title: The Toolbox for Modified Aptamers.
abstract: Aptamers are nucleic acid-based scaffolds that can bind with high affinity to a variety of biological targets. Aptamers are identified from large DNA or RNA libraries through a process of directed molecular evolution (SELEX). Chemical modification of nucleic acids considerably increases the functional and structural diversity of aptamer libraries and substantially increases the affinity of the aptamers. Additionally, modified aptamers exhibit much greater resistance to biodegradation. The evolutionary selection of modified aptamers is conditioned by the possibility of the enzymatic synthesis and replication of non-natural nucleic acids. Wild-type or mutant polymerases and their non-natural nucleotide substrates that can support SELEX are highlighted in the present review. A focus is made on the efforts to find the most suitable type of nucleotide modifications and the engineering of new polymerases. Post-SELEX modification as a complementary method will be briefly considered as well.
authors.affiliation: Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow, Russia. lapa@biochip.ru.
authors.forename: Sergey A
authors.initials: SA
authors.lastname: Lapa
authors.affiliation: Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow, Russia.
authors.forename: Alexander V
authors.initials: AV
authors.lastname: Chudinov
authors.affiliation: Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow, Russia.
authors.forename: Edward N
authors.initials: EN
authors.lastname: Timofeev
mesh_terms: D052157:Aptamers, Nucleotide / Q000737:chemistry; D004259:DNA-Directed DNA Polymerase / Q000235:genetics / Q000378:metabolism; D009711:Nucleotides / Q000737:chemistry; D052156:SELEX Aptamer Technique / Q000379:methods*
chemical_list: D052157:Aptamers, Nucleotide; D009711:Nucleotides; D004259:DNA-Directed DNA Polymerase
keywords: Aptamer; Modification; Molecular evolution; Non-natural nucleoside triphosphates; Nucleic acids; Nucleotides; PCR; Polymerases; Primer extension; SELEX