研究偶氮苯单元修饰在核酸上控制引物延伸的行为。系统地筛选5、6、7和8个碱基的保护链通过4,4′-二羟甲基偶氮苯连接的25 mer DNA模板,并研究其在紫外光照前后调控的引物延伸效率。结果表明,具有7个保护碱基的C3对Pri.15和6个碱基短链...研究偶氮苯单元修饰在核酸上控制引物延伸的行为。系统地筛选5、6、7和8个碱基的保护链通过4,4′-二羟甲基偶氮苯连接的25 mer DNA模板,并研究其在紫外光照前后调控的引物延伸效率。结果表明,具有7个保护碱基的C3对Pri.15和6个碱基短链的C2对Pri.17都具有较好的光调控延伸效果。其中C3,在Vent酶作用下紫外光照后引物延伸效率增加1倍以上。而C2,尽管紫外光照前增加了引物延伸的背景,在Vent酶催化下紫外光照射后的延伸产率达到91.4%,比紫外光照前增加84%。本工作为分子水平上研究基因功能、基因表达网络以及疾病的发生和发展提供了一种新的策略和研究手段。展开更多
Green fluorescent protein（GFP） plasmid was caged by 8-bromo-7-hydroxyquinolinyl chromophore（BHQ） for controlling its expression with exact spatiotemporal resolution.In vitro and in vivo experiments clearly verifie...Green fluorescent protein（GFP） plasmid was caged by 8-bromo-7-hydroxyquinolinyl chromophore（BHQ） for controlling its expression with exact spatiotemporal resolution.In vitro and in vivo experiments clearly verified that,comparing with Bhc caging, the expression level of caged GFP plasmid was dramatically decreased and then efficiently restored after subsequent photolysis.展开更多
Hormogonium, which was thought to play an important role in the dispersal and survival of these microorganisms in their natural habitats, is a distinguishable developmental stage of heterocystous cyanobacteria. The pr...Hormogonium, which was thought to play an important role in the dispersal and survival of these microorganisms in their natural habitats, is a distinguishable developmental stage of heterocystous cyanobacteria. The present study examined the effects of different light conditions and sugars on the differentiation ofNostoc sphaeroides Kiitzing to the hormogonia stage. Results showed that differentiation of hormogonia was light dependent in the absence of sugar, but that close to 100% of cyanobacteria differentiated to hormogonia in the presence of glucose or sucrose, irrespective of the light conditions. This differentiation was inhibited, even in the presence of sugars, upon application of an inhibitor of respiration. Following the testing of different sugars, the effects of different lights were examined. It was found that 5-10μmol·m^-2·s^-1 photon flux density was optimal for hormogonia differentiation. One hundred percent differentiation was obtained with white light irradiation, in contrast with irradiation with green light (80% differentiation) and red light (0-10% differentiation). Although they showed different efficiencies in inducing hormogonia differentiation in N. sphaeroides, the green and red radiation did not display antagonistic effects. When the additional aspect of time dependence was investigated through the application of different fight radiations and an inhibitor of protein synthesis, it was found that the initial 6 h of the differentiation process was crucial for hormogonia differentiation. Taken together, these results show that hormogonia differentiation in N. sphaeroides is either a photoregulated or an energy deoendent orocess.展开更多
The exploration of low-cost and metal-free nanozymes with oxidase-mimicking activity is highly desired due to their attractive properties and potential applications.However,it is still challenging and remains unexploi...The exploration of low-cost and metal-free nanozymes with oxidase-mimicking activity is highly desired due to their attractive properties and potential applications.However,it is still challenging and remains unexploited to fully realize oxidase-like nanozyme in the emerging covalent organic frameworks(COFs)due to their polymeric nature and weak photoelectric activity.We herein report the first example of the preparation and oxidase-mimicking activity of novel ultrathin two-dimensional(2D)COF(termed as TTPA-COF)nanosheets.The ultrathin TTPA-COF nanosheets with hexagonal layered structure are constructed from two flexible photoactive(diarylamino)benzene-based linkers,and exhibit remarkable catalytic activity toward the oxidation of 3,3',5,5'-tetramethylbenzidine(TMB)in the presence of O_(2) due to their large specific surface areas and abundant active sites.Moreover,it is worth noting that the nanozyme activity could be regulated by external light irradiation.Based on the oxidasemimicking activity of TTPA-COF nanosheets,a green colorimetric sensor is proposed for the sensitive and selective determination of glutathione(GSH)in a wide linear range of 0.5–40μM with a detection limit of 0.5μM.This work reported here would open new avenues for the exploration of low-cost and high-efficiency nanozymes,as well as extend the application of 2D COF nanosheets in the fields of catalysis and sensing.展开更多
文摘研究偶氮苯单元修饰在核酸上控制引物延伸的行为。系统地筛选5、6、7和8个碱基的保护链通过4,4′-二羟甲基偶氮苯连接的25 mer DNA模板,并研究其在紫外光照前后调控的引物延伸效率。结果表明,具有7个保护碱基的C3对Pri.15和6个碱基短链的C2对Pri.17都具有较好的光调控延伸效果。其中C3,在Vent酶作用下紫外光照后引物延伸效率增加1倍以上。而C2,尽管紫外光照前增加了引物延伸的背景,在Vent酶催化下紫外光照射后的延伸产率达到91.4%,比紫外光照前增加84%。本工作为分子水平上研究基因功能、基因表达网络以及疾病的发生和发展提供了一种新的策略和研究手段。
基金supported by the National Natural Science Foundation of China(No90713009)
文摘Green fluorescent protein（GFP） plasmid was caged by 8-bromo-7-hydroxyquinolinyl chromophore（BHQ） for controlling its expression with exact spatiotemporal resolution.In vitro and in vivo experiments clearly verified that,comparing with Bhc caging, the expression level of caged GFP plasmid was dramatically decreased and then efficiently restored after subsequent photolysis.
文摘Hormogonium, which was thought to play an important role in the dispersal and survival of these microorganisms in their natural habitats, is a distinguishable developmental stage of heterocystous cyanobacteria. The present study examined the effects of different light conditions and sugars on the differentiation ofNostoc sphaeroides Kiitzing to the hormogonia stage. Results showed that differentiation of hormogonia was light dependent in the absence of sugar, but that close to 100% of cyanobacteria differentiated to hormogonia in the presence of glucose or sucrose, irrespective of the light conditions. This differentiation was inhibited, even in the presence of sugars, upon application of an inhibitor of respiration. Following the testing of different sugars, the effects of different lights were examined. It was found that 5-10μmol·m^-2·s^-1 photon flux density was optimal for hormogonia differentiation. One hundred percent differentiation was obtained with white light irradiation, in contrast with irradiation with green light (80% differentiation) and red light (0-10% differentiation). Although they showed different efficiencies in inducing hormogonia differentiation in N. sphaeroides, the green and red radiation did not display antagonistic effects. When the additional aspect of time dependence was investigated through the application of different fight radiations and an inhibitor of protein synthesis, it was found that the initial 6 h of the differentiation process was crucial for hormogonia differentiation. Taken together, these results show that hormogonia differentiation in N. sphaeroides is either a photoregulated or an energy deoendent orocess.
基金supported by the financial support from the National Natural Science Foundation of China(NSFC)(Nos.21976166,22006122,and 21405144)the research funding of“Leading Innovative and Entrepreneur Team Introduction Program of Zhejiang”(No.2020R01002)+4 种基金the Class D of Qianjiang Talent Program(No.ZD20011250001)the Science Challenge Project(No.TZ2016004)he Project of State Key Laboratory of Environment-friendly Energy Materials(No.18zd320303)the Scientific Research Starting Foundation for Returned Overseas Chinese Scholars of Sichuan Province(No.19zd3200)support from the Opening Project of Jiangsu Province Engineering Research Center of Agricultural Breeding Pollution Control and Resource(No.2021ABPCR004).
文摘The exploration of low-cost and metal-free nanozymes with oxidase-mimicking activity is highly desired due to their attractive properties and potential applications.However,it is still challenging and remains unexploited to fully realize oxidase-like nanozyme in the emerging covalent organic frameworks(COFs)due to their polymeric nature and weak photoelectric activity.We herein report the first example of the preparation and oxidase-mimicking activity of novel ultrathin two-dimensional(2D)COF(termed as TTPA-COF)nanosheets.The ultrathin TTPA-COF nanosheets with hexagonal layered structure are constructed from two flexible photoactive(diarylamino)benzene-based linkers,and exhibit remarkable catalytic activity toward the oxidation of 3,3',5,5'-tetramethylbenzidine(TMB)in the presence of O_(2) due to their large specific surface areas and abundant active sites.Moreover,it is worth noting that the nanozyme activity could be regulated by external light irradiation.Based on the oxidasemimicking activity of TTPA-COF nanosheets,a green colorimetric sensor is proposed for the sensitive and selective determination of glutathione(GSH)in a wide linear range of 0.5–40μM with a detection limit of 0.5μM.This work reported here would open new avenues for the exploration of low-cost and high-efficiency nanozymes,as well as extend the application of 2D COF nanosheets in the fields of catalysis and sensing.
