8re0

Soluble glucose dehydrogenase from acinetobacter calcoaceticus - double mutant pH8

spinqualitylabelsall models 8re0, resolution 1.56Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 8re0 is a 2 chain structure with sequence from Acinetobacter calcoaceticus. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 1.56Å Ligands: A1H0D, CA, LI Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function DHGB_ACICA Oxidizes glucose to gluconolactone. Publication Abstract from PubMed The soluble glucose dehydrogenase (sGDH) from Acinetobacter calcoaceticus has been widely studied and is used, in biosensors, to detect the presence of glucose, taking advantage of its high turnover and insensitivity to molecular oxygen. This approach, however, presents two drawbacks: the enzyme has broad substrate specificity (leading to imprecise blood glucose measurements) and shows instability over time (inferior to other oxidizing glucose enzymes). We report the characterization of two sGDH mutants: the single mutant Y343F, and the double mutant D143E/Y343F. The mutants present enzyme selectivity and specificity of 1.2 (Y343F) and 5.7 (D143E/Y343F) times higher for glucose compared to that of the wild type. Crystallographic experiments, designed to characterise these mutants, surprisingly revealed that the prosthetic group PQQ (pyrroloquinoline quinone), essential for the enzymatic activity, is in a cleaved form for both wild-type and mutant structures. We provide evidence suggesting that the sGDH produces H2O2, the level of production depending on the mutation. In addition, spectroscopic experiments allowed us to follow the self-degradation of the prosthetic group and the disappearance of sGDH's glucose oxidation activity. These studies suggest that the enzyme is sensitive to its self-production of H2O2. We show that the premature aging of sGDH can be slowed down by adding catalase to consume the H2O2 produced, allowing the design of a more stable biosensor over time. Our research opens questions about the mechanism of H2O2 production and the physiological role of this activity by sGDH. Does Acinetobacter calcoaceticus glucose dehydrogenase produce self-damaging H2O2?,Lublin V, Kauffmann B, Engilberge S, Durola F, Gounel S, Bichon S, Jean C, Mano N, Giraud MF, Chavas L, Thureau A, Thompson A, Stines-Chaumeil C Biosci Rep. 2024 Apr 30:BSR20240102. doi: 10.1042/BSR20240102. PMID:38687614 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

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