[Study on the binding reaction features between naphthol green B and bovine serum albumin by fluorescence...

At different temperatures, the binding of naphthol green B (NGB) to bovine serum albumin (BSA) was studied by the fluorescence spectroscopy, three-dimensional fluorescence spectrum, synchronous fluorescence spectrum and ultra-violet spectrum. It was shown that this compound has a quite strong ability to quench the fluorescence from BSA. After analyzing the fluorescence quenching data according to Sterm-Volmer equation and Lineweaver-Burk equation, it was found that BSA had reacted with naphthol green B and formed a new compound, the quenching action was due to static fluorescence quenching, and the action force was electrostatic interaction. According to the Lineweaver-Burk equation and thermodynamic equation, the average value of the binding constant (KLe: 1.411 x 10(5) L x mol(-1)), the thermodynamic parameters (DeltaHtheta: -5.707 kJ x mol(-1), DeltaGtheta: -30.25 kJ x mol(-1) and DeltaStheta: 79.95 J x K(-1)) and the amounts of binding sites (1.258) were obtained, providing important information for the research on the configuration modification of BSA because of the added naphthol green B, biological effects in a living body, and the coloration mechanism of naphthol green B.