Study on binding reaction between flucytosine and bovine serum albumin

The binding of flucytosine to bovine serum albumin (BSA) was studied by means of fluorescence and absorption spectra under the conditions of simulant clay physiology. It showed a powerful ability to quench the fluorescence launching from BSA. After analyzing the fluorescence quenching data by Stern-Voltner equation and Lineweaver-Burk double-reciprocal equation, it was found that they matched the latter better and so they belonged to static quenching. The binding constant was calculated to be 5.710 X 10(3) L(.)mol(-1) at 297 K. The binding locality was a distance 2.49 nm away from tryptophan residue-212 based on Fbrster's non-radiation energy transfer mechanism. The binding power is mainly the hydrogen bond and van der Waals force according to the thermodynamic parameters. The information of BSA conformation was acquired by synchronous fluorescence spectrum and three-dimensional fluorescence spectrum.