Interaction of Salicylic Acid with Bovine Hemoglobin and Effect of the Coexistent Metal Ion on the Reaction

ABSTRACT The interaction between bovine hemoglobin (BHb) and salicylic acid (SA) was investigated at different temperatures by fluorescence spectroscopy, as was the effect of common metal ions (Mg2+, Zn2+, Cu2+, Co2+, Fe3+, Ni2+) on the BHb–SA system. Results showed that the quenching mechanism of SA on BHb was a static quenching process. The electrostatic force played an important role in the conjugation reaction between BHb and SA. Besides, the values of Hill's coefficients were approximately equal to 1. Synchronous and CD spectra revealed that the microenvironment and the conformation of BHb were changed during the binding reaction.