Nucleic acid aptamers are short single-stranded DNA or RNA oligonucleotides that can bind to their targets with very high affinity and specificity, and are generally selected by a process referred to as systematic evolution of ligands by exponential enrichment. Conventional antibody-based therapeutic and diagnostic approach currently employed against biotoxins pose major limitations such as the requirement of a live animal for the in vivo enrichment of the antibody species, decreased stability, high production cost, and side effects. Aptamer technology is a viable alternative that can be used to combat these problems. Fully sequestered in vitro, aptamers eliminate the need for a living host. Furthermore, one of the key advantages of using aptamers instead of antibodies is that they can be selected against very weakly immunogenic and cytotoxic substances. In this review, we focus on nucleic acid aptamers developed against various biotoxins of plant, microorganism, or animal origin and show how ...
TY - JOUR. T1 - BODIPY-labeled fluorescent aptamer sensors for turn-on sensing of interferon-gamma and adenine compounds on cells. AU - Tsuchiya, Akira. AU - Hashim, Siti N.. AU - Ise, Shoko. AU - Furuhata, Takafumi. AU - Kawai, Kiyohiko. AU - Wakabayashi, Rie. AU - Goto, Masahiro. AU - Kamiya, Noriho. AU - Sando, Shinsuke. PY - 2016/1/1. Y1 - 2016/1/1. N2 - An on-cell aptamer sensor has the potential to reveal cell-cell communications by signalling molecules. We attempted to design new fluorescent aptamer sensors for the sensing of IFN-? and adenine compounds on cells. BODIPY-labeled external quencher-free aptamer sensors have allowed a turn-on detection of the target molecule with improved off/on efficiency.. AB - An on-cell aptamer sensor has the potential to reveal cell-cell communications by signalling molecules. We attempted to design new fluorescent aptamer sensors for the sensing of IFN-? and adenine compounds on cells. BODIPY-labeled external quencher-free aptamer sensors have allowed a ...
TY - JOUR. T1 - Nucleic Acid Aptamers as a Potential Nucleus Targeted Drug Delivery System. AU - Shrivastava, Garima. AU - Bakshi, Hamid A.. AU - Aljabali, Alaa A.. AU - Mishra, Vijay. AU - Faruck, Lukmanul Hakkim. AU - Charbe, Nitin B.. AU - Kesharwani, Prashant. AU - Chellappan, Dinesh Kumar. AU - Dua, Kamal. AU - Tambuwala, Murtaza M.. N1 - Email sent to journal requesting confirmation of publication date - awaiting reply (27/4/20). PY - 2020/1/31. Y1 - 2020/1/31. N2 - Background: Nucleus targeted drug delivery provides several opportunities for the treatment of fatal diseases such as cancer. However, the complex nucleocytoplasmic barriers pose significant challenges for delivering a drug directly and efficiently into the nucleus. Aptamers representing single-stranded DNA and RNA qualify as next-generation highly advanced and personalized medicinal agents that successfully inhibit the expression of certain proteins; possess extraordinary gene-expression for manoeuvring the diseased cells ...
TY - JOUR. T1 - Programmable hydrogels for the controlled release of therapeutic nucleic acid aptamers via reversible DNA hybridization. AU - Zhang, Xiaolong. AU - Battig, Mark R.. AU - Wang, Yong. N1 - Copyright: Copyright 2013 Elsevier B.V., All rights reserved.. PY - 2013/10/25. Y1 - 2013/10/25. N2 - Reversible DNA hybridization can be used as a new mechanism to control the sustained and triggered release of therapeutic oligonucleotides from hydrogels.. AB - Reversible DNA hybridization can be used as a new mechanism to control the sustained and triggered release of therapeutic oligonucleotides from hydrogels.. UR - http://www.scopus.com/inward/record.url?scp=84884614812&partnerID=8YFLogxK. UR - http://www.scopus.com/inward/citedby.url?scp=84884614812&partnerID=8YFLogxK. U2 - 10.1039/c3cc45594g. DO - 10.1039/c3cc45594g. M3 - Article. C2 - 24018965. AN - SCOPUS:84884614812. VL - 49. SP - 9600. EP - 9602. JO - Chemical Communications. JF - Chemical Communications. SN - 1359-7345. IS - 83. ER - ...
Human Immunodeficiency Virus (HIV) reverse transcriptase (RT) is the most common molecular target of current HIV treatments. Oligonucleotide aptamers bind and inhibit the RNA- and DNA-dependent polymerization activities of HIV RT. Libraries consisting of aptamers including 32, 70 or 80 nucleotide variable regions were previously screened by Systematic Evolution of Ligands by Exponential Enrichment (SELEX) against RT. Roughly half of the resulting aptamers were represented by pseudoknots with well defined signature sequences (the Family I), but also additional pseudoknots with little sequence convergence (Family II), and non-pseudoknot aptamers (Family III). Nucleic acid aptamers bind RT in the primer/template binding site. Aptamers are generally non-toxic and non-immunogenic molecules making them enticing drug prospects. Many aptamers inhibit DNA dependent DNA polymerization by RT from several phenotypically different recombinant viruses, but inhibition depends on a single amino acid mutation at ...
RNA APTAMERS AGAINST BAFF-R AS CELL-TYPE SPECIFIC DELIVERY AGENTS AND METHODS FOR THEIR USE - In one embodiment, a B cell specific aptamer-siRNA chimera is provided. The B cell specific aptamer-siRNa chimera may include an RNA aptamer that binds BAFF-R and an siRNA molecule conjugated to the RNA aptamer via a nucleotide linker. In another embodiment, a B cell specific RNA aptamer is provided. The RNA aptamer may be a molecule that binds to BAFF-R that has the sequence SEQ ID NO:37, SEQ ID NO:38 or SEQ ID NO:39. In some embodiments, the RNA aptamer is conjugated, via a nucleotide linker, to an siRNA molecule that suppresses expression of one or more target oncogenes in one or more B cells. In one aspect, the one or more target oncogenes are selected from Bcl6, Bcl2, STAT3, Cyclin D1, Cyclin E2 and c-myc. In another embodiment, methods for treating a B cell malignancy in a cancer patient are provided. Such methods may include administering a therapeutically effective amount of a therapeutic ...
Aptamer Solutions Ltd is a York based Biotechnology Company specialising in the custom selection of high-affinity and highly specific nucleic acid aptamers for use in the life sciences sector. Our proprietary automated high-throughput aptamer selection processes allow us to offer a flexible and competitive pricing structure for the development of RNA and DNA aptamers. In addition, we are about to launch a new complementary technology in the area of biomarker discovery.. Our proprietary aptamer based biomarker discovery platform and proprietary combinatorial libraries contain up to and over 1018 different molecules, this diversity and bespoke library design is fundamental to the success of the screening process. This technology enables us to greatly speed up the identification of novel biomarkers as well as diagnostics and/or therapeutic candidate molecules. This technology builds on one of the most powerful uses of aptamer technology, which is the ability for aptamers to be isolated against ...
Macugen (pegaptanib sodium injection) is a sterile, aqueous solution containing pegaptanib sodium for intravitreous injection. Macugen is supplied in a single-dose, pre-filled syringe.
Anti-thrombin aptamers are G-quadruplex-bearing oligonucleotides, which recognizes the exosites of human thrombin. The first anti-thrombin aptamer, TBA, was generated through via SELEX (Systematic Evolution of Ligands by Exponential Enrichment) technology in 1992 by L.C. Bock, J.J. Toole and colleagues. A second thrombin-binding aptamer, HD22, recognizes thrombin exosite II and was discovered in 1997 by NeXstar (now Gilead Sciences). These two aptamers have high affinity and good specificity and have been widely studied and used for the development of aptamer-based therapeutics and diagnostics. The aptamer TBA (also known as G15D, HTQ, HD1 or ARC183) is a 15-mer single-stranded DNA with the sequence 5-GGTTGGTGTGGTTGG-3. It interacts with the exosite I of human alpha-thrombin, which is the binding site of fibrinogen, so this aptamer acts as an anti-coagulant agent inhibiting the activation of fibrinogen as well as platelet aggregation. In addition, TBA shows good affinity and specificity ...
The demand has increased for sophisticated molecular tools with improved detection limits. Such molecules should be simple in structure, yet stable enough for clinical applications. Nucleic acid aptamers (NAAs) represent a class of molecules able to meet this demand. In particular, aptamers, a class of small nucleic acid ligands that are composed of single-stranded modified/unmodified RNA/DNA molecules, can be evolved from a complex library using Systematic Evolution of Ligands by EXponential enrichment (SELEX) against almost any molecule. Since its introduction in 1990, in stages, SELEX technology has itself undergone several modifications, improving selection and broadening the repertoire of targets. This review summarizes these milestones that have pushed the field forward, allowing researchers to generate aptamers that can potentially be applied as therapeutic and diagnostic agents.
An L-ribonucleic acid aptamer (L-RNA aptamer, trade name Spiegelmer - from German Spiegel mirror - by Noxxon Pharma) is an RNA-like molecule built from L-ribose units. It is an artificial oligonucleotide named for being a mirror image of natural oligonucleotides. L-RNA aptamers are a form of aptamers. Due to their L-nucleotides, they are highly resistant to degradation by nucleases. Spiegelmers are considered potential drugs and are currently being tested in clinical trials. Spiegelmers, built using L-ribose, are the enantiomers of natural oligonucleotides, which are made with D-ribose. Nucleic acid aptamers, including L-RNA aptamers, contain adenosine monophosphate, guanosine monophosphate, cytidine monophosphate, uridine monophosphate, a phosphate group, a nucleobase and a ribose sugar. Like other aptamers, L-RNA aptamers are able to bind molecules such as peptides, proteins, and substances of low molecular weight. The affinity of L-RNA aptamers to their target molecules often lies in the ...
70846 Oilseed contains sterols and related compounds with economic potential. The extraction and analysis of these compounds would be aided by the availability of highly selective aptamers with high affinities for their particular sterol ligands. This project will develop aptamers for use in microarrays to analyze and extract sterol contents of oil and other biological extracts. Bacterial expression vectors will be prepared from which the aptamers can be expressed in large quantities. In Phase I, one or more DNA aptamers for sitosterol will be selected. The aptamers will be evaluated for their specificity and affinity for sitosterol and related compounds. A bacterial expression vector will be developed from which aptamers can be prepared. Commercial Applications and Other Benefits as described by the awardee: Commercial applications include (1) the use of aptamers in the analysis and extraction of sitosterol and related compounds, and (2) a general method for economically mass-producing DNA ...
Apple Stem Pitting Virus of PSAH PearIsolate, DNA Aptamer, Biotinylated DNA Aptamers AD-107-B Apple Stem Pitting Virus of PSAH PearIsolate, DNA Aptamer, Biotinylated DNA Aptamers AD-107-B
Apple Stem Pitting Virus of PSAH PearIsolate, DNA Aptamer, Biotinylated DNA Aptamers AD-107-B Apple Stem Pitting Virus of PSAH PearIsolate, DNA Aptamer, Biotinylated DNA Aptamers AD-107-B
Human Neutrophil Elastase (DNA I) , DNA Aptamer, Biotinylated DNA Aptamers AD-155-B Human Neutrophil Elastase (DNA I) , DNA Aptamer, Biotinylated DNA Aptamers AD-155-B
After three decades, the human immunodeficiency virus type 1 (HIV-1) remains a global pandemic. It has been difficult to develop therapeutic agents and vaccines against HIV due partly to the virus s ability to mutate rapidly. As a result, there is a constant need to develop new therapeutic agents that target HIV-1. This research seeks to develop an RNA aptamer that would bind tightly to the Pre-Hairpin Intermediate state of the HIV-1 envelope glycoprotein gp41 to inhibit viral fusion. The project targets the envelope glycoprotein of HIV-1, gp41, with nucleic acid aptamers. Aptamers are selected from random pools (libraries) by an in vitro selection called Systematic Evolution of Ligands by Exponential Enrichment (SELEX). The aptamers go through rounds of selection, where the weak binders will be washed off in each round. Once these aptamers are developed, they will be tested for their ability to prevent viral membrane fusion, and their potential use in HIV therapeutics. ...
However, even among aptamers, those nucleic acid aptamers that are polynucleotides (i.e. high-molecular-weight compounds with nucleic acid bases and sugars bound together) are biological high-molecular-weight compounds that offer the below advantages not shown by peptides, proteins or antibodies, and it is hoped that they will be new molecular-targeted agents and molecular-recognition elements.. Advantages of nucleic acid aptamers ...
4DII: High-resolution structures of two complexes between thrombin and thrombin-binding aptamer shed light on the role of cations in the aptamer inhibitory activity.
Aptamers are nucleic acid-based ligands identified through a process of molecular evolution named SELEX (Systematic Evolution of Ligands by Exponential enrichment). During the last 10-15 years, numerous aptamers have been developed specifically against targets present on or associated with the surface of human cells or infectious pathogens such as viruses, bacteria, fungi or parasites. Several of the aptamers have been described as potent probes, rivalling antibodies, for use in flow cytometry or microscopy. Some have also been used as drugs by inhibiting or activating functions of their targets in a manner similar to neutralizing or agonistic antibodies. Additionally, it is straightforward to conjugate aptamers to other agents without losing their affinity and they have successfully been used in vitro and in vivo to deliver drugs, siRNA, nanoparticles or contrast agents to target cells. Hence, aptamers identified against cell surface biomarkers represent a promising class of ligands. This review
Aptamers are single-stranded oligonucleotides isolated via in vitro systematic evolution of ligands by exponential enrichment (SELEX),1,2 which can specifically bind to a wide range of targets including proteins, small molecules and metal ions.3 Aptamers offer several advantages as recognition elements for biosensor applications relative to antibodies. First, aptamers can be chemically synthesized with high reproducibility at relatively low cost.4,5 Second, the high chemical stability of DNA aptamers means that they can be used under harsher conditions and stored with a longer shelf life.6 Finally, it is possible to generate unstructured aptamers that form specific secondary structures such as three-way junctions7,8 or tertiary folds such as G-quadruplex structures9,10 upon target binding. Such target-induced conformational changes can be readily exploited for specific target detection in a variety of applications, including medical diagnostics, environmental monitoring and drug screening.11-13 ...
Standard DNA Aptamer Microarray from LC Sciences,Microarrays designed for DNA aptamer screening and binding optimization and built on the flexible and powerful Paraflo microfluidic on-chip synthesis platform. These microarrays are available as part of our comprehensive DNA/RNA Aptamer Microarray Service. Our Standar,biological,biology supply,biology supplies,biology product
ELRIG are busily preparing for the 8th Annual Drug Discovery conference which will be held at Manchester Convention Centre on 2nd & 3rd September 2014. The programme contain presentations from leading scientists across Europe and beyond, covering exciting advances in basic and translational aspects of drug discovery and brings together Academia, Biotech, Vendors and Pharma into a single community.. Aptamer Group are delighted to be invited back to the Innovation Zone (stand IZ12) for the second year running, where we will be exhibiting our new and exciting technologies. We have over 20 years combined expertise in the development of nucleic acid aptamers to peptides, proteins, cells, tissue samples, micro-organisms and small molecules.. Dr David Bunka, CTO, world leading high-throughput aptamer selection expert will be addressing the Target Validation audience on 3 September at 12.00 in Charter 1. Dr Bunka will be discussing how our technology enables us to greatly speed up the identification of ...
Background: RNA aptamers are small RNA molecules that bind antigens like antibodies and are currently being explored as alternatives to antibodies for diagnosis and therapy. A potential merit of aptamers is that they can be generated against native cellular antigens, such as those with unique post-translational modifications or receptor-ligand complexes, for which antibody generation can be difficult. Here, we report the use of a cell-based systematic enrichment approach (SELEX) to develop a novel Treg-binding RNA aptamer specific to IL2Rα-IL2 receptor-ligand complex.. Methods and Results:. A. Generation of Treg-binding aptamers:. We designed a cell-based SELEX strategy to generate RNA aptamers specific to human T regulatory (Treg) cells. The starting library consisted of random RNA aptamers with a structural diversity of ~1012. Aptamers against common T cell antigens were pre-cleared using CD4+CD25- Teff cells. Treg-binding aptamers were then positively selected using CD4+CD25+ Tregs from the ...
Multitasking by Multivalent Circular DNA Aptamers | Daniel A. Di Giusto; Sarah M. Knox; Yuching Lai; Gregory D. Tyrelle; May T. Aung; Garry C. King | download | BookSC. Download books for free. Find books
and / or polyclonal antibodies specific to a particular target for capture and / or quantitative detection. Most ELISAs employ a 96-well plate-based format. ELISAs are currently used in a wide range of industries, with wide-spread application for the detection of protein biomarkers in research, diagnostics and therapeutics. While antibody-based immunoassays have proven to be very sensitive and specific, there are some limitations which can be overcome with the ELASA, or Enzyme-Linked Aptamer Sorbent Assay. Unlike antibodies, aptamers can be selected for specific binding to poorly immunogenic and toxic compounds. Aptamers can also distinguish between highly conserved molecules. Chemical aptamer synthesis enables rapid, low-cost production of new batches with low lot-to-lot variability. As with traditional ELISAs, ELASAs can be direct, indirect, and sandwich assays. Several sandwich ELASA assays have been developed at Base Pair Biotechnologies. Biotinylated capture aptamers are typically bound to ...
Shigdar, Sarah, Lv, Li, Wang, Lifen and Duan, Wei 2016, Application of aptamers in histopathology. In Mayer, Gunter (ed), Nucleic acid aptamers : selection, characterization and application, Humana Press, New York, N.Y., pp.191-196, doi: 10.1007/978-1-4939-3197-2_16. ...
TY - JOUR. T1 - Oligonucleotide-based systems. T2 - DNA, microRNAs, DNA/RNA aptamers. AU - Jolly, Pawan. AU - Estrela, Pedro. AU - Ladomery, Michael. N1 - Special volume Biosensor technologies for detection of biomolecules (Ed: P. Estrela) PY - 2016/6/30. Y1 - 2016/6/30. N2 - There is an increasing number of applications that have been developed for oligonucleotide-based biosensing systems in genetics and biomedicine. Oligonucleotide-based biosensors are those where the probe to capture the analyte is a strand of DNA, RNA or a synthetic analogue to naturally occurring nucleic acids. This chapter will draw light upon various types of nucleic acids such as DNA, RNA (particularly microRNAs), their role and their application in biosensing. Also, it will cover DNA/RNA aptamers, which can be used as bioreceptors to a wide range of targets such as proteins, small molecules, bacteria and even cells. It will also highlight how the invention of synthetic oligonucleotides like PNA or LNA has pushed the ...
endothelial progenitor cells in a porcine myocardial infarction model. Nucleic Acid Therapeutics, 25: 20-26.. Ireson, C. and Kelland, L. (2006): Discovery and development of anticancer aptamers. Molecular Cancer Therapeuics, 5: 2957-2962.. Kaittanis, C., Santra, S. and Perez, J. (2010): Emerging nanotechnologybased strategies for the identification of microbial pathogenesis. Advanced Drug Delivery Reviews, 62: 408-442.Kanamori, H., Yuhashi, K., Uchiyama, Y., Kodama, T., and Ohnishi, S. (2009). In vitro selection of RNA aptamers that bind the RNAdependent RNA polymerase of hepatitis C virus: a possible role of GC-rich RNA motifs in NS5B binding. Virology, 388: 91-102.. Keefe, A., Pai, S. and Ellington, A. (2010). Aptamers as therapeutics. Nature Reviews Drug Discovery, 9: 537-550.. Kikuchi, K., Umehara, T., Fukuda, K., Hwang, J., Kuno, A., Hasegawa, T. and Nishikawa, S. (2003): RNA aptamers targeted to domain II of hepatitis C virus IRES that bind to its apical loop region. Journal of ...
The functionality of aptamers is similar to that of antibodies. Aptamer are selected for specific target molecules by an in vitro selection and amplification method called SELEX. They can recognise and bind their targets with high affinity and specificity. As single-stranded oligonucleotides, aptamers are able to fold into complex and stable three-dimensional structures, which allow them to specifically interact with their targets. Aptamers are receiving increasing attention as alternative affinity reagents and represent essential tools in both basic and applied research. Aptamers can be used to detect and characterise their targets but also to modify the activity of their targets. Therefore, they provide a broad range of applications, e.g., affinity enrichment, analytics, medical diagnostics, or therapy.. Research focuses ...
p,To further understand the transcriptome, new tools capable of measuring folding, interactions, and localization of RNA are needed. Although Förster resonance energy transfer (FRET) is an angle- and distance-dependent phenomenon, the majority of FRET measurements have been used to report distances, by assuming rotationally averaged donor-acceptor pairs. Angle-dependent FRET measurements have proven challenging for nucleic acids due to the difficulties in incorporating fluorophores rigidly into local substructures in a biocompatible manner. Fluorescence turn-on RNA aptamers are genetically encodable tags that appear to rigidly confine their cognate fluorophores, and thus have the potential to report angular-resolved FRET. Here, we use the fluorescent aptamers Broccoli and Mango-III as donor and acceptor, respectively, to measure the angular dependence of FRET. Joining the two fluorescent aptamers by a helix of variable length allowed systematic rotation of the acceptor fluorophore relative to ...
Aptamers are typically selected from libraries of random DNA (or RNA) sequences through systematic evolution of ligands by exponential enrichment (SELEX), which involves several rounds of alternating steps of partitioning of candidate oligonucleotides and their PCR amplification. Here we describe a protocol for non-SELEX selection of aptamers - a process that involves repetitive steps of partitioning with no amplification between them. Non-equilibrium capillary electrophoresis of equilibrium mixtures (NECEEM), which is a highly efficient affinity method, is used for partitioning. NECEEM also facilitates monitoring of bulk affinity of enriched libraries at every step of partitioning and screening of individual clones for their affinity to the target. NECEEM allows all clones to be screened prior to sequencing, so that only clones with suitable binding parameters are sequenced. The entire protocol can be completed in 1 wk, whereas conventional SELEX protocols take several weeks even in a specialized
Infectious diseases are a subject of public health safety. In case of events such as bioterrorism or food samples tainted with a disease causing bacteria or virus the standard traditional methods of detection of viral or bacterial detection are too slow. We have developed molecular probes known as ?aptamers? to detect infection with high specificity and sensitivity. Aptamer, a word derived from Latin ?aptus? meaning ?to fit?; are molecular probes which are generated using nucleic acids which recognize and bind their target with a very high affinity and specificity. Aptamers are evolved in vitro in a test tube for its target. Aptamers are generated using a screening process known an SELEX, which stands for Systematic Evolution of Ligands by Exponential Enrichment. A library of 10 14 to 10 16 unique sequences is synthesized. These sequences are fractionated based on interactions with the target for which the aptamer is generated. The weaker binding sequences are weeded out after each successive ...
https://mallikaratchylab.org/wp-content/uploads/2016/08/mallikaratchy-banner-wide.png 0 0 Prabodhika Mallikaratchy https://mallikaratchylab.org/wp-content/uploads/2016/08/mallikaratchy-banner-wide.png Prabodhika Mallikaratchy2009-07-30 07:30:062019-05-22 19:52:41Cell-specific aptamer probes for membrane protein elucidation in cancer cells ...
The adenosine aptamer was split into two halves and linked to a fluid liposome surface; addition of adenosine resulted in aptamer assembly, which did not occur if the split aptamer was attached to silica nanoparticles, demonstrating the feasibility of using aptamer probes to study diffusion within lipid membranes ...
Aptamers are an interesting class of molecules that have potential in many facets of human health. They are characterized by high affinity and specificity to their targets, are small in size, have similar properties to antibodies, but are made synthetically. All of these properties, among others, give aptamers the potential to diagnose, image and treat like no other molecules. By combining the unique properties of aptamers with the ever expanding field of nanotechnology and all it has to offer, we are entering a very promising new area of targeted nanodelivery treatments. These treatments have found success in the complex disease processes of cancer, eye and inflammatory diseases ...
LC Sciences provides unique aptamer microarray services using a novel µParaflo technology, a list of aptamer sequences, and sequence design software. The
We have recently described the isolation of 2-fluoropyrimidine-substituted RNA aptamers that bind selectively to disease-associated beta-sheet-rich forms of the prion protein, PrP, from a number of mammalian species. These aptamers inhibit the accumulation of protease-resistant forms of PrP in a prion-seeded, in vitro conversion assay. Here we identify the minimal portions of two of these aptamers that retain binding specificity. We determine their secondary structures by a combination of modeling and solution probing. Finally, we identify an internal site for biotinylation of a minimized, synthetic aptamer and use the resultant reagent in the detection of abnormal forms of PrP in vitro.
Aptamers, synthetic oligonucleotide‐based molecular recognition probes, have found use in a wide array of biosensing technologies based on their tight and highly selective binding to a variety of molecular targets
Membrane Accelerator and Membrane Rudder are both post-translational controlling device to regulate metabolic flux of the host cell. To connect this relatively isolated post-translational control system to genetic circuits, we employed RNA signal, which is present in cytoplasm. Rationally designed RNA D0 with MS2 and PP7 aptamer domain is recruited. When RNA molecule with this two aptamer domains is present in cells, their cognate aptamer binding proteins can thus aggregate together. Furthermore, if we place RNA D0 (with PP7 and MS2 aptamer domains) under various promoters regulated by different signals, approaches to induce dimerization would be expanded sharply. Thus, Membrane Rudder could sense much more signals. We constructed our device as demonstrated in Fig.3. In RNA-sensing Membrane Rudder, VioA, VioB, VioE and VioC with interacting Membrane Anchors constitutively aggregate. RNA D0, can aggregate with RNA aptamer binding protein MS2 and PP7. So when RNA D0 is present, VioD with ...
RNA interference (RNAi) is an important biological process that ultimately leads to suppression of gene expression. Activators of RNAi are typically s..
antibody-antibodies.com is the marketplace for research antibodies. Find the right antibody for your research needs. Enzymatic conjugation of multiple proteins on a DNA aptamer in a tail-specific manner.
An Aptamer-siRNA Chimera Suppresses HIV-1 Viral Loads and Protects from Helper CD4+ T Cell Decline in Humanized Mice. C. Preston Neff, Jiehua Zhou, Leila Remling, Jes Kuruvilla, Jane Zhang, Haitang Li, David Smith, Piotr Swiderski, John Rossi and Ramesh Akkina. Science Translational Medicine Vol 3: 66ra6. Yes faithful readers of the MIPnews, for the first time in history we have an MIP laboratory who has garnered back-to-back MIPublication of the Month honors! Ramesh Akkina and his collaborators at the City of Hope have come out with a very exciting approach to harness the awesome power of in vitro-evolved RNA aptamers and RNA interference. In this paper in the Science spin off Science Translational Medicine journal, they report on a form of superdrug that not only effectively targets HIV in cells but appears to overcome one of the main hurdles for these RNA-based technologies - effective in vivo delivery.. Ramesh et al make their superdrug in a very straightforward fashion on a ribonucleic ...
Aptamers are single-stranded RNA or DNA oligonucleotides, which could be screened and synthesized for specific target (including any cell type), using systematic evolution of ligands by exponential enrichment (SELEX) technology..... Read More ...
Kit 30500-050 Kit 30500-096 DNA marker 81-0020 DNA marker 81-0100 DNA marker 82-0100 DNA marker 82-0200 DNA marker 82-0500 DNA marker 82-1000 DNA marker 83-2500 DNA marker 83-5000 DNA Aptamers AD-155-B DNA Aptamers AD-155-F DNA Aptamers AD-155-U Peptide Aptamers AP-302-B Peptide Aptamers AP-302-F Peptide Aptamers AP-302-U Peptide Aptamers AP-304-B Peptide Aptamers AP-304-F Peptide Aptamers AP-304-U Peptide Aptamers AP-306-B Peptide Aptamers AP-306-F Peptide Aptamers AP-306-U Peptide Aptamers AP-308-B Peptide Aptamers AP-308-F Peptide Aptamers AP-308-U Peptide Aptamers AP-309-B Peptide Aptamers AP-309-F Peptide Aptamers AP-309-U Peptide Aptamers AP-310-B Peptide Aptamers AP-310-F Peptide Aptamers AP-310-U Peptide Aptamers AP-312-B Peptide Aptamers AP-312-F Peptide Aptamers AP-312-U Peptide Aptamers AP-315-B Peptide Aptamers AP-315-F Peptide Aptamers AP-315-U Peptide Aptamers AP-318-B Peptide Aptamers AP-318-F Peptide Aptamers AP-318-U Peptide Aptamers AP-319-B Peptide Aptamers AP-319-F Peptide Aptamers
TY - JOUR. T1 - Cancer-targeted Nucleic Acid Delivery and Quantum Dot Imaging Using EGF Receptor Aptamer-conjugated Lipid Nanoparticles. AU - Kim, Min Woo. AU - Jeong, Hwa Yeon. AU - Kang, Seong Jae. AU - Choi, Moon Jung. AU - You, Young Myoung. AU - Im, Chan Su. AU - Lee, Tae Sup. AU - Song, In Ho. AU - Lee, Chang Gun. AU - Rhee, Ki Jong. AU - Lee, Yeon Kyung. AU - Park, Yong Serk. PY - 2017/12/1. Y1 - 2017/12/1. N2 - Co-application of fluorescent quantum dot nanocrystals and therapeutics has recently become a promising theranostic methodology for cancer treatment. We developed a tumor-targeted lipid nanocarrier that demonstrates notable efficacy in gene delivery as well as tumor bio-imaging. Coupling of aptamer molecules against the EGF receptor (EGFR) to the distal termini of lipid nanoparticles provided the carrier with tumor-specific recognition capability. The cationic lipid component, referred to as O,O-dimyristyl-N-lysyl glutamate (DMKE), was able to effectively complex with anionic ...
TY - JOUR. T1 - First-in-human experience of an antidote-controlled anticoagulant using RNA aptamer technology. T2 - A phase 1a pharmacodynamic evaluation of a drug-antidote pair for the controlled regulation of factor IXa activity. AU - Dyke, Christopher K.. AU - Steinhubl, Steven R.. AU - Kleiman, Neal S.. AU - Cannon, Richard O.. AU - Aberle, Laura G.. AU - Lin, Min. AU - Myles, Shelley K.. AU - Melloni, Chiara. AU - Harrington, Robert A.. AU - Alexander, John H.. AU - Becker, Richard C.. AU - Rusconi, Christopher P.. N1 - Copyright: Copyright 2010 Elsevier B.V., All rights reserved.. PY - 2006/12. Y1 - 2006/12. N2 - BACKGROUND - Selectivity, titratability, rapidity of onset, and active reversibility are desirable pharmacological properties of anticoagulant therapy administered for acute indications and collectively represent an attractive platform to maximize patient safety. A novel anticoagulation system (REG1, Regado Biosciences), developed using a protein-binding oligonucleotide to factor ...
TY - JOUR. T1 - A novel RNA aptamer identifies plasma membrane ATP synthase beta subunit as an early marker and therapeutic target in aggressive cancer. AU - Speransky, S.. AU - Serafini, Paolo. AU - Caroli, J.. AU - Bicciato, S.. AU - Lippman, M. E.. AU - Bishopric, N. H.. PY - 2019/1/1. Y1 - 2019/1/1. N2 - Purpose: Primary breast and prostate cancers can be cured, but metastatic disease cannot. Identifying cell factors that predict metastatic potential could guide both prognosis and treatment. Methods: We used Cell-SELEX to screen an RNA aptamer library for differential binding to prostate cancer cell lines with high vs. low metastatic potential. Mass spectroscopy, immunoblot, and immunohistochemistry were used to identify and validate aptamer targets. Aptamer properties were tested in vitro, in xenograft models, and in clinical biopsies. Gene expression datasets were queried for target associations in cancer. Results: We identified a novel aptamer (Apt63) that binds to the beta subunit of F 1 ...
TY - JOUR. T1 - DNA aptamer-based sandwich microfluidic assays for dual quantification and multi-glycan profiling of cancer biomarkers. AU - Jolly, Pawan. AU - Damborsky, P.. AU - Madaboosi, N.. AU - Soares, R.R.G.. AU - Chu, V.. AU - Conde, J.P.. AU - Katrlik, J.. AU - Estrela, Pedro. PY - 2016/5/16. Y1 - 2016/5/16. N2 - Two novel sandwich-based immunoassays for prostate cancer (PCa) diagnosis are reported, in which the primary antibody for capture is replaced by a DNA aptamer. The assays, which can be performed in parallel, were developed in a microfluidic device and tested for the detection of free Prostate Specific Antigen (fPSA). A secondary antibody (Aptamer-Antibody Assay) or a lectin (Aptamer-Lectin Assay) is used to quantify, by chemiluminescence, both the amount of fPSA and its glycosylation levels. The use of aptamers enables a more reliable, selective and controlled sensing of the analyte. The dual approach provides sensitive detection of fPSA along with selective fPSA ...
TY - JOUR. T1 - A sensitive method to detect Escherichia coli based on immunomagnetic separation and real-time PCR amplification of aptamers. AU - Lee, Hye Jin. AU - Kim, Byoung Chan. AU - Kim, Kyung Woo. AU - Kim, Young Keun. AU - Kim, Jungbae. AU - Oh, Min Kyu. PY - 2009/8/15. Y1 - 2009/8/15. N2 - Aptamers, single-stranded nucleic acids, provide a unique opportunity as amplifiable molecules using polymerase chain reaction (PCR) as well as recognition molecules like antibodies. We report a highly sensitive detection of Escherichia coli by taking advantage of the aptamer amplification as well as the specific binding of aptamers onto E. coli. This unique approach consists of three steps. First, the target E. coli was captured by antibody-conjugated magnetic beads. Second, the RNA aptamers were bound onto the surface of captured E. coli in a sandwich way. Finally, the heat-released aptamers were amplified by using real-time reverse-transcriptase-PCR (RT-PCR). The aptamer amplification in this ...
Easy capture and easy release! The cover illustrates a nanostructured platform that combines silicon nanowire arrays and targeted DNA aptamers, realizing significant capture and efficient release of T lymphocytes. This method of capture and release provides an artful strategy to fulfill the demands of cell isolation and diagnostics, as reported by Dong Han, Shutao Wang, and co-workers on page 4376.. ...
Article Aptamer-based and DNAzyme-based biosensors for environmental monitoring. Aptamers and DNAzymes are small single-stranded nucleic acids that fold into a well-defined three-dimensional structure with high specificity to various ligands, such as...
Thrombin is an important serine protease in blood and a therapeutic biomarker. The aptamer-based assays for thrombin take advantage of unique features of nucleic acid aptamers in selection, preparation, stability, and modification of functional groups. Aptamer affinity capillary electrophoresis coupled with
Aptamer selection protocols, named cell-SELEX, have been developed to target trans-membrane proteins using whole living cells as target. This technique presents several advantages. (1) It does not...
摘要:A simple approach based on exfoliating and disintegrating treatments for graphite oxide, followed by hydrothermal synthesis, was developed to prepare water-soluble graphene quantum dots (GQDs). The as-prepared GQDs exhibited bright blue emission under ultraviolet irradiation (similar to 365 nm), and showed an excitation-independent photoluminescence feature. More importantly, a newly anodic electrochemiluminescence (ECL) was observed from the water-soluble GQDs with H2O2 as coreactant for the first time, and the ECL induced a strong light emission at a low potential (ca. 0.4 V vs. Ag/AgCl). The ECL mechanism is investigated in detail. Employing SiO2 nanospheres as signal carrier, a novel SiO2/GQDs ECL signal amplification labels were synthesized based on which a ultrasensitive ECL aptamer sensor was proposed. Under the optimized experimental conditions, the proposed ECL aptamer sensor exhibited excellent analytical performance for adenosine triphosphate (ATP) determination, ranging from ...
The present invention provides an aptamer-based calorimetric sensor system for determining the presence and optionally the concentration of an analyte in a sample. Methods of utilizing the sensor syst
There is currently an urgent need for biomarkers that can be used to monitor the efficacy of experimental therapies for Duchenne Muscular Dystrophy (DMD) in clinical trials. Identification of novel protein biomarkers has been limited due to the massive complexity of the serum proteome and the presence of a small number of very highly abundant proteins. Here we have utilised an aptamer-based proteomics approach to profile 1,129 proteins in the serum of wild-type and mdx (dystrophin deficient) mice. The serum levels of 96 proteins were found to be significantly altered (P | 0.001, q | 0.01) in mdx mice. Additionally, systemic treatment with a peptide-antisense oligonucleotide conjugate designed to induce Dmd exon skipping and recover dystrophin protein expression caused many of the differentially abundant serum proteins to be restored towards wild-type levels. Results for five leading candidate protein biomarkers (Pgam1, Tnni3, Camk2b, Cycs and Adamts5) were validated by ELISA in the mouse samples.
Some bioterrorism agents cause disease at very low infective doses and their presence can be masked by the environment. Therefore, ultrasensitive detection is required for homeland defense applications. In this Phase I research project, Operational Technologies Corporation (OpTech) proposes to couple DNA aptamers made by the Systematic Evolution of Ligands by Exponential Enrichment (SELEX) process to commercially available fluorescent nanoparticles (NPs, composed of chelated europium in polystyrene). OpTech will demonstrate aptamer-NP-mediated detection of a bacterial, viral, and toxin simulant at low levels. Fluorescent NPs are nanometer-sized plastic and metallic ¿beads¿ that endow superior sensitivity in clinical assays (up to zeptomolar [10-21] detection limits). OpTech also will couple the DNA aptamers to magnetic microbeads and demonstrate magnetic separation and purification of the bioterrorism agent simulants from natural water samples in conjunction with aptamer-fluorescent NP ...
For the development of K(+)-responsive RNA aptamers, we proposed a new general strategy that makes use of a G-quadruplex formation in response to K(+). This is the first report of developing an RNA aptamer that demonstrates ON/OFF switching of its target-binding activity by sensing the addition/removal of K(+).. ...
Molecular and Functional Characterization of ssDNA Aptamers that Specifically Bind Leishmania infantum PABP. . Biblioteca virtual para leer y descargar libros, documentos, trabajos y tesis universitarias en PDF. Material universiario, documentación y tareas realizadas por universitarios en nuestra biblioteca. Para descargar gratis y para leer online.
Trying to incorporate quantum dots into biological systems has proven difficult due to their lack of biocompatibility and the toxicity of heavy metals inside cells. Recently developed carbon nanodots retain the advantages of quantum dots, but can function in biological media. Xianogang Qu and researchers at the Chinese Academy of Sciences incorporated carbon nanodots in a thrombin detection assay using DNA aptamers. Thrombin contains two binding sites that are recognized by different aptamers on both a silica nanoparticle and carbon nanodot. The multi-binding site capabilities of aptamers allow for greater sensitivity when compared to single site antibodies, and the fluorescent signal of the carbon nanodot is only detected when bound to thrombin on the silica nanoparticle. Click on the paper below to read more, it will be free to read until November 16th.. Aptamer carbon nanodot sandwich used for fluorescent detection of protein ...
Data accumulated over the latest two decades have established that the serine protease urokinase-type plasminogen activator (uPA) is a potential therapeutic target in cancer. When designing inhibitors of the proteolytic activity of serine proteases, obtaining sufficient specificity is problematic, because the topology of the proteases active sites are highly similar. In an effort to generate highly specific uPA inhibitors with new inhibitory modalities, we isolated uPA-binding RNA aptamers by screening a library of 35 nucleotides long 2′-fluoro-pyrimidine RNA molecules using a version of human pro-uPA lacking the epidermal growth factor-like and kringle domains as bait. One pro-uPA-binding aptamer sequence, referred to as upanap-126, proved to be highly specific for human uPA. Upanap-126 delayed the proteolytic conversion of human pro-uPA to active uPA, but did not inhibit plasminogen activation catalyzed by two-chain uPA. The aptamer also inhibited the binding of pro-uPA to uPAR and the ...
Disclosed are single-stranded DNA molecules which bind adenosine or an adenosine-5-phosphate and methods for their production and isolation. Also disclosed are methods for producing and isolating related catalytic DNA molecules.
Pivotal Scientific Ltd and Base Pair Biotechnologies Partner to Expand Access to Novel Aptamer Technologies to Global Markets. Oxfordshire, UK and Texas, US, June 3, 2013 - Pivotal Scientific Ltd, a consultancy company specialising in developing the international growth of biotech SMEs, and Base Pair Biotechnologies, a specialist developer of novel aptamer based technologies for research and diagnostics, are pleased to announce their collaboration to expand the reach of Base Pair Biotechnologies products and services.. A mainstay of bioscience research is the antibody. Yet standard antibody technologies can take months to produce an antibody against a new target; a long time in the fast paced and global arena of the biosciences. Base Pair Biotechnologies patented development process can turn around aptamers - short strands of DNA or RNA that specifically bind a target with equal specificity and affinity to antibodies - in weeks instead of months, getting researchers the reagents they need ...
2. http://www3.interscience.wiley.com.ezp1.harvard.edu/cgi-bin/fulltext/110526995/PDFSTART This paper is also talking about how protein arrays can be self-assembled using DNA nanostructures in the shape of a lattice. The biotin-streptavidin interaction provides only one type of protein-ligand interaction; while it is possible to fuse other proteins with streptavidin, this process is both complicated and may affect the functionality of the proteins themselves during the process. They then introduce aptamers, which are DNA or RNA molecules that have the ability to bind to other molecules such as proteins, nucleic acids, organic compounds, and organisms. There are a wide range of aptamers suited to a variety of proteins that guarantee specificity and high affinity. This method has three components: the DNA lattice nanostructure, a DNA-docking site with the aptamer sequence that will bind the protein of interest to the nanostructure, and the protein itself. In the paper, they use the ...
Systemic administration of the noncompetitive NMDA-receptor antagonist, MK-801, has been proposed to model cognitive deficits similar to those seen in patients with schizophrenia. The present work investigated the ability of a dopamine-binding DNA aptamer to regulate these MK-801-induced cognitive deficits when injected into the nucleus accumbens. Rats were trained to bar press for chocolate pellet rewards then randomly assigned to receive an intra-accumbens injection of a DNA aptamer (200 nM; n = 7), tris buffer (n = 6) or a randomized DNA oligonucleotide (n = 7). Animals were then treated systemically with MK-801 (0.1 mg/kg) and tested for their ability to extinguish their bar pressing response. Two control groups were also included that did not receive MK-801. Data revealed that injection of Tris buffer or the random oligonucleotide sequence into the nucleus accumbens prior to treatment with MK-801 did not reduce the MK-801-induced extinction deficit. Animals continued to press at a high rate over
Background SELEX is a well established in vitro selection tool to analyze the structure of ligand-binding nucleic acid sequences called aptamers. Genomic SELEX transforms SELEX into a tool to discover novel, genomically encoded RNA or DNA sequences binding a ligand of interest, called genomic aptamers. Concerns have been raised regarding requirements imposed on RNA sequences undergoing SELEX selection. Methodology/Principal Findings To evaluate SELEX and assess the extent of these effects, we designed and performed a Neutral SELEX experiment omitting the selection step, such that the sequences are under the sole selective pressure of SELEXs amplification steps. Using high-throughput sequencing, we obtained thousands of full-length sequences from the initial genomic library and the pools after each of the 10 rounds of Neutral SELEX. We compared these to sequences obtained from a Genomic SELEX experiment deriving from the same initial library, but screening for RNAs binding with high affinity to the E.
Dynamical systems are often used to model biochemical and biological processes. In Seo et al. (2010, 2014) we studied two mathematical models of the iterative biochemical procedure known as SELEX (Systematic Evolution of Ligands by EXponential Enrichment): multiple target SELEX and alternate SELEX. It is the purpose of this paper to revisit the mathematics of these processes in the language of dynamical systems on compact manifolds but for a dynamical system on a manifold with compact closure. From the experimentalists point of view, multiple target SELEX provides a way of obtaining the best binding ligands to a pool of several fixed targets, whereas alternate SELEX provides a way to specify which of the best binding ligands also bind best to a specified subtarget. Because these procedures are iterative, it is natural to investigate them in the context of the theory of discrete dynamical systems. Although the iterative schemes are nonautonomous, they have the same limiting properties as two closely
CURRENT STEM CELL NEWS. 1. Bioengineered protein -The latest Therapeutic Invention to fight Leukemia. In a fascinating discovery US scientists have reported a bioengineered protein CD19-L, that can target the CD19-positive leukemic stem cells and destroy them Click to read more... 2. Worlds First RNA Aptamer -The chemical Guided missile against cancer. Deakin University medical scientists along with scientists in India and Australia have created the worlds first RNA aptamer which can act as a cell target missile against cancer cells that in future can help in designing Cell Therapy Bombs against Cancer cells Click to read more... 3. Reprogramming Cells may result in Genomic Aberrations, reveal studies. Recent studies have reported that reprogrammed stem cells exhibit a genomic instability that results in genetic mutations akin to mutations found in cancer cells which has lead to the conclusion that reprogrammed stem cells need to be extensively investigated before applied clinically Click to ...
A new Transparency Market Research report states that the global aptamers market stood at US$0.93 bn in 2012 and is predicted to reach US$4.3 bn by 2019. It...
FNAs), as described by Dr. S.K. Silverman, are DNA and RNA aptamers that bind targets, or they are deoxyribozymes (single stranded DNA) and ribozymes (RNA) that have catalytic activity.,cite,Silverman2012,/cite, Aptamers, Ribozymes, and Deoxyribozymes are grouped into three main categories that are further classified into either natural or artificial depending on their origin. The exception being Deoxyribozymes as they have yet to be discovered in a living organism. Although the first ribozyme was discovered only in the 1980s, the search for new and better FNAs continues. This has led the development of new methodologies, such as the SELEX ,cite,Stozack1990, Gold1990 ,/cite, or In vitro selection, as we strive to expand their potential both as tools for exploring biology and solving real world problem solving ...
AgNCs are complexes between few Ag atoms and a specific DNA sequence template to stabilize the clusters. In most cases, AgNCs are synthesized either at the 3 or 5 end of the template. Our results show that AgNCs can successfully be generated from a template embedded in the middle of a hybridization probe, used for the isothermal amplification of aptamers, called rolling circle amplification (RCA). RCA uses circular oligonucleotide probes to generate long, ssDNA molecules containing periodic repeats of the circular probe.[4][5] Previous works show that overexpression of aptamers by RCA increases target binding efficiency compared to monovalent aptamers.[6] The RCA concatemer combines both the aptamer and the fluorescent AgNC template. Subsequently synthetized AgNCs exhibit strong, robust and tunable fluorescence, eliminating the need for labeling.[7] Importantly, it has been shown that aptamer-AgNCs retain the same specificity and affinity for the cognate protein and that target binding results ...
View PROTEIN DETECTION for MB.BS.pptx from AA 1PROTEIN DETECTION Dr.Sajida Parveen Shaikh OBJECTIVES Define proteins List major body proteins in various body fluids. Proteinuria State Principle of
Flow cytometry has gained popularity and demand in the field of biology because of its accurate analysis and high throughput. The use of multiple lasers, affinity ligands and attached fluorophores allows simultaneous analysis of several markers expressed on thousands of cells per second (Figure 1). Some of the most widely used applications include drug testing, microbiological analysis of bacteria and viruses, cell phenotyping, stem cell research and most importantly detecting cancer cells. Aptamers compete with antibodies in many such applications, in which high-affinity and specificity ligands are needed. Moreover, low specificity and inconsistent labelling of antibodies may lead to significant loss of function and reliability in detecting the target of interest. In this regard, fluorescence-tagged aptamers have shown increased use in flow and imaging cytometry for detecting cells expressing distinct antigens.. ...
Riboswitches are defined as RNA domains at the 5-ends of mRNA that recognize small molecules and respond by changing their three-dimensional structure. This change in turn affects the translation of the mRNA or, sometimes, its premature termination, especially during protein synthesis in the cell, including microbial cells. A riboswitch can be defined as an RNA domain, usually in an mRNA molecule, that can bind a specific small molecule and alter its secondary structure. And this alteration in turn controls translation of the mRNA in the affected cell. Riboswitching as explained above is an important process in molecular biology because it helps to control biosynthetic pathways for amino acids and other metabolites in the cell of an organism. Riboswitches are mostly used to control biosynthetic pathways for amino acids, purines, and other metabolites produced in the cells of microbes.. One of the most interesting findings in molecular biology has been the discovery that RNA molecules can carry ...
The integration of anatomic, molecular, and genomic pathology into surgical pathology practice is conspicuous in oncology, where definition of molecular pathways important for specific tumors has enabled development of new biomarkers and innovative approaches to the detection of cancer and metastases. The so-called liquid biopsy includes a wide array of new technologies, including tumor-derived tumor vesicles and aptamer probes. The surgical pathologist will need to understand these new technologies and be aware of their advantages and pitfalls as they are applied into practice. Upon completion of this educational activity, participants should be able to:. ...
In this study, we investigated the efficacy of an LNA (locked nucleic acid)-modified DNA aptamer named RNV66 targeting VEGF against various breast cancer cell lines. Our results demonstrate that RNV66 efficiently inhibits breast cancer cell proliferation both in vitro and in vivo. Introduction of LNA nucleotides were crucial for higher efficacy. Furthermore, the binding interaction of RNV66 with VEGF was investigated using molecular dynamic simulations leading to the first computational model of the LNA aptamer-VEGF complex blocking its interaction with VEGF-receptor.. ...
My research interests lie in the interface of engineering, nanotechnology and biology towards the utilization of the fundamentals of biomolecular recognition in the development of ultra sensitive diagnostic assays to meet the urgent and critical need for the early diagnosis of disease. My research includes the use of standard biophysical techniques such as, fluorescence anisotropy and SPR to acquire a mechanistic understanding of the details of antibody-antigen and DNA aptamer -protein recognition. It extends to the development of nanoparticle-based assays with main focus on optimizing surface chemistry for controlling specificity and fine tuning of the ligand-analyte detection schemes.. ...
There is growing appreciation that small, non-coding RNAs can participate in gene regulation. Can small RNAs inhibit DNA-binding proteins? We have developed an artificial example by performing in vitro genetic selection experiments identifying a small RNA aptamer that competitively inhibits human transcription factor NF-kappaB binding to DNA in vitro. Optimization by yeast in vivo genetic selections resulted in an RNA that inhibits NF-kappaB in living yeast cells. We have solved the X-ray co-crystal structure of this unusual RNA/NF-I ...
The design and implementation of synthetic biological systems often require information on transcription and translation rates and on the impact of both RNA and protein levels on metabolic activities of host cells. Such information is needed when both strong and low levels of expression are desired, depending on the biologists goal, e.g. high production or cell localization of a protein, respectively. To date, however, quantitative information about the expression strength of a promoter is difficult to obtain due to the lack of noninvasive and quick approaches to measure the levels of RNA and protein in cells. Here, we engineer a fluorescence-based sensor that can provide information on both transcription strength and translation efficiency that is noninvasive, easily applied to a variety of promoters, and capable of providing results in a time frame that is short when compared to current technologies. The sensor is based on the use of an RNA aptamer (termed Spinach) and a fluorogen activating ...
There are surprisingly few ways to directly observe how cells and proteins work inside living creatures. Weian Zhao devised simple sensors that let scientists do exactly that.. Zhao starts by identifying a short, single-stranded piece of DNA called an aptamer that selectively binds with a protein or other biomolecule researchers are interested in. He attaches a fluorescent dye to the aptamer and then attaches the aptamer-dye combination to the surface of a type of stem cell, found in bone marrow and fat tissue, that homes in on inflamed tissue and tumors.. When the combination of dye, aptamer, and stem cell is injected into a living organism, the stem cell seeks out the targeted biomolecules. For example, if researchers want to look at unhealthy tissue, the aptamer latches onto the biomolecule suspected of being at the root of the problem, and the dye lights up or changes color.. By putting mice that have been injected with these sensors under a special microscope designed to hold a living ...
Press release - Transparency Market Research - Aptamer Market to Reflect Impressive Growth Rate by 2025 - published on openPR.com