Switching on the Fluorescence of 2-aminopurine by Site-selective Microhydration

Sinha, Rajeev K (2014) Switching on the Fluorescence of 2-aminopurine by Site-selective Microhydration. Nature Chemistry, 6. pp. 989-993.

[img] PDF
2014_Nature-Chemistry-2AP.pdf - Published Version
Restricted to Registered users only

Download (1MB) | Request a copy

Abstract

2-Aminopurine (2AP) is a fluorescent isomer of adenine and has a fluorescence lifetime of ∼11 ns in water. It is widely used in biochemical settings as a site-specific fluorescent probe of DNA and RNA structure and base-flipping and -folding. These assays assume that 2AP is intrinsically strongly fluorescent. Here, we show this not to be the case, observing that gas-phase, jet-cooled 2-aminopurine and 9-methyl-2-aminopurine have very short fluorescence lifetimes (156 ps and 210 ps, respectively); they are, to all intents and purposes, non-fluorescent. We find that the lifetime of 2-aminopurine increases dramatically when it is part of a hydrate cluster, 2AP·(H2O)n, where n = 1–3. Not only does it depend on the presence of water molecules, it also depends on the specific hydrogen-bonding site to which they attach and on the number of H2O molecules at that site. We selectively microhydrate 2-aminopurine at its sugar-edge, cis-amino or transamino sites and see that its fluorescence lifetime increases by 4, 50 and 95 times (to 14.5 ns), respectively.

Item Type: Article
Subjects: Departments at MU > Atomic Molecular Physics
Depositing User: KMC Manipal
Date Deposited: 03 Feb 2015 05:05
Last Modified: 03 Feb 2015 05:05
URI: http://eprints.manipal.edu/id/eprint/141796

Actions (login required)

View Item View Item