Recent ligand binding studies of acrylodan conjugated protein revealed fluorescent lifetimes shorter than water-solvated acrylodan and prodan.1 It is believed that these fast decay components are due to amino acid interactions with the acrylodan chromophore leading to non-radiative energy or electron transfer quenching of the excited state.

Acrylodan is a useful probe for studying protein dynamics because of its polarity-dependent fluorescence and a reasonably large Stoke's shift.2,3 However, a complete solvent-dependent study has never been published that would enable discussion of protein enviroments in terms of solvent polarities. At Centenary, we are looking at steady-state and time-dependent fluorescence measurements of acrylodan and prodan in binary solvents with varying polarity and hydrogen bonding capabilities to elucidate the exact polarity dependence. Quantum mechanical calculations are also being performed to better understand the excited state properties.

References

  1. T. C. Messina and D. S. Talaga, "Free energy landscapes remodeled by ligand binding," Biophys. J. 93 579-585 (2007).

  2. F. G. Prendergast, M. Meyers, G. L. Carlson, S. Iida, and J. D. Potter, "Synthesis, Spectral Properties, and Use of 6-Acryloyl-2-dimethylaminonaphthalene (Acrylodan)," J. Biol. Chem. 258, 7541-7544 (1983).

  3. A. Kawski, P. Bojarski, and B. Kuklinski, "Excitation Wavelength Dependence of ACRYLODAN Fluorescence Spectra in Some Polar Solvents," Z. Naturforsch. 57a, 9497 (2002).

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