Search Results (127)

Large-conductance, voltage- and calcium-activated potassium (BK) channels are crucial regulators of cellular excitability, influenced by various signaling molecules, including heme. The BK channel contains a heme-sensitive motif located at the sequence ⁶¹²CKACH⁶¹⁶, which is a conserved heme regulatory motif (HRM) found in the cytochrome c protein family. This motif is situated within a linker region of approximately 120 residues that connect the RCK1 and RCK2 domains, and it also includes terminal α-helices similar to those found in cytochrome c family proteins. However, much of this region has yet to be structurally defined. We conducted a sequence alignment of the BK linker region with mitochondrial cytochrome c and cytochrome c domains from various hemoproteins to better understand this functionally significant region. In addition to the HRM motif, we discovered that important structural and functional elements of cytochrome c proteins are conserved in the BK RCK1-RCK2 linker. Firstly, the part of the BK region that is resolved in available atomic structures shows similarities in secondary structural elements with cytochrome c domain proteins. Secondly, the Met80 residue in cytochrome c domains, which acts as the second axial ligand to the heme iron, aligns with the BK channel. Beyond its role in electron shuttling, cytochrome c domains exhibit various catalytic properties, including peroxidase activity—specifically, the oxidation of suitable substrates using peroxides. Our findings reveal that the linker region endows human BK channels with peroxidase activity, showing an apparent H₂O₂ affinity approximately 40-fold greater than that of mitochondrial cytochrome c under baseline conditions. This peroxidase activity was reduced when substitutions were made at ⁶¹²CKACH⁶¹⁶ and other relevant sites. These results indicate that the BK channel possesses a novel module similar to the cytochrome c domains of hemoproteins, which may give rise to unique physiological functions for these widespread ion channels. Full article

Oxidative stress overwhelms cellular antioxidant defenses, causing DNA damage and pro-tumorigenic signaling that accelerate cancer initiation and progression. Electron shuttles (ESs) from phytocompounds offer precise redox control but lack quantitative benchmarks. This study aims to give a clearer definition to electron shuttles by characterizing mulberry’s electrochemical capabilities via the three defined ES criteria and deciphering its mechanism against oxidative stress-related cancer. Using double-chambered microbial-fuel-cell power metrics, cyclic voltammetry, and compartmental fermentation modeling, we show that anthocyanin shows a significant difference (p < 0.05) in power density at ≥500 µg/mL (maximum of 2.06-fold power-density increase) and reversible redox cycling (ratio = 1.65), retaining >90% activity over four fermentation cycles. Molecular docking implicates meta-dihydroxyl motifs within the core scaffold in receptor binding, overturning the view that only ortho- and para-substituents participate in bioactivity. In vitro, anthocyanins both inhibit nitric oxide release and reduce DU-145 cell viability dose-dependently. Overall, our findings establish mulberry anthocyanins as robust electron shuttles with potential for integration into large-scale bio-electrochemical platforms and targeted redox-based cancer therapies. Full article

Microbial Electrochemistry Technology (MET) leverages the unique process of extracellular electron transfer (EET) between electroactive bacteria (EAB) and electrodes to enable various applications, such as electricity generation, bioremediation, and wastewater treatment. This review highlights significant advancements in EET mechanisms, emphasizing both outward and inward electron transfer pathways mediated by diverse electroactive microorganisms. Notably, the role of electron shuttles, genetic modifications, and innovative electrode materials are discussed as strategies to enhance EET efficiency. Recent studies illustrate the importance of redox-active molecules, such as flavins and metal nanoparticles, in facilitating electron transfer, while genetic engineering has proven effective in optimizing microbial physiology to boost EET rates. The review also examines the impact of electrode materials on microbial attachment and performance, showcasing new composites and nanostructures that enhance power output in microbial fuel cells. By synthesizing the recent findings and proposing emerging research directions, this work provides an overview of EET enhancement strategies, aiming to inform future technological innovations in bioelectrochemical systems (BESs). Full article

Lithium–sulfur batteries (LSBs) are favorable candidates for advanced energy storage, boasting a remarkable theoretical energy density of 2600 Wh kg⁻¹. Moreover, several challenges hinder their practical implementation, including sulfur’s intrinsic electrical insulation, the shuttle effect of lithium polysulfides (LiPSs), sluggish redox kinetics of Li₂S₂/Li₂S, and the uncontrolled growth of Li dendrites. These issues pose significant obstacles to the commercialization of LSBs. A viable strategy to address these challenges involves using MXene materials, 2D transition metal carbides, and nitrides (TMCs/TMNs) as hosts, functional separators, or interlayers. MXenes offer exceptional electronic conductivity, adjustable structural properties, and abundant polar functional groups, enabling strong interactions with both S cathodes and Li anodes. Despite their advantages, current MXene synthesis methods predominantly rely on acid etching, which is associated with environmental concerns, low production efficiency, and limited structural versatility, restricting their potential in LSBs. This review provides a comprehensive overview of traditional and environmentally sustainable MXene synthesis techniques, emphasizing their applications in developing S cathodes, Li anodes, and functional separators for LSBs. Additionally, it discusses the challenges and outlines future directions for advancing MXene-based solutions in LSBs technology. Full article

Zinc-halogen batteries are usually based on two-electron transfer reactions from X⁻ to X₂. However, the halogen is capable of being further oxidized to higher valence states, thereby achieving the higher capacity of zinc- halogen batteries. Here, a six-electron reaction based on I⁻/I⁺ and Br⁻/Br⁰ is activated successfully by introducing KI into the electrolyte. ZIF-8-derived porous carbon (ZPC), serving as the host of halogen, effectively suppresses polybromide/polyiodide shuttle owing to the chemisorption/physical adsorption. Additionally, the adsorption of I⁻ on the surface of the zinc anode effectively inhibits the growth of dendrites and the formation of by-products. Consequently, zinc-bromine batteries exhibit outstanding electrochemical performance, including a specific capacity of 345 mAh g⁻¹ at 1 A g⁻¹ and an excellent capacity retention of 80% after 3000 cycles at 2 A g⁻¹. This strategy provides a novel way for enhancing the electrochemical performance of zinc-halogen batteries. Full article

OT has gained attention for its high polyphenol content and therapeutic potential. To elucidate this further, this study investigated the electron-shuttling bioactive compounds of OT and evaluated their effect on dysregulated breast cancer (BC) genes. OT extracts were obtained via solvent extraction (SE) and supercritical fluid extraction (SFE), followed by in vitro assays. Phytochemical analysis revealed that ethanol-extracted OT (OTL-E) had the highest polyphenol, flavonoid, and tannin contents, correlating with strong antioxidant activity, while water-extracted OT (OTL-W) exhibited greater bioelectricity-stimulating properties in microbial fuel cells (MFC), confirmed by cyclic voltammetry (CV). Based on phytochemical analyses, SE displayed a better extraction technique for isolating OT bioactive compounds compared to SFE. In silico approaches through network pharmacology, molecular docking and dynamics simulations revealed that polyphenols with ortho- or para-dihydroxyl groups targeted dysregulated BC proteins involved in kinase signaling, apoptosis, and hormone receptor pathways. Luteolin exhibited the highest binding affinities to MAPK1 and PIK3CA with free energy (ΔG) of −9.1 and −8.4 kcal/mol, respectively. Trajectory-based analyses confirmed enthalpy-favored ligand-induced conformational changes to these oncoproteins, altering their function in BC development. These findings suggest the potential of OT as a bioelectricity-stimulating and chemopreventive agent, warranting further in vitro and in vivo validation. Full article

Bioenergetic membranes of mitochondria, thylakoids, and chromatophores are primary sites of ATP production in living cells. These membranes contain an electron transport chain (ETC) in which electrons are shuttled between a series of redox proteins during the generation of ATP via oxidative phosphorylation. The phospholipid composition of these membranes, which often include negative lipids, plays a role in determining the electrostatics of their surface owing to the spatial distribution of their charged head groups. Cardiolipin (CDL) is a phospholipid commonly associated with bioenergetic membranes and is also a significant contributor to the negative surface charge. Interactions between cytochromes and phospholipid head groups in the membrane can in principle affect the rate of its travel between ETC components, hence influencing the rate of ATP turnover. Here, we use molecular dynamic (MD) simulations that feature an accelerated membrane model, termed highly mobile membrane mimetic (HMMM), to study protein–lipid interactions during the diffusion of cytochrome c₂ between redox partners in a bioenergetic membrane. We observe a “skipping” mode of diffusion for cytochromes along with a bias for binding to anionic lipids, particularly with a strong preference for CDL. During diffusion, cytochrome c₂ maintains a relatively fixed tilt with respect to the membrane normal with wider fluctuations in its angle with respect to the plane of the membrane. The obtained results describing the behavior of cytochrome c₂ on a representative bioenergetic membrane have direct ramifications in shuttling motions of other similar electron-carrying elements in other bioenergetic membranes, which are composed of a significant amount of anionic lipids. The mode of surface-restricted diffusion reported here would modulate rapid electron transfer between the ETC complexes anchored in bioenergetic membranes by reducing the search space between them. Full article

The excessive levels of neonicotinoid insecticides, particularly thiacloprid (THI), in the environment have become a significant threat to ecosystems. This study investigates the catalytic degradation of THI using pinewood biochar (PBC), zero-valent iron (ZVI), and ZVI/PBC composite, with a particular focus on the reaction activity modulation mediated by organic acids (humic acid: HA and oxalic acid: OA). Reductive dechlorination dominated THI degradation as observed by Cl⁻ release kinetics. Compared to HA (39.73%), the OA (73.44%) addition markedly increased the THI removal efficiency by ZVI/PBC, which alone has a lower removal efficacy, i.e., 37.29%. The increase in the THI removal rate was attributed to its enhanced electron transfer capacity. As confirmed by electrochemical characterization, the addition of organic acids promotes electron transfer between THI and catalysts (ZVI, PBC, or ZVI/PBC), thereby improving the removal efficiency of THI. XRD/XPS analyses elucidated that OA preferentially converted passivating Fe₂O₃/Fe₃O₄ on ZVI/PBC to reactive FeOOH and formed electron-conductive Fe–COO bonds, thereby suppressing oxide layer formation. PBC amplified these effects through ZVI dispersion and electron shuttling, reducing aggregation-induced activity loss. These findings provide a mechanistic framework for optimizing ligand-engineered iron composites, offering practical strategies to enhance pesticide remediation efficiency in organic acid-rich environmental systems. Full article

Tuberous sclerosis complex (TSC) is caused by mutations in TSC1 or TSC2 genes and affects multiple organs. TSC proteins control cell growth by regulating the activity of the mechanistic target of rapamycin complex 1. Extracellular vesicles (EVs) are membrane-bound particles produced by cells that mediate cellular communication, function, and growth. Although extensive studies regarding the genetic basis of TSC exist, the exact mechanism contributing to its pathogenesis remains unresolved. It has been proposed that EVs generated by renal cyst epithelia of mice and cells with Tsc gene mutations contain factors that alter the function and proliferation of TSC-sufficient cells. To test this, EVs from the kidneys and kidney explants of wildtype and Tsc1KO mice were isolated and characterized by Western blotting, transmission electron microscopy, dynamic light scattering, and fluorescent nanoparticle tracking. Our results show an enrichment in EV-associated markers and particle sizes of similar ranges. RNA-seq and proteomic analyses identified EV shuttle factors. EV RNA and protein shuttle factors showed significant differences. Furthermore, EVs isolated from Tsc1KO mice inhibited the proliferation of M-1 cells. Understanding the role of EVs in cell proliferation and cystogenesis in TSC may lead to the development of new approaches for the treatment of this disease. Full article

The conversion of food waste into caproate via anaerobic chain elongation has gained increasing attention. However, limitations such as reliance on external electron donors, low carbon conversion efficiency under high loads, and unclear microbial mechanisms hinder its application. Fe₃O₄ reportedly can act as an electron shuttle and mitigate product inhibition during anaerobic digestion of sludge. Thus, Fe₃O₄ addition could overcome the challenges from high loads under certain conditions. In this study, the experiments were conducted under batch and semi-continuous conditions. This study investigated the effects of organic loads on the hydrolysis, acidification, and chain elongation of fermentation. Furthermore, the influences of Fe₃O₄ on caproate production and microbial profile under varying substrate-to-inoculation ratios and dosages were examined. The key results harvested from the semi-continuous trial indicate that high organic loads severely inhibited caproate production. And in batch tests, at an F/M ratio of 1:2, increasing Fe₃O₄ dosage evidently enhanced caproate production by promoting lactate conversion to butyrate and carbon chain elongation. At an F/M ratio of 6:1, maximum caproate yield reached 0.45 g COD/g COD at Fe₃O₄ of 2.0 g/L. High organic load reduced the abundance of butyrate-producing bacteria (Latilactobacillus and Stenotrophomonas). Nevertheless, the addition of Fe₃O₄ increased the abundance of butyrate-producing and caproate-producing bacteria (Caproiciproducens). In conclusion, Fe₃O₄ at an optimal dosage evidently enhanced caproate production under high organic loads by stimulating microbial electron transport and enriching relevant microorganisms. Full article

Previous studies have linked the electron-shuttling properties of Traditional Chinese Medicine (TCM) species to antiviral efficacy. This study explores the antiviral potential of Cassia obtusifolia seeds through electrochemical analyses using microbial fuel cells (MFCs) and cyclic voltammetry (CV) complemented by in silico methods. The phytochemical contents and antioxidant activity of Cassia seed extracts were assessed and correlated with bioenergy generation and electrochemical stability. A principal component analysis (PCA) indicated that phytochemical and antioxidant activity influence Cassia’s power-generating potential. The MFC study revealed a 1.87-fold power amplification in unprocessed Cassia seed water extract (CTS-W), while CV analysis demonstrated enhanced electrochemical stability and reversibility due to the presence of electron-shuttling (ES) species. In silico analyses, including network pharmacology and molecular docking, provided supporting evidence for the antiviral potential of bioactive metabolites in Cassia seeds, particularly in targeting Hepatitis B virus-related genes. Furthermore, a mathematical model highlighted the superior therapeutic efficacy of electron-shuttling (ES) species compared to antioxidants in disease treatment. These findings demonstrate a strong correlation between the electron-shuttling properties and the antiviral potential of C. obtusifolia seed extracts, suggesting that bioenergy-mediated mechanisms may play a crucial role in the development of effective antiviral therapies. Full article

Room-temperature sodium–sulfur (RT Na–S) batteries offer a superior, high-energy-density solution for rechargeable batteries using earth-abundant materials. However, conventional RT Na–S batteries typically use sulfur as the cathode, which suffers from severe volume expansion and requires pairing with a sodium metal anode, raising significant safety concerns. Utilizing Na₂S as the cathode material addresses these issues, yet challenges such as Na₂S’s low conductivity as well as the shuttle effect of polysulfide still hinder RT Na–S battery development. Herein, we present a simple and cost-effective method to fabricate a Na₂S–Na₆CoS₄/Co@C cathode, wherein Na₂S nanoparticles are embedded in a conductive carbon matrix and coupled with dual catalysts, Na₆CoS₄ and Co, generated via the in situ carbothermal reduction of Na₂SO₄ and CoSO₄. This approach creates a three-dimensional porous composite cathode structure that facilitates electrolyte infiltration and forms a continuous conductive network for efficient electron transport. The in situ formed Na₆CoS₄/Co electrocatalysts, tightly integrated with Na₂S, exhibit strong catalytic activity and robust physicochemical stabilization, thereby accelerating redox kinetics and mitigating the polysulfide shuttle effect. As a result, the Na₂S–Na₆CoS₄/Co@C cathode achieves superior capacity retention, demonstrating a discharge capacity of 346 mAh g⁻¹ after 100 cycles. This work highlights an effective strategy for enhancing Na₂S cathodes with embedded catalysts, leading to enhanced reaction kinetics and superior cycling stability. Full article

In recent decades, several discoveries have been made that force us to reconsider old ideas about mitochondria and energy metabolism in the light of these discoveries. In this review, we discuss metabolic interaction between various organs, the metabolic significance of the primary substrates and their metabolic pathways, namely aerobic glycolysis, lactate shuttling, and fatty acids β-oxidation. We rely on the new ideas about the supramolecular structure of the mitochondrial respiratory chain (respirasome), the necessity of supporting substrates for fatty acids β-oxidation, and the reverse electron transfer via succinate dehydrogenase during β-oxidation. We conclude that ATP production during fatty acid β-oxidation has its upper limits and thus cannot support high energy demands alone. Meanwhile, β-oxidation creates conditions that significantly accelerate the cycle: glucose-aerobic glycolysis-lactate-gluconeogenesis-glucose. Therefore, glycolytic ATP production becomes an important energy source in high energy demand. In addition, lactate serves as a mitochondrial substrate after converting to pyruvate + H⁺ by the mitochondrial lactate dehydrogenase. All coupled metabolic pathways are irreversible, and the enzymes are organized into multienzyme structures. Full article

Se_xS_y composite cathode materials, which offer superior theoretical capacity compared to pure selenium and improved electrochemical properties relative to pure sulfur, have aroused considerable interest in recent decades on account of their applications in electric vehicles and energy storage grids. In the current work, the feasibility of a Co@C₂N monolayer as a promising host candidate for the cathode material of Li-Se_xS_y batteries has been evaluated using first-principles calculations, and particular efforts have been devoted to underscoring the anchoring mechanism and catalytic performance of the Co@C₂N monolayer. The pronounced synergistic effects of Co-S and Li-N bonds lead to increased anchoring performance for Li₂Se_xS_y/Se_xS_y clusters on the surface of Co@C₂N monolayer, which effectively inhibit the shuttle effect. The charge density difference and Mulliken charge analysis underscores a substantial charge transfer from the Li₂Se_xS_y and Se_xS_y clusters to the Co@C₂N monolayer, which indicates a noticeable chemical interaction between them. Further electronic property calculations show that the Co@C₂N monolayer can improve the electrical conductivity of cathode materials for Li-Se_xS_y batteries by maintaining semi-metallic characteristics after anchoring of Li₂Se_xS_y/Se_xS_y clusters. Additionally, the catalytic performance of the Co@C₂N monolayer is evaluated in terms of the reduction pathway of Se₈ and the decomposition energy barrier of the Li₂SeS cluster, which highlights the catalytic role of the Co@C₂N monolayer in the formation and decomposition of the Li₂SeS cluster during the cycle processes. Overall, the Co@C₂N monolayer emerges as a promising host material and catalyst for Li-Se_xS_y batteries with remarkable anchoring and catalytic performance. Full article

Typha angustifolia L. (TA) pollen has been utilized as a traditional Chinese medicine for treating various internal and external traumas. Moreover, bioactive compounds possess diverse pharmacological activities. This study aims to evaluate the antiviral properties of TA based on its ability to generate bioenergy, capable of inhibiting viruses. TA pollens were extracted using water and ethanol solvents. These extracts were utilized to identify the phytochemical contents and correlate with the antioxidant activity via 2,2-diphenyl-1-picrylhydrazyl (DPPH) and ferric reducing antioxidant power (FRAP) assays. HPLC analysis was conducted to identify its electron-shuttling compositions. The bioenergy-generating characteristics were determined via microbial fuel cells. The water extract (TA-W) showed higher antioxidant activity due to a higher phenolic and flavonoid content compared to the ethanol extract (TA-E). Quercetin-3-O-(2^G-α-L-rhamnosyl)-rutinoside, quercetin-3-O-neohesperidoside, and quercetin are the electron shuttles (ES) identified out of the 11 compounds. TA obtained a 1.39 ± 0.10 amplification factor of power generation that indicates potential bioenergy-generating and associated antiviral characteristic properties. The findings may provide a foundation for developing antiviral medications specifically designed to target virus-related diseases, while minimizing the risk of drug toxicity and reducing the costs of drug development. Full article