Deoxyribozyme

About: Deoxyribozyme is a research topic. Over the lifetime, 1236 publications have been published within this topic receiving 49991 citations.

Antisense technologies. Improvement through novel chemical modifications.

Abstract: Antisense agents are valuable tools to inhibit the expression of a target gene in a sequence-specific manner, and may be used for functional genomics, target validation and therapeutic purposes. Three types of anti-mRNA strategies can be distinguished. Firstly, the use of single stranded antisense-oligonucleotides; secondly, the triggering of RNA cleavage through catalytically active oligonucleotides referred to as ribozymes; and thirdly, RNA interference induced by small interfering RNA molecules. Despite the seemingly simple idea to reduce translation by oligonucleotides complementary to an mRNA, several problems have to be overcome for successful application. Accessible sites of the target RNA for oligonucleotide binding have to be identified, antisense agents have to be protected against nucleolytic attack, and their cellular uptake and correct intracellular localization have to be achieved. Major disadvantages of commonly used phosphorothioate DNA oligonucleotides are their low affinity towards target RNA molecules and their toxic side-effects. Some of these problems have been solved in 'second generation' nucleotides with alkyl modifications at the 2' position of the ribose. In recent years valuable progress has been achieved through the development of novel chemically modified nucleotides with improved properties such as enhanced serum stability, higher target affinity and low toxicity. In addition, RNA-cleaving ribozymes and deoxyribozymes, and the use of 21-mer double-stranded RNA molecules for RNA interference applications in mammalian cells offer highly efficient strategies to suppress the expression of a specific gene.

DNAzymes for sensing, nanobiotechnology and logic gate applications

Abstract: Catalytic nucleic acids (DNAzymes or ribozymes) are selected by the systematic evolution of ligands by exponential enrichment process (SELEX). The catalytic functions of DNAzymes or ribozymes allow their use as amplifying labels for the development of optical or electronic sensors. The use of catalytic nucleic acids for amplified biosensing was accomplished by designing aptamer–DNAzyme conjugates that combine recognition units and amplifying readout units as in integrated biosensing materials. Alternatively, “DNA machines” that activate enzyme cascades and yield DNAzymes were tailored, and the systems led to the ultrasensitive detection of DNA. DNAzymes are also used as active components for constructing nanostructures such as aggregated nanoparticles and for the activation of logic gate operations that perform computing.

Metal Sensing by DNA

Abstract: Metal ions are essential to many chemical, biological, and environmental processes. In the past two decades, many DNA-based metal sensors have emerged. While the main biological role of DNA is to store genetic information, its chemical structure is ideal for metal binding via both the phosphate backbone and nucleobases. DNA is highly stable, cost-effective, easy to modify, and amenable to combinatorial selection. Two main classes of functional DNA were developed for metal sensing: aptamers and DNAzymes. While a few metal binding aptamers are known, it is generally quite difficult to isolate such aptamers. On the other hand, DNAzymes are powerful tools for metal sensing since they are selected based on catalytic activity, thus bypassing the need for metal immobilization. In the last five years, a new surge of development has been made on isolating new metal-sensing DNA sequences. To date, many important metals can be selectively detected by DNA often down to the low parts-per-billion level. Herein, each me...