58-68-4Relevant articles and documents
Mechanistic Aspects of the Electrochemical Oxidation of Dihydronicotinamide Adenine Dinucleotide (NADH)
Moiroux, Jacques,Elving, Philip J.
, p. 6533 - 6538 (1980)
The apparently single stage anodic oxidation of NADH involving removal of two electrons and a proton to form NAD+ has been examined with particular attention to the deprotonation step and its relationship to the initial potential-determining electron-transfer step, primarily at glassy carbon electrodes (GCE) in aqueous media with supplementary studies at pyrolytic graphite and platinum electrodes in aqueous media and at GCE in Me2SO; the carbon electrodes were generally first covered with an adsorbed NAD+ layer in order to eliminate adsorption-controlled faradaic processes.The initial step is an irreversible heterogeneous electron transfer (transfer coefficient β = 0.37 at carbon electrodes and 0.43 at platinum).The resulting cation radical NAD.H+ loses a proton (first-order reaction; rate constant k) to form the neutral radical NAD. which may participate in a second heterogeneous electron transfer (ECE mechanism) or in a homogeneous electron transfer with NAD.H+ (disproportionation mechanism DISP 1 or half-regeneration mechanism), yielding NAD+.The near identities of current functions, viscosity-corrected diffusion coefficients D and β values, point to essentially similar solute species and charge-transfer paths being involved in different media and at different electrodes.D is ca. 2 x 10-6 cm2 s-1 in aqueous solution; k is ca. 60 s-1 at the GCE covered with adsorbed NAD+.
Engineering Olefin-Linked Covalent Organic Frameworks for Photoenzymatic Reduction of CO2
Chen, Yao,Guo, Menglei,Yu, Jiangyue,Zhang, Sainan,Zhang, Zhenjie,Zhao, Zhengfeng,Zheng, Dong
supporting information, (2022/02/10)
It is of profound significance concerning the global energy and environmental crisis to develop new techniques that can reduce and convert CO2. To address this challenge, we built a new type of artificial photoenzymatic system for CO2 reduction, using a rationally designed mesoporous olefin-linked covalent organic framework (COF) as the porous solid carrier for co-immobilizing formate dehydrogenase (FDH) and Rh-based electron mediator. By adjusting the incorporating content of the Rh electronic mediator, which facilitates the regeneration of nicotinamide cofactor (NADH) from NAD+, the apparent quantum yield can reach as high as 9.17±0.44 %, surpassing all reported NADH-regenerated photocatalysts constructed by crystalline framework materials. Finally, the assembled photocatalyst–enzyme coupled system can selectively convert CO2 to formic acid with high efficiency and good reusability. This work demonstrates the first example using COFs to immobilize enzymes for artificial photosynthesis systems that utilize solar energy to produce value-added chemicals.
Design of artificial metalloenzymes for the reduction of nicotinamide cofactors
Basle, Mattias,Padley, Henry A.W.,Martins, Floriane L.,Winkler, Gerlof Sebastiaan,J?ger, Christof M.,Pordea, Anca
, (2021/04/19)
Artificial metalloenzymes result from the insertion of a catalytically active metal complex into a biological scaffold, generally a protein devoid of other catalytic functionalities. As such, their design requires efforts to engineer substrate binding, in addition to accommodating the artificial catalyst. Here we constructed and characterised artificial metalloenzymes using alcohol dehydrogenase as starting point, an enzyme which has both a cofactor and a substrate binding pocket. A docking approach was used to determine suitable positions for catalyst anchoring to single cysteine mutants, leading to an artificial metalloenzyme capable to reduce both natural cofactors and the hydrophobic 1-benzylnicotinamide mimic. Kinetic studies revealed that the new construct displayed a Michaelis-Menten behaviour with the native nicotinamide cofactors, which were suggested by docking to bind at a surface exposed site, different compared to their native binding position. On the other hand, the kinetic and docking data suggested that a typical enzyme behaviour was not observed with the hydrophobic 1-benzylnicotinamide mimic, with which binding events were plausible both inside and outside the protein. This work demonstrates an extended substrate scope of the artificial metalloenzymes and provides information about the binding sites of the nicotinamide substrates, which can be exploited to further engineer artificial metalloenzymes for cofactor regeneration. Synopsis about graphical abstract: The manuscript provides information on the design of artificial metalloenzymes based on the bioconjugation of rhodium complexes to alcohol dehydrogenase, to improve their ability to reduce hydrophobic substrates. The graphical abstract presents different binding modes and results observed with native cofactors as substrates, compared to the hydrophobic benzylnicotinamide.
Implantable Biosupercapacitor Inspired by the Cellular Redox System
Jang, Yongwoo,Park, Taegyu,Kim, Eunyoung,Park, Jong Woo,Lee, Dong Yeop,Kim, Seon Jeong
, p. 10563 - 10567 (2021/04/05)
The carbon nanotube (CNT) yarn supercapacitor has high potential for in vivo energy storage because it can be used in aqueous environments and stitched to inner parts of the body, such as blood vessels. The biocompatibility issue for frequently used pseudocapacitive materials, such as metal oxides, is controversial in the human body. Here, we report an implantable CNT yarn supercapacitor inspired by the cellular redox system. In all living cells, nicotinamide adenine dinucleotide (NAD) is a key redox biomolecule responsible for cellular energy transduction to produce adenosine triphosphate (ATP). Based on this redox system, CNT yarn electrodes were fabricated by inserting a twist in CNT sheets with electrochemically deposited NAD and benzoquinone for redox shuttling. Consequently, the NAD/BQ/CNT yarn electrodes exhibited the maximum area capacitance (55.73 mF cm?2) under physiological conditions, such as phosphate-buffered saline and serum. In addition, the yarn electrodes showed a negligible loss of capacitance after 10 000 repeated charge/discharge cycles and deformation tests (bending/knotting). More importantly, NAD/BQ/CNT yarn electrodes implanted into the abdominal cavity of a rat's skin exhibited the stable in vivo electrical performance of a supercapacitor. Therefore, these findings demonstrate a redox biomolecule-applied platform for implantable energy storage devices.
A highly active Cp*Ir complex with an anionic N,N-donor chelate ligand catalyzes the robust regeneration of NADH under physiological conditions
Qi, Caixia,Shi, Yusheng,Su, Huijuan,Sun, Libo,Sun, Wen,Sun, Xun,Xia, Linyan,Yin, Zequn,Zhang, Weiling,Zhao, Li-Jun
, p. 7982 - 7991 (2021/12/27)
A highly active [N^N?] iridium complex [Cp*Ir(pba)Cl] (3, Cp* = pentamethylcyclopentadiene, pba = 4-(picolinamido)benzoic acid) has been obtained with an anionic ligand, which exhibited the most robust performance for cofactor NADH regeneration in physiological conditions with HCOONa as the hydrogen source. The structure of complex3was revealed by X-ray single-crystal structure analysis. The turnover frequency (TOF) of complex3in the regeneration of NADH is 7825 h?1, which is about 22.7 times and 178 times higher than that of the C?^N type complex2(345 h?1) and N^N complex1(44 h?1) at 37 °C, respectively. The high activity of complex3seems to be critically affected by the negatively charged N?of the amide chelating ligand, which could promote the reaction rate of Ir-Cl conversion to Ir-H2O. Furthermore, complex3shows good biocompatibility for various biomolecules except SH-compounds (such as reduced glutathione (GSH)). When combined with NADH-dependent enzymes (KRED-101), the complex3-based NADH-regeneration catalytic system shows stable chemoenzymatical coordinate catalytic activity for reducing acetophenone to the corresponding alcohol with high enantioselectivity.
Highly Efficient S-g-CN/Mo-368 Catalyst for Synergistically NADH Regeneration Under Solar Light
Gupta, Abhishek Kumar,Gupta, Sarvesh Kumar,Singh, Ajeet,Yadav, Bal Chandra,Yadav, Rajesh Kumar
, (2021/07/31)
Sulfur-doped graphitic carbon nitride (S-g-CN) has gained significant attention in recent years. Sulfur-doped graphitic carbon nitride (S-g-CN) is a promising metal-free photocatalyst because of its band orientation, natural abundance and groundwork. Improved photocatalytic activity of S-g-CN material for solar chemical production persists a hot yet challenging problem. Herein, we provide an adaptable method for the synthesis of S-g-CN nanocomposite decorated with the moiety of giant polyoxometalate (S-g-CN/Mo-368) that subsequently showed highly efficient photocatalytic activity. The as-synthesized S-g-CN/Mo-368 as a recyclable artificial photocatalyst revealed excellent activity for solar chemical production, that is nicotinamide adenine dinucleotide (NADH) regeneration under visible light. The immobilized Mo-368 on the S-g-CN surface increased the visible light adsorption capacity of the S-g-CN/Mo-368 photocatalyst. The visible light absorption activity, morphology, element compositions, particle size and zeta potential of S-g-CN powder and S-g-CN/Mo-368 were thoroughly investigated. From the application point of view, S-g-CN/Mo-368 was applied to determine the solar chemical production (i.e. NADH regeneration) under visible light with a higher yield% of about ~ 94.85%.
Chemo-bio catalysis using carbon supports: application in H2-driven cofactor recycling
Cleary, Sarah E.,Grobert, Nicole,Reeve, Holly A.,Vincent, Kylie A.,Zhao, Xu,Zor, Ceren
, p. 8105 - 8114 (2021/06/22)
Heterogeneous biocatalytic hydrogenation is an attractive strategy for clean, enantioselective CX reduction. This approach relies on enzymes powered by H2-driven NADH recycling. Commercially available carbon-supported metal (metal/C) catalysts are investigated here for direct H2-driven NAD+reduction. Selected metal/C catalysts are then used for H2oxidation with electrons transferredviathe conductive carbon support material to an adsorbed enzyme for NAD+reduction. These chemo-bio catalysts show improved activity and selectivity for generating bioactive NADH under ambient reaction conditions compared to metal/C catalysts. The metal/C catalysts and carbon support materials (all activated carbon or carbon black) are characterised to probe which properties potentially influence catalyst activity. The optimised chemo-bio catalysts are then used to supply NADH to an alcohol dehydrogenase for enantioselective (>99% ee) ketone reductions, leading to high cofactor turnover numbers and Pd and NAD+reductase activities of 441 h?1and 2347 h?1, respectively. This method demonstrates a new way of combining chemo- and biocatalysis on carbon supports, highlighted here for selective hydrogenation reactions.
Visible light driven selective NADH regeneration using a system of water-soluble zinc porphyrin and homogeneous polymer-dispersed rhodium nanoparticles
Amao, Yutaka,Katagiri, Takayuki
, p. 15748 - 15752 (2021/09/22)
We discovered the catalytic activity of Rh nanoparticles dispersed by polyvinylpyrrolidone (Rh-PVP) for NADH regeneration. The selective reduction of NAD+to enzyme active NADH has successfully been achieved in the presence of an electron donor, ZnTPPS as a photosensitizer, and Rh-PVP. Only 1,4-NADH was produced as the reduction product of NAD+, which was validated by an enzymatic assay and HPLC.
Fluorescent and Biocompatible Ruthenium-Coordinated Oligo(p-phenylenevinylene) Nanocatalysts for Transfer Hydrogenation in the Mitochondria of Living Cells
Chen, Yanyan,Dai, Nan,Liu, Libing,Lv, Fengting,Qi, Ruilian,Wang, Shu,Zhao, Hao
, (2020/03/23)
It is challenging to design metal catalysts for in situ transformation of endogenous biomolecules with good performance inside living cells. Herein, we report a multifunctional metal catalyst, ruthenium-coordinated oligo(p-phenylenevinylene) (OPV-Ru), for intracellular catalysis of transfer hydrogenation of nicotinamide adenine dinucleotide (NAD+) to its reduced format (NADH). Owing to its amphiphilic characteristic, OPV-Ru possesses good self-assembly capability in water to form nanoparticles through hydrophobic interaction and π–π stacking, and numerous positive charges on the surface of nanoparticles displayed a strong electrostatic interaction with negatively charged substrate molecules, creating a local microenvironment for enhancing the catalysis efficiency in comparison to dispersed catalytic center molecule (TOF value was enhanced by about 15 fold). OPV-Ru could selectively accumulate in the mitochondria of living cells. Benefiting from its inherent fluorescence, the dynamic distribution in cells and uptake behavior of OPV-Ru could be visualized under fluorescence microscopy. This work represents the first demonstration of a multifunctional organometallic complex catalyzing natural hydrogenation transformation in specific subcellular compartments of living cells with excellent performance, fluorescent imaging ability, specific mitochondria targeting and good chemoselectivity with high catalysis efficiency.
Construction of Fully Conjugated Covalent Organic Frameworks via Facile Linkage Conversion for Efficient Photoenzymatic Catalysis
Chen, Renzeng,Hao, Wenbo,Li, Zhibo,Liu, Hui,Liu, Jian,Pan, Qingyan,Wang, Yuancheng,Wu, Chenyu,Xu, Jie,Zhao, Yingjie
supporting information, p. 5958 - 5963 (2020/04/27)
Covalent organic frameworks (COFs) with improved stability and extended ?-conjugation structure are highly desirable. Here, two imine-linked COFs were converted into ultrastable and ?-conjugated fused-aromatic thieno[3,2-c]pyridine-linked COFs (B-COF-2 and T-COF-2). The successful conversion was confirmed by infrared and solid-state 13C NMR spectroscopies. Furthermore, the structures of thieno[3,2-c]pyridine-linked COFs were evaluated by TEM and PXRD. It is noted that a slight difference in the structure leads to totally different photoactivity. The fully ?-conjugated T-COF-2 containing triazine as the core exhibited an excellent photocatalytic NADH regeneration yield of 74% in 10 min.
