Component
Ovine glutamine synthetase / GLUL
Sheep glutamine synthetase; kept separate from human GLUL.
4 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
Ovine brain GLUL assays showed optimal Mg:ATP at 2:1 and Mn:ATP at 1:1, with different reported pH optima of 7.5 and 5.0, respectively.
Experimental context and source evidence
- cross_nutrient
- Mn and Mg can support activity in vitro, with distinct metal:ATP ratios and pH conditions.
- experimental_model
- Ovine brain glutamine synthetase steady-state kinetics and metal-binding measurements
- exposure
- Mn(II) and Mg(II) titrations; binding and tissue metal measurements
- limitations
- Different assay optima are not evidence that Mn is the preferred cofactor at physiological brain pH.
- nutrient_topic
- Manganese research collection; topical membership is not evidence of a direct dietary effect. · Manganese
- organism
- Ovis aries
- plain_language
- Magnesium and manganese supported GLUL under different assay conditions.
- primary_references
- [mn-enz-6129892] Glutamine synthetase from ovine brain is a manganese(II) enzyme. (1982). https://pubmed.ncbi.nlm.nih.gov/6129892/ DOI: 10.1021/bi00268a011
- tissue_or_cell_type
- Brain-derived purified enzyme
Manganese: enzyme cofactors, glycosylation, transport and nutrient interactions (2026-09-17) · lines 620–631
AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Ovine brain glutamine synthetase steady-state kinetics and metal-binding measurements · source_derived_draft · unverified_draft
### mn-enz-ovine-glul-metal-kinetics Ovine brain GLUL assays showed optimal Mg:ATP at 2:1 and Mn:ATP at 1:1, with different reported pH optima of 7.5 and 5.0, respectively. Condition category: normal nutrient_topic: Manganese research collection; topical membership is not evidence of a direct dietary effect. plain_language: Magnesium and manganese supported GLUL under different assay conditions. organism: Ovis aries tissue_or_cell_type: Brain-derived purified enzyme experimental_model: Ovine brain glutamine synthetase steady-state kinetics and metal-binding measurements limitations: Different assay optima are not evidence that Mn is the preferred cofactor at physiological brain pH. exposure: Mn(II) and Mg(II) titrations; binding and tissue metal measurements cross_nutrient: Mn and Mg can support activity in vitro, with distinct metal:ATP ratios and pH conditions. [mn-enz-6129892] Glutamine synthetase from ovine brain is a manganese(II) enzyme. (1982). https://pubmed.ncbi.nlm.nih.gov/6129892/ DOI: 10.1021/bi00268a011
Complete structured claim and evidence
What acts on it
Cofactor-trapped GLUL from bovine or ovine brain contained 1.5±0.2 Mg per subunit and less than 0.05 Mn per subunit.
Experimental context and source evidence
- cross_nutrient
- Direct native-metal trapping distinguishes Mg occupancy from Mn-supported activity in vitro.
- experimental_model
- Cofactor trapping and immunoprecipitation of bovine and ovine brain glutamine synthetase
- exposure
- Methionine sulfoximine phosphate/ADP cofactor trapping
- limitations
- Extraction with methionine sulfoximine phosphate and ADP; bovine/ovine brain, not direct living human brain measurement.
- nutrient_topic
- Manganese research collection; topical membership is not evidence of a direct dietary effect. · Manganese
- organism
- Bos taurus; Ovis aries
- plain_language
- A cofactor-trapping study recovered mainly magnesium from brain GLUL.
- primary_references
- [mn-enz-2870682] Mg2+ is bound to glutamine synthetase extracted from bovine or ovine brain in the presence of L-methionine-S-sulfoximine phosphate. (1986). https://pubmed.ncbi.nlm.nih.gov/2870682/ DOI: 10.1016/0003-9861(86)90496-0
- tissue_or_cell_type
- Brain extracts and purified enzyme
Manganese: enzyme cofactors, glycosylation, transport and nutrient interactions (2026-09-17) · lines 646–657
AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Cofactor trapping and immunoprecipitation of bovine and ovine brain glutamine synthetase · source_derived_draft · unverified_draft
### mn-enz-brain-glul-cofactor-trapping Cofactor-trapped GLUL from bovine or ovine brain contained 1.5±0.2 Mg per subunit and less than 0.05 Mn per subunit. Condition category: normal nutrient_topic: Manganese research collection; topical membership is not evidence of a direct dietary effect. plain_language: A cofactor-trapping study recovered mainly magnesium from brain GLUL. organism: Bos taurus; Ovis aries tissue_or_cell_type: Brain extracts and purified enzyme experimental_model: Cofactor trapping and immunoprecipitation of bovine and ovine brain glutamine synthetase limitations: Extraction with methionine sulfoximine phosphate and ADP; bovine/ovine brain, not direct living human brain measurement. exposure: Methionine sulfoximine phosphate/ADP cofactor trapping cross_nutrient: Direct native-metal trapping distinguishes Mg occupancy from Mn-supported activity in vitro. [mn-enz-2870682] Mg2+ is bound to glutamine synthetase extracted from bovine or ovine brain in the presence of L-methionine-S-sulfoximine phosphate. (1986). https://pubmed.ncbi.nlm.nih.gov/2870682/ DOI: 10.1016/0003-9861(86)90496-0
Complete structured claim and evidenceThe 1986 cofactor-trapping study concluded that Mg, rather than Mn, appears to be bound to bovine/ovine brain GLUL in vivo, although either metal supports assays.
Experimental context and source evidence
- cross_nutrient
- Competing primary interpretation of native GLUL Mn versus Mg identity.
- experimental_model
- Cofactor trapping and immunoprecipitation of bovine and ovine brain glutamine synthetase
- exposure
- Methionine sulfoximine phosphate/ADP cofactor trapping
- limitations
- Author interpretation of extracted enzyme; overlaps the ovine brain question in 1982, with different methods.
- nutrient_topic
- Manganese research collection; topical membership is not evidence of a direct dietary effect. · Manganese
- organism
- Bos taurus; Ovis aries
- plain_language
- Another primary study supported magnesium as the native brain GLUL metal.
- primary_references
- [mn-enz-2870682] Mg2+ is bound to glutamine synthetase extracted from bovine or ovine brain in the presence of L-methionine-S-sulfoximine phosphate. (1986). https://pubmed.ncbi.nlm.nih.gov/2870682/ DOI: 10.1016/0003-9861(86)90496-0
- tissue_or_cell_type
- Brain extracts and purified enzyme
Manganese: enzyme cofactors, glycosylation, transport and nutrient interactions (2026-09-17) · lines 659–670
AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Cofactor trapping and immunoprecipitation of bovine and ovine brain glutamine synthetase · source_derived_draft · unverified_draft
### mn-enz-brain-glul-native-mg-interpretation The 1986 cofactor-trapping study concluded that Mg, rather than Mn, appears to be bound to bovine/ovine brain GLUL in vivo, although either metal supports assays. Condition category: normal nutrient_topic: Manganese research collection; topical membership is not evidence of a direct dietary effect. plain_language: Another primary study supported magnesium as the native brain GLUL metal. organism: Bos taurus; Ovis aries tissue_or_cell_type: Brain extracts and purified enzyme experimental_model: Cofactor trapping and immunoprecipitation of bovine and ovine brain glutamine synthetase limitations: Author interpretation of extracted enzyme; overlaps the ovine brain question in 1982, with different methods. exposure: Methionine sulfoximine phosphate/ADP cofactor trapping cross_nutrient: Competing primary interpretation of native GLUL Mn versus Mg identity. [mn-enz-2870682] Mg2+ is bound to glutamine synthetase extracted from bovine or ovine brain in the presence of L-methionine-S-sulfoximine phosphate. (1986). https://pubmed.ncbi.nlm.nih.gov/2870682/ DOI: 10.1016/0003-9861(86)90496-0
Complete structured claim and evidenceFrom ovine-brain GLUL binding and tissue-metal measurements, the 1982 authors proposed that the enzyme may be manganese-bound in vivo.
Experimental context and source evidence
- cross_nutrient
- Published inference about Mn versus Mg native occupancy; paired with the competing 1986 cofactor-trapping interpretation.
- experimental_model
- Ovine brain glutamine synthetase steady-state kinetics and metal-binding measurements
- exposure
- Mn(II) and Mg(II) titrations; binding and tissue metal measurements
- limitations
- Author inference; not a universal human GLUL cofactor assignment. Contradicted by a later overlapping ovine/bovine study using endogenous-cofactor trapping.
- nutrient_topic
- Manganese research collection; topical membership is not evidence of a direct dietary effect. · Manganese
- organism
- Ovis aries
- plain_language
- One primary study proposed manganese as the native sheep-brain GLUL metal.
- primary_references
- [mn-enz-6129892] Glutamine synthetase from ovine brain is a manganese(II) enzyme. (1982). https://pubmed.ncbi.nlm.nih.gov/6129892/ DOI: 10.1021/bi00268a011
- tissue_or_cell_type
- Brain-derived purified enzyme
Manganese: enzyme cofactors, glycosylation, transport and nutrient interactions (2026-09-17) · lines 633–644
AI-assisted literature curation; primary study URLs and scope retained in the document and extraction. Not publisher full text. · supports · Ovine brain glutamine synthetase steady-state kinetics and metal-binding measurements · source_derived_draft · unverified_draft
### mn-enz-ovine-glul-native-mn-interpretation From ovine-brain GLUL binding and tissue-metal measurements, the 1982 authors proposed that the enzyme may be manganese-bound in vivo. Condition category: normal nutrient_topic: Manganese research collection; topical membership is not evidence of a direct dietary effect. plain_language: One primary study proposed manganese as the native sheep-brain GLUL metal. organism: Ovis aries tissue_or_cell_type: Brain-derived purified enzyme experimental_model: Ovine brain glutamine synthetase steady-state kinetics and metal-binding measurements limitations: Author inference; not a universal human GLUL cofactor assignment. Contradicted by a later overlapping ovine/bovine study using endogenous-cofactor trapping. exposure: Mn(II) and Mg(II) titrations; binding and tissue metal measurements cross_nutrient: Published inference about Mn versus Mg native occupancy; paired with the competing 1986 cofactor-trapping interpretation. [mn-enz-6129892] Glutamine synthetase from ovine brain is a manganese(II) enzyme. (1982). https://pubmed.ncbi.nlm.nih.gov/6129892/ DOI: 10.1021/bi00268a011
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.