A comparison of surface properties for bovine serum albumin and human serum albumin - Dynamic/equilibrium surface tension and dilational modulus

The biological functionalities of Human Serum Albumin (HSA) and Bovine Serum Albumin (BSA) have been extensively studied in the literature. However, limited information is available on their surface properties [dy-namic/equilibrium surface tension (ST) and dilational modulus (E)]. This study compared the dynamic/equi-librium ST of HSA and BSA solutions and the E of the adsorbed films. A pendant bubble tensiometer was employed for measuring the relaxations of ST of HSA/BSA solutions at C = 0.01 - 90 (10-10 mol/cm3). The data revealed that while the dynamic ST of HSA(aq) and BSA(aq) exhibited a similar relaxation in general, the ST of HSA(aq) relaxed notably faster at the post-induction regime than BSA(aq). The equilibrium ST of both HSA and BSA was constant at 52.6 and 52.3 mN/m over a wide concentration range, C = 0.01 - 90 (10-10 mol/cm3). The E of HSA and BSA films exhibited a near-identical concentration dependency to each other: E was reasonably constant at -21 mN/m from C = 0.05 to 0.2 (10-10 mol/cm3), and at further concentration elevations, E rose notably, and eventually leveled off at -52 and -45 mN/m for HSA and BSA films, respectively.