A. Angelakou et al., USE OF 1-ANILINO-8-NAPTHALENESULPHONATE AS AN ION PROBE FOR THE POTENTIOMETRIC STUDY OF THE BINDING OF SULFONAMIDES TO BOVINE SERUM-ALBUMINAND PLASMA, Journal of Pharmacy and Pharmacology, 45(5), 1993, pp. 434-438
The binding of sulphafurazole, sulphamethizole and sulphamethoxazole t
o bovine serum albumin (BSA) and human plasma has been studied in-vitr
o by potentiometry using an electrode selective for the ion probe 1-an
ilino-8-napthalenesulphonate (ANS). The method requires two separate p
otentiometric titrations of the binder solution with ANS in the absenc
e and in the presence of sulphonamides. ANS displaced sulphonamides fr
om the first-class of binding sites of both binders. The binding const
ants for sulphonamide-BSA interactions were higher than those for sulp
honamide-human plasma. The expansion of the least linear limit of the
response curve of the electrode down to 10(-7) M in the presence of BS
A was also demonstrated. The reverse reaction, i.e. the displacement o
f the probe from the binding sites induced by the sulphonamides, was a
lso explored. The proposed method is suitable for studying competitive
binding interactions in biological specimens.