Direct measurements of base stacking interactions in DNA by single-molecule atomic-force spectroscopy.


Journal Article

We investigate the elasticity of two types of single-stranded synthetic DNA homopolydeoxynucletides, poly(dA) and poly(dT), by AFM-based single-molecule force spectroscopy. We find that poly(dT) exhibits the expected entropic elasticity behavior, while poly(dA) unexpectedly displays two overstretching transitions in the force-extension relationship. We suggest that these transitions, which occur at approximately 23 pN and approximately 113 pN, directly capture, for the first time, the mechanical signature of base-stacking interactions among adenines in DNA, in the absence of base pairing.

Full Text

Duke Authors

Cited Authors

  • Ke, C; Humeniuk, M; S-Gracz, H; Marszalek, PE

Published Date

  • July 5, 2007

Published In

Volume / Issue

  • 99 / 1

Start / End Page

  • 018302 -

PubMed ID

  • 17678193

Pubmed Central ID

  • 17678193

Electronic International Standard Serial Number (EISSN)

  • 1079-7114

International Standard Serial Number (ISSN)

  • 0031-9007

Digital Object Identifier (DOI)

  • 10.1103/physrevlett.99.018302


  • eng