8RFK

Soluble glucose dehydrogenase from acinetobacter calcoaceticus - single mutant pH8

これはPDB形式変換不可エントリーです。

8RFK の概要

• エントリーDOI: 10.2210/pdb8rfk/pdb
• 分子名称: Quinoprotein glucose dehydrogenase B, CALCIUM ION, 3-(3,5-dicarboxy-1~{H}-pyrrol-2-yl)pyridine-2,4,6-tricarboxylic acid, ... (4 entities in total)
• 機能のキーワード: double point mutation, oxidoreductase
• 由来する生物種: Acinetobacter calcoaceticus
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 101523.32

構造登録者

Lublin, V.,Chavas, L.,Stines-Chaumeil, C.,Kauffmann, B.,Giraud, M.F.,Thompson, A. (登録日: 2023-12-13, 公開日: 2024-05-08, 最終更新日: 2024-10-23)

主引用文献

Lublin, V.,Kauffmann, B.,Engilberge, S.,Durola, F.,Gounel, S.,Bichon, S.,Jean, C.,Mano, N.,Giraud, M.F.,Chavas, L.M.G.H.,Thureau, A.,Thompson, A.,Stines-Chaumeil, C.
Does Acinetobacter calcoaceticus glucose dehydrogenase produce self-damaging H2O2?
Biosci.Rep., 44:-, 2024

PubMed Abstract: 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 with that of the wild-type. Crystallographic experiments, designed to characterize 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.

PubMed: 38687614
DOI: 10.1042/BSR20240102

実験手法

X-RAY DIFFRACTION (1.56 Å)