Structural Heterogeneity in DNA: Temperature Dependence of 2-Aminopurine Fluorescence in Dinucleotides

✍ Scribed by Oscar J. G. Somsen; Linda B. Keukens; M. Niels de Keijzer; Arie van Hoek; Herbert van Amerongen

• Book ID: 102116283
• Publisher: John Wiley and Sons
• Year: 2005
• Tongue: English
• Weight: 106 KB
• Volume: 6
• Category: Article
• ISSN: 1439-4235
• DOI: 10.1002/cphc.200400648

✦ Synopsis

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.