Characterization of paracetamol binding with normal and glycated human serum albumin assayed by a new electrochemical method

Abstract

In the present study the interactions between paracetamol (PC) and human serum albumin, in non-glycated (HSA) and glycated form (GHSA), were investigated using continuous cyclic voltammetry in acetate buffer pH 7.4. The results showed lack of significant changes in formal potential E0 and electrode reaction constant rate, ks, of PC. The decay in the drug current, after the addition of protein, showed a decrease in free drug concentration and formation of a biocomplex. The contentious coulometry was also used to determine the binding parameters. The binding constant and binding ratio for HSA and GHSA were 2.0×104 and 7.8×10 3 mol L-1, respectively, and the number of binding was 2:1 for HSA-PC and 1:1 for GHSA-PC. These results were confirmed by UV-Vis spectroscopy. Thus, the new electrochemical analysis method described here provides an easy and fast method for evaluation of drug-protein interactions with significant clinical implication in diabetes. © 2012 Sociedade Brasileira de Química.