Oxidation of isomaltose, gentiobiose, and melibiose by membrane-bound quinoprotein glucose dehydrogenase from acetic acid bacteria. Issue 3 (3rd March 2020)

• Record Type: Journal Article
• Authors: Kiryu, Takaaki; Kiso, Taro; Sato, Hirofumi; Murakami, Hiromi
• Is Part Of: Bioscience, biotechnology, and biochemistry. Volume 84:Issue 3(2020)
• Page Start: 507
• Page End: 517
• Publication Date: 2020-03-03
• Subjects: Isomaltobionic acid -- membrane-bound quinoprotein glucose dehydrogenase -- oxidation -- acetic acid bacterium; Biotechnology -- Periodicals; Biochemistry -- Periodicals; 660.6
• DOI: 10.1080/09168451.2019.1689095
• Languages: English
• ISSNs: 0916-8451

Abstract

ABSTRACT: Membrane-bound quinoprotein glucose dehydrogenase from acetic acid bacteria produces lactobionic acid by the oxidation of lactose. Its enzymatic activity on lactose and maltose is much lower than that on d -glucose. For that reason, the activity of the enzyme on disaccharides has been considered low. In this study, we show that the isomaltose-oxidizing activity of acetic acid bacteria is much higher than their lactose-oxidizing activity. In addition to isomaltose, the enzyme oxidized gentiobiose and melibiose to the same extent. According to the characteristics of the isomaltose-oxidizing activity and investigations using dehydrogenase-deficient mutant bacteria, we identified the responsible enzyme as membrane-bound quinoprotein glucose dehydrogenase. Abbreviations: AAB: acetic acid bacteria; m-GDH: membrane-bound quinoprotein glucose dehydrogenase; DCIP: 2, 6-dichlorophenolindophenol; DP: degree of polymerization; HPAEC-PAD: high-performance anion-exchange chromatography with pulsed amperometric detection; NMR: nuclear magnetic resonance; TLC: thin layer chromatography; COSY: correlation spectroscopy Graphic Abstract: : Membrane-bound quinoprotein glucose dehydrogenase (m-GDH) from acetic acid bacteria oxidizes disaccharides having α/β-1➝6 glycosidic linkages.