Evidence map›Paper›PMID 26050651›Full record

ArticleBMC biotechnology2015

Characterization of the 4,6-α-glucanotransferase GTFB enzyme of Lactobacillus reuteri 121 isolated from inclusion bodies.

Yuxiang Bai, Rachel Maria van der Kaaij, Albert Jan Jacob Woortman, Zhengyu Jin, Lubbert Dijkhuizen

Open access · goldAbstract readComparative Study
In one paragraph

Article in BMC biotechnology, 2015. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 3 papers.

0numbers the graph read from it
0cells of the map it votes in
3citing papers in PubMed
2.9field-weighted citation impact, top 11% 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

3 citing papers in PubMed, 18 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 2 countries.

Yuxiang BaiMicrobial Physiology, Groningen Biomolecular Sciences and Biotechnology Institute (GBB), University of Groningen, Nijenborgh 7, 9747 AG, Groningen, The Netherlands. y.bai@rug.nl.
Rachel Maria van der KaaijMicrobial Physiology, Groningen Biomolecular Sciences and Biotechnology Institute (GBB), University of Groningen, Nijenborgh 7, 9747 AG, Groningen, The Netherlands. r.m.van.der.kaaij@rug.nl.
Albert Jan Jacob WoortmanDepartment of Polymer Chemistry, Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, 9747 AG, Groningen, The Netherlands. a.j.j.woortman@rug.nl.
Zhengyu JinThe State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Jiangnan University, Wuxi, 214122, China. zjin@jiangnan.edu.cn.
Lubbert DijkhuizenMicrobial Physiology, Groningen Biomolecular Sciences and Biotechnology Institute (GBB), University of Groningen, Nijenborgh 7, 9747 AG, Groningen, The Netherlands. l.dijkhuizen@rug.nl.
University of Groningen · NLState Key Laboratory of Food Science and Technology · CN

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

backgroundThe GTFB enzyme of the probiotic bacterium Lactobacillus reuteri 121 is a 4,6-α-glucanotransferase of glycoside hydrolase family 70 (GH70; http://www.cazy.org ). Contrary to the glucansucrases in GH70, GTFB is unable to use sucrose as substrate, but instead converts malto-oligosaccharides and starch into isomalto-/malto- polymers that may find application as prebiotics and dietary fibers. The GTFB enzyme expresses well in Escherichia coli BL21 Star (DE3), but mostly accumulates in inclusion bodies (IBs) which generally contain wrongly folded protein and inactive enzyme.

methodsDenaturation followed by refolding, as well as ncIB preparation were used for isolation of active GTFB protein from inclusion bodies. Soluble, refolded and ncIB GTFB were compared using activity assays, secondary structure analysis by FT-IR, and product analyses by NMR, HPAEC and SEC.

resultsExpression of GTFB in E. coli yielded > 100 mg/l relatively pure and active but mostly insoluble GTFB protein in IBs, regardless of the expression conditions used. Following denaturing, refolding of GTFB protein was most efficient in double distilled H2O. Also, GTFB ncIBs were active, with approx. 10 % of hydrolysis activity compared to the soluble protein. When expressed as units of activity obtained per liter E. coli culture, the total amount of ncIB GTFB expressed possessed around 180 % hydrolysis activity and 100 % transferase activity compared to the amount of soluble GTFB enzyme obtained from one liter culture. The product profiles obtained for the three GTFB enzyme preparations were similar when analyzed by HPAEC and NMR. SEC investigation also showed that these 3 enzyme preparations yielded products with similar size distributions. FT-IR analysis revealed extended β-sheet formation in ncIB GTFB providing an explanation at the molecular level for reduced GTFB activity in ncIBs. The thermostability of ncIB GTFB was relatively high compared to the soluble and refolded GTFB.

conclusionIn view of their relatively high yield, activity and high thermostability, both refolded and ncIB GTFB derived from IBs in E. coli may find industrial application in the synthesis of modified starches.

Indexed as

Bacterial ProteinsEnzyme StabilityEscherichia coliGlycogen Debranching Enzyme SystemInclusion BodiesLimosilactobacillus reuteriModels, MolecularProtein DenaturationProtein RefoldingProtein Structure, SecondarySolubilitySubstrate Specificity4 alpha-glucanotransferaseBacterial ProteinsGlycogen Debranching Enzyme System

Identifiers

PMID26050651
PMCPMC4459449
OpenAlexW2140878050

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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.