scholarly journals Selection, Characterization, and Application of ssDNA Aptamer against Furaneol

Molecules ◽  
2018 ◽  
Vol 23 (12) ◽  
pp. 3159 ◽  
Author(s):  
Natalia Komarova ◽  
Mariia Andrianova ◽  
Sergey Glukhov ◽  
Alexander Kuznetsov
Keyword(s):  
Magnetic Beads ◽  
Aroma Compound ◽  
Fluorescent Method ◽  
Volatile Organic ◽  
Ssdna Aptamer ◽  
Effect Transistor ◽  
Systematic Evolution ◽  
Dna Pool ◽  
Exponential Enrichment ◽  
Apparent Equilibrium

Furaneol is an aroma compound which occurs naturally in foods and is used as an artificial flavor. Detection of furaneol is required in food science and food processing industry. Capture- Systematic Evolution of Ligands by EXponential enrichment (SELEX) protocol was applied for the isolation of an aptamer binding to furaneol, a small volatile organic substance contributing to the flavor of various products. Thirteen cycles of selection were performed. The resulting DNA pool was cloned, using blunt-end cloning, and ninety-six plasmids were sequenced and analyzed. Eight oligonucleotides were selected as aptamer candidates and screened for the ability to bind to furaneol, using three different methods—magnetic-beads associated elution assay, SYBR Green I assay, and exonuclease protection assay. One of the candidates was further characterized as an aptamer. The apparent equilibrium constant was determined to be (1.1 ± 0.4) µM, by the fluorescent method. The reported aptamer was applied for development of the ion-sensitive field-effect transistor (ISFET)-based biosensor, for the analysis of furaneol, in the concentration range of 0.1–10 µM.

scholarly journals Magnetic Beads in Marine Toxin Detection: A Review

2019 ◽  
Vol 5 (4) ◽  
pp. 62 ◽  
Author(s):  
Greta Gaiani ◽  
Ciara K. O’Sullivan ◽  
Mònica Campàs
Keyword(s):  
Human Health ◽  
Magnetic Beads ◽  
Marine Toxins ◽  
Marine Toxin ◽  
Efficient Detection ◽  
Fish Samples ◽  
Systematic Evolution ◽  
Potential Impact ◽  
Exponential Enrichment ◽  
Selection Of

Due to the expanding occurrence of marine toxins, and their potential impact on human health, there is an increased need for tools for their rapid and efficient detection. We give an overview of the use of magnetic beads (MBs) for the detection of marine toxins in shellfish and fish samples, with an emphasis on their incorporation into electrochemical biosensors. The use of MBs as supports for the immobilization of toxins or antibodies, as signal amplifiers as well as for target pre-concentration, is reviewed. In addition, the exploitation of MBs in Systematic Evolution of Ligands by Exponential enrichment (SELEX) for the selection of aptamers is presented. These MB-based strategies have led to the development of sensitive, simple, reliable and robust analytical systems for the detection of toxins in natural samples, with applicability in seafood safety and human health protection.

scholarly journals Preparation of a Specific ssDNA Aptamer for Brevetoxin-2 Using SELEX

2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Rui-Yun Tian ◽  
Chao Lin ◽  
Shi-Yu Yu ◽  
Sheng Gong ◽  
Pan Hu ◽  
...  
Keyword(s):  
Research Direction ◽  
High Affinity ◽  
Complex Processes ◽  
Ssdna Aptamer ◽  
Coefficient Corrélation ◽  
Recognition Probe ◽  
Detection Probe ◽  
Systematic Evolution ◽  
Alternative Detection ◽  
Exponential Enrichment

The existing assays for detecting brevetoxin (BTX) depend on expensive equipment with a professional operator or on an antibody with limited stability, which requires complex processes, a high cost, and a considerable amount of time. The development of an alternative detection probe is another promising research direction. This paper reports the use of aptamers binding to BTX-2 in an analytical assay using the systematic evolution of ligands by exponential enrichment (SELEX). After 12 rounds of selection, the secondary structures of 25 sequences were predicted. Compared to other aptamers, Bap5 has relatively high affinity with the lowest dissociation constant of 4.83 μM, and IC50is 73.81 ng mL−1. A good linear regression formula ofy=30.688x-7.329with a coefficient correlation ofR2= 0.9798 was obtained using a biotin-avidin ELISA. Moreover, there is no cross-reaction with the detected marine toxins, except for BTX-2. Thus, Bap5 has potential to detect BTX-2 in shellfish in the future as a substitute for the recognition probe.

scholarly journals A ssDNA Aptamer That Blocks the Function of the Anti-FLAG M2 Antibody

2011 ◽  
Vol 2011 ◽  
pp. 1-11 ◽  
Author(s):  
Amanda S. Lakamp ◽  
Michel M. Ouellette
Keyword(s):  
Lupus Erythematosus ◽  
Binding Pocket ◽  
Dna Aptamer ◽  
Commercial Application ◽  
Antigen Binding ◽  
Systemic Lupus ◽  
Therapeutic Modalities ◽  
Ssdna Aptamer ◽  
Systematic Evolution ◽  
Exponential Enrichment

Using SELEX (systematic evolution of ligands by exponential enrichment), we serendipitously discovered a ssDNA aptamer that binds selectively to the anti-FLAG M2 antibody. The aptamer consisted of two motifs (CCTTA and TGTCTWCC) separated by 2-3 bases, and the elimination of one or the other motif abrogated binding. The DNA aptamer and FLAG peptide competed for binding to the antigen-binding pocket of the M2 antibody. In addition, the aptamer eluted FLAG-tagged proteins from the antibody, suggesting a commercial application in protein purification. These findings demonstrate the feasibility of using SELEX to develop ssDNA aptamers that block the function of a specific antibody, a capability that could lead to the development of novel therapeutic modalities for patients with systemic lupus erythematosus, rheumatoid arthritis, and other autoimmune diseases.

FEATURES OF ORGANOPHOSPHATES IMMOBILIZATION VIA STREPTAVIDIN-BIOTIN SYSTEM FOR EXPERIMENTS ON SELECTION OF APTAMERS

2020 ◽  
pp. 12-20
Author(s):  
D. A. Belinskaya ◽  
Yu. V. Chelusnova ◽  
V. V. Abzianidze ◽  
N. V. Goncharov
Keyword(s):  
Polyethylene Glycol ◽  
Organophosphorus Compounds ◽  
Binding Energies ◽  
Rna Aptamers ◽  
Main Method ◽  
Modeling Methods ◽  
Molecular Dynamics Methods ◽  
Systematic Evolution ◽  
Exponential Enrichment ◽  
Selection Of

Poisoning with organophosphorus compounds occupy one of the leading places in exotoxicosis. At the first stage, the detoxification of organophosphates can be provided with the help of DNA or RNA aptamers that bind the poison in the bloodstream. Currently, the main method of searching for aptamers is the experimental method of systematic evolution of ligands by exponential enrichment (SELEX). In the process of aptamer selection, the target molecule must be immobilized via the streptavidin-biotin complex. Since the poison molecule is small in size, to increase its availability for binding to aptamer, it is necessary to use a spacer between organophosphorus compounds and biotin. The aim of this work was to optimize the selection of aptamers for organophosphorus compounds by increasing the availability of a poison molecule immobilized via the streptavidin-biotin complex on the example of paraoxon. For this purpose, three spacers between organophosphorus compounds and biotin were tested using molecular modeling methods: three links of polyethylene glycol (3-PEG), four links of polyethylene glycol (4-PEG) and aminohexyl. The conformation of the biotinylated paraoxon complex with streptavidin and the interaction of paraoxon with the binding fragment of the aptamer were modeled using molecular docking and molecular dynamics methods. The ability of biotinylated paraoxon to bind to the aptamer has been evaluated by analyzing the surface area of the paraoxon available to the solvent, as well as by calculating the free binding energies. It has been shown that only in the case of aminohexyl immobilized paraoxon can contact the aptamer. At the final stage, the synthesis of paraoxon bound to biotin via aminohexyl was carried out.

scholarly journals The interaction landscape between transcription factors and the nucleosome

2017 ◽  
Author(s):  
Fangjie Zhu ◽  
Lucas Farnung ◽  
Eevi Kaasinen ◽  
Biswajyoti Sahu ◽  
Yimeng Yin ◽  
...  
Keyword(s):  
Transcription Factors ◽  
Affinity Purification ◽  
Rotational Symmetry ◽  
Free Dna ◽  
Nucleosomal Dna ◽  
Direct Gene ◽  
Systematic Evolution ◽  
Modes Of Interaction ◽  
Exponential Enrichment ◽  
Rich Interaction

Nucleosomes cover most of the genome and are thought to be displaced by transcription factors (TFs) in regions that direct gene expression. However, the modes of interaction between TFs and nucleosomal DNA remain largely unknown. Here, we use nucleosome consecutive affinity-purification systematic evolution of ligands by exponential enrichment (NCAP-SELEX) to systematically explore interactions between the nucleosome and 220 TFs representing diverse structural families. Consistently with earlier observations, we find that the vast majority of TFs have less access to nucleosomal DNA than to free DNA. The motifs recovered from TFs bound to nucleosomal and free DNA are generally similar; however, steric hindrance and scaffolding by the nucleosome result in specific positioning and orientation of the motifs. Many TFs preferentially bind close to the end of nucleosomal DNA, or to periodic positions at its solvent-exposed side. TFs often also bind nucleosomal DNA in a particular orientation, because the nucleosome breaks the local rotational symmetry of DNA. Some TFs also specifically interact with DNA located at the dyad position where only one DNA gyre is wound, whereas other TFs prefer sites spanning two DNA gyres and bind specifically to each of them. Our work reveals striking differences in TF binding to free and nucleosomal DNA, and uncovers a rich interaction landscape between the TFs and the nucleosome.

Pattern recognition of enrichment levels of SELEX-based candidate aptamers for human C-reactive protein

2017 ◽  
Vol 62 (3) ◽  
Author(s):  
Xinliang Yu ◽  
Ruqin Yu ◽  
Xiaohai Yang
Keyword(s):  
Pattern Recognition ◽  
Latent Variables ◽  
Molecular Descriptors ◽  
Principal Component ◽  
Support Vector ◽  
C Reactive Protein ◽  
Reactive Protein ◽  
Systematic Evolution ◽  
Model C ◽  
Exponential Enrichment

AbstractSelecting aptamers for human C-reactive protein (CRP) would be of critical importance in predicting the risk for cardiovascular disease. The enrichment level of DNA aptamers is an important parameter for selecting candidate aptamers for further affinity and specificity determination. This paper is the first report on pattern recognition used for CRP aptamer enrichment levels in the systematic evolution of ligands by exponential enrichment (SELEX) process, by applying structure-activity relationship models. After generating 10 rounds of graphene oxide (GO)-SELEX and 1670 molecular descriptors, eight molecular descriptors were selected and five latent variables were then obtained with principal component analysis (PCA), to develop a support vector classification (SVC) model. The SVC model (C=8.1728 and

Differentiating breast cancer molecular subtypes using a DNA aptamer selected against MCF-7 cells

2018 ◽  
Vol 6 (12) ◽  
pp. 3152-3159 ◽  
Author(s):  
Mei Liu ◽  
Tong Yang ◽  
Zhongsi Chen ◽  
Zhifei Wang ◽  
Nongyue He
Keyword(s):  
Breast Cancer ◽  
Molecular Subtypes ◽  
Personalized Therapy ◽  
Dna Aptamer ◽  
Single Stranded Dna ◽  
Systematic Evolution ◽  
Exponential Enrichment ◽  
Mcf 7

Aptamers are single-stranded DNA or RNA oligonucleotides selected by systematic evolution of ligands by exponential enrichment (SELEX), which show great potential in the diagnosis and personalized therapy of cancers, due to their specific advantages over antibodies.

scholarly journals G-Quadruplex-Forming Aptamers—Characteristics, Applications, and Perspectives

Molecules ◽  
2019 ◽  
Vol 24 (20) ◽  
pp. 3781 ◽  
Author(s):  
Carolina Roxo ◽  
Weronika Kotkowiak ◽  
Anna Pasternak
Keyword(s):  
Nucleic Acid ◽  
Production Costs ◽  
Biological Processes ◽  
Disease Treatment ◽  
Diagnostic Potential ◽  
G Quadruplex ◽  
Fast Development ◽  
Systematic Evolution ◽  
Nucleic Acid Structures ◽  
Exponential Enrichment

G-quadruplexes constitute a unique class of nucleic acid structures formed by G-rich oligonucleotides of DNA- or RNA-type. Depending on their chemical nature, loops length, and localization in the sequence or structure molecularity, G-quadruplexes are highly polymorphic structures showing various folding topologies. They may be formed in the human genome where they are believed to play a pivotal role in the regulation of multiple biological processes such as replication, transcription, and translation. Thus, natural G-quadruplex structures became prospective targets for disease treatment. The fast development of systematic evolution of ligands by exponential enrichment (SELEX) technologies provided a number of G-rich aptamers revealing the potential of G-quadruplex structures as a promising molecular tool targeted toward various biologically important ligands. Because of their high stability, increased cellular uptake, ease of chemical modification, minor production costs, and convenient storage, G-rich aptamers became interesting therapeutic and diagnostic alternatives to antibodies. In this review, we describe the recent advances in the development of G-quadruplex based aptamers by focusing on the therapeutic and diagnostic potential of this exceptional class of nucleic acid structures.

scholarly journals Aptamers, the Nucleic Acid Antibodies, in Cancer Therapy

2020 ◽  
Vol 21 (8) ◽  
pp. 2793 ◽  
Author(s):  
Zhaoying Fu ◽  
Jim Xiang
Keyword(s):  
Monoclonal Antibody ◽  
Clinical Trials ◽  
Cancer Therapy ◽  
Specific Binding ◽  
High Specificity ◽  
Medical Community ◽  
Therapeutic Uses ◽  
Repeated Use ◽  
Systematic Evolution ◽  
Exponential Enrichment

The arrival of the monoclonal antibody (mAb) technology in the 1970s brought with it the hope of conquering cancers to the medical community. However, mAbs, on the whole, did not achieve the expected wonder in cancer therapy although they do have demonstrated successfulness in the treatment of a few types of cancers. In 1990, another technology of making biomolecules capable of specific binding appeared. This technique, systematic evolution of ligands by exponential enrichment (SELEX), can make aptamers, single-stranded DNAs or RNAs that bind targets with high specificity and affinity. Aptamers have some advantages over mAbs in therapeutic uses particularly because they have little or no immunogenicity, which means the feasibility of repeated use and fewer side effects. In this review, the general properties of the aptamer, the advantages and limitations of aptamers, the principle and procedure of aptamer production with SELEX, particularly the undergoing studies in aptamers for cancer therapy, and selected anticancer aptamers that have entered clinical trials or are under active investigations are summarized.

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