Component

Human hepatic serine dehydratase / SDS

Context-specific entity; species, compartment and exposure are stated on each claim.

6 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. Human liver serine dehydratase uses PLP to convert L-serine to pyruvate and ammonia; its active holoenzyme was structurally characterized.

    Human hepatic serine dehydratase / SDS → Pyruvate source_derived_draftungraded
    Experimental context and source evidence
    evidence_access
    Primary abstract
    experimental_model
    Purified human hepatic enzyme, activity assay and 2.5-angstrom crystal structure.
    limitations
    Enzyme capacity does not quantify its share of whole-body serine disposal.
    nutrient_topic
    L-Serine collection; species, compartment, exposure, co-substrates and manipulation remain explicit. · L-Serine
    plain_language
    Serine carbon can enter central metabolism through a B6-dependent breakdown step.
    primary_references
    Crystal structure of the pyridoxal-5'-phosphate-dependent serine dehydratase from human liver. · 2005 · https://pubmed.ncbi.nlm.nih.gov/15689518/ · DOI 10.1110/ps.041179105

    L-Serine: synthesis, one-carbon metabolism, lipids and cross-nutrient mechanisms (2026-09-19) · lines 366–372

    AI-assisted research curation; primary references, access levels and experimental limitations individually identified. Not publisher full text. · supports · Purified human hepatic enzyme, activity assay and 2.5-angstrom crystal structure. · source_derived_draft · unverified_draft

    ## l-serine-sds-catabolism Serine carbon can enter central metabolism through a B6-dependent breakdown step. Human liver serine dehydratase uses PLP to convert L-serine to pyruvate and ammonia; its active holoenzyme was structurally characterized. Model: Purified human hepatic enzyme, activity assay and 2.5-angstrom crystal structure. Limitations: Enzyme capacity does not quantify its share of whole-body serine disposal. Evidence access: Primary abstract Crystal structure of the pyridoxal-5'-phosphate-dependent serine dehydratase from human liver. · 2005 · https://pubmed.ncbi.nlm.nih.gov/15689518/ · DOI 10.1110/ps.041179105
    Complete structured claim and evidence

  2. Purified human hepatic serine dehydratase showed L-threonine dehydratase activity in comparison with the human SDH-like isoform.

    Human hepatic serine dehydratase / SDS → Alpha-ketobutyrate source_derived_draftungraded
    Experimental context and source evidence
    evidence_access
    Primary abstract
    experimental_model
    Human recombinant enzymes expressed in E. coli and compared biochemically.
    limitations
    Activity in a purified system does not quantify whole-body human threonine flux. The threonine product is alpha-ketobutyrate, distinct from the serine product pyruvate.
    nutrient_topic
    L-Threonine collection; species, compartment, exposure, co-substrates and manipulation remain explicit. · L-Threonine
    plain_language
    Threonine can enter carbon metabolism through an enzyme it shares with serine.
    primary_references
    Enzymatic and biochemical properties of a novel human serine dehydratase isoform. · 2006 · https://pubmed.ncbi.nlm.nih.gov/16580895/ · DOI 10.1016/j.bbapap.2006.02.010

    L-Threonine: translation, intestinal barrier, metabolism and cross-nutrient mechanisms (2026-09-19) · lines 250–256

    AI-assisted research curation; primary references, access levels and experimental limitations individually identified. Not publisher full text. · supports · Human recombinant enzymes expressed in E. coli and compared biochemically. · source_derived_draft · unverified_draft

    ## l-threonine-human-sds-catabolism Threonine can enter carbon metabolism through an enzyme it shares with serine. Purified human hepatic serine dehydratase showed L-threonine dehydratase activity in comparison with the human SDH-like isoform. Model: Human recombinant enzymes expressed in E. coli and compared biochemically. Limitations: Activity in a purified system does not quantify whole-body human threonine flux. The threonine product is alpha-ketobutyrate, distinct from the serine product pyruvate. Evidence access: Primary abstract Enzymatic and biochemical properties of a novel human serine dehydratase isoform. · 2006 · https://pubmed.ncbi.nlm.nih.gov/16580895/ · DOI 10.1016/j.bbapap.2006.02.010
    Complete structured claim and evidence

What acts on it

  1. Human serine dehydratase-like protein had lower activity than the hepatic enzyme; structures and complementary mutations implicated active-site differences, including Gly72.

    Human serine dehydratase-like protein / SDSL → Human hepatic serine dehydratase / SDS source_derived_draftungraded
    Experimental context and source evidence
    evidence_access
    Primary abstract
    experimental_model
    Recombinant human enzymes, 2.8-angstrom SDSL structure and site-directed mutagenesis.
    limitations
    This is a comparison of enzyme constructs, not clinical evidence of a dietary shortage.
    nutrient_topic
    L-Serine collection; species, compartment, exposure, co-substrates and manipulation remain explicit. · L-Serine
    plain_language
    Related enzymes are not interchangeable just because they use the same substrate.
    primary_references
    A catalytic mechanism that explains a low catalytic activity of serine dehydratase like-1 from human cancer cells: crystal structure and site-directed mutagenesis studies. · 2008 · https://pubmed.ncbi.nlm.nih.gov/18342636/ · DOI 10.1016/j.bbagen.2008.01.020

    L-Serine: synthesis, one-carbon metabolism, lipids and cross-nutrient mechanisms (2026-09-19) · lines 374–380

    AI-assisted research curation; primary references, access levels and experimental limitations individually identified. Not publisher full text. · supports · Recombinant human enzymes, 2.8-angstrom SDSL structure and site-directed mutagenesis. · source_derived_draft · unverified_draft

    ## l-serine-sdsl-distinction Related enzymes are not interchangeable just because they use the same substrate. Human serine dehydratase-like protein had lower activity than the hepatic enzyme; structures and complementary mutations implicated active-site differences, including Gly72. Model: Recombinant human enzymes, 2.8-angstrom SDSL structure and site-directed mutagenesis. Limitations: This is a comparison of enzyme constructs, not clinical evidence of a dietary shortage. Evidence access: Primary abstract A catalytic mechanism that explains a low catalytic activity of serine dehydratase like-1 from human cancer cells: crystal structure and site-directed mutagenesis studies. · 2008 · https://pubmed.ncbi.nlm.nih.gov/18342636/ · DOI 10.1016/j.bbagen.2008.01.020
    Complete structured claim and evidence

  2. Deleting Pro128 from human hepatic SDS changed substrate kinetic constants and affinity for pyridoxal phosphate.

    PLP → Human hepatic serine dehydratase / SDS source_derived_draftungraded
    Experimental context and source evidence
    evidence_access
    Primary abstract
    experimental_model
    Purified wild-type and engineered human enzymes.
    limitations
    This manipulation does not show that additional B6 restores a mutant enzyme or that ordinary dietary B6 is limiting.
    nutrient_topic
    L-Threonine collection; species, compartment, exposure, co-substrates and manipulation remain explicit. · L-Threonine
    plain_language
    B6-dependent chemistry also depends on the enzyme structure that binds its cofactor.
    primary_references
    Enzymatic and biochemical properties of a novel human serine dehydratase isoform. · 2006 · https://pubmed.ncbi.nlm.nih.gov/16580895/ · DOI 10.1016/j.bbapap.2006.02.010

    L-Threonine: translation, intestinal barrier, metabolism and cross-nutrient mechanisms (2026-09-19) · lines 266–272

    AI-assisted research curation; primary references, access levels and experimental limitations individually identified. Not publisher full text. · supports · Purified wild-type and engineered human enzymes. · source_derived_draft · unverified_draft

    ## l-threonine-human-sds-plp B6-dependent chemistry also depends on the enzyme structure that binds its cofactor. Deleting Pro128 from human hepatic SDS changed substrate kinetic constants and affinity for pyridoxal phosphate. Model: Purified wild-type and engineered human enzymes. Limitations: This manipulation does not show that additional B6 restores a mutant enzyme or that ordinary dietary B6 is limiting. Evidence access: Primary abstract Enzymatic and biochemical properties of a novel human serine dehydratase isoform. · 2006 · https://pubmed.ncbi.nlm.nih.gov/16580895/ · DOI 10.1016/j.bbapap.2006.02.010
    Complete structured claim and evidence

Where it participates (unsigned role)

  1. Human serine racemase catalyzes the PLP-dependent formation of D-serine from L-serine; replacing Ser84 with alanine shifted its behavior toward serine dehydratase activity.

    Human serine racemase / SRR → D-Serine source_derived_draftungraded
    Experimental context and source evidence
    evidence_access
    Primary abstract
    experimental_model
    Recombinant human serine racemase and serine dehydratase mutants with functional comparisons.
    limitations
    Engineered reaction switching does not mean the native enzymes have identical functions.
    nutrient_topic
    L-Serine collection; species, compartment, exposure, co-substrates and manipulation remain explicit. · L-Serine
    plain_language
    One enzyme creates the D-form used in a distinct signaling pathway.
    primary_references
    Modulating the function of human serine racemase and human serine dehydratase by protein engineering. · 2012 · https://pubmed.ncbi.nlm.nih.gov/23112234/ · DOI 10.1093/protein/gzs078

    L-Serine: synthesis, one-carbon metabolism, lipids and cross-nutrient mechanisms (2026-09-19) · lines 406–412

    AI-assisted research curation; primary references, access levels and experimental limitations individually identified. Not publisher full text. · supports · Recombinant human serine racemase and serine dehydratase mutants with functional comparisons. · source_derived_draft · unverified_draft

    ## l-serine-srr-racemization One enzyme creates the D-form used in a distinct signaling pathway. Human serine racemase catalyzes the PLP-dependent formation of D-serine from L-serine; replacing Ser84 with alanine shifted its behavior toward serine dehydratase activity. Model: Recombinant human serine racemase and serine dehydratase mutants with functional comparisons. Limitations: Engineered reaction switching does not mean the native enzymes have identical functions. Evidence access: Primary abstract Modulating the function of human serine racemase and human serine dehydratase by protein engineering. · 2012 · https://pubmed.ncbi.nlm.nih.gov/23112234/ · DOI 10.1093/protein/gzs078
    Complete structured claim and evidence

  2. The recombinant human SDH-like protein also had threonine dehydratase activity, with kinetic constants differing substantially from hepatic SDS.

    Human serine dehydratase-like protein / SDSL → Alpha-ketobutyrate source_derived_draftungraded
    Experimental context and source evidence
    evidence_access
    Primary abstract
    experimental_model
    Comparative human enzyme kinetics and PLP-binding measurements.
    limitations
    Isoform abundance in cultured cells was low; catalytic capacity does not establish its dominant tissue role.
    nutrient_topic
    L-Threonine collection; species, compartment, exposure, co-substrates and manipulation remain explicit. · L-Threonine
    plain_language
    Closely related enzymes can process the same substrate at different rates.
    primary_references
    Enzymatic and biochemical properties of a novel human serine dehydratase isoform. · 2006 · https://pubmed.ncbi.nlm.nih.gov/16580895/ · DOI 10.1016/j.bbapap.2006.02.010

    L-Threonine: translation, intestinal barrier, metabolism and cross-nutrient mechanisms (2026-09-19) · lines 258–264

    AI-assisted research curation; primary references, access levels and experimental limitations individually identified. Not publisher full text. · supports · Comparative human enzyme kinetics and PLP-binding measurements. · source_derived_draft · unverified_draft

    ## l-threonine-human-sdsl-catabolism Closely related enzymes can process the same substrate at different rates. The recombinant human SDH-like protein also had threonine dehydratase activity, with kinetic constants differing substantially from hepatic SDS. Model: Comparative human enzyme kinetics and PLP-binding measurements. Limitations: Isoform abundance in cultured cells was low; catalytic capacity does not establish its dominant tissue role. Evidence access: Primary abstract Enzymatic and biochemical properties of a novel human serine dehydratase isoform. · 2006 · https://pubmed.ncbi.nlm.nih.gov/16580895/ · DOI 10.1016/j.bbapap.2006.02.010
    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.

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