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(2011). https://pubmed.ncbi.nlm.nih.gov/21346252/ DOI: 10.1182/blood-2010-09-307637","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"tissue_or_cell_type","value_text":"Cell-free","comparator":null,"unit":null,"notes":"","entity":null}],"evidence":[{"id":"dddac8c5-86f5-51da-999c-4fbc0ca73eef","evidence_kind":"source_excerpt","locator":"Lines 1145-1157","start_line":1145,"end_line":1157,"excerpt":"### c-reg-gsh-substitutes-phd\nReduced glutathione stimulated all three tested PHD isoforms in the absence of ascorbate; millimolar GSH could substitute in the peptide assay, indicating reductant redundancy in this setting.\nCondition category: normal\nnutrient_topic: Vitamin C research collection; topical membership is not evidence of a direct dietary effect.\nplain_language: These oxygen-sensing enzymes could use support from glutathione when vitamin C was absent in the test tube.\norganism: Homo sapiens proteins\ntissue_or_cell_type: Cell-free\nexperimental_model: Recombinant human PHD enzymes; HIF-1 alpha 556–574 peptide hydroxylation detected by VHL/elongin B/C binding\nlimitations: Alternative reductant effects vary with substrate and assay; this is not a nutritional substitution recommendation or proof of in-vivo compensation mechanism.\nexposure: 10 µM FeSO4, 0.5 mM 2-oxoglutarate, pH 7.5, room temperature, 1 h; ascorbate omission/titration and GSH titration; standard ascorbate 2 mM.\ncross_nutrient: true\nevidence_location: Figure 2A–B; hydroxylation Methods\n[c-reg-nytko] Vitamin C is dispensable for oxygen sensing in vivo. 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