Fluorophotometric Study on the Interaction Between Methotrexate and Serum Albumin

The combination of methotrexate(MTX) with bovine serum albumin (BSA) or human serum albumin (HSA) in aqueous solution was studied by fluorophotometry.It was shown that the combination constant were found to be 6.76×105 and 2.69×105L·mol-1 for BSA and HSA,and the number of binding sites (n) were 1.09 and 1.02,respectively.The mechanism of fluorescence quenching is a static quenching process.The binding distance between MTX and BSA or HSA and the rate of energy transfer were obtained based on the theory of Frester energy transfer.The effect of methotrexate on the configuration of BSA or HSA was also analyzed using synchronous fluorescence technique.