified human proteins limitations: Product formation is a coupled assay; cellular net flux was not measured. exposure: AdoCbl-loaded MMUT and methylmalonyl-CoA; thiokinase-coupled readout cross_nutrient: false evidence_location: Full text Results; Figures 2-4; cofactor off-loading and MMUT activity Methods [mascarenhas-2023-nanoassembly] Architecture of the human G-protein-methylmalonyl-CoA mutase nanoassembly for B12 delivery and repair. (2023). https://pubmed.ncbi.nlm.nih.gov/37468522/ DOI: 10.1038/s41467-023-40077-4
    Complete structured claim and evidence

  12. Purified human MTRR coupled cob(II)alamin reduction to MMAB-dependent adenosylcobalamin synthesis in vitro.

    Methionine synthase reductase / MTRR → Human ATP:cob(I)alamin adenosyltransferase / MMAB source_derived_draftungraded
    Experimental context and source evidence
    cross_nutrient
    true
    evidence_location
    Indexed primary abstract
    experimental_model
    Purified human proteins
    exposure
    Purified MTRR plus MMAB and reductants
    limitations
    MTRR coupling in vitro does not identify the physiological mitochondrial electron donor.
    nutrient_topic
    Vitamin B12 research collection; topical membership is not evidence of a direct dietary effect. · Vitamin B12 (cobalamins)
    organism
    Homo sapiens
    plain_language
    Human MTRR supported B12 activation in a test-tube system; this does not establish its mitochondrial role.
    primary_references
    [leal-2004-human-mmab] Human ATP:Cob(I)alamin adenosyltransferase and its interaction with methionine synthase reductase. (2004). https://pubmed.ncbi.nlm.nih.gov/15347655/ DOI: 10.1074/jbc.m405449200
    tissue_or_cell_type
    Purified protein assay

    Vitamin B12: mechanisms, deficiency and nutrient interactions (2026-09-17) · lines 991–1003

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

    ### mtrr-supports-mmab-in-vitro Purified human MTRR coupled cob(II)alamin reduction to MMAB-dependent adenosylcobalamin synthesis in vitro. Condition category: normal nutrient_topic: Vitamin B12 research collection; topical membership is not evidence of a direct dietary effect. plain_language: Human MTRR supported B12 activation in a test-tube system; this does not establish its mitochondrial role. organism: Homo sapiens tissue_or_cell_type: Purified protein assay experimental_model: Purified human proteins limitations: MTRR coupling in vitro does not identify the physiological mitochondrial electron donor. exposure: Purified MTRR plus MMAB and reductants cross_nutrient: true evidence_location: Indexed primary abstract [leal-2004-human-mmab] Human ATP:Cob(I)alamin adenosyltransferase and its interaction with methionine synthase reductase. (2004). https://pubmed.ncbi.nlm.nih.gov/15347655/ DOI: 10.1074/jbc.m405449200
    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