Small-Molecule Binding Aptamers: Selection Strategies, Characterization, and Applications.

Annamaria Ruscito,Maria C Derosa

doi:10.3389/fchem.2016.00014

Abstract

Aptamers are single-stranded, synthetic oligonucleotides that fold into 3-dimensional shapes capable of binding non-covalently with high affinity and specificity to a target molecule. They are generated via an in vitro process known as the Systematic Evolution of Ligands by EXponential enrichment, from which candidates are screened and characterized, and then used in various applications. These applications range from therapeutic uses to biosensors for target detection. Aptamers for small molecule targets such as toxins, antibiotics, molecular markers, drugs, and heavy metals will be the focus of this review. Their accurate detection is needed for the protection and wellbeing of humans and animals. However, the small molecular weights of these targets, including the drastic size difference between the target and the oligonucleotides, make it challenging to select, characterize, and apply aptamers for their detection. Thus, recent (since 2012) notable advances in small molecule aptamers, which have overcome some of these challenges, are presented here, while defining challenges that still exist are discussed.

Highlights

While DNA is generally known as the biological macromolecule responsible for the storage of hereditary information, it can act as an affinity probe or molecular recognition element for a variety of applications from therapeutics to biosensing
Aptamers are single-stranded, synthetic oligonucleotides (DNA or RNA) which fold into 3-dimensional shapes capable of binding non-covalently and with high affinity to a target molecule
The researchers of this study found sequence convergence and maximal binding at round 12, sequence families specific for the target began to emerge in round 8 where binding was observed

Summary

Introduction

While DNA is generally known as the biological macromolecule responsible for the storage of hereditary information, it can act as an affinity probe or molecular recognition element for a variety of applications from therapeutics to biosensing. A DNA molecule which functions as such is termed an aptamer. Aptamers are single-stranded, synthetic oligonucleotides (DNA or RNA) which fold into 3-dimensional shapes capable of binding non-covalently and with high affinity to a target molecule. They can bind with such specificity that they can differentiate enantiomers and molecules that differ by as little as one functional group. Aptamers are generated via an in vitro process known as the Systematic Evolution of Ligands by EXponential enrichment, known as SELEX. Tuerk and Gold (1990), aiming to find an RNA aptamer sequence that would bind T4 DNA polymerase, first termed the process. SELEX is made up of three main steps: selection, partitioning, and amplification (Figure 1)

Methods

Findings

Conclusion