Component
Collagen prolyl 4-hydroxylase, the alpha2beta2 tetramer
Collagen prolyl 4-hydroxylase, the alpha2beta2 tetramer. Species, exposure and limitations are retained in each linked claim.
2 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
Ascorbate is not consumed during most catalytic cycles, but the enzyme also decarboxylates 2-oxoglutarate without subsequent hydroxylation, and ascorbate is required as a specific alternative oxygen acceptor in those uncoupled cycles.
Experimental context and source evidence
- evidence_span
- {"source_cache": "artifacts/hbot-research/2537773.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "3fdda2e4cf4392ec7a88b137274cee8f321255473992a2d8df781df12cad6cfe", "start_char": 0, "end_char": 2024, "text_sha256": "3fdda2e4cf4392ec7a88b137274cee8f321255473992a2d8df781df12cad6cfe"}
- experimental_model
- Review of prolyl 4-hydroxylase enzymology and subunit structure
- exposure
- Hydroxylation of proline in X-Pro-Gly sequences
- limitations
- An authoritative enzymology review rather than a single experiment. It is the source for the cosubstrate list, which is the point at which oxygen, iron and vitamin C meet in collagen synthesis.
- 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
- Mammalian enzyme
- plain_language
- Vitamin C is not used up every turn; it is the reserve that resets the enzyme when a cycle misfires.
- primary_references
- [hbot-p2537773] Protein hydroxylation: prolyl 4-hydroxylase, an enzyme with four cosubstrates and a multifunctional subunit. (1989). https://pubmed.ncbi.nlm.nih.gov/2537773/ DOI: 10.1096/fasebj.3.5.2537773
- tissue_or_cell_type
- Endoplasmic reticulum
Hyperbaric oxygen: the exposure, its reactive species, the signals they carry, and the nutrient-dependent enzymes that handle them (2026-09-19) · lines 868–879
AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Review of prolyl 4-hydroxylase enzymology and subunit structure · source_derived_draft · unverified_draft
### hbot-ascorbate-uncoupled-cycles Ascorbate is not consumed during most catalytic cycles, but the enzyme also decarboxylates 2-oxoglutarate without subsequent hydroxylation, and ascorbate is required as a specific alternative oxygen acceptor in those uncoupled cycles. Condition category: normal 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: Vitamin C is not used up every turn; it is the reserve that resets the enzyme when a cycle misfires. organism: Mammalian enzyme tissue_or_cell_type: Endoplasmic reticulum experimental_model: Review of prolyl 4-hydroxylase enzymology and subunit structure limitations: An authoritative enzymology review rather than a single experiment. It is the source for the cosubstrate list, which is the point at which oxygen, iron and vitamin C meet in collagen synthesis. exposure: Hydroxylation of proline in X-Pro-Gly sequences evidence_span: {"source_cache": "artifacts/hbot-research/2537773.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "3fdda2e4cf4392ec7a88b137274cee8f321255473992a2d8df781df12cad6cfe", "start_char": 0, "end_char": 2024, "text_sha256": "3fdda2e4cf4392ec7a88b137274cee8f321255473992a2d8df781df12cad6cfe"} [hbot-p2537773] Protein hydroxylation: prolyl 4-hydroxylase, an enzyme with four cosubstrates and a multifunctional subunit. (1989). https://pubmed.ncbi.nlm.nih.gov/2537773/ DOI: 10.1096/fasebj.3.5.2537773
Complete structured claim and evidenceThe active enzyme is an alpha2beta2 tetramer whose beta subunit is identical to protein disulfide isomerase and a major cellular thyroid-hormone-binding protein, and whose C-terminal Lys-Asp-Glu-Leu sequence retains the enzyme in the endoplasmic reticulum.
Experimental context and source evidence
- evidence_span
- {"source_cache": "artifacts/hbot-research/2537773.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "3fdda2e4cf4392ec7a88b137274cee8f321255473992a2d8df781df12cad6cfe", "start_char": 0, "end_char": 2024, "text_sha256": "3fdda2e4cf4392ec7a88b137274cee8f321255473992a2d8df781df12cad6cfe"}
- experimental_model
- Review of prolyl 4-hydroxylase enzymology and subunit structure
- exposure
- Hydroxylation of proline in X-Pro-Gly sequences
- limitations
- An authoritative enzymology review rather than a single experiment. It is the source for the cosubstrate list, which is the point at which oxygen, iron and vitamin C meet in collagen synthesis.
- 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
- Mammalian enzyme
- plain_language
- One half of this enzyme is a different enzyme doing a second job, and a four-letter tail keeps it where collagen is made.
- primary_references
- [hbot-p2537773] Protein hydroxylation: prolyl 4-hydroxylase, an enzyme with four cosubstrates and a multifunctional subunit. (1989). https://pubmed.ncbi.nlm.nih.gov/2537773/ DOI: 10.1096/fasebj.3.5.2537773
- tissue_or_cell_type
- Endoplasmic reticulum
Hyperbaric oxygen: the exposure, its reactive species, the signals they carry, and the nutrient-dependent enzymes that handle them (2026-09-19) · lines 881–892
AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Review of prolyl 4-hydroxylase enzymology and subunit structure · source_derived_draft · unverified_draft
### hbot-p4h-structure The active enzyme is an alpha2beta2 tetramer whose beta subunit is identical to protein disulfide isomerase and a major cellular thyroid-hormone-binding protein, and whose C-terminal Lys-Asp-Glu-Leu sequence retains the enzyme in the endoplasmic reticulum. Condition category: normal 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: One half of this enzyme is a different enzyme doing a second job, and a four-letter tail keeps it where collagen is made. organism: Mammalian enzyme tissue_or_cell_type: Endoplasmic reticulum experimental_model: Review of prolyl 4-hydroxylase enzymology and subunit structure limitations: An authoritative enzymology review rather than a single experiment. It is the source for the cosubstrate list, which is the point at which oxygen, iron and vitamin C meet in collagen synthesis. exposure: Hydroxylation of proline in X-Pro-Gly sequences evidence_span: {"source_cache": "artifacts/hbot-research/2537773.abstract.txt", "locator": "Indexed abstract; zero-based, end-exclusive Unicode character offsets", "file_sha256": "3fdda2e4cf4392ec7a88b137274cee8f321255473992a2d8df781df12cad6cfe", "start_char": 0, "end_char": 2024, "text_sha256": "3fdda2e4cf4392ec7a88b137274cee8f321255473992a2d8df781df12cad6cfe"} [hbot-p2537773] Protein hydroxylation: prolyl 4-hydroxylase, an enzyme with four cosubstrates and a multifunctional subunit. (1989). https://pubmed.ncbi.nlm.nih.gov/2537773/ DOI: 10.1096/fasebj.3.5.2537773
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.