Evidence map›Paper›PMID 20615869›Full record

ArticleThe Journal of biological chemistry2010

Substrate orientation and catalytic specificity in the action of xanthine oxidase: the sequential hydroxylation of hypoxanthine to uric acid.

Hongnan Cao, James M Pauff, Russ Hille

Open access · hybridAbstract read
In one paragraph

Article in The Journal of biological chemistry, 2010. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 45 papers.

0numbers the graph read from it
0cells of the map it votes in
45citing papers in PubMed
2.9field-weighted citation impact, top 10% of its field
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

45 citing papers in PubMed, 128 citations in OpenAlex.

  1. ApaH decaps NpNature chemical biology · 2026
    Article
  2. Article
  3. Bovine xanthine oxidase electrocatalysis: substrate oxidation and its role in nitrite reduction.Journal of biological inorganic chemistry : JBIC : a publication of the Society of Biological Inorganic Chemistry · 2026
    Article
  4. Babassu (Foods (Basel, Switzerland) · 2026
    Article
  5. Article
  6. Article
  7. An Emerging Paradigm for ABCC5/MRP5 Function in Human Physiology.International journal of molecular sciences · 2025
    Review
  8. Review
  9. Review
  10. Microbiology spectrum · 2024
    Article
  11. Article
  12. Article
  13. Unveiling potent Schiff base derivatives with selective xanthine oxidase inhibition:Saudi pharmaceutical journal : SPJ : the official publication of the Saudi Pharmaceutical Society · 2024
    Article
  14. Insights into theFoods (Basel, Switzerland) · 2024
    Article
  15. Article
  16. Removal of substrate inhibition ofFood chemistry: X · 2023
    Article
  17. Article
  18. Article
  19. Article
  20. Antioxidants (Basel, Switzerland) · 2022
    Article
4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

3 authors at 2 institutions in 1 country.

Hongnan CaoDepartment of Biochemistry, University of California at Riverside, Riverside, California 92521, USA.
James M Pauff
Russ Hille
University of California, Riverside · USThe Ohio State University · US

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

Xanthine oxidase is a molybdenum-containing enzyme catalyzing the hydroxylation of a sp(2)-hybridized carbon in a broad range of aromatic heterocycles and aldehydes. Crystal structures of the bovine enzyme in complex with the physiological substrate hypoxanthine at 1.8 A resolution and the chemotherapeutic agent 6-mercaptopurine at 2.6 A resolution have been determined, showing in each case two alternate orientations of substrate in the two active sites of the crystallographic asymmetric unit. One orientation is such that it is expected to yield hydroxylation at C-2 of substrate, yielding xanthine. The other suggests hydroxylation at C-8 to give 6,8-dihydroxypurine, a putative product not previously thought to be generated by the enzyme. Kinetic experiments demonstrate that >98% of hypoxanthine is hydroxylated at C-2 rather than C-8, indicating that the second crystallographically observed orientation is significantly less catalytically effective than the former. Theoretical calculations suggest that enzyme selectivity for the C-2 over C-8 of hypoxanthine is largely due to differences in the intrinsic reactivity of the two sites. For the orientation of hypoxanthine with C-2 proximal to the molybdenum center, the disposition of substrate in the active site is such that Arg(880) and Glu(802), previous shown to be catalytically important for the conversion of xanthine to uric acid, play similar roles in hydroxylation at C-2 as at C-8. Contrary to the literature, we find that 6,8-dihydroxypurine is effectively converted to uric acid by xanthine oxidase.

Indexed as

BiocatalysisAnimalsCatalytic DomainCattleCrystallography, X-RayHydroxylationHypoxanthineKineticsMercaptopurineModels, MolecularOxidation-ReductionSubstrate SpecificityUric AcidXanthine OxidaseHypoxanthineMercaptopurineUric AcidXanthine Oxidase

Identifiers

PMID20615869
PMCPMC2934669
OpenAlexW2103062085

What OpenQuestion holds

Textmetadata
Read underepoch 390

Registered trials

None linked

Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.