Biopolymers and cell. 1991. Volume 7. № 6. 83 - 88

KLIMENKO I. V., GUSCHA T. O., KORNELYUK A. I.

Properties of Tryptophan Fluorescence of Two Forms of Tyrosyl-tRNA Synthetase From Bovine Liver

Summary

    The properties of intrinsic tryptophan fluorescence of two forms (molecular weight 2X X59 000 and 2X39 000) of tyrosyl-tRNA synthetase from bovine liver have been studied. The contributions of exposed and internal tryptophan residues into fluorescence spectrum of tyrosyl-tRNA synthetase have been determined in terms of the model of discrete struc¬ture-physical classes of tryptophanyls in the proteins. The temperature dependence of pa¬rameters of tryptophan fluorescence testified that temperature-induced mobility of sepa¬rate protein fragments increased in temperature range from 40 °C to 75 °C. Analysis of temperature quenching of enzyme fluorescence in co-ordinate of the l/q(T) and l/q(T/r\) indicated that the mobility of synthetase in the solution was regulated by diffusion cha¬racteristics of the solvent. It is true both for surface and for internal parts of protein.