2.1 Å Crystal Structure of Human PXR in Complex with the St. John's Wort Compound Hyperforin^,

Why is this work in the frame?

A frame that forgets how it found something cannot be audited. These are the routes that admitted this work.

No Canadian affiliation. An affiliation-only frame, the usual design, would never have seen this work. It is one of the works that make the case for inverting the frame.

Full frame distilled prediction

Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.

Candidate categories

Insufficient payload (model declined to judge)

Consensus categories

none

Domain

Candidate signal: noneConsensus signal: none

Study design

Candidate signal: Bench or experimentalConsensus signal: Bench or experimental

Genre

Candidate signal: EmpiricalConsensus signal: Empirical

Teacher disagreement score

0.111

Threshold uncertainty score

0.999

Validation status

machine_predicted_unvalidated · codex-gemma-dda1882f352a

Codex and Gemma teacher scores by category

Machine scores (provisional)

The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.

Teacher spread

0.308 · how far apart the two teachers sit on this one work

Validation status

score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from it

Abstract

The nuclear xenobiotic receptor PXR is activated by a wide variety of clinically used drugs and serves as a master regulator of drug metabolism and excretion gene expression in mammals. St. John's wort is used widely in Europe and the United States to treat depression. This unregulated herbal remedy leads to dangerous drug-drug interactions, however, in patients taking oral contraceptives, antivirals, or immunosuppressants. Such interactions are caused by the activation of the human PXR by hyperforin, the psychoactive agent in St. John's wort. In this study, we show that hyperforin induces the expression of numerous drug metabolism and excretion genes in primary human hepatocytes. We present the 2.1 A crystal structure of hyperforin in complex with the ligand binding domain of human PXR. Hyperforin induces conformational changes in PXR's ligand binding pocket relative to structures of human PXR elucidated previously and increases the size of the pocket by 250 A(3). We find that the mutation of individual aromatic residues within the ligand binding cavity changes PXR's response to particular ligands. Taken together, these results demonstrate that PXR employs structural flexibility to expand the chemical space it samples and that the mutation of specific residues within the ligand binding pocket of PXR tunes the receptor's response to ligands.

Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.

The record

Venue

Biochemistry

Topic

Pharmacogenetics and Drug Metabolism

Field

Pharmacology, Toxicology and Pharmaceutics

Canadian institutions

not available

Funders

National Institute of Diabetes and Digestive and Kidney DiseasesNational Cancer Institute

Keywords

HyperforinPregnane X receptorChemistryLigand (biochemistry)Hypericum perforatumPharmacologyLigand efficiencyTransporterNuclear receptorReceptorStereochemistryBiochemistryBiologyGeneTranscription factor

Has abstract in OpenAlex

yes

API

/api/v1/works/W2092190477