Leuna Jules-Blaise Mabou, Sop Sergeot Kungo, Makota Suzanne, Njanja Evangeline, Ebelle Thiery Christophe, Azebaze Anatole Guy, Ngameni Emmanuel, Nassi Achille
Université de Yaoundé 1, Laboratoire de Chimie Analytique, Faculté des Sciences, B.P. 812 Yaoundé, Cameroon.
Université de Douala, Laboratoire de Chimie Minérale, Faculté des Sciences, B.P. 24157 Douala, Cameroon.
Bioelectrochemistry. 2018 Feb;119:20-25. doi: 10.1016/j.bioelechem.2017.08.008. Epub 2017 Sep 7.
The electrochemical oxidation of Mammeisin (MA) was studied in a solution containing acetone and 0.1M phosphate buffer +0.1M KCl (pH=5.3) at a glassy carbon electrode (GCE), using cyclic (CV) and square wave voltammetry (SWV). MA showed a quasi-reversible process, which is pH dependent and that involves the exchange of two electrons and two protons. The oxidation product was adsorbed by the electrode surface to form a film that blocks active sites over repetitive cyclic. Moreover, the interaction of MA and bovine serum albumin (BSA) was studied by CV and SWV at different pHs (5.4, 7.2, 9.5). As a result of the affinity binding with BSA, electrochemically inactive complex was formed. In addition, the oxidation potential of MA in the presence of BSA depends on the pH. The diffusion coefficients of both free and bound MA were estimated from the cyclic voltammetry data using the method developed by Randles-Sevich (D=9.85×10cms and D=1.27×10cms) and the binding constant of MA-BSA complex, K=3.47×10Lmol, was obtained.
在含有丙酮和0.1M磷酸盐缓冲液+0.1M氯化钾（pH = 5.3）的溶液中，于玻碳电极（GCE）上，采用循环伏安法（CV）和方波伏安法（SWV）研究了马米辛（MA）的电化学氧化。MA呈现出准可逆过程，该过程依赖于pH值，且涉及两个电子和两个质子的交换。氧化产物被电极表面吸附，形成一层膜，在重复循环过程中会阻塞活性位点。此外，通过CV和SWV在不同pH值（5.4、7.2、9.5）下研究了MA与牛血清白蛋白（BSA）的相互作用。由于与BSA的亲和结合，形成了电化学惰性复合物。此外，存在BSA时MA的氧化电位取决于pH值。使用Randles - Sevich开发的方法，根据循环伏安数据估算了游离和结合态MA的扩散系数（D = 9.85×10⁻⁵cm²/s和D = 1.27×10⁻⁵cm²/s），并获得了MA - BSA复合物的结合常数K = 3.47×10³L/mol。
