Selenoprotein L-inspired nano-vesicular peroxidase mimics based onamphiphilic
diselenides
ABSTRACT
In this study, we developed selenoprotein L-inspired nano-vesicular peroxidase
mimics based onamphiphilic diselenides. Selenocystine (SeCyst) was used
as the starting material for the synthesis offour liposomal membrane-compatible
diselenide derivatives (R−Se−Se−R’) with two hydrophobic tailsand a polar
part. The diselenide derivatives were successfully incorporated into the
phosphatidylcholine(PC)-based nano-vesicular scaffold. The results of the
particle diameter and zeta-potential measure-ments suggested that the functional
diselenide moiety was placed around the outer surface, not in thehydrophobic
interior, of the liposomal membrane structures. The GPx-like catalytic
activity of the dis-elenide/PC liposomes was determined by the conventional
NADPH method using glutathione as thereducing substrate. For three peroxide
substrates, i.e., hydrogen peroxide, organic tert-butyl hydroperox-ide
and cummen hydroperoxide, the cationic property-possessing diselenide derivatives
in the PC-basedliposomes resulted in a higher catalytic activity in comparison
to electrically neutral and anionic deriva-tives. Overall, the diselenide
derivatives at the surface of a liposomal colloidal scaffold could exert
aGPx-like catalytic activity in physiological aqueous media.