Complex III in C. glutamicum has an unusual di-heme cyt. c and it co-purifies with complex IV in a supercomplex. Here, we investigated the kinetics of electron transfer within this supercomplex and in the cyt. aa alone (cyt. bc was removed genetically). In the reaction of the reduced cyt. aa with O, we identified the same sequence of events as with other A-type oxidases. However, even though this reaction is associated with proton uptake, no pH dependence was observed in the kinetics. For the cyt. bc-cyt. aa supercomplex, we observed that electrons from the c-hemes were transferred to Cu with time constants 0.1-1 ms. The b-hemes were oxidized with a time constant of 6.5 ms, indicating that this electron transfer is rate-limiting for the overall quinol oxidation/O reduction activity (~210 e/s). Furthermore, electron transfer from externally added cyt. c to cyt. aa was significantly faster upon removal of cyt. bc from the supercomplex, suggesting that one of the c-hemes occupies a position near Cu. In conclusion, isolation of the III-IV-supercomplex allowed us to investigate the kinetics of electron transfer from the b-hemes, via the di-heme cyt. c and heme a to the heme a-Cu catalytic site of cyt. aa.
Download full-text PDF |
Source |
|---|---|
| http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5040959 | PMC |
| http://dx.doi.org/10.1038/srep34098 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
The influence of the position and quantity of thiophene or acetylene groups on the photoelectric properties of dye-sensitized solar cells.
Spectrochim Acta A Mol Biomol Spectrosc
January 2025
Department of Physics, Liaoning University, Shenyang 110036, Liaoning, China. Electronic address:
To investigate the influence of the position and quantity of thiophene or acetylene groups on the photoelectric properties of dye-sensitized solar cells (DSSCs), density functional theory (DFT) were employed to simulate five zinc porphyrin dye molecules (T-3, T-3-D, T-3-A, T-3-AD, and T-3-ace). The optimized geometry indicated that T-3-ace possessed superior planar properties, attributed to incorporating the acetylene groups, facilitating the charge transfer process. The lower lowest unoccupied molecular orbital (LUMO) energy levels of T-3-ace and T-3-D suggested that introducing thiophene or acetylene groups on the donor side enhanced the electron absorption capability of the dyes.
View Article and Find Full Text PDFHighly selective and efficient AIEE active fluorescence probe for the detection of doxycycline in biological and environmental samples with extensive DFT support.
Spectrochim Acta A Mol Biomol Spectrosc
January 2025
Department of Chemistry, COMSATS University Islamabad, Abbottabad Campus, University Road, Abbottabad 22060 Pakistan.
A highly selective naphthalimide based fluorescent probe PBQ was designed for investigation of doxycycline (DOX) in various real samples. The synthesized probe PBQ showed maximum emission intensity at 395 nm and exhibited selective quenching response-based on photoinduced electron transfer (PET) mechanism even in the presence of various competing and interfering drugs, amino acids, cations and anions. Furthermore, probe PBQ showed excellent AIEE properties with red shift in maximum emission wavelength due to formations of J-aggregates.
View Article and Find Full Text PDFElectrochemical sensor based on tadpole-shaped Au nanostructures supported on TiO: Enhanced detection of nicotine in electronic cigarettes and clinical samples.
Talanta
January 2025
Ampere - Laboratório de Plataformas Eletroquímicas. Departamento de Química, Universidade Federal de Santa Catarina, 880400-900, Florianópolis, SC, Brazil. Electronic address:
Nicotine (NIC) detection is vital for monitoring its presence in various environments, including tobacco products, electronic cigarettes, and clinical samples; NIC's widespread use and health implications necessitate precise and reliable detection methods as it is linked to diseases such as lung cancer and vascular disorders. In this study, we developed and characterized Au tadpole-like nanostructures immobilized onto titanium oxide (TiO) to provide a cost-effective and sensitive NIC detection material. The comprehensive characterization of the composite used transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and X-ray diffraction (XRD), showing the robustness of the synthesis.
View Article and Find Full Text PDFCuS@Ag Heterostructure-based Surface Plasmonic Coupling Electrochemiluminescence Sensor for Glioma miRNA-124-3p Detection.
Biosens Bioelectron
January 2025
Department of Analytical Chemistry, College of Chemistry, Jilin University, Changchun, 130012, China. Electronic address:
As an emerging class of extended crystalline organic materials, covalent organic framework (COF)-based aggregation-induced emission luminogen (AIE-gen) exhibited encouraging emissive properties. In this work, 4',4'',4‴,4‴'-(1,1,2,2-Ethenetetrayl)tetra(4-biphenylcarbaldehyde) (ETBC) as AIEgen was used to prepare AIE-COF (ET-COF-COOH) luminescent nanoprobe. ETBC and 1,3,5-Tris(4-aminophenyl)benzene (TAPB) had an extended π electronic system that allowed electron delocalization and overlapping transport.
View Article and Find Full Text PDFValley charge-transfer insulator in twisted double bilayer WSe.
Nat Commun
January 2025
National Laboratory of Solid-State Microstructures, Collaborative Innovation Center of Advanced Microstructures, School of Physics, Nanjing University, Nanjing, China.
In flat-band systems, emergent physics can be substantially modified by the presence of another nearby electronic band. For example, a Mott˘Hubbard insulator can turn into a charge transfer insulator if other electronic states enter between the upper and lower Hubbard bands. Here, we introduce twisted double bilayer (TDB) WSe, with twist angles near 60°, as a controllable platform in which the K-valley band can be tuned to close vicinity of the Γ-valley moiré flat band.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!