Nanopores map the acid-base properties of a single site in a single DNA molecule.
Nucleic Acids Res
; 52(13): 7429-7436, 2024 Jul 22.
Article
em En
| MEDLINE
| ID: mdl-38884270
ABSTRACT
Nanopores are increasingly powerful tools for single molecule sensing, in particular, for sequencing DNA, RNA and peptides. This success has spurred efforts to sequence non-canonical nucleic acid bases and amino acids. While canonical DNA and RNA bases have pKas far from neutral, certain non-canonical bases, natural RNA modifications, and amino acids are known to have pKas near neutral pHs at which nanopore sequencing is typically performed. Previous reports have suggested that the nanopore signal may be sensitive to the protonation state of an individual moiety. We sequenced ion currents with the MspA nanopore using a single stranded DNA containing a single non-canonical DNA base (Z) at various pH conditions. The Z-base has a near-neutral pKa â¼ 7.8. We find that the measured ion current is remarkably sensitive to the protonation state of the Z-base. We demonstrate how nanopores can be used to localize and determine the pKa of individual moieties along a polymer. More broadly, these experiments provide a path to mapping different protonation sites along polymers and give insight in how to optimize sequencing of polymers that contain moieties with near-neutral pKas.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
DNA de Cadeia Simples
/
Nanoporos
Idioma:
En
Revista:
Nucleic Acids Res
Ano de publicação:
2024
Tipo de documento:
Article