Synthesis of Nanovesicular Glutathione Peroxidase Mimics with a Selenenylsulfide-Bearing
Lipid
ABSTRACT
In this article, we describe the development of a nanosized-glutathione
peroxidase (GPx) mimic based on liposomes of which the amphiphilic selenenylsulfide
derivative (R−Se−S−R′) was incorporated into a lipid membrane. A lipid
membrane-compatible selenenylsulfide derivative, 1-oxoheadecyl- seleno-L-cysteine-methyl-Se-yl-S-L-penicillamine
methyl ester (OHSeP), was synthesized. X-ray photoelectron spectroscopy
revealed that the sulfur and selenium atoms of the OHSeP molecule formed
a selenenylsulfide linkage. The use of OHSeP easily allowed the introduction
of the seleno-Lcysteine (SeCys) moiety into the liposomal membranes by
mixing with the phosphatidylcholines (PCs), which gave rise to the GPx-like
catalytic activity because of the selenium atom in the SeCys moiety. The
penicillamine moiety of the OHSeP molecule incorporated into the OHSeP/PC
liposomes was thought to orient toward the outer water phase. The OHSeP/PC
liposomes generated the GPx-like catalytic activity, which was ascribed
to the SeCys moiety that was introduced into the PC-based liposomes. Consequently,
the lipid/water interface of the liposomal membranes could possibly provide
an effective colloidal platform for the development of water-soluble nanosized
GPx mimics.