Catalytic oxidation and reduction reactions of hydrophilic carbon clusters with NADH and cytochrome C: features of an electron transport nanozyme

Nanoscale ◽  
2019 ◽  
Vol 11 (22) ◽  
pp. 10791-10807 ◽  
Author(s):  
Paul J. Derry ◽  
Lizanne G. Nilewski ◽  
William K. A. Sikkema ◽  
Kimberly Mendoza ◽  
Almaz Jalilov ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Electron Transport ◽  
Cytochrome C ◽  
Catalytic Oxidation ◽  
Carbon Clusters ◽  
Reduction Reactions

PEGylated hydrophilic carbon clusters are electron transfer catalysts between NADH and cytochrome C.

Coenzyme-dependent nanozymes playing dual roles in oxidase and reductase mimics with enhanced electron transport

Nanoscale ◽  
2020 ◽  
Vol 12 (46) ◽  
pp. 23578-23585
Author(s):  
Jinxing Chen ◽  
Qian Ma ◽  
Minghua Li ◽  
Weiwei Wu ◽  
Liang Huang ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Electron Transport ◽  
Cytochrome C ◽  
Dual Roles

PEI/ZIF-FMN mediated the electron transfer from NADH to cytochrome c.

Contribution of leucine 85 to the structure and function of Saccharomyces cerevisiae iso-1 cytochrome c

2001 ◽  
Vol 79 (4) ◽  
pp. 517-524 ◽  
Author(s):  
Jonathan C Parrish ◽  
J Guy Guillemette ◽  
Carmichael JA Wallace
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Electron Transfer ◽  
Electron Transport ◽  
Cytochrome C ◽  
Transport Processes ◽  
Complex Iii ◽  
Side Chain ◽  
Inner Mitochondrial Membrane ◽  
And Function ◽  
First Time

Cytochrome c is a small electron-transport protein whose major role is to transfer electrons between complex III (cytochrome reductase) and complex IV (cytochrome c oxidase) in the inner mitochondrial membrane of eukaryotes. Cytochrome c is used as a model for the examination of protein folding and structure and for the study of biological electron-transport processes. Amongst 96 cytochrome c sequences, residue 85 is generally conserved as either isoleucine or leucine. Spatially, the side chain is associated closely with that of the invariant residue Phe82, and this interaction may be important for optimal cytochrome c activity. The functional role of residue 85 has been examined using six site-directed mutants of Saccharomyces cerevisiae iso-1 cytochrome c, including, for the first time, kinetic data for electron transfer with the principle physiological partners. Results indicate two likely roles for the residue: first, heme crevice resistance to ligand exchange, sensitive to both the hydrophobicity and volume of the side chain; second, modulation of electron-transport activity through maintenance of the hydrophobic character of the protein in the vicinity of Phe82 and the exposed heme edge, and possibly of the ability of this region to facilitate redox-linked conformational change.Key words: protein engineering, cytochrome c, structure-function relations, electron transfer, hydrophobic packing.

Flavin Interaction in NADPH-Sulfite Reductase

1972 ◽  
Vol 27 (9) ◽  
pp. 1087-1089 ◽  
Author(s):  
Lewis M. Siegel ◽  
Edward J. Faeder ◽  
Henry Kamin
Keyword(s):  
Electron Transfer ◽  
Electron Transport ◽  
Cytochrome C ◽  
Ammonium Sulfate ◽  
Electron Transport Chain ◽  
Sulfite Reductase ◽  
E Coli ◽  
Transport Chain ◽  
Step Down ◽  
Reduced Forms

E. coli NADPH-sulfite reductase, depleted of FMN but retaining its FAD, has been prepared by photoirradiation of native enzyme in 30% — saturated ammonium sulfate. FMN-depleted enzyme loses its ability to reduce (using NADPH) ferricyanide, cytochrome c, sulfite, or the enzyme’s own heme-like chromophore. However, the FAD remains rapidly reducible by NADPH, and the FMN-depleted enzyme retains NADPH-acetylpyridine NADP* transhydrogenase activity. Thus, FAD can serve as entry port for NADPH electrons, and FMN is required for further transmission along the enzyme’s electron transport chain. These data, plus other studies, have enabled us to suggest a mechanism for catalysis which involves FAD cycling between the fully-oxidized and fully-reduced forms while FMN cycles between fully-reduced and semiquinone. This mechanism, which includes a disproportionation step, permits a “step-down” from the twoelectron donor, NADPH, to a succession of equipotential one-electron transfer steps.

scholarly journals The effect of cytochrome c and its ‘dimer’ on electron transfer and energy transformation

1972 ◽  
Vol 126 (3) ◽  
pp. 709-716 ◽  
Author(s):  
T. Shur-Perek ◽  
Y. Avi-Dor
Keyword(s):  
Electron Transfer ◽  
Electron Transport ◽  
Cytochrome C ◽  
Proton Translocation ◽  
Liver Mitochondria ◽  
Rat Liver Mitochondria ◽  
Energy Transformation ◽  
Early Step ◽  
Electron Carrier ◽  
Stimulation Of

A preparation that contained cytochrome c, mainly in the form of its ‘dimer’, was studied and compared with native cytochrome c with respect to its ability to support electron transfer and energy transformation in cytochrome c-depleted rat liver mitochondria. When the depleted mitochondria were titrated with either cytochrome c or the ‘dimer’, the extent of coupling between respiration and phosphorylation was enhanced, as manifested by an increase in the P/O ratio. The ‘dimer’ was relatively ineffective as an electron carrier in the respiratory system, but it was as effective as cytochrome c in reconstitution of oxidative phosphorylation in depleted mitochondria. Addition of ‘dimer’ to the depleted mitochondria, in the presence of a low, non-saturating concentration of cytochrome c, increased the P/O ratio without concomitant stimulation of respiration. Both cytochrome c and the ‘dimer’ stimulated spontaneous swelling and electron transport-driven proton translocation in depleted mitochondria. The pattern of action of cytochrome c and its ‘dimer’ is in accord with the assumption that they affect an early step in energy conservation.

scholarly journals Electrical characteristics of amyloid beta peptides in vertical junctions

2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Sohyeon Seo ◽  
Jinju Lee ◽  
Jungsue Choi ◽  
G. Hwan Park ◽  
Yeseul Hong ◽  
...  
Keyword(s):  
Electron Transfer ◽  
Electron Transport ◽  
Amyloid Beta ◽  
Field Effect Transistors ◽  
Brain Diseases ◽  
Electrical Characteristics ◽  
Transport Pathway ◽  
Sequence Dependence ◽  
Aβ Oligomers ◽  
Aβ Peptides

AbstractAssembled amyloid beta (Aβ) peptides have been considered pathological assemblies involved in human brain diseases, and the electron transfer or electron transport characteristics of Aβ are important for the formation of structured assemblies. Here, we report the electrical characteristics of surface-assembled Aβ peptides similar to those observed in Alzheimer’s patients. These characteristics correlate to their electron transfer characteristics. Electrical current–voltage plots of Aβ vertical junction devices show the Aβ sequence dependence of the current densities at both Aβ monomers (mono-Aβs) and Aβ oligomers (oli-Aβs), while Aβ sequence dependence is not clearly observed in the electrical characteristics of Aβ planar field effect transistors (FETs). In particular, surface oligomerization of Aβ peptides drastically decreases the activity of electron transfer, which presents a change in the electron transport pathway in the Aβ vertical junctions. Electron transport at oli-Aβ junctions is symmetric (tunneling/tunneling) due to the weak and voltage-independent coupling of the less redox-reactive oli-Aβ to the contacts, while that at mono-Aβ junctions is asymmetric (hopping/tunneling) due to redox levels of mono-Aβ voltage-dependently coupled with contact electrodes. Consequently, through vertical junctions, the sequence- and conformation-dependent electrical characteristics of Aβs can reveal their electron transfer activities.

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