Biopolymers and cell. 1992; 8 (3): 3 - 6

KLIMENKO I. V.

Polarization of Fluorescence and Viscosity of Microenvironment of Tryptophan Residues of Eukaryotic Tyrosyl-tRNA Synthetase

Summary

    Polarized spectra of intrinsic fluorescence of tyrosyl-tRNA synthetase from bovine liver have been studied. It is shown decreasing at polarization value from 0.37 to 0.05 along fluorescence spectrum in long wavelength field was caused both the change of energy transfer efficiency between tryptophanyl resudies, having different spectra of fluorescence, and relaxation process which appering in microenvironment of tryptophanyl resudies in enzyme after the photoexitation. The life time fluorescence of synthetase at room temperature has been determined in depending of emission wavelength (t=2.6±0.5 ns, Xem=337 nm). The viscosity of microenvironment of tryptophanyl resudies along the emission spectrum, that decreasing from 1.3 to 0.05 Pa•s in long wavelength field has been calculated by Levshin-Perren equation. The torsional mobility of tryptophan resudies in enzyme molecule has been estimated at different temperatures.