ReferenceID 546
A cellular system for quantitation of vitamin K cycle activity: structure-activity effects on vitamin K antagonism by warfarin metabolites
Blood
Warfarin and other 4-hydroxycoumarins inhibit vitamin K epoxide reductase (VKOR) by depleting reduced vitamin K that is required for posttranslational modification of vitamin K-dependent clotting factors. In vitro predi
Relationship Network
Interactive first-hop connections across herbs, ingredients, formulas, targets, diseases, symptoms, syndromes, evidence, and monographs.
Click a node to open it in a new tab
Ingredient: 1Reference: 1Links: 1
Arranging relationship network...
Record Fields
Scalar fields from the final reference record.
- Reference Id
- 546
- Evidence Id
- 17136
- Core Evidence Id
- 17136
- Source Reference Id
- 1065
- Herb2 Reference Id
- HBREF001797
- Subject Paper Key
- HBIN015565_24297869
- Pubmed Id
- 24297869
- Doi
- 10.1182/blood-2013-05-505123
- Paper Title
- A cellular system for quantitation of vitamin K cycle activity: structure-activity effects on vitamin K antagonism by warfarin metabolites
- Paper Abstract
- Warfarin and other 4-hydroxycoumarins inhibit vitamin K epoxide reductase (VKOR) by depleting reduced vitamin K that is required for posttranslational modification of vitamin K-dependent clotting factors. In vitro prediction of the in vivo potency of vitamin K antagonists is complicated by the complex multicomponent nature of the vitamin K cycle. Here we describe a sensitive assay that enables quantitative analysis of γ-glutamyl carboxylation and its antagonism in live cells. We engineered a human embryonic kidney (HEK) 293-derived cell line (HEK 293-C3) to express a chimeric protein (F9CH) comprising the Gla domain of factor IX fused to the transmembrane and cytoplasmic regions of proline-rich Gla protein 2. Maximal γ-glutamyl carboxylation of F9CH required vitamin K supplementation, and was dose-dependently inhibited by racemic warfarin at a physiologically relevant concentration. Cellular γ-glutamyl carboxylation also exhibited differential VKOR inhibition by warfarin enantiomers (S > R) consistent with their in vivo potencies. We further analyzed the structure-activity relationship for inhibition of γ-glutamyl carboxylation by warfarin metabolites, observing tolerance to phenolic substitution at the C-5 and especially C-6, but not C-7 or C-8, positions on the 4-hydroxycoumarin nucleus. After correction for in vivo concentration and protein binding, 10-hydroxywarfarin and warfarin alcohols were predicted to be the most potent inhibitory metabolites in vivo.
- Journal
- Blood
- Publish Year
- 2014
- Experiment Subject
- human embryonic kidney (hek) 293-derived cell line (hek 293-c3)
- Experiment Type
- Cell Experiment
- Phenotype Related
- Paper Title Cn
- Paper Title En
- A cellular system for quantitation of vitamin K cycle activity: structure-activity effects on vitamin K antagonism by warfarin metabolites
- Bilingual Status
- semi_complete