Native and denatured bovine serum albumin. D.c. polarography, stripping voltammetry and constant current chronopotentiometry

Native and denatured states of bovine serum albumin (BSA) were studied by d.c. polarographic and voltammetric Brdicka catalytic responses (BCR) in cobalt-containing solution and by constant current chronopotentiometric stripping analysis (CPSA) in borate buffer, pH 9.3. We found that 90 nM denatured BSA produced catalytic peak H (around − 1.8 V vs. Ag/AgCl/3 M KCl). This peak was about 50-fold higher than the native protein under the same conditions. Qualitatively similar results were obtained also with other proteins in native and denatured states, such as human serum albumin, γ-globulin, myoglobin and α-crystallin. 2 nM denatured BSA produced a well-developed CPS peak (at accumulation time 5 min) while native BSA yielded almost no signal under the same conditions.