In vivo assembly of a truncated H subunit mutant of the Rhodobacter sphaeroides photosynthetic reaction centre and direct electron transfer from the QA quinone to an electrode

2018 ◽  
Vol 137 (2) ◽  
pp. 227-239 ◽  
Author(s):  
D. Jun ◽  
H. S. Dhupar ◽  
A. Mahmoudzadeh ◽  
F. Duong ◽  
J. D. W. Madden ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Rhodobacter Sphaeroides ◽  
Direct Electron Transfer ◽  
Reaction Centre ◽  
Photosynthetic Reaction Centre

Ubiquinone reduction in the photosynthetic reaction centre of Rhodobacter sphaeroides: interplay between electron transfer, proton binding and flips of the quinone ring

2005 ◽  
Vol 33 (4) ◽  
pp. 845-850 ◽  
Author(s):  
A.Y. Mulkidjanian ◽  
M.A. Kozlova ◽  
D.A. Cherepanov
Keyword(s):  
Molecular Dynamics ◽  
Electron Transfer ◽  
Rhodobacter Sphaeroides ◽  
Structural Information ◽  
Binding Pocket ◽  
Initial Position ◽  
Reaction Centre ◽  
Gate Control ◽  
Dynamics Simulations ◽  
Photosynthetic Reaction Centre

This review is focused on reactions that gate (control) the electron transfer between the primary quinone QA and secondary quinone QB in the photosynthetic reaction centre of Rhodobacter sphaeroides. The results on electron and proton transfer are discussed in relation to structural information and to the steered molecular dynamics simulations of the QB ring flip in its binding pocket. Depending on the initial position of QB in the pocket and on certain conditions, the rate of electron transfer is suggested to be limited either by the quinone ring flip or by the charge-compensating proton equilibration between the surface and the buried QB site.

In Vitro Evaluation of Miniaturized Amperometric Enzyme Sensor Based on the Direct Electron Transfer Principle for Continuous Glucose Monitoring

2022 ◽  
pp. 193229682110706
Author(s):  
Yutaro Inoue ◽  
Yasuhide Kusaka ◽  
Kotaro Shinozaki ◽  
Inyoung Lee ◽  
Koji Sode
Keyword(s):  
Electron Transfer ◽  
Continuous Glucose Monitoring ◽  
Glucose Sensor ◽  
Direct Electron Transfer ◽  
Glucose Dehydrogenase ◽  
Glucose Monitoring ◽  
Reference Electrode ◽  
Enzyme Sensor

Background: The bacterial derived flavin adenine dinucleotide (FAD)-dependent glucose dehydrogenase (FADGDH) is the most promising enzyme for the third-generation principle-based enzyme sensor for continuous glucose monitoring (CGM). Due to the ability of the enzyme to transfer electrons directly to the electrode, recognized as direct electron transfer (DET)-type FADGDH, although no investigation has been reported about DET-type FADGDH employed on a miniaturized integrated electrode. Methods: The miniaturized integrated electrode was formed by sputtering gold (Au) onto a flexible film with 0.1 mm in thickness and divided into 3 parts. After an insulation layer was laminated, 3 openings for a working electrode, a counter electrode and a reference electrode were formed by dry etching. A reagent mix containing 1.2 × 10−4 Unit of DET-type FADGDH and carbon particles was deposited. The long-term stability of sensor was evaluated by continuous operation, and its performance was also evaluated in the presence of acetaminophen and the change in oxygen partial pressure (pO2) level. Results: The amperometric response of the sensor showed a linear response to glucose concentration up to 500 mg/dL without significant change of the response over an 11-day continuous measurement. Moreover, the effect of acetaminophen and pO2 on the response were negligible. Conclusions: These results indicate the superb potential of the DET-type FADGDH-based sensor with the combination of a miniaturized integrated electrode. Thus, the described miniaturized DET-type glucose sensor for CGM will be a promising tool for effective glycemic control. This will be further investigated using an in vivo study.

Bioconversion of Carbon Monoxide to Formate Using Artificially Designed Carbon Monoxide:Formate Oxidoreductase in Hyperthermophilic Archaea

2021 ◽  
Author(s):  
Jae Kyu Lim ◽  
Ji-In Yang ◽  
Yun Jae Kim ◽  
Yeong-Jun Park ◽  
Yong Hwan Kim
Keyword(s):  
Carbon Monoxide ◽  
Electron Transfer ◽  
Fusion Protein ◽  
Direct Electron Transfer ◽  
Co2 Reduction ◽  
Hyperthermophilic Archaea ◽  
Production Activity ◽  
Formate Production

Abstract Ferredoxin-dependent metabolic engineering of electron transfer circuits has been developed to enhance redox efficiency in the field of synthetic biology, e.g., for hydrogen production and for reduction of flavoproteins or NAD(P)+. Here, we present the bioconversion of carbon monoxide (CO) gas to formate via a synthetic CO:formate oxidoreductase (CFOR), designed as an enzyme complex for direct electron transfer between noninteracting CO dehydrogenase and formate dehydrogenase using an electron-transferring Fe-S fusion protein. The CFOR-introduced Thermococcus onnurineus mutant strains showed CO-dependent formate production in vivo and in vitro. The formate production rate from purified CFOR complex and specific formate productivity from the bioreactor were 348 ± 34 μmol/mg/min and 90.2 ± 20.4 mmol/g-cells/h, respectively. The CO-dependent CO2 reduction/formate production activity of synthetic CFOR was confirmed, indicating that direct electron transfer between two unrelated dehydrogenases was feasible via mediation of the FeS-FeS fusion protein.

Lipidic Cubic Phase Crystal Structure of the Photosynthetic Reaction Centre from Rhodobacter sphaeroides at 2.35Å Resolution

2003 ◽  
Vol 331 (3) ◽  
pp. 681-692 ◽  
Author(s):  
Gergely Katona ◽  
Ulf Andréasson ◽  
Ehud M. Landau ◽  
Lars-Erik Andréasson ◽  
Richard Neutze
Keyword(s):  
Crystal Structure ◽  
Rhodobacter Sphaeroides ◽  
Cubic Phase ◽  
Reaction Centre ◽  
Lipidic Cubic Phase ◽  
Phase Crystal ◽  
Photosynthetic Reaction Centre

Structure of the photosynthetic reaction centre from Rhodobacter sphaeroides reconstituted with anthraquinone as primary quinone QA

FEBS Letters ◽  
2000 ◽  
Vol 472 (1) ◽  
pp. 114-116 ◽  
Author(s):  
Andreas Kuglstatter ◽  
Jaroslava Miksovska ◽  
Pierre Sebban ◽  
Günter Fritzsch
Keyword(s):  
Rhodobacter Sphaeroides ◽  
Reaction Centre ◽  
Photosynthetic Reaction Centre
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