Mercury ion(Hg^(2+)),a highly noxious of heavy metalion,has detrimental effects on the ecological environment and human health.Herein,we have developed an exonuclease III(Exo III)assisted catalytic hairpin assembly fo...Mercury ion(Hg^(2+)),a highly noxious of heavy metalion,has detrimental effects on the ecological environment and human health.Herein,we have developed an exonuclease III(Exo III)assisted catalytic hairpin assembly formation of a trivalent G-quadruplex/hemin DNAzyme for colorimetric detection of Hg^(2+).A hairpin DNA(Hr)was designed with thymine-Hg^(2+)-thymine pairs that catalyzed by Exo III is prompted to happen upon binding Hg^(2+).A released DNA fragment triggers the catalytic assembly of other three hairpins(H1,H2,and H3)to form many trivalent G-quadruplex/hemin DNA enzymes for signal output.The developed sensor shows a dynamic range from 2 pM to 2μM,with an impressively low detection limit of 0.32 pM for Hg^(2+)detection.Such a sensor also has good selectivity toward Hg^(2+)detection in the presence of other common metal ions.This strategy shows the great potential for visual detection with portable type.展开更多
To overcome ampicillin-resistance of bacteria which is believed to attribute their endogenous B-lactamase, we designed three 10-23 DNAzymes（Dz1, Dz2. Dz3） targeting the coding region of B-lactamase mRNA and examined...To overcome ampicillin-resistance of bacteria which is believed to attribute their endogenous B-lactamase, we designed three 10-23 DNAzymes（Dz1, Dz2. Dz3） targeting the coding region of B-lactamase mRNA and examined their inhibitory capabilities of the ampicillin-resistance of TEM-1 and TEM-3 bacteria. Dz1 was a traditional 10-23 DNAzyme, Dz2 was the mutant of Dz1 by addition of the protected nucleotide to each ann of the enzyme, and Dz3 was a mutant of Dz1 at antisense arms of which phosphorothioate modifications were made. Kinetic analysis, bacterial growth, and β-lactamase activity measurement showed that all the three DNAzymes worked efficiently in vitro and in vivo. A 9 hours bacterial growth inhibition test showed that the inhibition rates of TEM-1 bacteria by Dz1, Dz2, and Dz3 were 27%, 50%, and 29%, respectively. In addition, the inhibition rates of TEM-3 bacteria by those three DNAzymes were found io be 49%, 58%, and 45%, respectively. The current findings suggest that DNAzymes may become potential candidates of alternative inhibitors for bacteria drug-resistance.展开更多
Detection of deoxyribozyme （DNAzyme） cleavage process usually needs complex and time-consuming radial labeling, gel electrophoresis and autoradiography. This paper reported an approach to detect DNAzyme cleavage pro...Detection of deoxyribozyme （DNAzyme） cleavage process usually needs complex and time-consuming radial labeling, gel electrophoresis and autoradiography. This paper reported an approach to detect DNAzyme cleavage process in real time using a fluorescence probe. The probe was employed as DNAzyme substrate to convert directly the cleavage information into fluorescence signal in real time. Compared with traditional approach, this non-isotope method not only brought a convenient means to monitor the DNAzyme cleavage reaction, but also offered abundant dynamic data for choosing potential gene therapeutic agents. It provides a new tool for DNAzyme research, as well as a new insight into research on human disease diagnosis. Based on this method, 8- 17deoxyribozyme （8-17DNAzyme） against hepatitis C virus RNA （HCV-RNA） was designed and the cleavage process was studied in real time. ？2009 Ke Min Wang. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All fights reserved.展开更多
金属离子几乎参与所有生命过程,它们的亚细胞定位与许多生物功能密切相关。亚细胞金属离子的扰动可导致细胞功能受损,并增加代谢相关疾病的风险。最近中国科学院国家纳米科学中心的李乐乐教授基于DNAzyme传感器构建了线粒体中金属离子...金属离子几乎参与所有生命过程,它们的亚细胞定位与许多生物功能密切相关。亚细胞金属离子的扰动可导致细胞功能受损,并增加代谢相关疾病的风险。最近中国科学院国家纳米科学中心的李乐乐教授基于DNAzyme传感器构建了线粒体中金属离子空间选择性成像的模块化工程,这一成果发表在Journal of The American Chemical Society上。展开更多
The development of stimuli-responsive nanodevices with high efficiency and specificity is very important in biosensing,drug delivery,and so on.DNAzymes are a class of DNA molecules with the specific catalytic activity...The development of stimuli-responsive nanodevices with high efficiency and specificity is very important in biosensing,drug delivery,and so on.DNAzymes are a class of DNA molecules with the specific catalytic activity.Owing to their unique catalytic activity and easy design and synthesis,the construction and application of DNAzymes-based nanodevices have attracted much attention in recent years.In this review,the classification and properties of DNAzyme are first introduced.The construction of several common kinds of DNAzyme-based nanodevices,such as DNA motors,signal amplifiers,and logic gates,is then systematically summarized.We also introduce the application of DNAzyme-based nanodevices in sensing and therapeutic fields.In addition,current limitations and future directions are discussed.展开更多
DNAzyme machines play critical roles in the fields of cell imaging, disease diagnosis, and cancer therapy. However, the applications of DNAzyme machines are limited by the nucleases-induced degradation,non-specific bi...DNAzyme machines play critical roles in the fields of cell imaging, disease diagnosis, and cancer therapy. However, the applications of DNAzyme machines are limited by the nucleases-induced degradation,non-specific binding of proteins, and insufficient provision of cofactors. Herein, protected DNAzyme machines with different cofactor designs(referred to as Pro Ds) were nanoengineered by the construction of multifunctional metal-phenolic nanoshells to deactivate the interferential proteins, including nucleases and non-specific binding proteins. Moreover, the nanoshells not only facilitate the cellular internalization of Pro Ds but provide specific metal ions acting as cofactors of the designed DNAzymes. Cellular imaging results demonstrated that Pro Ds could effectively and simultaneously monitor multiple tumor-related micro RNAs in living cells. This facile and rapid strategy that encapsulates DNAzyme machines into the protective metal-phenolic nanoshells is anticipated to extend to a wide range of functional nucleic acidsbased biomedical applications.展开更多
DNAzyme amplifiers have been extensively explored as a useful sensing platform,but single DNAzyme amplifier is limited in biosensing applications by its low sensitivity.Herein,a cascade DNAzyme amplifier was designed ...DNAzyme amplifiers have been extensively explored as a useful sensing platform,but single DNAzyme amplifier is limited in biosensing applications by its low sensitivity.Herein,a cascade DNAzyme amplifier was designed by exploiting concurrent amplification cycle principles of toehold-mediated strand displacement reaction(TSDR)and Zn^(2+)-assisted DNAzyme cycle with lower cost and simpler procedures.Compared with single DNAzyme amplifier,the proposed TSDR-propelled cascade DNAzyme amplifier exhibited higher sensitivity by releasing more DNAzyme through TSDR to cleave substrate strand during the DNAzyme cycle.Base on this,let-7a could be sensitively detected in the range of 5-50 nmol/L with a detection limit of 64 pmol/L.Furthermore,the dual signal amplification strategy of the cascade DNAzyme amplifier exhibited excellent selectivity to distinguish single-base mismatched DNA strands,which has been successfully applied to the determination of let-7a in blood serum,showing high promise in early cancer diagnosis.展开更多
Toxicity assessment is a major problem in pharmaceutical candidates and industry chemicals development.However,due to the lack of practical analytical methods for DNA adduct analysis,the safety evaluation of drug and ...Toxicity assessment is a major problem in pharmaceutical candidates and industry chemicals development.However,due to the lack of practical analytical methods for DNA adduct analysis,the safety evaluation of drug and industry chemicals was severely limited.Here,we develop a DNAzyme-based method to detect DNA adduct damage for toxicity assessment of drugs and chemicals.Among 18 structural variants of G4 DNAzyme,EA2 DNAzyme exhibits an obvious DNA damaging effect of styrene oxide(SO)due to its unstable structure.The covalent binding of SO to DNAzyme disrupts the Hoogsteen hydrogen bonding sites of G-plane guanines and affects the formation of the G4 quadruplex.DNA damage chemicals reduce the peroxidase activity of the G4 DNAzyme to monitor the DNA adduct damage by disrupting the structural integrity of the G4 DNAzyme.Our method for genotoxic assessment of pharmaceutical candidates and industrial chemicals can elucidate the complex chemical pathways leading to toxicity,predict toxic effects of chemicals,and evaluate possible risks to human health.展开更多
基金Supported by The Science and Technology Project of General Administration of Quality Supervision,Inspection and Quarantine (2015IK126)The Science and Technology Project of Changsha City of Hunan Province of China (KQ1602124).
文摘Mercury ion(Hg^(2+)),a highly noxious of heavy metalion,has detrimental effects on the ecological environment and human health.Herein,we have developed an exonuclease III(Exo III)assisted catalytic hairpin assembly formation of a trivalent G-quadruplex/hemin DNAzyme for colorimetric detection of Hg^(2+).A hairpin DNA(Hr)was designed with thymine-Hg^(2+)-thymine pairs that catalyzed by Exo III is prompted to happen upon binding Hg^(2+).A released DNA fragment triggers the catalytic assembly of other three hairpins(H1,H2,and H3)to form many trivalent G-quadruplex/hemin DNA enzymes for signal output.The developed sensor shows a dynamic range from 2 pM to 2μM,with an impressively low detection limit of 0.32 pM for Hg^(2+)detection.Such a sensor also has good selectivity toward Hg^(2+)detection in the presence of other common metal ions.This strategy shows the great potential for visual detection with portable type.
文摘目的分析肿瘤远处转移相关蛋白(Ezrin mRNA)的结构,寻找并验证DNAzymes作用的最佳靶点。方法利用RNAstructure与RNAdraw程序分析Ezrin mRNA结构,计算其一、二级结构,两种程序同时计算出碱基未配对的单链成环区,且连续存在4个以上,则将其设为反义技术的靶区域,在此区域内设计DNAzymes的作用靶点,再依据最低自由能原则,运用计算机中的OligoWalk程序进行筛选,以此方式得到各反义技术的作用靶点,以实验方法验证预测结果。结果两种软件预测的共同的单链区共42个,其中完全匹配的单链区21个,编码区具27个。AU1655、AU1751、AU1766、AU1789及GU2623位于连续未配对碱基超过10个的单链区,仅AU1655、AU1751、AU1766、AU1789符合要求。酶切反应结果显示DNAzymes在AU1751位点能够最为理想地切割Ezrin m RNA。结论相对于传统的单纯依靠实验来寻找靶点,核酸二级结构联合热动力学参数能够更精确、快速地处理靶点的设计和选取问题。AU1751位点相对应的DNAzymes不易形成稳定的自身杂合体,有利于DNAzymes结合RNA。
基金the National Natural Science Foundation of China(Nos.20771030 and 20671025)
文摘To overcome ampicillin-resistance of bacteria which is believed to attribute their endogenous B-lactamase, we designed three 10-23 DNAzymes（Dz1, Dz2. Dz3） targeting the coding region of B-lactamase mRNA and examined their inhibitory capabilities of the ampicillin-resistance of TEM-1 and TEM-3 bacteria. Dz1 was a traditional 10-23 DNAzyme, Dz2 was the mutant of Dz1 by addition of the protected nucleotide to each ann of the enzyme, and Dz3 was a mutant of Dz1 at antisense arms of which phosphorothioate modifications were made. Kinetic analysis, bacterial growth, and β-lactamase activity measurement showed that all the three DNAzymes worked efficiently in vitro and in vivo. A 9 hours bacterial growth inhibition test showed that the inhibition rates of TEM-1 bacteria by Dz1, Dz2, and Dz3 were 27%, 50%, and 29%, respectively. In addition, the inhibition rates of TEM-3 bacteria by those three DNAzymes were found io be 49%, 58%, and 45%, respectively. The current findings suggest that DNAzymes may become potential candidates of alternative inhibitors for bacteria drug-resistance.
基金supported in part by the National Key Basic Research Program of China(No.2002CB513110)Natural Science Foundation of China(No.90606003,No.20505007)+1 种基金Major International(Regional)Joint Research Program of Natural Science Foundation of China(No.20620120107)project supported by Hunan Provincial Natural Science Foundation of China(No.08JJ1002).
文摘Detection of deoxyribozyme （DNAzyme） cleavage process usually needs complex and time-consuming radial labeling, gel electrophoresis and autoradiography. This paper reported an approach to detect DNAzyme cleavage process in real time using a fluorescence probe. The probe was employed as DNAzyme substrate to convert directly the cleavage information into fluorescence signal in real time. Compared with traditional approach, this non-isotope method not only brought a convenient means to monitor the DNAzyme cleavage reaction, but also offered abundant dynamic data for choosing potential gene therapeutic agents. It provides a new tool for DNAzyme research, as well as a new insight into research on human disease diagnosis. Based on this method, 8- 17deoxyribozyme （8-17DNAzyme） against hepatitis C virus RNA （HCV-RNA） was designed and the cleavage process was studied in real time. ？2009 Ke Min Wang. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All fights reserved.
文摘金属离子几乎参与所有生命过程,它们的亚细胞定位与许多生物功能密切相关。亚细胞金属离子的扰动可导致细胞功能受损,并增加代谢相关疾病的风险。最近中国科学院国家纳米科学中心的李乐乐教授基于DNAzyme传感器构建了线粒体中金属离子空间选择性成像的模块化工程,这一成果发表在Journal of The American Chemical Society上。
基金supported by the National Natural Science Foundation of China (Nos.22122403,22274042,and 21890744)the Natural Science Foundation of Hunan Province,China (Nos.2021JJ10012,2022JJ30121)the Changsha Municipal Natural Science Foundation,China (No.kq2202145).
文摘The development of stimuli-responsive nanodevices with high efficiency and specificity is very important in biosensing,drug delivery,and so on.DNAzymes are a class of DNA molecules with the specific catalytic activity.Owing to their unique catalytic activity and easy design and synthesis,the construction and application of DNAzymes-based nanodevices have attracted much attention in recent years.In this review,the classification and properties of DNAzyme are first introduced.The construction of several common kinds of DNAzyme-based nanodevices,such as DNA motors,signal amplifiers,and logic gates,is then systematically summarized.We also introduce the application of DNAzyme-based nanodevices in sensing and therapeutic fields.In addition,current limitations and future directions are discussed.
基金supported by National Talents Program,Double First Class University Plan of Sichuan University,State Key Laboratory of Polymer Materials Engineering(No.sklpme 2020-0301)Natural Science Foundation of Sichuan Province(Nos.2022NSFSC1735,2023NSFSC1097)+5 种基金Fundamental Research Funds for the Central Universities(No.ZYN2022094)National Natural Science Foundation of China(Nos.22178233,22208228)China Postdoctoral Science Foundation(No.2020TQ0209)Fundamental Research Funds for the Central Universities(No.YJ201959)Science and Technology Support Program of Sichuan Province(No.2021YJ0414)Project of Chengdu Science and Technology Bureau(No.2021YF05-02110-SN)。
文摘DNAzyme machines play critical roles in the fields of cell imaging, disease diagnosis, and cancer therapy. However, the applications of DNAzyme machines are limited by the nucleases-induced degradation,non-specific binding of proteins, and insufficient provision of cofactors. Herein, protected DNAzyme machines with different cofactor designs(referred to as Pro Ds) were nanoengineered by the construction of multifunctional metal-phenolic nanoshells to deactivate the interferential proteins, including nucleases and non-specific binding proteins. Moreover, the nanoshells not only facilitate the cellular internalization of Pro Ds but provide specific metal ions acting as cofactors of the designed DNAzymes. Cellular imaging results demonstrated that Pro Ds could effectively and simultaneously monitor multiple tumor-related micro RNAs in living cells. This facile and rapid strategy that encapsulates DNAzyme machines into the protective metal-phenolic nanoshells is anticipated to extend to a wide range of functional nucleic acidsbased biomedical applications.
基金financially supported by the National Natural Science Foundation of China(NSFC,Nos.22074124 and 22134005)the fund of Fundamental Research Funds for the Central Universities(No.XDJK2020TY001)+1 种基金Chongqing Talents Program for Outstanding Scientists(No.cstc2021ycjh-bgzxm0178)the Chongqing Graduate Student Scientific Research Innovation Project(No.CYB21119)。
文摘DNAzyme amplifiers have been extensively explored as a useful sensing platform,but single DNAzyme amplifier is limited in biosensing applications by its low sensitivity.Herein,a cascade DNAzyme amplifier was designed by exploiting concurrent amplification cycle principles of toehold-mediated strand displacement reaction(TSDR)and Zn^(2+)-assisted DNAzyme cycle with lower cost and simpler procedures.Compared with single DNAzyme amplifier,the proposed TSDR-propelled cascade DNAzyme amplifier exhibited higher sensitivity by releasing more DNAzyme through TSDR to cleave substrate strand during the DNAzyme cycle.Base on this,let-7a could be sensitively detected in the range of 5-50 nmol/L with a detection limit of 64 pmol/L.Furthermore,the dual signal amplification strategy of the cascade DNAzyme amplifier exhibited excellent selectivity to distinguish single-base mismatched DNA strands,which has been successfully applied to the determination of let-7a in blood serum,showing high promise in early cancer diagnosis.
基金This work was supported by National Natural Science Foundation of China(81803720)Natural Science Foundation of Hunan Province(2019JJ50383)+3 种基金Natural Science Foundation of Changsha(kq2202256)Huxiang High-Level Talent Innovation Team(2018RS3072)Scientific and Technological Projects for Collaborative Prevention and Control of Birth Defect in Hunan Province(2019SK1012)Key Grant of Research and Development in Hunan Province(2020DK2002).Dr.Zhang acknowledges the support from Harvard/MIT.
文摘Toxicity assessment is a major problem in pharmaceutical candidates and industry chemicals development.However,due to the lack of practical analytical methods for DNA adduct analysis,the safety evaluation of drug and industry chemicals was severely limited.Here,we develop a DNAzyme-based method to detect DNA adduct damage for toxicity assessment of drugs and chemicals.Among 18 structural variants of G4 DNAzyme,EA2 DNAzyme exhibits an obvious DNA damaging effect of styrene oxide(SO)due to its unstable structure.The covalent binding of SO to DNAzyme disrupts the Hoogsteen hydrogen bonding sites of G-plane guanines and affects the formation of the G4 quadruplex.DNA damage chemicals reduce the peroxidase activity of the G4 DNAzyme to monitor the DNA adduct damage by disrupting the structural integrity of the G4 DNAzyme.Our method for genotoxic assessment of pharmaceutical candidates and industrial chemicals can elucidate the complex chemical pathways leading to toxicity,predict toxic effects of chemicals,and evaluate possible risks to human health.
