The inherent oxygen sensitivity of hydrogenases has limited their biomedical use.We report a hybrid peptide-nanocluster hydrogel that establishes a self-sustained anaerobic microenvironment,enabling hydrogenase-cataly...The inherent oxygen sensitivity of hydrogenases has limited their biomedical use.We report a hybrid peptide-nanocluster hydrogel that establishes a self-sustained anaerobic microenvironment,enabling hydrogenase-catalyzed hydrogen therapy under aerobic conditions.The Fmoc-KYF peptide network traps O_(2) in hydrophobic pockets,while photoexcited silver nanoclusters rapidly scavenge residual oxygen,ensuring stable hydrogen evolution.In vitro,the generated hydrogen mitigates oxidative stress and inflammation.In diabetic mice,the light-activated system accelerates wound closure,promotes angiogenesis,and drives macrophage polarization toward a reparative phenotype.This study introduces a bioengineering strategy that integrates material design,enzyme catalysis,and photodynamics to overcome oxygen limitation and advance hydrogenase-based therapeutic applications.展开更多
A compound containing[FeFe]‑hydrogenase,[Fe_(2)((SCH_(2))_(2)R)(CO)_(6)](1)(R=4‑{(1H‑benzo[d]imidazol‑1‑yl)methyl}‑anilino),was prepared and thoroughly characterized by infrared spectroscopy,single‑crystal X‑ray diffr...A compound containing[FeFe]‑hydrogenase,[Fe_(2)((SCH_(2))_(2)R)(CO)_(6)](1)(R=4‑{(1H‑benzo[d]imidazol‑1‑yl)methyl}‑anilino),was prepared and thoroughly characterized by infrared spectroscopy,single‑crystal X‑ray diffraction,and density functional theory calculations.Its performance as a photocatalyst for hydrogen production via water splitting was evaluated under simulated sunlight.Within 3 h,the amount of H_(2)produced was 386.5μmol,achieving a catalytic efficiency of 25.26μmol·mg^(-1)·h^(-1)and a turnover number(TON)of 0.45.CCDC:2457448.展开更多
AIM: To evaluate the relationship between drinking and polymorphisms of alcohol dehydrogenase 2 (ADH2) and/or aldehyde dehydrogenase 2 (ALDH2) for risk of colorectal cancer (CRC) in Chinese males. METHODS: A case-cont...AIM: To evaluate the relationship between drinking and polymorphisms of alcohol dehydrogenase 2 (ADH2) and/or aldehyde dehydrogenase 2 (ALDH2) for risk of colorectal cancer (CRC) in Chinese males. METHODS: A case-control study was conducted in 190 cases and 223 population-based controls. ADH2 Arg47His (G-A) and ALDH2 Glu487Lys (G-A)genotypes were identified by PCR and denaturing high-performance liquid chromatography (DHPLC). Information on smoking and drinking was collected and odds ratio (OR) was estimated. RESULTS: The ADH2 A/A and ALDH2 G/G genotypes showed moderately increased CRC risk. The age- and smoking-adjusted OR for ADH2 A/A relative to G/A and G/G was 1.60 (95% CI=1.08-2.36), and the adjusted OR for ALDH2 G/G relative to G/A and A/A was 1.79 (95% CI=1.19-2.69). Signif icant interactions between ADH2, ALDH2 and drinking were observed. As compared to the subjects with ADH2 G and ALDH2 A alleles, those with ADH2 A/A and ALDH2 G/G genotypes had a signif icantly increased OR (3.05, 95% CI= 1.67-5.57). The OR for CRC among drinkers with the ADH2 A/A genotype was increased to 3.44 (95% CI= 1.84-6.42) compared with non-drinkers with the ADH2 G allele. The OR for CRC among drinkers with the ALDH2 G/G genotype was also increased to 2.70 (95% CI= 1.57-4.66) compared with non-drinkers with the ALDH2 A allele. CONCLUSION: Polymorphisms of the ADH2 and ALDH2 genes are significantly associated with CRC risk. There are also signifi cant gene-gene and gene- environment interactions between drinking and ADH2 and ALDH2 polymorphisms regarding CRC risk in Chinese males.展开更多
Two mono iron complexes Fe（CO）2PR3（NN） （R = Cy （3）, Ph （4）, NN = o-phenylenediamine dianion ligand, N2H2Ph2-） derived from the ligand substitution of Fe（CO）3hPR3 by the NN ligand were isolated and structur...Two mono iron complexes Fe（CO）2PR3（NN） （R = Cy （3）, Ph （4）, NN = o-phenylenediamine dianion ligand, N2H2Ph2-） derived from the ligand substitution of Fe（CO）3hPR3 by the NN ligand were isolated and structurally characterized by single crystal X-ray diffraction. They have a similar first coordination sphere and oxidation state of the iron center as the [Fe]-hydrogenase active site, and can be a model of it IR demonstrated that the effect of the NN ligand on the coordinated CO stretch- ing frequencies was due to its excellent electron donating ability. The reversible protonation/deprotonation of the NN ligand was identified by infrared spectroscopy and density functional theory computation. The NN ligand is an effective proton acceptor as the internal base of the cysteine thiolate ligand in [Fe]-hydrogenase. The electrochemical properties of complexes 3, 4 were investigated by cyclic voltammograms. Complex 3 catalyzed the transfer hydrogenation of benzoquinone to hydroquinone effectively under mild conditions.展开更多
Hydrogenase is a paradigm of highly efficient biocatalyst for H_(2) production and utilization evolved in nature. A dilemma is that despite the high activity and efficiency expected for hydrogenases as promising catal...Hydrogenase is a paradigm of highly efficient biocatalyst for H_(2) production and utilization evolved in nature. A dilemma is that despite the high activity and efficiency expected for hydrogenases as promising catalysts for the hydrogen economy, the poor oxygen tolerance and low yield of hydrogenases largely hinder their practical application. In these years, the enigmas surrounding hydrogenases regarding their structures, oxygen tolerance, mechanisms for catalysis, redox intermediates, and proton-coupled electron transfer schemes have been gradually elucidated;the schemes, which can well couple hydrogenases with other highly efficient(in)organic and biological catalysts to build novel reactors and drive valuable reactions, make it possible for hydrogenases to find their niches. To see how scientists put efforts to tackle this issue and design novel reactors in the fields where hydrogenases play crucial roles, in this review,recent advances were summarized, including different strategies for protecting enzyme molecules from oxygen, enzyme-based assembling systems for H_(2) evolution in the photoelectronic catalysis, enzymatic biofuel cells for H_(2) utilization and storage and the efficient electricity-hydrogen-carbohydrate cycle for high-purity hydrogen and biofuel automobiles. Limitations and future perspectives of hydrogenasebased applications in H_(2) production and utilization with great impact are discussed. In addition, this review also provides a new perspective on the use of biohydrogen in healthcare beyond energy.展开更多
Photocatalytic reduction of CO2 to CO is a promising approach for storing solar energy in chemicals and mitigating the greenhouse effect of CO2.Our recent studies revealed that[(μ-bdt)Fe2(CO)6](1,bdt=benzene-1,2-dith...Photocatalytic reduction of CO2 to CO is a promising approach for storing solar energy in chemicals and mitigating the greenhouse effect of CO2.Our recent studies revealed that[(μ-bdt)Fe2(CO)6](1,bdt=benzene-1,2-dithiolato),a[FeFe]-hydrogenase model with a rigid and conjugate S-to-S bridge,was catalytically active for the selective photochemical reduction of CO2 to CO,while its analogous complex[(μ-edt)Fe2(CO)6](2,edt=ethane-1,2-dithiolato)was inactive.In this study,it was found that the turnover number of 1 for CO evolution reached 710 for the 1/[Ru(bpy)3]2+/BIH(BIH=1,3-dimethyl-2-phenyl-2,3-dihydro-1H-benzo[d]-imidazole)system under optimal conditions over 4.5 h of visible-light irradiation,with a turnover frequency of 7.12 min−1 in the first hour,a high selectivity of 97%for CO,and an internal quantum yield of 2.8%.Interestingly,the catalytic selectivity of 1 can be adjusted and even completely switched in a facile manner between the photochemical reductions of CO2 to CO and of protons to H2 simply by adding different amounts of triethanolamine to the catalytic system.The electron transfer in the photocatalytic system was studied by steady-state fluorescence and transient absorption spectroscopy,and a plausible mechanism for the photocatalytic reaction was proposed.展开更多
A component （s-factor） with obvious promoting effect on hydrogen evolution of hydrogenase has beenisolated and extracted from a Cell=free preparation of Spirulina platensis.The effect of the s-factor in the re-actio...A component （s-factor） with obvious promoting effect on hydrogen evolution of hydrogenase has beenisolated and extracted from a Cell=free preparation of Spirulina platensis.The effect of the s-factor in the re-action system is similar to that of Na<sub>2</sub>S<sub>2</sub>O<sub>4</sub>, but is coupled with ligh. The s-factor has the maximumabsorption peak at 620 nm in the oxidized state, at 590 nm in the reduced state. The partially purifieds-factor showed two bands by SDS-PAGE and is distinctly different from phycocyanin,which has nochange of oxidized state and reduced state absorption spectra, and also has no promoting effect onhydrogenase of Spirulina platensis under the light.展开更多
Structural and functional biomimicking of the active site of [NiFe]-hydrogenases can provide helpful hints for designing bioinspired catalysts to replace the expensive noble metal catalysts for H2 generation and uptak...Structural and functional biomimicking of the active site of [NiFe]-hydrogenases can provide helpful hints for designing bioinspired catalysts to replace the expensive noble metal catalysts for H2 generation and uptake.Treatment of dianion [Ni(phma)]2-[H4 phma=N,N’-1,2-phenylenebis(2-mercaptoacetamide)] with [NiCl2(dppp)](dppp=bis(diphenylphosphino)propane) yielded a dinickel product[Ni(phma)(μ-S,S’)Ni(dppp)](1) as the model complex relevant to the active site of [NiFe]-H2 ases.The structure of complex 1 has been characterized by single-crystal X-ray analysis.From cyclic voltammetry and controlled potential electrolysis studies,complex 1 was found to be a moderate electrocatalyst for the H2-evoluting reaction using ClCH2COOH as the proton source.展开更多
Hydrogen evolution was detected in an artificial system composed of light-harvesting unit of purified photosystem I, catalyst of hydrogenase, methyl viologen and electron donor under radiation. Absorption spectral fea...Hydrogen evolution was detected in an artificial system composed of light-harvesting unit of purified photosystem I, catalyst of hydrogenase, methyl viologen and electron donor under radiation. Absorption spectral features confirmed that electron transfer from electron donors to proton was via a photoinduced reductive process of methyl viologen.展开更多
In order to evaluate the hydrogen-producing efficiency of anaerobic activated sludge in Anaerobic Baffled Reactor(ABR)fermentation processes,the optimal conditions for hydrogen producing hydrogenase method on methyl v...In order to evaluate the hydrogen-producing efficiency of anaerobic activated sludge in Anaerobic Baffled Reactor(ABR)fermentation processes,the optimal conditions for hydrogen producing hydrogenase method on methyl viologen(MV)assay was used to detect the hydrogen production activity of the activated sludge.The most favorable parameters such as 0.6 mL sodium acetate buffer(pH 5.0),100 μL lysozyme,0.2 mL sodium dibromoethane(9.0 mmol/L)and 0.7 mmol/L iron added into 1 mL activated sludge(2.66～26.64 gMLVSS/L)were found.Furthermore,reaction temperature and culture time were detected as 40 ℃ and 30 min respectively.Sodium thiosulfate and sodium sulfides were taken as the reducing agent while trichloroacetic acid as terminator.Under the MV optimal conditions,micro-toxic Dimethyl sulfoxide(DMSO)get higher security and better accuracy.The sensitivity of the detection methods(DMSO as electron carrier)was increased by more than 30%.The results show that the optimal conditions can be applied to measure hydrogenase activity correlating with its specific hydrogen production rate in a hydrogen-producing anaerobic activated sludge system.展开更多
A comparative evaluation of three different cell-disruption methods for the release of hydrogenase from H2 -producing bacterium E. harbinenase YUAN-3T was investigated. The cell disruption techniques evaluated in this...A comparative evaluation of three different cell-disruption methods for the release of hydrogenase from H2 -producing bacterium E. harbinenase YUAN-3T was investigated. The cell disruption techniques evaluated in this study were uhrasonieation, high-speed homogenization and bead milling. Ultrasonication process was found to be the most effective method in terms of cell disruption. As for the specific activity of hydrogenase, there is no significant difference among the three kinds of methods. An orthogonal experiment L9 （34） was designed to optimize the procedures of ultrasonication for cell disruption. The optimized uhrasonication disruption conditions were the treatment at 250 W, 20 kHz, 30 s/15 s and 0. 30 g bacteria cell （dry weight） in 15 mL suspension buffer. As a result, the optimized conditions allow the hydrogenase to maintain the active form with the yield of 93.95 mg protein/g cell and the final activity of 0. 252 μmol/min/mg protein. In this work, we have developed and optimized an ultrasonication protocol for YUAN-3T cel]s, which is adapted to laboratory- scale release of hydrogenase proteins.展开更多
A model compound for the active sites of Fe-only hydrogenases, [Fe2（SCH2）2N（3- PhCF3）（CO）6]2, has been synthesized and structurally characterized by single-crystal X-ray diffraction. It crystallizes in tetragona...A model compound for the active sites of Fe-only hydrogenases, [Fe2（SCH2）2N（3- PhCF3）（CO）6]2, has been synthesized and structurally characterized by single-crystal X-ray diffraction. It crystallizes in tetragonal, space group P43, with α = 12.6324（3）, b = 12.6324（3）, c = 24.0453（12） A, V = 3837.1（2） A^3, Z= 4, Fe4S4N2C30O12F6H16, Mr= 1062.09, Dc= 1.839 g/cm^3, μ（MoKα） = 1.791 mm^-1, F（000） = 2112, T= 293（2） K, Flack = 0.034（9）, R = 0.0282 and wR = 0.0685 for 8148 observed reflections with I 〉 20（I）. In the title compound, each Fet atom is coordinated by three terminal carbonyl C atoms （Fe-C： 1.783（3）- 1.816（3） A）, two bridging S atoms （Fe-S： 2.2609（7）-2.2757（8） A） and another Fe atom （Fe-Fe 2.5011（5） A）, adopting a distorted octahedral geometry with trans angles ranging from 152.45（11） to 157.77（10）°.展开更多
A new five-heterocyclic-biphosphine-substituted Fe-only hydrogenase mimic,[（μ-pdt）Fe_2（CO）_5]_2（PTP）（1）,has been synthesized at room temperature. 1·H_2O crystallizes in triclinic system,space group P1,wi...A new five-heterocyclic-biphosphine-substituted Fe-only hydrogenase mimic,[（μ-pdt）Fe_2（CO）_5]_2（PTP）（1）,has been synthesized at room temperature. 1·H_2O crystallizes in triclinic system,space group P1,with a = 11.5897（4）,b = 13.6156（4）,c = 18.0333（6） ？,α = 76.306（3）,β = 72.742（3）,γ = 68.939（3）°,V = 2508.84（14） ？~3,Dc = 1.570 g/cm3,Z = 2,M_r = 1186.37,F（000） = 1204,the final R = 0.0748,and wR = 0.2012. In the tetranuclear complex 1·H_2O,each [2Fe_2S] butterfly unit is attached to one P atom of the diphosphine bridge and exhibits a square-pyramidal geometry. Complex 1 was characterized by elemental analysis,IR spectra,UV-vis absorption spectra,~1H-NMR and ^（31）P-NMR. The cyclic voltammetry behavior of compound 1 was investigated as well.展开更多
Hydrogen production is key to carbon-free energy production and the use of hydrogenases is an excellent approach for this achievement since they produce hydrogen with extraordinary efficiencies.However,these enzymes h...Hydrogen production is key to carbon-free energy production and the use of hydrogenases is an excellent approach for this achievement since they produce hydrogen with extraordinary efficiencies.However,these enzymes have several shortcomings,which may be resolved using hydrogenase mimics.The design and synthesis of these mimics is a very active area of research,and the understanding of the mode of the action of mimics is particularly relevant to the future design of robust and productive catalysts.In this review,we discuss the role of isotopes(mainly deuterium)in disentangling key steps of the mechanisms of H2 activation by mimics of hydrogenases.Through selected examples,we focus on the key aspects of processes that,in many cases,have allowed a better understanding of the mode of action of the natural enzymes,making a valuable contribution to the design of more efficient complexes for the production of hydrogen.展开更多
Mimics of [FeFe]-hydrogenases having two [(μ-adt)Fe_(2)(CO)_(6)] moieties linked through 1,2,3-triazole ringswith polyethylene glycol (PEG) chains [(-OCH_(2)CH_(2)O-)4 (7) and (-OCH_(2)CH_(2)O-)5 (8)] are able to coo...Mimics of [FeFe]-hydrogenases having two [(μ-adt)Fe_(2)(CO)_(6)] moieties linked through 1,2,3-triazole ringswith polyethylene glycol (PEG) chains [(-OCH_(2)CH_(2)O-)4 (7) and (-OCH_(2)CH_(2)O-)5 (8)] are able to coordinateto alkali ions (Na^(+), K^(+)) via the O-PEG atoms and the triazole-N3 positions. Electrocatalytic studies intrifluoroacetic acid (TFA) demonstrate that their catalytic performance is affected by the presence of Na+and K+ salts. The addition of NaPF6 decreases the electrocatalytic activity of 7 and 8 (about 50% reductionof the TOF values). As, in TFA, 7 and 8 could be protonated in both the triazole and adt-amino groups, thereduction in TOF values suggests that NaPF6 inhibits the contribution of the triazolium species to theelectrocatalytic process, likely due to the involvement of the triazole-N3 positions in Na^(+) binding.However, the addition of KPF_(6) either does not change (7) or increases the TOF values (8). ^(1)H NMR titrationexperiments demonstrate that, despite the presence of K^(+) ions in the media, triazolium salts are formed.Therefore, the TOF values should reflect the contribution of species protonated in both the triazole andadt-amino groups to the HER process.展开更多
In this study,we present a convenient method to obtain two types of novel tetra-substituted Fe/Se salts through a dehalogenation reaction,aiming to advance research on mimicking the FeⅡFeⅡ oxidation state of[FeFe]-H...In this study,we present a convenient method to obtain two types of novel tetra-substituted Fe/Se salts through a dehalogenation reaction,aiming to advance research on mimicking the FeⅡFeⅡ oxidation state of[FeFe]-H_(2) ases.Initially,by treating[Fe_(2)(μ-SeBn)_(2)(CO)_(4)(dppv)](Bn=CH_(2)C_(6)H_(5),dppv=cis-1,2-bis(diphenylphosphino)ethylene)with one equivalent of dppv under UV and reflux conditions,the neutral FeIFeI and FeⅡFeⅡ precursors[Fe_(2)(μ-SeBn)_(2)(CO)_(2)(dppv)_(2)](1)and[Fe_(2)(μ-SeBn)_(2)(μ-Se)(CO)_(2)(dppv)_(2)](2)were successfully isolated in good yields.Subsequently,1 underwent dehalogenation reactions with halocarbons(such as CCl_(4) and CBr4)or I_(2),leading to the formation of tetra-substituted salts[Fe_(2)(μ-SeBn)_(2)(μ-X)(CO)_(2)(dppv)_(2)]+(X=Cl,Br,and I)([3]Cl,[4]Br and[5]I_(3)).GC-MS analysis of the reaction with carbon tetrachloride detected the formation of the homo-coupled product CCl_(3)-CCl_(3)(m/z=235),indicating the presence of a CCl_(3)·species.Notably,2 also exhibited intriguing reactivity with R-X and I_(2).Unlike 1,the reaction of 2 with RX or I_(2) involved cleavage of the C-Se bond,leading to the isolation of[Fe_(2)(μ-SeBn)(μ-Se_(2))(CO)_(2)(dppv)_(2)]+X-(X=Cl,Br,I_(3))([6]Cl,[6]Br and[6]I_(3))in good yields.The reaction involved debenzylation of 2 and was confirmed by GC-MS detection of C6H5CH_(2)CCl_(3)(m/z=208)in the reaction with CCl_(4),suggesting a radical pathway.展开更多
A series of triiron clusters[Fe_(3)(CO)_(5)(κ^(2)-dppe)(μ-pdt^(R_(2)))(μ-pdt)]featuring different combinations of dithiolate bridges have been prepared by using dinuclear and mononuclear precursors,[Fe_(2)(CO)_(6)(...A series of triiron clusters[Fe_(3)(CO)_(5)(κ^(2)-dppe)(μ-pdt^(R_(2)))(μ-pdt)]featuring different combinations of dithiolate bridges have been prepared by using dinuclear and mononuclear precursors,[Fe_(2)(CO)_(6)(μ-xdt)](xdt=pdt,pdt^(Et_(2)),pdt^(Bn_(2)),adt^(Bn))and[Fe(CO)_(2)(κ^(2)-dppe)(κ^(2)-pdt)].Novel triiron compounds,featuring sterically crowded dithiolate bridges(pdt^(Et_(2)),pdt^(Bn_(2))),were spectroscopically and structurally characterized.Their protonation and redox behaviours are discussed.The effect of the dithiolate bridges on the electrochemical properties(oxidation and reduction)of the complexes[Fe_(3)(CO)_(5)(κ^(2)-dppe)(μ-xdt)(μ-pdt)]has been examined by cyclic voltammetry and rationalized by DFT calculations.Studies on the protonation of these species and their proton reduction behaviour were considered.展开更多
Although great progress has been made in improving hydrogen production,highly efficient catalysts,which are able to produce hydrogen in a fast and steady way at ambient temperature and pressure,are still in large dema...Although great progress has been made in improving hydrogen production,highly efficient catalysts,which are able to produce hydrogen in a fast and steady way at ambient temperature and pressure,are still in large demand.Here,we report a[NiCo]-based hydrogenase mimic,NiCo_(2)O_(4) nanozyme,that can catalyze robust hydrogen evolution spontaneously in water without external energy input at room temperature.This hydrogenase nanozyme facilitates water splitting reaction by forming a three-center Ni-OH-Co bond analogous to the[NiFe]-hydrogenase reaction by using aluminum as electron donor,and realizes hydrogen evolution with a high production rate of 915 L·h^(-1) per gram of nanozymes,which is hundreds of times higher than most of the natural hydrogenase or hydrogenase mimics.Furthermore,the NiCo_(2)O_(4) nanozyme can robustly disrupt the adhesive oxidized layer of aluminum and enable the full consumption of electrons from aluminum.In contrast to the often-expensive synthetic catalysts that rely on rare elements and consume high energy,we envision that this NiCo_(2)O_(4) nanozyme can potentially provide an upgrade for current hydrogen evolution,accelerate the development of scale-up hydrogen production,and generate a clean energy future.展开更多
Production of hydrogen from water by solar-energy conversion has long been considered a promising way to solve the climate change and energy crisis(1)However,some critical issues at this stage,such as catalysts for hy...Production of hydrogen from water by solar-energy conversion has long been considered a promising way to solve the climate change and energy crisis(1)However,some critical issues at this stage,such as catalysts for hydrogen evolution with high efficiency and low cost,definitely hinder the practical application of photocatalytic hydrogen production from water.[Fe Fe]-hydrogenase,an excellent natural biological enzyme catalyst bearing unique organometallic clusters with noble-metal-free element,is most efficient in reducing protons to hydrogen and demonstrates remarkable turnover frequencies(TOF 6000–9000 s1 per active site)[2].展开更多
文摘A compound containing[FeFe]‑hydrogenase,[Fe_(2)((SCH_(2))_(2)R)(CO)_(6)](1)(R=4‑{(1H‑benzo[d]imidazol‑1‑yl)methyl}‑anilino),was prepared and thoroughly characterized by infrared spectroscopy,single‑crystal X‑ray diffraction,and density functional theory calculations.Its performance as a photocatalyst for hydrogen production via water splitting was evaluated under simulated sunlight.Within 3 h,the amount of H_(2)produced was 386.5μmol,achieving a catalytic efficiency of 25.26μmol·mg^(-1)·h^(-1)and a turnover number(TON)of 0.45.CCDC:2457448.
基金(in part) A Grant-in Aid for International Scientifi c ResearchSpecial Cancer Research from the Ministry of Education, Science, Sports, Culture and Technology of Japan, No. 11137311Major International (Regional) Joint Research Projects from the National Natural Science Foundation of China (NSFC), No. 30320140461
文摘AIM: To evaluate the relationship between drinking and polymorphisms of alcohol dehydrogenase 2 (ADH2) and/or aldehyde dehydrogenase 2 (ALDH2) for risk of colorectal cancer (CRC) in Chinese males. METHODS: A case-control study was conducted in 190 cases and 223 population-based controls. ADH2 Arg47His (G-A) and ALDH2 Glu487Lys (G-A)genotypes were identified by PCR and denaturing high-performance liquid chromatography (DHPLC). Information on smoking and drinking was collected and odds ratio (OR) was estimated. RESULTS: The ADH2 A/A and ALDH2 G/G genotypes showed moderately increased CRC risk. The age- and smoking-adjusted OR for ADH2 A/A relative to G/A and G/G was 1.60 (95% CI=1.08-2.36), and the adjusted OR for ALDH2 G/G relative to G/A and A/A was 1.79 (95% CI=1.19-2.69). Signif icant interactions between ADH2, ALDH2 and drinking were observed. As compared to the subjects with ADH2 G and ALDH2 A alleles, those with ADH2 A/A and ALDH2 G/G genotypes had a signif icantly increased OR (3.05, 95% CI= 1.67-5.57). The OR for CRC among drinkers with the ADH2 A/A genotype was increased to 3.44 (95% CI= 1.84-6.42) compared with non-drinkers with the ADH2 G allele. The OR for CRC among drinkers with the ALDH2 G/G genotype was also increased to 2.70 (95% CI= 1.57-4.66) compared with non-drinkers with the ALDH2 A allele. CONCLUSION: Polymorphisms of the ADH2 and ALDH2 genes are significantly associated with CRC risk. There are also signifi cant gene-gene and gene- environment interactions between drinking and ADH2 and ALDH2 polymorphisms regarding CRC risk in Chinese males.
基金supported by the National Natural Science Foundation of China(21103121,21276187)Tianjin Municipal Natural Science Foundation(13JCQNJC05800)the Specialized Research Fund for the Doctoral Program of Higher Education(20121317110009)~~
文摘Two mono iron complexes Fe（CO）2PR3（NN） （R = Cy （3）, Ph （4）, NN = o-phenylenediamine dianion ligand, N2H2Ph2-） derived from the ligand substitution of Fe（CO）3hPR3 by the NN ligand were isolated and structurally characterized by single crystal X-ray diffraction. They have a similar first coordination sphere and oxidation state of the iron center as the [Fe]-hydrogenase active site, and can be a model of it IR demonstrated that the effect of the NN ligand on the coordinated CO stretch- ing frequencies was due to its excellent electron donating ability. The reversible protonation/deprotonation of the NN ligand was identified by infrared spectroscopy and density functional theory computation. The NN ligand is an effective proton acceptor as the internal base of the cysteine thiolate ligand in [Fe]-hydrogenase. The electrochemical properties of complexes 3, 4 were investigated by cyclic voltammograms. Complex 3 catalyzed the transfer hydrogenation of benzoquinone to hydroquinone effectively under mild conditions.
基金supported by the National Key Research and Development Program of China (Nos. 2020YFA0907300, 2020YFA0907800)the National Natural Science Foundation of China (No. 22077069)+1 种基金the Natural Science Foundation of Tianjin (Nos. 19JCZDJC33400 and 21JCYBJC00310)the Fundamental Research Funds for the Central Universities, Nankai University (No. 63201111)。
文摘Hydrogenase is a paradigm of highly efficient biocatalyst for H_(2) production and utilization evolved in nature. A dilemma is that despite the high activity and efficiency expected for hydrogenases as promising catalysts for the hydrogen economy, the poor oxygen tolerance and low yield of hydrogenases largely hinder their practical application. In these years, the enigmas surrounding hydrogenases regarding their structures, oxygen tolerance, mechanisms for catalysis, redox intermediates, and proton-coupled electron transfer schemes have been gradually elucidated;the schemes, which can well couple hydrogenases with other highly efficient(in)organic and biological catalysts to build novel reactors and drive valuable reactions, make it possible for hydrogenases to find their niches. To see how scientists put efforts to tackle this issue and design novel reactors in the fields where hydrogenases play crucial roles, in this review,recent advances were summarized, including different strategies for protecting enzyme molecules from oxygen, enzyme-based assembling systems for H_(2) evolution in the photoelectronic catalysis, enzymatic biofuel cells for H_(2) utilization and storage and the efficient electricity-hydrogen-carbohydrate cycle for high-purity hydrogen and biofuel automobiles. Limitations and future perspectives of hydrogenasebased applications in H_(2) production and utilization with great impact are discussed. In addition, this review also provides a new perspective on the use of biohydrogen in healthcare beyond energy.
文摘Photocatalytic reduction of CO2 to CO is a promising approach for storing solar energy in chemicals and mitigating the greenhouse effect of CO2.Our recent studies revealed that[(μ-bdt)Fe2(CO)6](1,bdt=benzene-1,2-dithiolato),a[FeFe]-hydrogenase model with a rigid and conjugate S-to-S bridge,was catalytically active for the selective photochemical reduction of CO2 to CO,while its analogous complex[(μ-edt)Fe2(CO)6](2,edt=ethane-1,2-dithiolato)was inactive.In this study,it was found that the turnover number of 1 for CO evolution reached 710 for the 1/[Ru(bpy)3]2+/BIH(BIH=1,3-dimethyl-2-phenyl-2,3-dihydro-1H-benzo[d]-imidazole)system under optimal conditions over 4.5 h of visible-light irradiation,with a turnover frequency of 7.12 min−1 in the first hour,a high selectivity of 97%for CO,and an internal quantum yield of 2.8%.Interestingly,the catalytic selectivity of 1 can be adjusted and even completely switched in a facile manner between the photochemical reductions of CO2 to CO and of protons to H2 simply by adding different amounts of triethanolamine to the catalytic system.The electron transfer in the photocatalytic system was studied by steady-state fluorescence and transient absorption spectroscopy,and a plausible mechanism for the photocatalytic reaction was proposed.
文摘A component （s-factor） with obvious promoting effect on hydrogen evolution of hydrogenase has beenisolated and extracted from a Cell=free preparation of Spirulina platensis.The effect of the s-factor in the re-action system is similar to that of Na<sub>2</sub>S<sub>2</sub>O<sub>4</sub>, but is coupled with ligh. The s-factor has the maximumabsorption peak at 620 nm in the oxidized state, at 590 nm in the reduced state. The partially purifieds-factor showed two bands by SDS-PAGE and is distinctly different from phycocyanin,which has nochange of oxidized state and reduced state absorption spectra, and also has no promoting effect onhydrogenase of Spirulina platensis under the light.
基金supported by National Natural Science Foundation of China(Nos.21773184,21671158 and 21601164)Natural Science Foundation of Henan(No.162300410052)Key Science and Technology Project of Henan(No.172102310137)。
文摘Structural and functional biomimicking of the active site of [NiFe]-hydrogenases can provide helpful hints for designing bioinspired catalysts to replace the expensive noble metal catalysts for H2 generation and uptake.Treatment of dianion [Ni(phma)]2-[H4 phma=N,N’-1,2-phenylenebis(2-mercaptoacetamide)] with [NiCl2(dppp)](dppp=bis(diphenylphosphino)propane) yielded a dinickel product[Ni(phma)(μ-S,S’)Ni(dppp)](1) as the model complex relevant to the active site of [NiFe]-H2 ases.The structure of complex 1 has been characterized by single-crystal X-ray analysis.From cyclic voltammetry and controlled potential electrolysis studies,complex 1 was found to be a moderate electrocatalyst for the H2-evoluting reaction using ClCH2COOH as the proton source.
基金the NEDO＇s International Joint Research Grant Program and the National Science Foundation of China （No. 20573025） for the financial supports.
文摘Hydrogen evolution was detected in an artificial system composed of light-harvesting unit of purified photosystem I, catalyst of hydrogenase, methyl viologen and electron donor under radiation. Absorption spectral features confirmed that electron transfer from electron donors to proton was via a photoinduced reductive process of methyl viologen.
基金Sponsored by the the National High Technology Research and Development Program of China(Grant No.2006AA05Z109)Harbin Municipal Scienceand Technology Innovation Talents of Special Fund Projects(Grant No.2009RFXXS004)
文摘In order to evaluate the hydrogen-producing efficiency of anaerobic activated sludge in Anaerobic Baffled Reactor(ABR)fermentation processes,the optimal conditions for hydrogen producing hydrogenase method on methyl viologen(MV)assay was used to detect the hydrogen production activity of the activated sludge.The most favorable parameters such as 0.6 mL sodium acetate buffer(pH 5.0),100 μL lysozyme,0.2 mL sodium dibromoethane(9.0 mmol/L)and 0.7 mmol/L iron added into 1 mL activated sludge(2.66～26.64 gMLVSS/L)were found.Furthermore,reaction temperature and culture time were detected as 40 ℃ and 30 min respectively.Sodium thiosulfate and sodium sulfides were taken as the reducing agent while trichloroacetic acid as terminator.Under the MV optimal conditions,micro-toxic Dimethyl sulfoxide(DMSO)get higher security and better accuracy.The sensitivity of the detection methods(DMSO as electron carrier)was increased by more than 30%.The results show that the optimal conditions can be applied to measure hydrogenase activity correlating with its specific hydrogen production rate in a hydrogen-producing anaerobic activated sludge system.
基金Sponsored by the Chinese Postdoctoral Science Foundation(Grant No.20070420861)the Heilongjiang Postdoctoral Fund(Grant No.LBH-Z07115)the National Natural Science Foundation of China(Grant No.31101316)
文摘A comparative evaluation of three different cell-disruption methods for the release of hydrogenase from H2 -producing bacterium E. harbinenase YUAN-3T was investigated. The cell disruption techniques evaluated in this study were uhrasonieation, high-speed homogenization and bead milling. Ultrasonication process was found to be the most effective method in terms of cell disruption. As for the specific activity of hydrogenase, there is no significant difference among the three kinds of methods. An orthogonal experiment L9 （34） was designed to optimize the procedures of ultrasonication for cell disruption. The optimized uhrasonication disruption conditions were the treatment at 250 W, 20 kHz, 30 s/15 s and 0. 30 g bacteria cell （dry weight） in 15 mL suspension buffer. As a result, the optimized conditions allow the hydrogenase to maintain the active form with the yield of 93.95 mg protein/g cell and the final activity of 0. 252 μmol/min/mg protein. In this work, we have developed and optimized an ultrasonication protocol for YUAN-3T cel]s, which is adapted to laboratory- scale release of hydrogenase proteins.
基金This project was supported by the NNSFC (No. 20471061) and the Science & Technology Innovation Foundation for the Young Scholar of Fujian Province (No. 2005J059)
文摘A model compound for the active sites of Fe-only hydrogenases, [Fe2（SCH2）2N（3- PhCF3）（CO）6]2, has been synthesized and structurally characterized by single-crystal X-ray diffraction. It crystallizes in tetragonal, space group P43, with α = 12.6324（3）, b = 12.6324（3）, c = 24.0453（12） A, V = 3837.1（2） A^3, Z= 4, Fe4S4N2C30O12F6H16, Mr= 1062.09, Dc= 1.839 g/cm^3, μ（MoKα） = 1.791 mm^-1, F（000） = 2112, T= 293（2） K, Flack = 0.034（9）, R = 0.0282 and wR = 0.0685 for 8148 observed reflections with I 〉 20（I）. In the title compound, each Fet atom is coordinated by three terminal carbonyl C atoms （Fe-C： 1.783（3）- 1.816（3） A）, two bridging S atoms （Fe-S： 2.2609（7）-2.2757（8） A） and another Fe atom （Fe-Fe 2.5011（5） A）, adopting a distorted octahedral geometry with trans angles ranging from 152.45（11） to 157.77（10）°.
基金supported by the NNSFC(Nos.21231003 and 21203195)
文摘A new five-heterocyclic-biphosphine-substituted Fe-only hydrogenase mimic,[（μ-pdt）Fe_2（CO）_5]_2（PTP）（1）,has been synthesized at room temperature. 1·H_2O crystallizes in triclinic system,space group P1,with a = 11.5897（4）,b = 13.6156（4）,c = 18.0333（6） ？,α = 76.306（3）,β = 72.742（3）,γ = 68.939（3）°,V = 2508.84（14） ？~3,Dc = 1.570 g/cm3,Z = 2,M_r = 1186.37,F（000） = 1204,the final R = 0.0748,and wR = 0.2012. In the tetranuclear complex 1·H_2O,each [2Fe_2S] butterfly unit is attached to one P atom of the diphosphine bridge and exhibits a square-pyramidal geometry. Complex 1 was characterized by elemental analysis,IR spectra,UV-vis absorption spectra,~1H-NMR and ^（31）P-NMR. The cyclic voltammetry behavior of compound 1 was investigated as well.
基金grants PID2019-108429RB-I00 and RED2018-102387-T from the MCI(Spain)is gratefully acknowledged.M.A.S.thanks the Fundación Ramón Areces for a grant from the XVIII Concurso Nacional de Ayudas a la Investigación(CIVP18A3938)。
文摘Hydrogen production is key to carbon-free energy production and the use of hydrogenases is an excellent approach for this achievement since they produce hydrogen with extraordinary efficiencies.However,these enzymes have several shortcomings,which may be resolved using hydrogenase mimics.The design and synthesis of these mimics is a very active area of research,and the understanding of the mode of the action of mimics is particularly relevant to the future design of robust and productive catalysts.In this review,we discuss the role of isotopes(mainly deuterium)in disentangling key steps of the mechanisms of H2 activation by mimics of hydrogenases.Through selected examples,we focus on the key aspects of processes that,in many cases,have allowed a better understanding of the mode of action of the natural enzymes,making a valuable contribution to the design of more efficient complexes for the production of hydrogen.
基金Support for this work from the Ministerio de Ciencia,Innovación y Universidades(Grants PID2022-139177OB-I00 and RED2022-134287-T)is acknowledgedrecipient of an FPU fellowship(FPU16/02062).
文摘Mimics of [FeFe]-hydrogenases having two [(μ-adt)Fe_(2)(CO)_(6)] moieties linked through 1,2,3-triazole ringswith polyethylene glycol (PEG) chains [(-OCH_(2)CH_(2)O-)4 (7) and (-OCH_(2)CH_(2)O-)5 (8)] are able to coordinateto alkali ions (Na^(+), K^(+)) via the O-PEG atoms and the triazole-N3 positions. Electrocatalytic studies intrifluoroacetic acid (TFA) demonstrate that their catalytic performance is affected by the presence of Na+and K+ salts. The addition of NaPF6 decreases the electrocatalytic activity of 7 and 8 (about 50% reductionof the TOF values). As, in TFA, 7 and 8 could be protonated in both the triazole and adt-amino groups, thereduction in TOF values suggests that NaPF6 inhibits the contribution of the triazolium species to theelectrocatalytic process, likely due to the involvement of the triazole-N3 positions in Na^(+) binding.However, the addition of KPF_(6) either does not change (7) or increases the TOF values (8). ^(1)H NMR titrationexperiments demonstrate that, despite the presence of K^(+) ions in the media, triazolium salts are formed.Therefore, the TOF values should reflect the contribution of species protonated in both the triazole andadt-amino groups to the HER process.
基金the Natural Science Foundation of Shandong Province(No.ZR2020MB019)Introduction and Cultivation Project for Young Innovative Talents in Shandong Provincial Colleges and Universities for financial support.
文摘In this study,we present a convenient method to obtain two types of novel tetra-substituted Fe/Se salts through a dehalogenation reaction,aiming to advance research on mimicking the FeⅡFeⅡ oxidation state of[FeFe]-H_(2) ases.Initially,by treating[Fe_(2)(μ-SeBn)_(2)(CO)_(4)(dppv)](Bn=CH_(2)C_(6)H_(5),dppv=cis-1,2-bis(diphenylphosphino)ethylene)with one equivalent of dppv under UV and reflux conditions,the neutral FeIFeI and FeⅡFeⅡ precursors[Fe_(2)(μ-SeBn)_(2)(CO)_(2)(dppv)_(2)](1)and[Fe_(2)(μ-SeBn)_(2)(μ-Se)(CO)_(2)(dppv)_(2)](2)were successfully isolated in good yields.Subsequently,1 underwent dehalogenation reactions with halocarbons(such as CCl_(4) and CBr4)or I_(2),leading to the formation of tetra-substituted salts[Fe_(2)(μ-SeBn)_(2)(μ-X)(CO)_(2)(dppv)_(2)]+(X=Cl,Br,and I)([3]Cl,[4]Br and[5]I_(3)).GC-MS analysis of the reaction with carbon tetrachloride detected the formation of the homo-coupled product CCl_(3)-CCl_(3)(m/z=235),indicating the presence of a CCl_(3)·species.Notably,2 also exhibited intriguing reactivity with R-X and I_(2).Unlike 1,the reaction of 2 with RX or I_(2) involved cleavage of the C-Se bond,leading to the isolation of[Fe_(2)(μ-SeBn)(μ-Se_(2))(CO)_(2)(dppv)_(2)]+X-(X=Cl,Br,I_(3))([6]Cl,[6]Br and[6]I_(3))in good yields.The reaction involved debenzylation of 2 and was confirmed by GC-MS detection of C6H5CH_(2)CCl_(3)(m/z=208)in the reaction with CCl_(4),suggesting a radical pathway.
基金CNRS(Centre National de la Recherche Scientifique),the University of Brest,and the University of Milano-Bicocca are acknowledged for financial support。
文摘A series of triiron clusters[Fe_(3)(CO)_(5)(κ^(2)-dppe)(μ-pdt^(R_(2)))(μ-pdt)]featuring different combinations of dithiolate bridges have been prepared by using dinuclear and mononuclear precursors,[Fe_(2)(CO)_(6)(μ-xdt)](xdt=pdt,pdt^(Et_(2)),pdt^(Bn_(2)),adt^(Bn))and[Fe(CO)_(2)(κ^(2)-dppe)(κ^(2)-pdt)].Novel triiron compounds,featuring sterically crowded dithiolate bridges(pdt^(Et_(2)),pdt^(Bn_(2))),were spectroscopically and structurally characterized.Their protonation and redox behaviours are discussed.The effect of the dithiolate bridges on the electrochemical properties(oxidation and reduction)of the complexes[Fe_(3)(CO)_(5)(κ^(2)-dppe)(μ-xdt)(μ-pdt)]has been examined by cyclic voltammetry and rationalized by DFT calculations.Studies on the protonation of these species and their proton reduction behaviour were considered.
基金supported by the National Natural Science Foundation of China(Nos.T2225026,82172087,22025604,82071308,52202344)the National Key R&D Program of China(No.2022YFA120012501)Beijing Institute of Technology Research Fund Program for Young Scholars.
文摘Although great progress has been made in improving hydrogen production,highly efficient catalysts,which are able to produce hydrogen in a fast and steady way at ambient temperature and pressure,are still in large demand.Here,we report a[NiCo]-based hydrogenase mimic,NiCo_(2)O_(4) nanozyme,that can catalyze robust hydrogen evolution spontaneously in water without external energy input at room temperature.This hydrogenase nanozyme facilitates water splitting reaction by forming a three-center Ni-OH-Co bond analogous to the[NiFe]-hydrogenase reaction by using aluminum as electron donor,and realizes hydrogen evolution with a high production rate of 915 L·h^(-1) per gram of nanozymes,which is hundreds of times higher than most of the natural hydrogenase or hydrogenase mimics.Furthermore,the NiCo_(2)O_(4) nanozyme can robustly disrupt the adhesive oxidized layer of aluminum and enable the full consumption of electrons from aluminum.In contrast to the often-expensive synthetic catalysts that rely on rare elements and consume high energy,we envision that this NiCo_(2)O_(4) nanozyme can potentially provide an upgrade for current hydrogen evolution,accelerate the development of scale-up hydrogen production,and generate a clean energy future.
文摘Production of hydrogen from water by solar-energy conversion has long been considered a promising way to solve the climate change and energy crisis(1)However,some critical issues at this stage,such as catalysts for hydrogen evolution with high efficiency and low cost,definitely hinder the practical application of photocatalytic hydrogen production from water.[Fe Fe]-hydrogenase,an excellent natural biological enzyme catalyst bearing unique organometallic clusters with noble-metal-free element,is most efficient in reducing protons to hydrogen and demonstrates remarkable turnover frequencies(TOF 6000–9000 s1 per active site)[2].
