Different materials,such as metal sulphides,are often combined with metal‐organic frameworks(MOFs)to develop multi‐functional composites and improve their photocatalytic properties.However,the high interfacial energ...Different materials,such as metal sulphides,are often combined with metal‐organic frameworks(MOFs)to develop multi‐functional composites and improve their photocatalytic properties.However,the high interfacial energy barrier limits the formation and nano‐assembly of the heterogeneous junctions between MOFs and metal sulphides.Herein,the heterostructured Zr‐MOF‐S@CdS are successfully constructed through a sequential synthesis method,in which the mesoporous Zr‐MOF are firstly decorated with thioglycolic acid through pore functionalization,and followed by the S^(2-)anion exchange process resulting in the surface close attached growth of CdS onto Zr‐MOF‐S materials.Due to the presence of molecules linkers,the CdS can be precisely decorated onto Zr‐MOF‐S without aggregation,which can provide more active sites.Moreover,the intimate connections and the suitable band structures between two materials can also facilitate the photogenerated electron‐hole pairs separation.Therefore,the resulting Zr‐MOF‐S@CdS with appropriate ratio exhibits high photocatalytic activity for water reduction,in which the H_(2) evolution rate can reach up to 1861.7μmol·g^(‒1)·h^(‒1),4.5 times higher than pure CdS and 2.3 times higher than of Zr‐MOF/CdS,respectively.Considering the promising future of MOF‐based photocatalysts,this work may provide an avenue for the further design and synthesis MOF‐based composite photocatalysts for efficient H_(2) evolution.展开更多
An efficient genetic transformation system and suitable promoters are essential prerequisites for gene expression studies and genetic engineering in streptomycetes.In this study,firstly,a genetic transformation system...An efficient genetic transformation system and suitable promoters are essential prerequisites for gene expression studies and genetic engineering in streptomycetes.In this study,firstly,a genetic transformation system based on intergeneric conjugation was developed in Streptomyces rimosus M527,a bacterial strain which exhibits strong antagonistic activity against a broad range of plant-pathogenic fungi.Some experimental parameters involved in this procedure were optimized,including the conjugative media,ratio of donor to recipient,heat shock temperature,and incubation time of mixed culture.Under the optimal conditions,a maximal conjugation frequency of 3.05^10-5 per recipie nt was obtai ned.Subseque ntly,based on the above developed and optimized tran sformati on system,the synthetic promoters SPL-21 and SPL-57,a native promoter potrB,and a constitutive promoter permE commonly used for gene expression in streptomycetes were selected and their activity was analyzed using gusA as a reporter gene in S.rimosus M527.Among the four tested promoters,SPL-21 exhibited the strongest expression activity and gave rise to a 2.2-fold increase in p-glucuronidase(GUS)activity compared with the control promoter permE.Promoter SPL-57 showed activity comparable to that of permE.Promoter potrB,which showed the lowest activity,showed a 50%decrease in GUS activity compared with the control permE.The transformation system developed in this study and the tested promotors provide a basis for the further modification of S.rimosus M527.展开更多
Transthyretin(TTR),a plasma protein with a tetramer structure,could form amyloid fibril associated with several human diseases through the dissociation of tetramer and the misfolding of monomer.These amyloidogenesis c...Transthyretin(TTR),a plasma protein with a tetramer structure,could form amyloid fibril associated with several human diseases through the dissociation of tetramer and the misfolding of monomer.These amyloidogenesis can be inhibited by small molecules which bind to the central channel of TTR.A number of small molecules like 2-arylbenzoxazoles(ABZ)analogues are proposed as promising therapeutic strategy to treat amyloidosis.In this work,comparative molecular field analysis(CoMFA)and comparative molecular similarity indices analysis(CoMSIA)three-dimensional quantitative structure-activity relationship(3D-QSAR)and docking studies were performed on series of 2-arylbenzoxazoles(ABZ)and linker-Y analogues to investigate the inhibitory activities of TTR amyloidogenesis at atomic level.Significant correlation coefficients for ABZ series(CoMFA,r2=0.877,q2=0.431;CoMSIA,r2=0.836,q2=0.447)and those for linker-Y series(CoMFA,r2=0.828,q2=0.522;CoMSIA,r2=0.800,q2=0.493)were obtained,and the generated models were validated using test sets.In addition,docking studies on 6 compounds binding to TTR were performed to analyze the forward or reverse binding mode and interactions between molecules and TTR.These results from 3D-QSAR and docking studies have great significance for designing novel TTR amyloidogenesis inhibitors in the future.展开更多
文摘Different materials,such as metal sulphides,are often combined with metal‐organic frameworks(MOFs)to develop multi‐functional composites and improve their photocatalytic properties.However,the high interfacial energy barrier limits the formation and nano‐assembly of the heterogeneous junctions between MOFs and metal sulphides.Herein,the heterostructured Zr‐MOF‐S@CdS are successfully constructed through a sequential synthesis method,in which the mesoporous Zr‐MOF are firstly decorated with thioglycolic acid through pore functionalization,and followed by the S^(2-)anion exchange process resulting in the surface close attached growth of CdS onto Zr‐MOF‐S materials.Due to the presence of molecules linkers,the CdS can be precisely decorated onto Zr‐MOF‐S without aggregation,which can provide more active sites.Moreover,the intimate connections and the suitable band structures between two materials can also facilitate the photogenerated electron‐hole pairs separation.Therefore,the resulting Zr‐MOF‐S@CdS with appropriate ratio exhibits high photocatalytic activity for water reduction,in which the H_(2) evolution rate can reach up to 1861.7μmol·g^(‒1)·h^(‒1),4.5 times higher than pure CdS and 2.3 times higher than of Zr‐MOF/CdS,respectively.Considering the promising future of MOF‐based photocatalysts,this work may provide an avenue for the further design and synthesis MOF‐based composite photocatalysts for efficient H_(2) evolution.
基金Project supported by the National Natural Science Foundation of China(Nos.31772213 and 31972320)the Excellent Youth Fund of Zhejiang Province,China(No.LR17C140002)
文摘An efficient genetic transformation system and suitable promoters are essential prerequisites for gene expression studies and genetic engineering in streptomycetes.In this study,firstly,a genetic transformation system based on intergeneric conjugation was developed in Streptomyces rimosus M527,a bacterial strain which exhibits strong antagonistic activity against a broad range of plant-pathogenic fungi.Some experimental parameters involved in this procedure were optimized,including the conjugative media,ratio of donor to recipient,heat shock temperature,and incubation time of mixed culture.Under the optimal conditions,a maximal conjugation frequency of 3.05^10-5 per recipie nt was obtai ned.Subseque ntly,based on the above developed and optimized tran sformati on system,the synthetic promoters SPL-21 and SPL-57,a native promoter potrB,and a constitutive promoter permE commonly used for gene expression in streptomycetes were selected and their activity was analyzed using gusA as a reporter gene in S.rimosus M527.Among the four tested promoters,SPL-21 exhibited the strongest expression activity and gave rise to a 2.2-fold increase in p-glucuronidase(GUS)activity compared with the control promoter permE.Promoter SPL-57 showed activity comparable to that of permE.Promoter potrB,which showed the lowest activity,showed a 50%decrease in GUS activity compared with the control permE.The transformation system developed in this study and the tested promotors provide a basis for the further modification of S.rimosus M527.
基金supported by the National Natural Science Foundation of China(21072018)the Fundamental Research Funds for the Central Universities(ZY1213)the Foundation of State Key Laboratory of Natural and Biomimetic Drugs(K20120202)
文摘Transthyretin(TTR),a plasma protein with a tetramer structure,could form amyloid fibril associated with several human diseases through the dissociation of tetramer and the misfolding of monomer.These amyloidogenesis can be inhibited by small molecules which bind to the central channel of TTR.A number of small molecules like 2-arylbenzoxazoles(ABZ)analogues are proposed as promising therapeutic strategy to treat amyloidosis.In this work,comparative molecular field analysis(CoMFA)and comparative molecular similarity indices analysis(CoMSIA)three-dimensional quantitative structure-activity relationship(3D-QSAR)and docking studies were performed on series of 2-arylbenzoxazoles(ABZ)and linker-Y analogues to investigate the inhibitory activities of TTR amyloidogenesis at atomic level.Significant correlation coefficients for ABZ series(CoMFA,r2=0.877,q2=0.431;CoMSIA,r2=0.836,q2=0.447)and those for linker-Y series(CoMFA,r2=0.828,q2=0.522;CoMSIA,r2=0.800,q2=0.493)were obtained,and the generated models were validated using test sets.In addition,docking studies on 6 compounds binding to TTR were performed to analyze the forward or reverse binding mode and interactions between molecules and TTR.These results from 3D-QSAR and docking studies have great significance for designing novel TTR amyloidogenesis inhibitors in the future.
