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Études structurales et fonctionnelles d'alpha-glucosidases

What does -glucosidase do?
α-Glucosidase (AGase; EC 3.2.1.20) is a typical exohydrolase that reacts with the α-glucosidic linkage of the non-reducing terminal of substrates and releases α-glucose [ 1, 2 ]. Under high substrate concentrations, the enzyme also catalyzes transglucosylation, synthesizing oligosaccharides (Fig. 1 a).
What temperature is -glucosidase active?
Mesophilic bacteria with α-glucosidase activity are active at neutral and alkaline pHs values, and at temperatures between 20 and 40 °C (Ojima et al. 2012; Delgado et al. 2017; Kim et al. 2017; Wang et al. 2017 ). Specificity characteristics vary according to the enzyme.
How are alpha-glucosidases classified?
Alpha-glucosidases are produced by all kinds of organisms (bacteria, molds, animals, and plants), and due to this wide distribution, its substrate specificity is broader, basically depending on the enzyme origin. These enzymes are conventionally classified according to their substrate specificity.
What are the optimum parameters for biochemical characterization of a Niger -glucosidase?
Biochemical characterization was performed on A. niger ITV-01 α-glucosidase; its optimum parameters were pH 4.3, temperature 80 °C but stable at 40 °C, with an energy of activation (Ea) 176.25 kJ mol −1. Using soluble starch as the substrate, K m and V max were 5 mg mL −1 and 1000 U mg −1, respectively.

Introduction

The CAZy database1 classifies proteins into glycoside hydrolases (GHs), glycosyl transferases, polysaccharide lyases, carbohydrate esterases, auxiliary activities, and carbohydrate-binding modules based on amino acid sequence similarity and spatial structure of their catalytic structural domains (Henrissat, 1991; Cantarel et al., 2009). The GH13 fa

Materials and Methods

Bioinformatic Analysis The amino acid sequences with the first 100 similarities to QsGH13 sequences were obtained using NCBI BLASTp.2 Clustal was used for amino acid multiple sequence alignment of QsGH13 and its homologs3 (Larkin et al., 2007). Secondary structure alignment results were obtained using ESpript based on multiple sequence alignment results and QsGH13 spatial coordinates4 (Robert and Gouet, 2014). The maximum likelihood estimation (MLE) in MEGA X was used to construct the phylogenetic tree (Kumar et al

Results

Cloning, Expression, and Purification of QsGH13 Nucleotide sequence analysis showed that the open reading frame of 1,587 bp qsgh13 gene sequence from deep-sea sediment metagenomic screening encodes a protein of 528 amino acids with a theoretical molecular weight of 59.3 kD. Phylogenetic tree sequence analysis based on NCBI, PDB, and CAZy databases showed that the protein QsGH13 belongs to the GH13 family (Supplementary Figure 1), and predicted that the protein QsGH13 had α-glucosidase characteristics. To explore the physicochemical charact

Discussion

The commercial demands for α-glucosidases are so great that even small increments in catalytic efficiency and production might provide enormous commercial value. Traditional genetic engineering techniques have largely solved the production problem, but the main challenge remains to improve its process performance to a practical level. Thus, the key

Data Availability Statement

The datasets presented in this study can be found in online repositories. The names of the repository/repositories and accession number(s) can be found below: doi: 10.2210/pdb7VOH/pdb. See full list on frontiersin.org

Author Contributions

JH and XZ conceived the study. XZ, KW, RJ, YZ, JL, and ZY performed the experiments and analyzed the data. XZ, XX, and JH wrote and edited its final manuscript. All authors contributed to the article and approved the submitted version. See full list on frontiersin.org

Funding

This work was supported by the Natural Science Foundation of Hunan Province (2020JJ5700 to JH and 2020JJ5702 to ZY), and the start-up funding for young talents of Central South University (202045004 to JH). See full list on frontiersin.org

Conflict of Interest

The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. See full list on frontiersin.org

Publisher’S Note

All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article, or claim that may be made by its manufacturer, is not guaranteed or endorsed by the publisher. See full list on frontiersin.org

Acknowledgments

We thank Jixi Li from the Fudan University for the vector construction and study design. We thank the staff from the BL17U1 beamlines at Shanghai Synchrotron Radiation Facility for the assistance during the data collection. We also thank Weidong Liu from the Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, for the structu