Conformation and dynamics of bovine brain S-100a protein determined by fluorescence spectroscopy

The intensity and anisotrophy decays of the single tryptophan in bovine brain S-100a (alpha, beta) protein were determined by time-resolved fluorescence spectroscopy. The effects of Ca2+-binding on the conformation of the protein was studied at pH 7. 2 and 8.4. The results show that the binding of calcium ion induces a conformational change in the protein and indicate differences in the localized and global conformations of the protein at the two pH values.