Abstract
The technique of 10 GHz frequency-domain fluorometry was used to resolve the complex picosecond intensity and anisotropy decays of the tyrosyl emission of [Leu5] enkephalin. Enhanced resolution of anisotropy decay was obtained by using acrylamide quenching of the tyrosyl fluorescence and global analysis of the frequency-domain anisotropy data obtained with different amounts of acrylamide. The data indicates a 44 ps correlation time for local tyrosine motions, and a 219 ps correlation time for overall rotational diffusion of the pentapeptide. Our data are consistent with an initial loss of fluorescence anisotropy from r0 = 0.4 to a value of r0 = 0.326 occurring during the first two picoseconds after excitation.
Original language | English |
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Pages (from-to) | 33-40 |
Number of pages | 8 |
Journal | Biophysical Chemistry |
Volume | 47 |
Issue number | 1 |
DOIs | |
State | Published - Jul 1993 |
Keywords
- Anisotropy decays
- Fluorescence spectroscopy
- Frequency-domain fluorometry
- Molecular dynamics
- [Leu] enkephalin