Ca(II) -γ-Thionin complex: Interaction Studies by Differential Pulse Voltammetry and MALDI-TOF / MS

In this work we investigated the formation of a complex between γ-thionin SIα1 and Ca2+ using differential pulse voltammetry and MALDI-TOF / MS. A stoichiometry rate of one calcium ion per one SIα1 molecule was obtained. Kd values of 1.31 x 10-9 mol L-1, 2.63 x 10-8 mol L-1 and 2.71 x 10 -8 mol L-1 were determined for the Ca2+-SIα1 complex by three different methodologies. These findings contribute to a better understanding of the SIα1 inhibition mechanism towards insect and mammalian α-amylases.