Double nanohole optical tweezers visualize protein p53 suppressing unzipping of single DNA-hairpins

Date

2014-05

Authors

Kotnala, Abhay
Gordon, Reuven

Journal Title

Journal ISSN

Volume Title

Publisher

Biomedical Optics Express

Abstract

Here we report on the use of double-nanohole (DNH) optical tweezers as a label-free and free-solution single-molecule probe for protein–DNA interactions. Using this approach, we demonstrate the unzipping of individual 10 base pair DNA-hairpins, and quantify how tumor suppressor p53 protein delays the unzipping. From the Arrhenius behavior, we find the energy barrier to unzipping introduced by p53 to be 2 × 10−20 J, whereas cys135ser mutant p53 does not show suppression of unzipping, which gives clues to its functional inability to suppress tumor growth. This transformative approach to single molecule analysis allows for ultra-sensitive detection and quantification of protein–DNA interactions to revolutionize the fight against genetic diseases.

Description

Keywords

Optical tweezers, optical manipulation, Subwavelength structures, nanostructures, Biological sensing and sensors

Citation

Kotnala, A. & Gordon, R. (2014). Double nanohole optical tweezers visualize protein p53 suppressing unzipping of single DNA-hairpins. Biomedical Optics Express, 5(6), 1886-1894.