Red-edge excitation fluorescence spectroscopy of proteins in reversed micelles.
The dependence of fluorescence emission maxima of L-tryptophan and single-tryptophan-containing proteins (ribonuclease T1, melittin, and parvalbumin) on excitation wavelength has been studied in reversed micelle systems of sodium bis(2-ethyl-1-oxyl) sulfosuccinate (AOT). No effect of fluorescence maximum shift for different excitation wavelengths is observed for ribonuclease T1, in which a single tryptophan residue is located in the nonrelaxating, nonpolar protein interior. L-Tryptophan and the rest of the studied proteins, which contain single tryptophan residues exposed to the solvent, exhibit the dipolar relaxational processes of partly immobilized water molecules in micelles. This effect depends on the molar H2O/AOT ratio. Circular dichroism measurements prove that there have been no structural changes of the studied proteins in micellar systems. The results provide information about dynamic relaxational processes in proteins.
Guz
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A
Department of Physical Biochemistry, Jagiellonian University, Kraków, Poland.
Wasylewski
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D000818:Animals; D002942:Circular Dichroism; D004143:Dioctyl Sulfosuccinic Acid; D005399:Fishes; D008555:Melitten / Q000737:chemistry; D008823:Micelles; D010320:Parvalbumins / Q000737:chemistry; D011487:Protein Conformation; D011506:Proteins / Q000737:chemistry*; D006163:Ribonuclease T1 / Q000737:chemistry; D013050:Spectrometry, Fluorescence / Q000379:methods*; D014364:Tryptophan / Q000032:analysis
D008823:Micelles; D010320:Parvalbumins; D011506:Proteins; D004143:Dioctyl Sulfosuccinic Acid; D008555:Melitten; D014364:Tryptophan; D006163:Ribonuclease T1