Component
Recombinant rat thioredoxin reductase with SeCys498 replaced by cysteine
Recombinant rat thioredoxin reductase with SeCys498 replaced by cysteine. Species, exposure and limitations are retained in each linked claim.
1 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 it acts on
The SeCys498 to Cys enzyme retained catalytic activity in thioredoxin reduction with a 100-fold lower kcat and a 10-fold lower Km, and its pH optimum shifted from 7 to 9, strongly suggesting involvement of the low-pKa selenol in the mechanism.
Experimental context and source evidence
- availability_state
- nutrient_deficiency Imported condition classification; unverified.
- evidence_span
- {"source_cache": "artifacts/hbot-research/10849437.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "13fe79ebefbddac9a76f4cae2e0f1aede8d648b6568adca72f0b0a550e66bc90", "start_char": 0, "end_char": 1374, "text_sha256": "13fe79ebefbddac9a76f4cae2e0f1aede8d648b6568adca72f0b0a550e66bc90"}
- experimental_model
- Recombinant rat thioredoxin reductase with selenocysteine mutations expressed in E. coli
- exposure
- SeCys498 replaced by cysteine or serine, and a truncated protein lacking the C-terminal SeCys-Gly dipeptide
- limitations
- The truncated construct is described by the authors as the form expected in selenium deficiency, which is what links this enzyme chemistry to nutrient supply. It remains a recombinant model, not a measurement in a selenium-deficient animal.
- nutrient_topic
- Hyperbaric oxygen research collection; topical membership is not evidence of a direct clinical effect, and a therapeutic exposure is not a dietary intake. · Hyperbaric oxygen therapy
- organism
- Rat enzyme in a bacterial expression host
- plain_language
- Swapping selenium for sulphur leaves an enzyme that barely works and only in the wrong conditions.
- primary_references
- [hbot-p10849437] Essential role of selenium in the catalytic activities of mammalian thioredoxin reductase revealed by characterization of recombinant enzymes with selenocysteine mutations. (2000). https://pubmed.ncbi.nlm.nih.gov/10849437/ DOI: 10.1074/jbc.m000690200
- tissue_or_cell_type
- Purified enzyme
- trigger_kind
- nutrient_deficiency Imported condition classification; unverified.
Hyperbaric oxygen: the exposure, its reactive species, the signals they carry, and the nutrient-dependent enzymes that handle them (2026-09-19) · lines 465–476
AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Recombinant rat thioredoxin reductase with selenocysteine mutations expressed in E. coli · source_derived_draft · unverified_draft
### hbot-trxr-secys-mutant-activity The SeCys498 to Cys enzyme retained catalytic activity in thioredoxin reduction with a 100-fold lower kcat and a 10-fold lower Km, and its pH optimum shifted from 7 to 9, strongly suggesting involvement of the low-pKa selenol in the mechanism. Condition category: nutrient_deficiency nutrient_topic: Hyperbaric oxygen research collection; topical membership is not evidence of a direct clinical effect, and a therapeutic exposure is not a dietary intake. plain_language: Swapping selenium for sulphur leaves an enzyme that barely works and only in the wrong conditions. organism: Rat enzyme in a bacterial expression host tissue_or_cell_type: Purified enzyme experimental_model: Recombinant rat thioredoxin reductase with selenocysteine mutations expressed in E. coli limitations: The truncated construct is described by the authors as the form expected in selenium deficiency, which is what links this enzyme chemistry to nutrient supply. It remains a recombinant model, not a measurement in a selenium-deficient animal. exposure: SeCys498 replaced by cysteine or serine, and a truncated protein lacking the C-terminal SeCys-Gly dipeptide evidence_span: {"source_cache": "artifacts/hbot-research/10849437.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "13fe79ebefbddac9a76f4cae2e0f1aede8d648b6568adca72f0b0a550e66bc90", "start_char": 0, "end_char": 1374, "text_sha256": "13fe79ebefbddac9a76f4cae2e0f1aede8d648b6568adca72f0b0a550e66bc90"} [hbot-p10849437] Essential role of selenium in the catalytic activities of mammalian thioredoxin reductase revealed by characterization of recombinant enzymes with selenocysteine mutations. (2000). https://pubmed.ncbi.nlm.nih.gov/10849437/ DOI: 10.1074/jbc.m000690200
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.