Please use this identifier to cite or link to this item: https://hdl.handle.net/10356/179919
Title: Revealing the intricate mechanism governing the pH-dependent activity of a quintessential representative of flavoproteins, glucose oxidase
Authors: Tu, Tao
Zhang, Yunju
Yan, Yaru
Li, Lanxue
Liu, Xiaoqing
Hakulinen, Nina
Zhang, Wei
Mu, Yuguang
Luo, Huiying
Yao, Bin
Li, Weifeng
Huang, Huoqing
Keywords: Medicine, Health and Life Sciences
Issue Date: 2024
Source: Tu, T., Zhang, Y., Yan, Y., Li, L., Liu, X., Hakulinen, N., Zhang, W., Mu, Y., Luo, H., Yao, B., Li, W. & Huang, H. (2024). Revealing the intricate mechanism governing the pH-dependent activity of a quintessential representative of flavoproteins, glucose oxidase. Fundamental Research. https://dx.doi.org/10.1016/j.fmre.2024.04.009
Project: RG97/22 
Journal: Fundamental Research 
Abstract: Glucose oxidase (Gox), a prototypical flavoprotein, exhibits diverse industrial applications in glucose sensing and gluconic acid production. Its enzymatic activity is pH-dependent, with maximum activity observed at approximately neutral pH but less than 5% of peak activity at pH ≤ 3.0. However, the underlying mechanism governing these pH-dependent changes in activity remains elusive. Therefore, our objective was to investigate conformational alterations in Gox across different pH levels for engineering purposes. Our mutagenesis results suggest that protein degradation does not primarily contribute to the enzyme's pH-dependent activity. Fluorescence spectroscopy findings reveal subtle influences of pH on Gox's conformation while maintaining a similar overall microenvironment. Furthermore, the crystal structure and molecular dynamics simulations reveal that alterations in pH have a significant impact on the conformation of His514, a crucial catalytic residue for Gox function. These changes also result in structural variations within the substrate-binding pocket for both flavin adenine dinucleotide (cofactor) and β-D-glucose (substrate) between pH 6.0 and 2.5. Consequently, under acidic conditions (pH 2.5), β-D-glucose exhibits unstable binding within this pocket, leading to rapid dissociation from the active site. In summary, our findings underscore the intimate relationship between the conformational dynamics of His514 and the pH-dependent reaction mechanism, offering valuable insights for engineering acid-active Gox variants.
URI: https://hdl.handle.net/10356/179919
ISSN: 2667-3258
DOI: 10.1016/j.fmre.2024.04.009
Schools: School of Biological Sciences 
Rights: © 2024 The Authors. Publishing Services by Elsevier B.V. on behalf of KeAi Communications Co. Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).
Fulltext Permission: open
Fulltext Availability: With Fulltext
Appears in Collections:SBS Journal Articles

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