Background: DNAzymes cleave at predetermined sequences within RNA. A prerequisite for cleavage is that the DNAzyme can gain access to its target, and thus the DNAzyme must be capable of unfolding higher-order structures that are present in the RNA substrate. However, in many cases the RNA target sequence is hidden in a region that is too tightly structured to be accessed under physiological conditions by DNAzymes.
Results: We investigated how incorporation of LNA (locked nucleic acid) monomers into DNAzymes improves their ability to gain access and cleave at highly-structured RNA targets. The binding arms of DNAzymes were varied in length and were substituted with up to three LNA and alpha-L-LNA monomers (forming LNAzymes). For one DNAzyme, the overall cleavage reaction proceeded fifty times faster after incorporation of two alpha-L-LNA monomers per binding arm (kobs increased from 0.014 min-1 to 0.78 min-1).
Conclusion: The data demonstrate how hydrolytic performance can be enhanced by design of LNAzymes, and indicate that there are optimal lengths for the binding arms and for the number of modified LNA monomers.
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http://dx.doi.org/10.1186/1471-2199-7-19 | DOI Listing |
Talanta
January 2025
School of Life Science, Jiangsu Normal University, Xuzhou, 221116, China.
Sensitive and accurate detection and imaging of different microRNAs (miRNAs) in cancer cells hold great promise for early disease diagnosis. Herein, a DNA tetrahedral scaffold (DTS)-corbelled autonomous-motion (AM) molecular machine based fluorescent sensing platform was designed for simultaneous detection of two types of miRNAs (miRNA-21 and miRNA-155) in HeLa cells. Locking-strand-silenced DNAzymes (P:L duplex) were firstly grafted at the loop of target-analogue-embedded double-stem hairpin substrates (TDHS) of DTS, making the sensor in a "signal off" state due to the closely distance between modified fluorophores (FAM and Cy5) with the corresponding quenchers (BHQ1 and BHQ2).
View Article and Find Full Text PDFTalanta
January 2025
College of Food Science and Technology, Hebei Agricultural University, Baoding, 071001, China; Hebei Provincial Key Laboratory of Analysis and Control for Zoonoses Microbial, Baoding, 071001, China; College of Life Sciences, Hebei Agricultural University, Baoding, 071001, China. Electronic address:
Zearalenone has a high level of detection and exceedance in cereals and by-products. Herein, an electrochemical aptasensor for ZEN detection was proposed. The selected aptamer, which has a high affinity for ZEN, serves as a molecular recognition element and effectively avoids interference from other toxins.
View Article and Find Full Text PDFBMC Bioinformatics
January 2025
International Institute "Solution Chemistry of Advanced Materials and Technologies", ITMO University, Saint-Petersburg, Russian Federation, 191002.
Background: Deoxyribozymes or DNAzymes represent artificial short DNA sequences bearing many catalytic properties. In particular, DNAzymes able to cleave RNA sequences have a huge potential in gene therapy and sequence-specific analytic detection of disease markers. This activity is provided by catalytic cores able to perform site-specific hydrolysis of the phosphodiester bond of an RNA substrate.
View Article and Find Full Text PDFBiosens Bioelectron
December 2024
Department of Gastroenterology, Hubei Key Laboratory of Tumor Biological Behavior, Zhongnan Hospital of Wuhan University, Wuhan, 430072, PR China; Research Institute of Shenzhen, Wuhan University, Shenzhen, 518057, PR China. Electronic address:
Biomolecules play essential roles in regulating the orderly progression of biochemical reaction networks. DNA-based biocircuits supplement an attractive and ideal approach for the visual imaging of endogenous biomolecules, yet their sensing performance is commonly encumbered by the undesired signal leakage. To solve this issue, here we proposed a glutathione (GSH)-activated DNA circuit for achieving the spatio-selective microRNA imaging through the successive response of a GSH-specific activation procedure and a non-enzymatic catalytic signal amplification procedure.
View Article and Find Full Text PDFBioelectrochemistry
December 2024
Department of Laboratory Medicine, The Affiliated Hospital of Southwest Medical University, 25 Taiping Street, Luzhou 646000, Sichuan, China; Sichuan Province Engineering Technology Research Center of Molecular Diagnosis of Clinical Diseases, China; Molecular Diagnosis of Clinical Diseases Key Laboratory of Luzhou, Sichuan, China. Electronic address:
In this study, an innovative electrochemical biosensor was developed for the rapid, specific, and sensitive detection of Acinetobacter baumannii without the need for sample pretreatment. The biosensor utilized an aptamer as a specific capture probe for A. baumannii and employed a self-powered DNAzyme walker cleavage cycle reaction to achieve signal amplification.
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