"Fluorescent properties of an unnatural nucleobase, 2-amino-6-(2-thienyl)purine, in DNA and RNA fragments."

Mitsui T, Kimoto M, Yokoyama S, Hirao I



Published 2005-09-01 in Nucleic Acids Symp Ser (Oxf) volume (49):285-6 .

Pubmed ID: 17150745
DOI identifier: -

Abstract:
Nucleoside derivatives of 2-amino-6-(2-thienyl)purine (s) are fluorescent and can be site-specifically incorporated into RNA by transcription mediated by unnatural base pairs between s and its complementary bases. To utilize the fluorescent s base as a probe, we examined the fluorescent properties of s in DNA and RNA fragments. The nucleoside of s exhibited a fluorescence emission centered at 432 nm, characterized by two major excitation maxima (299 and 352 nm), and its quantum yield was 0.41 at pH 7.0. The fluorescence intensity of s in DNA fragments (12-mer) differed depending on circumstances such as the base components, stacking, and pairings. The s base was introduced into a tRNA at specific positions by specific transcription using the unnatural base pairs. The fluorescence intensity of s at each position reflected the local structural features of the tRNA molecules.


Entry added on: 2012-07-03 16:20:04.816560, by a user: magda