Evidence map›Paper›PMID 23872454›Full record

ArticleFEBS letters2013

pH-rate profiles support a general base mechanism for galactokinase (Lactococcus lactis).

Laurie A Reinhardt, James B Thoden, Greg S Peters, Hazel M Holden, W W Cleland

Open access · greenAbstract read
In one paragraph

Article in FEBS letters, 2013. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 1 paper.

0numbers the graph read from it
0cells of the map it votes in
1citing papers in PubMed
0.9field-weighted citation impact, top 27% 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

1 citing paper in PubMed, 14 citations in OpenAlex.

  1. 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

5 authors at 1 institution in 1 country.

Laurie A ReinhardtInstitute For Enzyme Research and Department of Biochemistry, University of Wisconsin-Madison, Madison, WI 53726, USA. lareinha@wisc.edu
James B Thoden
Greg S Peters
Hazel M Holden
W W Cleland
University of Wisconsin–Madison · US

Funding

X-ray Studies of Sugar-Modifying EnzymesR01DK047814 · NIDDK · UNIVERSITY OF WISCONSIN-MADISON · PI HOLDEN, HAZEL M. · 1994 to 2015
$4.3M
KINETIC STUDIES OF ENZYME MECHANISMSR01GM018938 · NIGMS · UNIVERSITY OF WISCONSIN-MADISON · PI RAYMENT, IVAN · 1985 to 2013
$3.9M
X-ray Studies of Sugar-Modifying EnzymesR56DK047814 · NIDDK · UNIVERSITY OF WISCONSIN-MADISON · PI HOLDEN, HAZEL · 2006 to 2006
$88k
KINETIC STUDIES OF ENZYME MECHANISMSR37GM018938 · NIGMS · UNIVERSITY OF WISCONSIN MADISON · PI CLELAND, WILLIAM WALLACE · 1987 to 1996
–
NIDDK NIH HHS DK47814NIDDK NIH HHS R01 DK047814NIDDK NIH HHS R56 DK047814NIGMS NIH HHS GM18938NIGMS NIH HHS R01 GM018938
6 · The paper itself

Abstract

Galactokinase (GALK), a member the Leloir pathway for normal galactose metabolism, catalyzes the conversion of α-d-galactose to galactose-1-phosphate. For this investigation, we studied the kinetic mechanism and pH profiles of the enzyme from Lactococcus lactis. Our results show that the mechanism for its reaction is sequential in both directions. Mutant proteins D183A and D183N are inactive (< 10000 fold), supporting the role of Asp183 as a catalytic base that deprotonates the C-1 hydroxyl group of galactose. The pH-kcat profile of the forward reaction has a pKa of 6.9 ± 0.2 that likely is due to Asp183. The pH-k(cat)/K(Gal) profile of the reverse reaction further substantiates this role as it is lacking a key pKa required for a direct proton transfer mechanism. The R36A and R36N mutant proteins show over 100-fold lower activity than that for the wild-type enzyme, thus suggesting that Arg36 lowers the pKa of the C-1 hydroxyl to facilitate deprotonation.

Indexed as

Adenosine TriphosphateAmino Acid SubstitutionBacterial ProteinsGalactokinaseGalactoseHydrogen-Ion ConcentrationKineticsLactococcus lactisModels, ChemicalMutagenesis, Site-DirectedOxidation-ReductionAdenosine TriphosphateBacterial ProteinsGalactokinaseGalactoseGalactokinaseGeneral baseKineticsMechanismpH-rate profile

Identifiers

PMID23872454
PMCPMC3786675
OpenAlexW2039029939

What OpenQuestion holds

Textmetadata
LicenceTDM
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.