title: Structural heterogeneity in DNA: temperature dependence of 2-aminopurine fluorescence in dinucleotides.
abstract: 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.
authors.affiliation: Wageningen University, Laboratory of Biophysics, P.O. Box 8128, 6700 ET Wageningen, The Netherlands. oscar.somsen@wur.nl
authors.forename: Oscar J G
authors.initials: OJ
authors.lastname: Somsen
authors.forename: Linda B
authors.initials: LB
authors.lastname: Keukens
authors.forename: M Niels
authors.initials: MN
authors.lastname: de Keijzer
authors.forename: Arie
authors.initials: A
authors.lastname: van Hoek
authors.forename: Herbert
authors.initials: H
authors.lastname: van Amerongen
mesh_terms: 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
chemical_list: D009711:Nucleotides; D015075:2-Aminopurine; D004247:DNA