DYNAMIC AND THERMODYNAMIC EFFECTS OF GLYCEROL ON BOVINE SERUM-ALBUMININ AQUEOUS-SOLUTION - A TRYPTOPHAN PHOSPHORESCENCE STUDY

The phosphorescence decay of bovine serum albumin in water-glycerol so lutions at room temperature is analysed by the maximum entropy method. While in pure water the decay was found to be quasi-monoexponential, in water-glycerol mixtures it is associated with more complex lifetime distributions. This is a direct proof for the existence of multiple p rotein conformers, It was also found that the increase of the glycerol concentration induces a continuous shift of the lifetime pattern to l onger lifetimes. This effect is analysed in connection with the coupli ng between the solvent viscosity and the internal protein mobility. (C ) 1997 Elsevier Science S.A.