Single-stranded DNA Oligonucleotides Research Articles

Single-stranded DNA oligonucleotides containing CpG motifs are non-stimulatory in vitro but offer protection in vivo against Burkholderia pseudomallei

Single-stranded DNA oligonucleotides containing CpG motifs are non-stimulatory in vitro but offer protection in vivo against Burkholderia pseudomallei

Identification of Podoplanin Aptamers by SELEX for Protein Detection and Inhibition of Platelet Aggregation Stimulated by C-Type Lectin-like Receptor 2.

Tumor cell-induced platelet aggregation (TCIPA) is a mechanism for the protection of tumor cells in the bloodstream and the promotion of tumor progression and metastases. The platelet C-type lectin-like receptor 2 (CLEC-2) can bind podoplanin (PDPN) on a cancer cell surface to facilitate TCIPA. Selective blockage of PDPN-mediated platelet-tumor cell interaction is a plausible strategy for inhibiting metastases. In this study, we aimed to screen for aptamers, which are the single-stranded DNA oligonucleotides that form a specific three-dimensional structure, bind to specific molecular targets with high affinity and specificity, bind to PDPN, and interfere with PDPN/CLEC-2 interactions. The systematic evolution of ligands by exponential enrichment (SELEX) was employed to enrich aptamers that recognize PDPN. The initial characterization of ssDNA pools enriched by SELEX revealed a PDPN aptamer designated as A1 displaying parallel-type G-quadruplexes and long stem-and-loop structures and binding PDPN with a material with a dissociation constant (Kd) of 1.3 ± 1.2 nM. The A1 aptamer recognized both the native and denatured form of PDPN. Notably, the A1 aptamer was able to quantitatively detect PDPN proteins in Western blot analysis. The A1 aptamer could interfere with the interaction between PDPN and CLEC-2 and inhibit PDPN-induced platelet aggregation in a concentration-dependent manner. These findings indicated that the A1 aptamer is a candidate for the development of biosensors in detecting the levels of PDPN expression. The action by A1 aptamer could result in the prevention of tumor cell metastases, and if so, could become an effective pharmacological agent in treating cancer patients.

Exploring the Fibrous Nature of Single-Stranded DNA-Collagen Complexes: Nanostructural Observations and Physicochemical Insights.

Nucleic acid-collagen complexes (NACCs) are a self-assembled biomimetic fibrillary platform arising from the spontaneous complexation of single-stranded DNA (ssDNA) oligonucleotides and collagen. NACCs merge the extracellular matrix functionality of collagen with the tunable bioactivity of ssDNA as aptamers for broad biomedical applications. We hypothesize that NACCs offer a hierarchical architecture across multiple length scales that significantly varies compared to native collagen. We investigate this using atomic force microscopy and electron microscopy (transmission electron microscopy and cryogenic electron microscopy). Results demonstrate key topographical differences induced by adding ssDNA oligonucleotides to collagen type I. NACCs form a dense network of intertwined collagen fiber bundles in the microscale and nanoscale while retaining their characteristic D-band periodicities (∼67 nm). Additionally, our exploration of thermodynamic parameters governing the interaction indicates an entropically favorable NACC formation driven by ssDNA. Thermal analysis demonstrates the preservation of collagen's triple helical domains and a more stabilized polypeptide structure at higher temperatures than native collagen. These findings offer important insights into our understanding of the ssDNA-induced complexation of collagen toward the further establishment of structure-property relationships in NACCs and their future development into practical biomaterials. They also provide pathways for manipulating and enhancing collagenous matrices' properties without requiring complex chemical modifications or fabrication procedures.

Specificity of U2 and GOL1 aptamers to EGFR-positive human glioblastoma cells in vitro

Overexpression of the epidermal growth factor receptor (EGFR) or its mutations mediate signaling pathways leading to proliferation, invasion of tumor cells, as well as to an increase in their survival. Despite the success of the clinical use of antibodies against EGFR in patients with colorectal cancer and squamous cell carcinoma of the head and neck, their low effectiveness in glioblastoma has been shown. Therefore, for the treatment of gliomas, a specific EGFR drug is needed, capable of penetrating into the tumor focus in the brain, and having low immunogenicity. In this work, aptamers – single-stranded DNA oligonucleotides specific to EGFR, U2 and Gol1 are presented as such a preparation. In this study, we obtained a cellular model of human glioma with EGFR and EGFRvIII overexpression, which showed the specificity of U2 and Gol1 aptamers to these receptors using classical methods, as well as the method of aptaimmunocytochemistry. A study of the effect of binding of the Gol1 aptamer to the EGFRvIII receptor on the next steps of the signaling pathway showed a change in the expression levels of genes associated with cell proliferation and survival (JUN, FOS, CCND1, PI3K and AKT3), while the U2 aptamer did not demonstrate a significant effect on cells in vitro. These results showed that the Gol1 aptamer has therapeutic potential against human glioblastoma tumor cells overexpressing the EGFRvIII mutant type receptor.

Dynamic stem–loop extension by Pol θ and templated insertion during DNA repair

Theta-mediated end-joining (TMEJ) is critical for survival of cancer cells when other DNA double-stranded break repair pathways are impaired. Human DNA polymerase theta (Pol θ) can extend single-stranded DNA oligonucleotides, but little is known about preferred substrates and mechanism. We show that Pol θ can extend both single-stranded DNA and RNA substrates by unimolecular stem loop synthesis initiated by only two 3ʹ terminal base-pairs. Given sufficient time, Pol θ uses alternative pairing configurations that greatly expand the repertoire of sequence outcomes. Further primer-template adjustments yield low-fidelity outcomes when the nucleotide pool is imbalanced. Unimolecular stem loop synthesis competes with bimolecular end-joining, even when a longer terminal microhomology for end-joining is available. Both reactions are partially suppressed by the ssDNA binding protein RPA. Protein-primer grasp residues that are specific to Pol θ are needed for rapid stem-loop synthesis. The ability to perform stem-loop synthesis from a minimally paired primer is rare amongst human DNA polymerases but we show that human DNA polymerases Pol η and Pol λ can catalyze related reactions. Using purified human Pol θ, we reconstituted in vitro TMEJ incorporating an insertion arising from a stem loop extension. These activities may help explain TMEJ repair events that include inverted repeat sequences.

Development of an Integrated CMUTs-Based Resonant Biosensor for Label-Free Detection of DNA with Improved Selectivity by Ethylene-Glycol Alkanethiols

Gravimetric resonant-inspired biosensors have attracted increasing attention in industrial and point-of-care applications, enabling label-free detection of biomarkers such as DNA and antibodies. Capacitive micromachined ultrasonic transducers (CMUTs) are promising tools for developing miniaturized high-performance biosensing complementary metal–oxide–silicon (CMOS) platforms. However, their operability is limited by inefficient functionalization, aggregation, crosstalk in the buffer, and the requirement for an external high-voltage (HV) power supply. In this study, we aimed to propose a CMUTs-based resonant biosensor integrated with a CMOS front–end interface coupled with ethylene–glycol alkanethiols to detect single-stranded DNA oligonucleotides with large specificity. The topography of the functionalized surface was characterized by energy-dispersive X-ray microanalysis. Improved selectivity for on-chip hybridization was demonstrated by comparing complementary and non-complementary single-stranded DNA oligonucleotides using fluorescence imaging technology. The sensor array was further characterized using a five-element lumped equivalent model. The 4 mm2 application-specific integrated circuit chip was designed and developed through 0.18 μm HV bipolar-CMOS-double diffused metal–oxide–silicon (DMOS) technology (BCD) to generate on-chip 20 V HV boosting and to track feedback frequency under a standard 1.8 V supply, with a total power consumption of 3.8 mW in a continuous mode. The measured results indicated a detection sensitivity of 7.943 × 10−3 μmol∙L−1∙Hz−1 over a concentration range of 1 to 100 μmol∙L−1. In conclusion, the label-free biosensing of DNA under dry conditions was successfully demonstrated using a microfabricated CMUT array with a 2 MHz frequency on CMOS electronics with an internal HV supplier. Moreover, ethylene–glycol alkanethiols successfully deposited self-assembled monolayers on aluminum electrodes, which has never been attempted thus far on CMUTs, to enhance the selectivity of bio-functionalization. The findings of this study indicate the possibility of full-on-chip DNA biosensing with CMUTs.

Development of the BAT-26 mutation-based electrochemical genosensor for identifying microsatellite instability in relationship to cancer

Screening for microsatellite instability is one of the biggest challenges in the cancer diagnosis due to its association with different types of cancer development. In this sense, the development of fast and highly sensitive analytical devices for early the cancer detection is a high priority. In the present work, a highly sensitive electrochemistry genosensor is developed and described for BAT-26 mutation detection using: differential pulse voltammetry (DPV), and cyclic voltametric (CV) supported by scanning tunnel microscopy (STM). The redox reaction of Fe(CN)63−/4– was monitored to probe the presence DNA target. The results demonstrate that modifying the screen-printed gold electrode surface (SPGE) 250AT with a combination of 11-mercaptoundecanoic acid (MUA) and a single-stranded DNA oligonucleotide successfully altered the electrode's properties, particularly its affinity for detecting the BAT-26 mutation under physiological conditions. The genosensor exhibited a wide linear range (100 aM to 1 μM) and achieved a low detection limit of 71.74 aM under optimal parameters. These characteristics, coupled with its high sensitivity and rapid analysis time, make it a promising candidate for development into a portable microsatellite instability diagnostic kit.

Aptamers-based Strategies for the Treatment of Microbial Infections

Background: Nowadays, infectious diseases caused by bacteria are one of the major risks for the human population worldwide. Antimicrobial resistance determined the necessity to develop both, new drugs and therapeutic approaches as alternatives to antibiotics and novel methods to detect bacteria. Aptamers have revealed their potential in combating antimicrobial infections. Aptamers are small singlestranded DNA or RNA oligonucleotides obtained through an in vitro process able to bind several targets with high affinity and specificity. Objective: The aim of this review is to provide an overview of the state of the art of aptamer-based antimicrobial therapeutic strategies, new methods of detection of bacteria, and their potential use as delivery systems. Conclusion: Recent applications on research about aptamers suggest their important potential in discovering novel pharmacological tools for the treatment of microbial infections.

Synthetic eco-evolutionary dynamics in simple molecular environment.

The understanding of eco-evolutionary dynamics, and in particular the mechanism of coexistence of species, is still fragmentary and in need of test bench model systems. To this aim we developed a variant of SELEX in vitro selection to study the evolution of a population of ∼1015 single-strand DNA oligonucleotide 'individuals'. We begin with a seed of random sequences which we select via affinity capture from ∼1012 DNA oligomers of fixed sequence ('resources') over which they compete. At each cycle ('generation'), the ecosystem is replenished via PCR amplification of survivors. Massive parallel sequencing indicates that across generations the variety of sequences ('species') drastically decreases, while some of them become populous and dominate the ecosystem. The simplicity of our approach, in which survival is granted by hybridization, enables a quantitative investigation of fitness through a statistical analysis of binding energies. We find that the strength of individual resource binding dominates the selection in the first generations, while inter- and intra-individual interactions become important in later stages, in parallel with the emergence of prototypical forms of mutualism and parasitism.

Synthetic eco-evolutionary dynamics in simple molecular environment

The understanding of eco-evolutionary dynamics, and in particular the mechanism of coexistence of species, is still fragmentary and in need of test bench model systems. To this aim we developed a variant of SELEX in vitro selection to study the evolution of a population of ∼1015 single-strand DNA oligonucleotide ‘individuals’. We begin with a seed of random sequences which we select via affinity capture from ∼1012 DNA oligomers of fixed sequence (‘resources’) over which they compete. At each cycle (‘generation’), the ecosystem is replenished via PCR amplification of survivors. Massive parallel sequencing indicates that across generations the variety of sequences (‘species’) drastically decreases, while some of them become populous and dominate the ecosystem. The simplicity of our approach, in which survival is granted by hybridization, enables a quantitative investigation of fitness through a statistical analysis of binding energies. We find that the strength of individual resource binding dominates the selection in the first generations, while inter- and intra-individual interactions become important in later stages, in parallel with the emergence of prototypical forms of mutualism and parasitism.

Ionic Strength-Mediated "DNA Corona Defects" for Efficient Arrangement of Single-Walled Carbon Nanotubes.

Single-stranded DNA oligonucleotides wrapping on the surface of single-walled carbon nanotubes (SWCNTs), described as DNA corona, are often used as a dispersing agent for SWCNTs. The uneven distribution of DNA corona along SWCNTs is related to the photoelectric properties and the surface activity of SWCNTs. An ionic strength-mediated "DNA corona defects" (DCDs) strategy is proposed to acquire an exposed surface of SWCNTs (accessible surface) as large as possible while maintaining good dispersibility via modulating the conformation of DNA corona. By adjusting the solution ionic strength, the DNA corona phase transitioned from an even-distributed and loose conformation to a locally compact conformation. The resulting enlarged exposed surface of SWCNTs is called DCDs, which provide active sites for molecular adsorption. This strategy is applied for the arrangement of SWCNTs on DNA origami. SWCNTs with ≈11nm DCD, providing enough space for the adsorption of "capture ssDNA" (≈7nm width required for 24-nt) extended from DNA origami structures are fabricated. The DCD strategy has potential applications in SWCNT-based optoelectronic devices.

Sensing of gene expression in live cells using electrical impedance spectroscopy and DNA-functionalized gold nanoparticles

A novel electrical impedance spectroscopy-based method for non-destructive sensing of gene expression in living cells is presented. The approach used takes advantage of the robustness and responsiveness of electrical impedance spectroscopy and the highly specific and selective nature of DNA hybridization. The technique uses electrical impedance spectroscopy and gold nanoparticles functionalized with single-stranded DNA complementary to an mRNA of interest to provide reliable, real-time, and quantifiable data on gene expression in live cells. The system was validated by demonstrating specific detection of the uidA mRNA, which codes for the β-glucuronidase (GUS) enzyme, in Solanum lycopersicum MsK8 cells. Gold nanoparticles were functionalized with single-stranded DNA oligonucleotides consisting of either a sequence complementary to uidA mRNA or an arbitrary sequence. The DNA-functionalized gold nanoparticles were mixed with cell suspensions, allowing the gold nanoparticles to penetrate into the cells. The impedance spectra of suspensions of cells with gold nanoparticles inserted within them were then studied. In suspensions of uidA-expressing cells and gold nanoparticles functionalized with the complementary single-stranded DNA oligonucleotide, the impedance magnitude in the frequency range of interest was significantly higher (146 %) in comparison to all other controls. Due to its highly selective nature, the methodology has the potential to be used as a precision agricultural sensing system for accurate and real-time detection of markers of stress, viral infection, disease, and normal physiological activities.

Robust Enzymatic Production of DNA G-Quadruplex, Aptamer, DNAzyme, and Other Oligonucleotides: Applications for NMR.

Single-stranded DNA (ssDNA) oligonucleotides are widely used in biological research, therapeutics, biotechnology, and nanomachines. Large-scale enzymatic production of ssDNA oligonucleotides forming noncanonical structures has been difficult. Here, we present a simple and robust method named "palindrome-nicking-dependent amplification" (PaNDA) for enzymatic production of a large amount of ssDNA oligonucleotides. It utilizes a strand-displacing DNA polymerase and a nicking enzyme together with input DNA and deoxynucleotide triphosphates at 55 °C. Scaling up of PaNDA is straightforward due to its isothermal nature. The ssDNA products can easily be isolated through anion-exchange chromatography under nondenaturing conditions. We demonstrate applications of PaNDA to 13C/15N-labeling of various DNA strands, including a 22-nt telomere repeat G-quadruplex, a 26-nt therapeutic aptamer, and a 33-nt DNAzyme. The 13C/15N-labeling by PaNDA greatly facilitates the characterization of noncanonical DNA by nuclear magnetic resonance (NMR) spectroscopy. For example, the behavior of therapeutic DNA aptamers in human serum can be investigated.

APTAMERS: NANOMATERIALS AS A POTENTIAL AGENT FOR ANTIVIRAL THERAPEUTIC DRUG DELIVERY DEVELOPMENT: A SYSTEMATIC LITERATURE REVIEW

Chemotherapeutic experts have been utilised to cure a variety of disorders, but their practical application is restricted due to their regrettable selectivity and outrageous fundamental optional effects. Short single-stranded DNA or RNA oligonucleotides known as aptamers are released from randomised libraries and have strong propensity and differentiation towards targets like antibodies as well as characterised structures and ties to targets like proteins. They commonly suppress protein interactions while restricting proteins, which may elicit positive effects like threat. Aptamers have recently demonstrated their amazing promise for use in medicines, biosensors, and bioimaging thanks to a number of advantages, such as minimal immunogenicity, simplicity of giant degree blend, low pack to-bunch collection, genuinely substance modification, and programmability. At any rate, the steady for the most part accomplishment speed of aptamer is far from being brilliant, despite everything needs to overwhelm the gigantic obstruction in propensity, constancy for utilitarian application, explicit illness cell affirmation. The sensible method of controlling the binding execution of aptamers and dealing with their show in the practical application is of great significance and these single-abandoned DNA or RNA aptamers could outline with astoundingly poisonous chemotherapy drugs, hurts, strong RNAs or different particles as novel aptamer-drug structures, which are prepared to do endlessly out working on the obliging plentifulness and decreasing the critical danger of solutions and have unprecedented possible in living spaces for appointed ailment treatment. In this survey, we have extensively covered and summarised the ongoing improvements in the aptamer-drug structure philosophy for designated drug transport in the assessment methodologies of aptamers for unambiguous disease biomarkers. A modified strategy utilising aptamers could be a reliable system for quick and precise advancement of biopharmaceutics for use in infection-related treatment, especially in light of the enormous advances in modernised thinking for protein and RNA structure conjectures. Additionally, the likelihood of future conception is also summarised.

Cell-SELEX and application research of a DNA aptamer against esophageal squamous cell carcinoma (ESCC) cell line TE-1.

Esophageal cancer is a common cancer with high morbidity and mortality that severely threatens the safety and quality of human life. The strong metastatic nature of esophageal cancer enables it to metastasize more quickly and covertly, making it difficult for current diagnostic and treatment methods to achieve efficient early screening, as well as timely and effective treatment. As a promising solution, nucleic acid aptamers, a kind of special single-stranded DNA or RNA oligonucleotide selected by the Systematic Evolution of Ligands by Exponential Enrichment (SELEX) technology, can specifically bind with different molecular targets. In this paper, random DNA single-stranded oligonucleotides were used as the initial library. Using TE-1 cells and HEEC cells as targets, specific binding sequences were selected by 15 rounds of the cell-SELEX method, and the aptamer sequence that binds to TE-1 cells with the most specificity was obtained and named Te4. The Te4 aptamer was further validated for binding specificity, binding affinity, type of target, in vitro cytotoxicity when conjugated with DOX(Te4-DOX), and in vivo distribution. Results of in vitro validation showed that Te4 has outstanding binding specificity with a Kd value of 51.16 ± 5.52 nM, and the target type of Te4 was preliminarily identified as a membrane protein. Furthermore, the cytotoxicity experiment showed that Te4-DOX has specific cytotoxicity towards cultured TE-1 cells. Finally, the results of the in vivo distribution experiment showed that the Te4 aptamer is able to specifically target tumor regions in nude mice, showing great potential to be applied in future diagnosis and targeted therapy of esophageal cancer.

Generation of Specific Aptamers.

Nucleic acid aptamers are therapeutic agents consisting of short single-strand DNA or RNA oligonucleotides, which have the ability to bind to target therapeutic molecules with high affinity and specificity and have been developed as potent drugs for the treatment of rheumatoid arthritis. Aptamers have unique and advantageous features over antibodies, such as superior affinity with nano- or pico-molar dissociation constants and ease of chemical synthesis, modification, and inactivation by designing antisense sequences. In this chapter, using a DNA-oligonucleotide pool, the technology of proteoliposome-systematic evolution of ligands by exponential enrichment (SELEX) is introduced. By using this technique, potential therapeutic agents with high affinity and specificity could be obtained.

Novel RNA genosensor based on highly stable gold nanoparticles decorated phosphorene nanohybrid with graphene for highly sensitive and low-cost electrochemical detection of coconut cadang-cadang viroid.

Coconut cadang-cadang viroid (CCCVd) is an infectious single-stranded RNA (ssRNA) pathogen, which leads directly to the death of a large number of coconut palm trees and heavy economic loss to coconut farmers. Herein, a novel electrochemical impedance RNA genosensor is presented based on highly stable gold nanoparticles (AuNPs) decorated phosphorene (BP) nanohybrid with graphene (Gr) for highly sensitive, low-cost, and label-free detection of CCCVd. BP-AuNPs are environmentally friendly prepared by ultrasonic-assisted liquid-phase exfoliation of black phosphorus, accompanying direct reduction of chloroauric acid. Gr/BP-AuNPs are facilely prepared by the in situ growth of AuNPs onto the BP surface and its nanohybrid with Gr to improve environmental stability of BP. Gr/BP-AuNP-based RNA genosensor is fabricated by immobilizing the thiol-functionalized single-stranded DNA (ssDNA) oligonucleotide probe onto the surface of Gr/BP-AuNP-modified glassy carbon electrode via gold-thiol interactions, which served as an electrochemical genosensing platform for the label-free impedance detection of CCCVd by hybridization between the functionalized ssDNA probe and the complementary CCCVd ssRNA sequence in a wide linear range from 1.0 × 10-11 to 1.0 × 10-7M with a low limit of detection of 2.8 × 10-12M. This work supplies an experimental support and theoretical direction for the fabrication of RNA biosensors based on graphene-like materials and potential application for a specific diagnosis of plant RNA viral disease in Arecaceae planting industry.

Template-Assisted Assembly of Hybrid DNA/RNA Nanostructures Using Branched Oligodeoxy- and Oligoribonucleotides

A template-assisted assembly approach to a C24 fullerene-like double-stranded DNA polyhedral shell is proposed. The assembly employed a supramolecular oligonucleotide dendrimer as a 3D template that was obtained via the hybridization of siRNA strands and a single-stranded DNA oligonucleotide joined to three- or four-way branched junctions. A four-way branched oligonucleotide building block (a starlet) was designed for the assembly of the shell composed of three identical self-complementary DNA single strands and a single RNA strand for hybridization to the DNA oligonucleotides of the template. To prevent premature auto-hybridization of the self-complementary oligonucleotides in the starlet, a photolabile protecting group was introduced via the N3-substituted thymidine phosphoramidite. Cleavable linkers such as a disulfide linkage, RNase A sensitive triribonucleotides, and di- and trideoxynucleotides were incorporated into the starlet and template at specific points to guide the post-assembly disconnection of the shell from the template, and enzymatic disassembly of the template and the shell in biological media. At the same time, siRNA strands were modified with 2′-OMe ribonucleotides and phosphorothioate groups in certain positions to stabilize toward enzymatic digestion. We report herein a solid-phase synthesis of branched oligodeoxy and oligoribonucleotide building blocks for the DNA/RNA dendritic template and the branched DNA starlet for a template-assisted construction of a C24 fullerene-like DNA shell after initial molecular modeling, followed by the assembly of the shell around the DNA-coated RNA dendritic template, and visualization of the resulting nanostructure by transmission electron microscopy.

Nanofilm-enhanced electrochemical DNA sensing: a breakthrough for yellow rust detection in wheat

This study showcases the development of a genosensor utilizing a nanoscale NiO thin film. The genosensor is constructed on a glass substrate coated with tin-doped indium oxide (ITO) and is designed for the specific detection of DNA sequences associated with Puccinia striiformis f. sp. tritici (Pst), the causal agent of wheat yellow rust. The detection process relies on the utilization of methylene blue (MB) as an electrochemical indicator, with NiO acting as the matrix and the electrochemical measurement system serving as the transducer. Various single-stranded DNA oligonucleotide sequences related to Pst pathogenesis are employed as probes to enable sensing. The electrochemical response of the nanoscale bioelectrode is characterized and studied using two distinct electrochemical techniques, cyclic voltammetry (CV) and differential pulse voltammetry (DPV), in conjunction with a potentiostat. The detection ranges spans from 40 pg μl−1 to 115 ng μl−1, demonstrating a linear correlation with exceptional precision. The absence of DNA-based biosensors for the detection of Puccinia striiformis f. sp. tritici (Pst) has prompted the need for a new method to address the limitations associated with previously reported technologies. Although surface plasmon resonance (SPR) immunoassays have been reported for Pst detection, the development of DNA-based biosensors specifically tailored for Pst detection remains unexplored. Introducing a novel method aims to overcome the challenges and shortcomings of existing techniques, providing a new approach to detect and combat the devastating effects of Pst on wheat crops. By leveraging the advantages of DNA-based biosensors, such as their sensitive and precise detection capabilities, this new method seeks to enhance the accuracy and efficiency of Pst detection, ultimately contributing to the development of effective strategies for disease management and crop protection. The developed nanoscale electrochemical DNA sensor offers outstanding sensitivity, extended shelf life, and reliable recovery, effectively minimizing the likelihood of obtaining erroneous results. A significant highlight of this study is the first-time utilization of conserved sequences associated with pathogenesis in selected Pst strains for the development of a nanoscale genosensor.

Bioorthogonal Aptamer-ATTEC Conjugates for Degradation of Alpha-Synuclein via Autophagy-Lysosomal Pathway.

Autophagosome-tetheringcompound (ATTEC) technology has recently been emerging as a novel approach for degrading proteins of interest (POIs). However, it still faces great challenges in how to design target-specific ATTEC molecules. Aptamers are single-stranded DNA or RNA oligonucleotides that can recognize their target proteins with high specificity and affinity. Here, ATTEC is combined with aptamers for POIs degradation. As a proof of concept, pathological protein α-synuclein (α-syn) is chosen as the target and an efficient α-syn degrader is generated. Aptamer as a targeting warhead of α-syn is conjugated with LC3B-binding compound 5,7-dihydroxy-4-phenylcoumarin (DP) via bioorthogonal click reaction. It is demonstrated that the aptamer conjugated with DP is capable of clearing α-syn through LC3 and autophagic degradation. These results indicate that aptamer-based ATTECs are a versatile approach to degrade POIs by taking advantage of the well-defined different aptamers for targeting diverse proteins, which provides a new way for the design of ATTECs to degradation of targeted proteins.