[The research on the quenching of fluorescence spectra of TOP I by iodine anion].

Comparing the fluorescence spectra of tobacco peroxidase I (TOP I) solution and the solutions titrated by iodine anions, the number of binding locus and the binding constant of iodine anion to TOP I were calculated by using the modified Stern-Volmer equation. The mechanism of the quenching of fluorescence spectra and the distribution of tryptophane residues in the TOP I molecule were discussed.