Effect of inorganic anions on the binding of thyroxine by bovine serum albumin.
The fluorescence method was used to investigate the effect of inorganic anions, SCN-, I-, ClO4- and Br- on the binding of thyroxine (T4) by bovine serum albumin (BSA). The apparent binding constants were evaluated in 0.1M sodium phosphate buffer, pH 7.4 at 25 degrees C containing various concentrations of the anions up to 0.15M. Their values decreased at high anion concentrations. The effectiveness of anions in reducing T4 binding was in the following order: SCN- > I= > ClO4- > Br-. Thermodynamic parameters determined in the presence of 0.1M SCN- suggested that the hydrophobic interaction between T4 and BSA could be reduced by these inorganic anions.
Faculty of Pharmaceutical Sciences, Kinki University, Osaka, Japan.
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Okabe
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Hokaze
D000838:Anions / Q000494:pharmacology*; D001965:Bromides / Q000494:pharmacology; D003486:Cyanides / Q000494:pharmacology; D007454:Iodides / Q000494:pharmacology; D010472:Perchlorates / Q000494:pharmacology; D011485:Protein Binding; D012710:Serum Albumin, Bovine / Q000378:metabolism*; D017670:Sodium Compounds; D013974:Thyroxine / Q000378:metabolism*
D000838:Anions; D001965:Bromides; D003486:Cyanides; D007454:Iodides; D010472:Perchlorates; D017670:Sodium Compounds; D012710:Serum Albumin, Bovine; C031068:sodium perchlorate; D013974:Thyroxine