Synergetic inhibition of metal ions and genistein on α-glucosidase

Abstract

Inhibition of metal ions and synergetic inhibition of metal ions/genistein on α-glucosidase activity has been investigated. We have examined the inhibitory effect of Cu 2+, Ni 2+, Mg 2+, Fe 2+, Hg 2+, Zn 2+, Ca 2+, Pb 2+, Ag +, V 5+, V 4+ and Mn 2+ ions. The results show that the nature of the inhibition was reversible, slow-binding, non-competitive, and the K i values of some ions such as Cu 2+, Ni 2+ and Zn 2+ range from 10 −5 to 10 −6 M. Moreover, synergetic inhibitory effect of metal ions and genistein on α-glucosidase were studied with kinetics method. It is concluded that the inhibitory effect was much greater when both of them were added to the reactant solution simultaneously than that they were added, respectively, which suggests that the inhibitors seem to bind to the different sites of α-glucosidase at the same time. Furthermore, the mechanism of the synergetic inhibition was examined by spectrophotometry.