Acarbose binding to human serum albumin studied by affinity capillary electrophoresis

ABSTRACT

The equilibrium interaction between acarbose and albumin was studied using affinity capillary electrophoresis. The migration time of albumin was shown to increase as a result of increasing concentration of acarbose within the sample. Peak area of albumin was decreasing as a result of acarbose binding. The progressive decrease in peak area associated with increasing acarbose concentration was employed to obtain Scatchard plot and consequently the binding constant. The estimated binding constant was 6.7 x 10[-4] M[-1]. The rather unexpected increase in migration time of albumin as a result of acarbose binding was explained in terms of potential change in the three dimensional structure of albumin. Such structural changes might facilitate the binding of other compounds such as digoxin. Therefore, these findings might explain the frequently reported decrease in free digoxin concentration when given concomitantly with acarbose