Evidence map›Paper›PMID 26334568›Full record

ArticleBMC biochemistry2015

Complex kinetics and residual structure in the thermal unfolding of yeast triosephosphate isomerase.

Ariana Labastida-Polito, Georgina Garza-Ramos, Menandro Camarillo-Cadena, Rafael A Zubillaga, Andrés Hernández-Arana

Open access · hybridAbstract read
In one paragraph

Article in BMC biochemistry, 2015. 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
0.9field-weighted citation impact, top 25% 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

2 citing papers in PubMed, 6 citations in OpenAlex.

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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 2 institutions in 1 country.

Ariana Labastida-PolitoÁrea de Biofisicoquímica, Departamento de Química, Universidad Autónoma Metropolitana-Iztapalapa, San Rafael Atlixco 186, Iztapalapa, D.F. 09340, Mexico. arianalabastida@gmail.com.
Georgina Garza-RamosDepartamento de Bioquímica, Facultad de Medicina, Universidad Nacional Autónoma de México, Coyoacán, D.F. 04510, Mexico. ggarza@laguna.fmedic.unam.mx.
Menandro Camarillo-CadenaÁrea de Biofisicoquímica, Departamento de Química, Universidad Autónoma Metropolitana-Iztapalapa, San Rafael Atlixco 186, Iztapalapa, D.F. 09340, Mexico. menandro90@gmail.com.
Rafael A ZubillagaÁrea de Biofisicoquímica, Departamento de Química, Universidad Autónoma Metropolitana-Iztapalapa, San Rafael Atlixco 186, Iztapalapa, D.F. 09340, Mexico. zlra@xanum.uam.mx.
Andrés Hernández-AranaÁrea de Biofisicoquímica, Departamento de Química, Universidad Autónoma Metropolitana-Iztapalapa, San Rafael Atlixco 186, Iztapalapa, D.F. 09340, Mexico. aha@xanum.uam.mx.
Universidad Autónoma Metropolitana · MXUniversidad Nacional Autónoma de México · MX

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

backgroundSaccharomyces cerevisiae triosephosphate isomerase (yTIM) is a dimeric protein that shows noncoincident unfolding and refolding transitions (hysteresis) in temperature scans, a phenomenon indicative of the slow forward and backward reactions of the native-unfolded process. Thermal unfolding scans suggest that no stable intermediates appear in the unfolding of yTIM. However, reported evidence points to the presence of residual structure in the denatured monomer at high temperature.

resultsThermally denatured yTIM showed a clear trend towards the formation of aggregation-prone, β-strand-like residual structure when pH decreased from 8.0 to 6.0, even though thermal unfolding profiles retained a simple monophasic appearance regardless of pH. However, kinetic studies performed over a relatively wide temperature range revealed a complex unfolding mechanism comprising up to three observable phases, with largely different time constants, each accompanied by changes in secondary structure. Besides, a simple sequential mechanism is unlikely to explain the observed variation of amplitudes and rate constants with temperature. This kinetic complexity is, however, not linked to the appearance of residual structure. Furthermore, the rate constant for the main unfolding phase shows small, rather unvarying values in the pH region where denatured yTIM gradually acquires a β-strand-like conformation. It appears, therefore, that the residual structure has no influence on the kinetic stability of the native protein. However, the presence of residual structure is clearly associated with increased irreversibility.

conclusionsThe slow temperature-induced unfolding of yeast TIM shows three kinetic phases. Rather than a simple sequential pathway, a complex mechanism involving off-pathway intermediates or even parallel pathways may be operating. β-strand-type residual structure, which appears below pH 8.0, is likely to be associated with increased irreversible aggregation of the unfolded protein. However, this denatured form apparently accelerates the refolding process.

Indexed as

Protein DenaturationTemperatureHydrogen-Ion ConcentrationKineticsProtein RefoldingProtein Structure, SecondarySaccharomyces cerevisiaeTriose-Phosphate IsomeraseTriose-Phosphate Isomerase

Identifiers

PMID26334568
PMCPMC4558838
OpenAlexW2111302555

What OpenQuestion holds

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LicenceCC BY
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Registered trials

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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.