INTERACTION OF BOVINE SERUM-ALBUMIN WITH METHYL-ORANGE IN ACIDIC SOLUTION

The interaction of methyl orange (MO) with bovine serum albumin (BSA) in acidic solution was investigated by a spectrophotometric method. It was considered that the combination of BSA with MO is due to the nonc ovalent binding forces. The color change during the binding process is because of the transformation of MO from free-acidic form into bound- basic form. The relationship between absorbance and concentrations of MO species was studied. The Scatchard model was discussed in a new poi nt of view. Two conditional constants, apparent binding constant and m aximum binding number, were proposed to express the binding ability of MO on BSA, and two linear regression equations were derived to estima te these two parameters. It was found that sodium chloride concentrati on and acidity have significantly effect on the binding reaction.