Wired Pyrroloquinoline Quinone Soluble Glucose Dehydrogenase Enzyme Electrodes Operating at Unprecedented Low Redox Potential

2014 ◽  
Vol 86 (5) ◽  
pp. 2465-2473 ◽  
Author(s):  
Victoria Flexer ◽  
Nicolas Mano
Keyword(s):  
Redox Potential ◽  
Glucose Dehydrogenase ◽  
Pyrroloquinoline Quinone ◽  
Enzyme Electrodes ◽  
Dehydrogenase Enzyme

Ca2+ stabilizes the semiquinone radical of pyrroloquinoline quinone

2001 ◽  
Vol 357 (3) ◽  
pp. 893-898 ◽  
Author(s):  
Akihiro SATO ◽  
Kazuyoshi TAKAGI ◽  
Kenji KANO ◽  
Nobuo KATO ◽  
Johannis A. DUINE ◽  
...  
Keyword(s):  
Redox Potential ◽  
Active Site ◽  
Continuous Flow ◽  
Glucose Dehydrogenase ◽  
Acinetobacter Calcoaceticus ◽  
Substrate Oxidation ◽  
Pyrroloquinoline Quinone ◽  
Free State ◽  
Semiquinone Radical ◽  
Chemical Mechanisms

Spectroelectrochemical studies were performed on the interaction between Ca2+ and pyrroloquinoline quinone (PQQ) in soluble glucose dehydrogenase (sGDH) and in the free state by applying a mediated continuous-flow column electrolytic spectroelectrochemical technique. The enzyme forms used were holo-sGDH (the holo-form of sGDH from Acinetobacter calcoaceticus) and an incompletely reconstituted form of this, holo-X, in which the PQQ-activating Ca2+ is lacking. The spectroelectrochemical and ESR data clearly demonstrated the generation of the semiquinone radical of PQQ in holo-sGDH and in the free state in the presence of Ca2+. In contrast, in the absence of Ca2+ no semiquinone was observed, either for PQQ in the free state (at pH7.0) or in the enzyme (holo-X). Incorporation of Ca2+ into the active site of holo-X, yielding holo-sGDH, caused not only stabilization of the semiquinone form of PQQ but also a negative shift (of 26.5mV) of the two-electron redox potential, indicating that the effect of Ca2+ is stronger on the oxidized than on the reduced PQQ. Combining these data with the observations on the kinetic and chemical mechanisms, it was concluded that the strong stimulating effect of Ca2+ on the activity of sGDH can be attributed to facilitation of certain kinetic steps, and not to improvement of the thermodynamics of substrate oxidation. The consequences of this conclusion are discussed for the oxidative as well as for the reductive part of the reaction of sGDH.

scholarly journals Screening of Peptide Ligands for Pyrroloquinoline Quinone Glucose Dehydrogenase Using Antagonistic Template-Based Biopanning

2013 ◽  
Vol 14 (12) ◽  
pp. 23244-23256 ◽  
Author(s):  
Koichi Abe ◽  
Wataru Yoshida ◽  
Kotaro Terada ◽  
Yukiko Yagi-Ishii ◽  
Stefano Ferri ◽  
...  
Keyword(s):  
Glucose Dehydrogenase ◽  
Pyrroloquinoline Quinone ◽  
Peptide Ligands

scholarly journals Identification of Pantoea ananatis gene encoding membrane pyrroloquinoline quinone (PQQ)-dependent glucose dehydrogenase and pqqABCDEF operon essential for PQQ biosynthesis

2011 ◽  
Vol 318 (1) ◽  
pp. 55-60 ◽  
Author(s):  
Irina G. Andreeva ◽  
Lyubov I. Golubeva ◽  
Tatiana M. Kuvaeva ◽  
Evgueni R. Gak ◽  
Joanna I. Katashkina ◽  
...  
Keyword(s):  
Glucose Dehydrogenase ◽  
Pyrroloquinoline Quinone ◽  
Pantoea Ananatis ◽  
Gene Encoding ◽  
Pqq Biosynthesis

scholarly journals Amino Acid Residues Interacting with Both the Bound Quinone and Coenzyme, Pyrroloquinoline Quinone, inEscherichia coliMembrane-bound Glucose Dehydrogenase

2008 ◽  
Vol 283 (32) ◽  
pp. 22215-22221 ◽  
Author(s):  
Golam Mustafa ◽  
Yoshinori Ishikawa ◽  
Kazuo Kobayashi ◽  
Catharina T. Migita ◽  
M. D. Elias ◽  
...  
Keyword(s):  
Amino Acid ◽  
Glucose Dehydrogenase ◽  
Pyrroloquinoline Quinone ◽  
Amino Acid Residues

scholarly journals A Novel Pyrroloquinoline Quinone-Dependent 2-Keto-d-Glucose Dehydrogenase from Pseudomonas aureofaciens

2015 ◽  
Vol 197 (8) ◽  
pp. 1322-1329 ◽  
Author(s):  
Kiwamu Umezawa ◽  
Kouta Takeda ◽  
Takuya Ishida ◽  
Naoki Sunagawa ◽  
Akiko Makabe ◽  
...  
Keyword(s):  
Glucose Dehydrogenase ◽  
Expression System ◽  
Pyrroloquinoline Quinone ◽  
Recombinant Enzyme ◽  
Reaction Products ◽  
Gene Encoding ◽  
Multiple Sequence ◽  
Content Type ◽  
Pseudomonas Aureofaciens ◽  
Arginine Residues

A gene encoding an enzyme similar to a pyrroloquinoline quinone (PQQ)-dependent sugar dehydrogenase from filamentous fungi, which belongs to new auxiliary activities (AA) family 12 in the CAZy database, was cloned fromPseudomonas aureofaciens. The deduced amino acid sequence of the cloned enzyme showed only low homology to previously characterized PQQ-dependent enzymes, and multiple-sequence alignment analysis showed that the enzyme lacks one of the three conserved arginine residues that function as PQQ-binding residues in known PQQ-dependent enzymes. The recombinant enzyme was heterologously expressed in anEscherichia coliexpression system for further characterization. The UV-visible (UV-Vis) absorption spectrum of the oxidized form of the holoenzyme, prepared by incubating the apoenzyme with PQQ and CaCl2, revealed a broad peak at approximately 350 nm, indicating that the enzyme binds PQQ. With the addition of 2-keto-d-glucose (2KG) to the holoenzyme solution, a sharp peak appeared at 331 nm, attributed to the reduction of PQQ bound to the enzyme, whereas no effect was observed upon 2KG addition to authentic PQQ. Enzymatic assay showed that the recombinant enzyme specifically reacted with 2KG in the presence of an appropriate electron acceptor, such as 2,6-dichlorophenol indophenol, when PQQ and CaCl2were added.1H nuclear magnetic resonance (1H-NMR) analysis of reaction products revealed 2-keto-d-gluconic acid (2KGA) as the main product, clearly indicating that the recombinant enzyme oxidizes the C-1 position of 2KG. Therefore, the enzyme was identified as a PQQ-dependent 2KG dehydrogenase (Pa2KGDH). Considering the high substrate specificity, the physiological function ofPa2KGDH may be for production of 2KGA.

Sign in / Sign up

Export Citation Format

Share Document