ABSTRACT

The binding of triprolidine hydrochloride, an Hj-receptor antagonist, to bovine serum albumin (BSA) was studied by equilibrium dialvsis (ED) method at various temperatures. Scatchard method of analvsis showed that the binding of triprolidine hydrochloride has two sets of association constants: the high affinity association constant SÇj) with Imv capacitv (nf and low affinity association constant (kf with high capacitv (n2), II ith the increase in temperature from 10 to 25°C the vahie of high affinity association constant increase d and again this vahie decreased at 30°C. Binding data siiggested the presence of three high affinity binding sites with k2 valiie of 2.9x106 M1 and ten low affinity binding sites with k2 valiie of 3.9x1ü5 M'1 at pH 7.4 and 25°C. Site-specific probe displacenient data siiggested that triprolidine hydrochloride binds to site 11, the benzodiazepine site, with a higher affinity, while to site 1, the warfa-rin site, with relatively lower affinity. The binding process involved in the triprolidine hvdrochloride-BSA interaction could not be concliided from the binding parameters obtained from the experimeiit because of the non-linear rela-tionship between temperature and association constants.