Due to high penetration,low photo-toxicity,and low background signal of red-shifted visible light,the development of visible-light photochromic materials is of great importance but still a challenging task.In this stu...Due to high penetration,low photo-toxicity,and low background signal of red-shifted visible light,the development of visible-light photochromic materials is of great importance but still a challenging task.In this study,four one-dimensional(1D)naphthalenediimide(NDI)photochromic coordination polymers(CPs),namely{[ZnCl_(2)(4-PMNDI)]·H_(2)O}_(n)(1),{[ZnBr_(2)(4-PMNDI)]·2H_(2)O}_(n)(2),{[ZnCl_(2)(3-PMNDI)]}_(n)(3)and{[ZnBr_(2)(3-PMNDI)]}_(n)(4)(4-/3-PMNDI=N,N’-bis(4-/3-pyridylmethyl)-1,4,5,8-naphthalenediimide),have been designed and synthesized by the combination of positional isomeric electron-deficient PMNDI(electron acceptors,EAs)and electron-rich zinc halides(electron donors,EDs)under solvothermal conditions.The distinct photochromic properties of 1-4 should be attributed to the formation of different interfacial contacts of EDs/EAs due to the introduction of 4-/3-PMNDI positional isomers and different halogen anions.Noteworthily,the much more rapid photoresponsive rates of visible-light photochromism for 1-4 with respect to those of UV-light photochromism exposits that the electronic absorption band of charge transfer(CT)interactions in the visible light region can effectively trigger electron transfer(ET)promptly.Furthermore,1 exhibits a high photosensitivity property in response to wavelengths of 390-450 nm,and it can be applied in detection/filtration of harmful blue rays.This work breaks through an orthodox concept that the ET reaction can only be activated by the electronic absorption band of EDs or EAs(usually in the UV light region),and provides a simple and feasible method for the construction of visible-light photochromic materials.展开更多
β-nicotinamide mononucleotide(β-NMN)is a bioactive nucleotide that indirectly affects various cellular metabolic pathways,and has tremendous potential in the food,pharmaceutical,and cosmetics industries.In the prese...β-nicotinamide mononucleotide(β-NMN)is a bioactive nucleotide that indirectly affects various cellular metabolic pathways,and has tremendous potential in the food,pharmaceutical,and cosmetics industries.In the present study,a multi-enzymatic cascade biocatalyst for the efficient synthesis ofβ-NMN was established.First,the optimal ribokinase gene was selected to construct a biocatalyst in a lower-endotoxin-level Escherichia coli strain to produce NMN from D-ribose.After fine-tuning the gene expression of the three cascade enzymes(RK/PRS/NAMPT),the production of NMN improved to 3.14 g/L.Next,the functions of membrane transporters that import NAM and export NMN were verified for NMN biosynthesis.Through the introduction of an ATP regeneration system,a drastic improvement in NMN biosynthesis at a yield of 8.74 g/L was achieved.The degradation of NMN and NAM in the bioconversion system was further inhibited after systematic modification of the related metabolic pathways.Finally,by incorporating two more copies of the key enzyme NAMPT and one copy of pyrophosphatase involved in inorganic pyrophosphate hydrolysis into the genome of the biocatalyst,the titer of NMN reached 12.2 g/L,with a molar conversion ratio of 98.7%from nicotinamide.This result provides an efficient and economical approach for producing NMN on an industrial scale.展开更多
Dear Editor,The occurrence of concentrated pneumonia cases in Wuhan city,Hubei province of China was first reported on December 30,2019 by the Wuhan Municipal Health Commission(WHO,2020).The pneumonia cases were found...Dear Editor,The occurrence of concentrated pneumonia cases in Wuhan city,Hubei province of China was first reported on December 30,2019 by the Wuhan Municipal Health Commission(WHO,2020).The pneumonia cases were found to be linked to a large seafood and animal market in Wuhan,and measures for sanitation and disinfection were taken swiftly by the local government agency.The Centers for Disease Control and Prevention(CDC)and Chinese health authorities later determined and announced that a novel coronavirus(CoV),denoted as 2019-nCoV,had caused the pneumonia outbreak in Wuhan city(CDC,2020).Scientists from multiple groups had obtained the virus samples from hospitalized patients(Normile,2020).The isolated viruses were morphologically identical when observed under electron microscopy.展开更多
Background:Arsenic has a broad anti-cancer ability against hematologic malignancies and solid tumors.To systematically understand the biological functions of arsenic,we need to identify arsenic-binding proteins in hum...Background:Arsenic has a broad anti-cancer ability against hematologic malignancies and solid tumors.To systematically understand the biological functions of arsenic,we need to identify arsenic-binding proteins in human cells.However,due to lack of effective theoretical tools and experimental methods,only a few arsenic-binding proteins have been identified.Methods:Based on the crystal structure of ArsM,we generated a single mutation free energy profile for arsenic binding using free energy perturbation methods.Multiple validations provide an indication that our computational model has the ability to predict arsenic-binding proteins with desirable accuracy.We subsequently apply this computational model to scan the entire human genome to identify all the potential arsenic-binding proteins.Results:The computationally predicted arsenic-binding proteins show a wide range of biological functions,especially in the signaling transduction pathways.In the signaling transduction pathways,arsenic directly binds to the key factors(e.g.,Notch receptors,Notch ligands,Wnt family proteins,TGF-beta,and their interacting proteins)and results in significant inhibitions on their enzymatic activities,further having a crucial impact on the related signaling pathways.Conclusions:Arsenic has a significant impact on signaling transduction in cells.Arsenic binding to proteins can lead to dysfunctions of the target proteins,having crucial impacts on both signaling pathway and gene transcription.We hope that the computationally predicted arsenic-binding proteins and the functional analysis can provide a novel insight into the biological functions of arsenic,revealing a mechanism for the broad anti-cancer of arsenic.展开更多
基金supported by the National Natural Science Foundation of China(21171110)the Natural Science Foundation of Science and Technology Agency of Shanxi Province(20210302123324,201901D111275)+1 种基金the Graduate Education Innovation Project of Shanxi Province(2024XBY05)the 1331 Project of Shanxi Province.
文摘Due to high penetration,low photo-toxicity,and low background signal of red-shifted visible light,the development of visible-light photochromic materials is of great importance but still a challenging task.In this study,four one-dimensional(1D)naphthalenediimide(NDI)photochromic coordination polymers(CPs),namely{[ZnCl_(2)(4-PMNDI)]·H_(2)O}_(n)(1),{[ZnBr_(2)(4-PMNDI)]·2H_(2)O}_(n)(2),{[ZnCl_(2)(3-PMNDI)]}_(n)(3)and{[ZnBr_(2)(3-PMNDI)]}_(n)(4)(4-/3-PMNDI=N,N’-bis(4-/3-pyridylmethyl)-1,4,5,8-naphthalenediimide),have been designed and synthesized by the combination of positional isomeric electron-deficient PMNDI(electron acceptors,EAs)and electron-rich zinc halides(electron donors,EDs)under solvothermal conditions.The distinct photochromic properties of 1-4 should be attributed to the formation of different interfacial contacts of EDs/EAs due to the introduction of 4-/3-PMNDI positional isomers and different halogen anions.Noteworthily,the much more rapid photoresponsive rates of visible-light photochromism for 1-4 with respect to those of UV-light photochromism exposits that the electronic absorption band of charge transfer(CT)interactions in the visible light region can effectively trigger electron transfer(ET)promptly.Furthermore,1 exhibits a high photosensitivity property in response to wavelengths of 390-450 nm,and it can be applied in detection/filtration of harmful blue rays.This work breaks through an orthodox concept that the ET reaction can only be activated by the electronic absorption band of EDs or EAs(usually in the UV light region),and provides a simple and feasible method for the construction of visible-light photochromic materials.
基金supported by grant from the National Natural Science Foundation of China(Grant No.22377012).
文摘β-nicotinamide mononucleotide(β-NMN)is a bioactive nucleotide that indirectly affects various cellular metabolic pathways,and has tremendous potential in the food,pharmaceutical,and cosmetics industries.In the present study,a multi-enzymatic cascade biocatalyst for the efficient synthesis ofβ-NMN was established.First,the optimal ribokinase gene was selected to construct a biocatalyst in a lower-endotoxin-level Escherichia coli strain to produce NMN from D-ribose.After fine-tuning the gene expression of the three cascade enzymes(RK/PRS/NAMPT),the production of NMN improved to 3.14 g/L.Next,the functions of membrane transporters that import NAM and export NMN were verified for NMN biosynthesis.Through the introduction of an ATP regeneration system,a drastic improvement in NMN biosynthesis at a yield of 8.74 g/L was achieved.The degradation of NMN and NAM in the bioconversion system was further inhibited after systematic modification of the related metabolic pathways.Finally,by incorporating two more copies of the key enzyme NAMPT and one copy of pyrophosphatase involved in inorganic pyrophosphate hydrolysis into the genome of the biocatalyst,the titer of NMN reached 12.2 g/L,with a molar conversion ratio of 98.7%from nicotinamide.This result provides an efficient and economical approach for producing NMN on an industrial scale.
基金This work was supported in part by grants from the National Science and Technology Major Projects for“Major New Drugs Innovation and Development”(directed by Dr.Song Li)(2018ZX09711003)of Chinathe National Key R&D Program(2018YFC0310600)of China+1 种基金the National Natural Science Foundation of China(31771412)Special Fund for strategic bio-resources from Chinese Academy of Sciences(ZSYS-014).
文摘Dear Editor,The occurrence of concentrated pneumonia cases in Wuhan city,Hubei province of China was first reported on December 30,2019 by the Wuhan Municipal Health Commission(WHO,2020).The pneumonia cases were found to be linked to a large seafood and animal market in Wuhan,and measures for sanitation and disinfection were taken swiftly by the local government agency.The Centers for Disease Control and Prevention(CDC)and Chinese health authorities later determined and announced that a novel coronavirus(CoV),denoted as 2019-nCoV,had caused the pneumonia outbreak in Wuhan city(CDC,2020).Scientists from multiple groups had obtained the virus samples from hospitalized patients(Normile,2020).The isolated viruses were morphologically identical when observed under electron microscopy.
基金This work was supported by the National Key R&D Program of China(Nos.2016YFC0901704 and 2017YFA0505500)National High-Tech R&D Program(863 Program,No.2015AA020105)+2 种基金the National Natural Science Foundation of China(Nos.21377085 and 31770070)MOE New Century Excellent Talents in University(No.NCET-12-0354)SJTU Med-Eng Joint Program(No.YG2016MS33)for financial supports.
文摘Background:Arsenic has a broad anti-cancer ability against hematologic malignancies and solid tumors.To systematically understand the biological functions of arsenic,we need to identify arsenic-binding proteins in human cells.However,due to lack of effective theoretical tools and experimental methods,only a few arsenic-binding proteins have been identified.Methods:Based on the crystal structure of ArsM,we generated a single mutation free energy profile for arsenic binding using free energy perturbation methods.Multiple validations provide an indication that our computational model has the ability to predict arsenic-binding proteins with desirable accuracy.We subsequently apply this computational model to scan the entire human genome to identify all the potential arsenic-binding proteins.Results:The computationally predicted arsenic-binding proteins show a wide range of biological functions,especially in the signaling transduction pathways.In the signaling transduction pathways,arsenic directly binds to the key factors(e.g.,Notch receptors,Notch ligands,Wnt family proteins,TGF-beta,and their interacting proteins)and results in significant inhibitions on their enzymatic activities,further having a crucial impact on the related signaling pathways.Conclusions:Arsenic has a significant impact on signaling transduction in cells.Arsenic binding to proteins can lead to dysfunctions of the target proteins,having crucial impacts on both signaling pathway and gene transcription.We hope that the computationally predicted arsenic-binding proteins and the functional analysis can provide a novel insight into the biological functions of arsenic,revealing a mechanism for the broad anti-cancer of arsenic.
