Evidence map›Paper›PMID 15320869›Full record

ArticleThe Biochemical journal2005

Contribution of the two conserved tryptophan residues to the catalytic and structural properties of Proteus mirabilis glutathione S-transferase B1-1.

Nerino Allocati, Michele Masulli, Marilena Pietracupa, Bartolo Favaloro, Luca Federici, Carmine Di Ilio

Abstract read
In one paragraph

Article in The Biochemical journal, 2005. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 2 papers.

0numbers the graph read from it
0cells of the map it votes in
2citing papers in PubMed
–field-weighted citation impact
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

2 citing papers in PubMed.

  1. Article
  2. 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.

Nerino AllocatiDipartimento di Scienze Biomediche, Universita' G. d'Annunzio, Via dei Vestini 31, I-66013 Chieti, Italy. n.allocati@dsb.unich.it
Michele Masulli
Marilena Pietracupa
Bartolo Favaloro
Luca Federici
Carmine Di Ilio

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

PmGSTB1-1 (Proteus mirabilis glutathione S-transferase B1-1) has two tryptophan residues at positions 97 and 164 in each monomer. Structural data for this bacterial enzyme indicated that Trp97 is positioned in the helix a4, whereas Trp164 is located at the bottom of the helix a6 in the xenobiotic-binding site. To elucidate the role of the two tryptophan residues they were replaced by site-directed mutagenesis. Trp97 and Trp164 were mutated to either phenylalanine or alanine. A double mutant was also constructed. The effects of the replacement on the activity, structural properties and antibiotic-binding capacity of the enzymes were examined. On the basis of the results obtained, Trp97 does not seem to be involved in the enzyme active site and structural stabilization. In contrast, different results were achieved for Trp164 mutants. Conservative substitution of the Trp164 with phenylalanine enhanced enzyme activity 10-fold, whereas replacement with alanine enhanced enzyme activity 17-fold. Moreover, the catalytic efficiency for both GSH and 1-chloro-2,4-dinitrobenzene substrates improved. In particular, the catalytic efficiency for 1-chloro-2,4-dinitrobenzene improved for both W164F (Trp164-->Phe) and W164A by factors of 7- and 22-fold respectively. These results are supported by molecular graphic analysis. In fact, W164A presented a more extensive substrate-binding pocket that could allow the substrates to be better accommodated. Furthermore, both Trp164 mutants were significantly more thermolabile than wild-type, suggesting that the substitution of this residue affects the overall stability of the enzyme. Taken together, these results indicate that Trp164 is an important residue of PmGSTB1-1 in the catalytic process as well as for protein stability.

Indexed as

Conserved SequenceAmino Acid SubstitutionAnti-Bacterial AgentsCatalysisEnzyme StabilityGlutathione TransferaseGuanidineKineticsModels, MolecularProtein BindingProtein ConformationProtein DenaturationProtein RenaturationProteus mirabilisSpectrum AnalysisStatic ElectricityAnti-Bacterial AgentsGlutathione TransferaseGuanidineTryptophan

Identifiers

PMID15320869
PMCPMC1134671

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.