Evidence map›Paper›PMID 16686601›Full record

ArticleThe Biochemical journal2006

Kinetic and chemical analyses of the cytokinin dehydrogenase-catalysed reaction: correlations with the crystal structure.

Hana Popelková, Marco W Fraaije, Ondrej Novák, Jitka Frébortová, Kristin D Bilyeu, Ivo Frébort

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In one paragraph

Article in The Biochemical journal, 2006. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 6 papers.

0numbers the graph read from it
0cells of the map it votes in
6citing papers in PubMed
1.3field-weighted citation impact, top 23% 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

6 citing papers in PubMed, 30 citations in OpenAlex.

  1. Article
  2. Article
  3. Article
  4. Article
  5. Article
  6. Cytokinins modulate auxin-induced organogenesis in plants via regulation of the auxin efflux.Proceedings of the National Academy of Sciences of the United States of America · 2009
    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

6 authors at 3 institutions in 2 countries.

Hana PopelkováDepartment of Biochemistry, Faculty of Science, Palacký University, Slechtitelů 11, 783 71 Olomouc, Czech Republic.
Marco W Fraaije
Ondrej Novák
Jitka Frébortová
Kristin D Bilyeu
Ivo Frébort
Czech Academy of Sciences, Institute of Experimental Botany · CZPalacký University Olomouc · CZUniversity of Groningen · NL

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

CKX (cytokinin dehydrogenase) is a flavoprotein that cleaves cytokinins to adenine and the corresponding side-chain aldehyde using a quinone-type electron acceptor. In the present study, reactions of maize (Zea mays) CKX with five different substrates (N6-isopentenyladenine, trans-zeatin, kinetin, p-topolin and N-methyl-isopentenyladenine) were studied. By using stopped-flow analysis of the reductive half-reaction, spectral intermediates were observed indicative of the transient formation of a binary enzyme-product complex between the cytokinin imine and the reduced enzyme. The reduction rate was high for isoprenoid cytokinins that showed formation of a charge-transfer complex of reduced enzyme with bound cytokinin imine. For the other cytokinins, flavin reduction was slow and no charge-transfer intermediates were observed. The binary complex of reduced enzyme and imine product intermediate decays relatively slowly to form an unbound product, cytokinin imine, which accumulates in the reaction mixture. The imine product only very slowly hydrolyses to adenine and an aldehyde derived from the cytokinin N6 side-chain. Mixing of the substrate-reduced enzyme with Cu2+/imidazole as an electron acceptor to monitor the oxidative half-reaction revealed a high rate of electron transfer for this type of electron acceptor when using N6-isopentenyladenine. The stability of the cytokinin imine products allowed their fragmentation analysis and structure assessment by Q-TOF (quadrupole-time-of-flight) MS/MS. Correlations of the kinetic data with the known crystal structure are discussed for reactions with different cytokinins.

Indexed as

AnaerobiosisCatalysisCrystallography, X-RayCytokininsIminesKineticsMass SpectrometryOxidation-ReductionOxidoreductasesStructure-Activity RelationshipSubstrate SpecificityZea mayscytokinin oxidaseCytokininsIminesOxidoreductases

Identifiers

PMID16686601
PMCPMC1525011
OpenAlexW2059693097

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.