scholarly journals In Silico Selection of Gp120 ssDNA Aptamer to HIV-1

2020 ◽  
Vol 25 (9) ◽  
pp. 1087-1093
Author(s):  
Hamideh Sepehri Zarandi ◽  
Mandana Behbahani ◽  
Hassan Mohabatkar
Keyword(s):  
In Silico ◽  
Dna Aptamer ◽  
Surface Glycoprotein ◽  
Aptamer Selection ◽  
Glycoprotein Gp120 ◽  
Systematic Evolution ◽  
Exponential Enrichment ◽  
Hiv 1 ◽  
Aptamer Sequence ◽  
Selection Of

Nucleic acid aptamers that specifically bind to other molecules are mostly obtained through the systematic evolution of ligands by exponential enrichment (SELEX). Because SELEX is a time-consuming procedure, the in silico design of specific aptamers has recently become a progressive approach. HIV-1 surface glycoprotein gp120, which is involved in the early stages of HIV-1 infection, is an attractive target for RNA and DNA aptamer selection. In this study, four single-stranded DNA aptamers, referred to as HD2, HD3, HD4, and HD5, that had the ability of HIV-1 inhibition were designed in silico. In a proposed non-SELEX approach, some parts of the B40 aptamer sequence, which interacted with gp120, were isolated and considered as a separate aptamer sequence. Then, to obtain the best docking scores of the HDOCK server and Hex software, some modifications, insertions, and deletions were applied to each selected sequence. Finally, the cytotoxicity and HIV inhibition of the selected aptamers were evaluated experimentally. Results demonstrated that the selected aptamers could inhibit HIV-1 infection by up to 80%, without any cytotoxicity. Therefore, this new non-SELEX approach could be considered a simple, fast, and efficient method for aptamer selection.

scholarly journals Capture-SELEX: Selection of DNA Aptamers for Aminoglycoside Antibiotics

2012 ◽  
Vol 2012 ◽  
pp. 1-14 ◽  
Author(s):  
Regina Stoltenburg ◽  
Nadia Nikolaus ◽  
Beate Strehlitz
Keyword(s):  
Magnetic Beads ◽  
Selection Process ◽  
Aminoglycoside Antibiotic ◽  
Dna Aptamer ◽  
Dna Aptamers ◽  
Common Procedure ◽  
Aptamer Selection ◽  
Starting Point ◽  
Exponential Enrichment ◽  
Selection Of

Small organic molecules are challenging targets for an aptamer selection using the SELEX technology (SELEX—Systematic Evolution of Ligans by EXponential enrichment). Often they are not suitable for immobilization on solid surfaces, which is a common procedure in known aptamer selection methods. The Capture-SELEX procedure allows the selection of DNA aptamers for solute targets. A special SELEX library was constructed with the aim to immobilize this library on magnetic beads or other surfaces. For this purpose a docking sequence was incorporated into the random region of the library enabling hybridization to a complementary oligo fixed on magnetic beads. Oligonucleotides of the library which exhibit high affinity to the target and a secondary structure fitting to the target are released from the beads for binding to the target during the aptamer selection process. The oligonucleotides of these binding complexes were amplified, purified, and immobilized via the docking sequence to the magnetic beads as the starting point of the following selection round. Based on this Capture-SELEX procedure, the successful DNA aptamer selection for the aminoglycoside antibiotic kanamycin A as a small molecule target is described.

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.

A single-round selection of selective DNA aptamers for mammalian cells by polymer-enhanced capillary transient isotachophoresis

The Analyst ◽  
2017 ◽  
Vol 142 (21) ◽  
pp. 4030-4038 ◽  
Author(s):  
Kazuki Hirose ◽  
Maho Tsuchida ◽  
Hinako Asakura ◽  
Koji Wakui ◽  
Keitaro Yoshimoto ◽  
...  
Keyword(s):  
Capillary Electrophoresis ◽  
Mammalian Cells ◽  
Dna Aptamer ◽  
Dna Aptamers ◽  
Aptamer Selection ◽  
Selection For ◽  
First Time ◽  
Selection Of

A single-round DNA aptamer selection for mammalian cells was successfully achieved for the first time using a capillary electrophoresis (CE)-based methodology.

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.

Systematic Evolution of Ligands by Exponential Enrichment Selection of Specific Aptamer for Sensing of Methamphetamine

2013 ◽  
Vol 11 (3) ◽  
pp. 566-570 ◽  
Author(s):  
Mohsen Ebrahimi ◽  
Hossein Hamzeiy ◽  
Jaleh Barar ◽  
Abolfazl Barzegari ◽  
Yadollah Omidi
Keyword(s):  
Systematic Evolution ◽  
Exponential Enrichment ◽  
Selection Of

Selection of aptamers specific for glycated hemoglobin and total hemoglobin using on-chip SELEX

Lab on a Chip ◽  
2015 ◽  
Vol 15 (2) ◽  
pp. 486-494 ◽  
Author(s):  
Hsin-I Lin ◽  
Ching-Chu Wu ◽  
Ching-Hsuan Yang ◽  
Ko-Wei Chang ◽  
Gwo-Bin Lee ◽  
...  
Keyword(s):  
Microfluidic Chip ◽  
Glycated Hemoglobin ◽  
Dna Aptamers ◽  
Single Stranded Dna ◽  
Total Hemoglobin ◽  
Systematic Evolution ◽  
On Chip ◽  
Exponential Enrichment ◽  
Selection Of

Selection of blood glycated hemoglobin (HbA1c)- and total hemoglobin (Hb)-specific single-stranded DNA aptamers was performed on a microfluidic chip to continuously and automatically carry out multiple rounds of systematic evolution of ligands by exponential enrichment (SELEX) processes.

scholarly journals Potent Inhibition of Human Immunodeficiency Virus Type 1 Replication by Template Analog Reverse Transcriptase Inhibitors Derived by SELEX (Systematic Evolution of Ligands by Exponential Enrichment)

2002 ◽  
Vol 76 (13) ◽  
pp. 6545-6557 ◽  
Author(s):  
Pheroze Joshi ◽  
Vinayaka R. Prasad
Keyword(s):  
Human Immunodeficiency Virus ◽  
Reverse Transcriptase ◽  
Human Immunodeficiency Virus Type ◽  
Virus Type ◽  
Pcr Analysis ◽  
Immunodeficiency Virus ◽  
Systematic Evolution ◽  
Exponential Enrichment ◽  
Hiv 1

ABSTRACT RNA aptamers derived by SELEX (systematic evolution of ligands by exponential enrichment) and specific for human immunodeficiency virus type 1 (HIV-1) reverse transcriptase (RT) bind at the template-primer cleft with high affinity and inhibit its activity. In order to determine the potential of such template analog RT inhibitors (TRTIs) to inhibit HIV-1 replication, 10 aptamers were expressed with flanking, self-cleaving ribozymes to generate aptamer RNA transcripts with minimal flanking sequences. From these, six aptamers (70.8,13, 70.15, 80.55,65, 70.28, 70.28t34, and 1.1) were selected based on binding constants (K d ) and the degree of inhibition of RT in vitro (50% inhibitory concentration [IC50]). These six aptamers were each stably expressed in 293T cells followed by transfection of a molecular clone of HIVR3B. Analysis of the virion particles revealed that the aptamers were encapsidated into the virions released and that the packaging of the viral genomic RNA or the cognate primer, tRNA3Lys, was apparently unaffected. Infectivity of virions produced from 293T cell lines expressing the aptamers, as measured by infecting LuSIV reporter cells, was reduced by 90 to 99.5% compared to virions released from cells not expressing any aptamers. PCR analysis of newly made viral DNA upon infection with virions containing any of the three aptamers with the strongest binding affinities (70.8,13, 70.15, and 80.55,65) showed that all three were able to form the minus-strand strong-stop DNA. However, virions with the aptamers 70.8 and 70.15 were defective for first-strand transfer, suggesting an early block in viral reverse transcription. Jurkat T cells expressing each of the three aptamers, when infected with HIVR3B, completely blocked the spread of HIV in culture. We found that the replication of nucleoside analog RT inhibitor-, nonnucleoside analog RT inhibitor-, and protease inhibitor-resistant viruses was strongly suppressed by the three aptamers. In addition, some of the HIV subtypes were severely inhibited (subtypes A, B, D, E, and F), while others were either moderately inhibited (subtypes C and O) or were naturally resistant to inhibition (chimeric A/D subtype). As virion-encapsidated TRTIs can predispose virions for inhibition immediately upon entry, they should prove to be efficacious agents in gene therapy approaches for AIDS.

scholarly journals Aptamers selection for platelets using droplet digital PCR

2021 ◽  
pp. 100-103
Author(s):  
A.V. Blagodatova ◽  
◽  
K.V. Kochkina ◽  
M.A. Komarova ◽  
N.Y. Trofina ◽  
...  
Keyword(s):  
Platelet Aggregation ◽  
Anticoagulant Activity ◽  
Digital Pcr ◽  
Droplet Digital Pcr ◽  
Platelet Glycoprotein ◽  
Systematic Evolution ◽  
Selection For ◽  
Exponential Enrichment ◽  
Selection Of

The aim of the research. To obtain aptamers-inhibitors of platelet glycoprotein IIb / IIIa receptors, blocking platelet aggregation. Material and methods. Th e selection of aptamers for IIb / IIIa receptors of platelets was carried out according to the SELEX method (Systematic Evolution of Ligands by Exponential Enrichment), modifi ed to select aptamers for a specifi c epitope. Th e method allows selection and in vitro evolution of aptamers with selectivity to a specifi c target from a large library of oligonucleotides. Th e affi nity of aptamers for platelet IIb / IIIa receptors was determined using fl ow cytometry. Results. Pools of aptamers of aptamers with high affi nity for IIb / IIIa platelet receptors were obtained. Th e study of the antiaggregation properties of the pools with the best binding showed that platelet aggregation was minimal when using the aptamers from the pool of the 5th round of selection. Th us, the aptamers of this pool have the greatest potential to be used as an analogue of a synthetic peptide that blocks thromboaggregation. Aptamers from this pool were taken for sequencing in order to obtain sequences of aptamers with the best antiaggregatory properties. Conclusion. Pools of aptamers with high affi nity for IIb / IIIa receptors of platelets and anticoagulant activity were obtained.

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.

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