Structural heterogeneity in DNA: temperature dependence of 2-aminopurine fluorescence in dinucleotides.
The fluorescent base analogue 2-aminopurine is a sensitive probe for local dynamics of DNA. Its fluorescence is quenched by interaction with the neighboring bases, but the underlying mechanisms are still under investigation. We studied 2-aminopurine fluorescence in dinucleotides with each of the natural bases. Consistently, two of the four fluorescence-decay components depend strongly on temperature. Our results indicate that these components are due to the excited-state dynamics of a single conformational state. We propose a variation of the gating model in which transient unstacking occurs in the excited state.
Somsen
Oscar J G
OJ
Wageningen University, Laboratory of Biophysics, P.O. Box 8128, 6700 ET Wageningen, The Netherlands. oscar.somsen@wur.nl
Keukens
Linda B
LB
de Keijzer
M Niels
MN
van Hoek
Arie
A
van Amerongen
Herbert
H
D015075:2-Aminopurine / Q000737:chemistry*; D004247:DNA / Q000737:chemistry*; D005453:Fluorescence; D009711:Nucleotides / Q000737:chemistry*; D012680:Sensitivity and Specificity; D013050:Spectrometry, Fluorescence / Q000379:methods; D013696:Temperature; D013997:Time Factors
D009711:Nucleotides; D015075:2-Aminopurine; D004247:DNA