Structural characterization of α-galactosylated O-glycans from miniature pig kidney and endothelial cells

O-Glycan is a major oligosaccharide expressed on the surface of eukaryotic cells that plays a role in immune responses via cell-protein and cell-cell interaction. Unlike N-glycan and glycolipid-derived glycan, O-glycans have not been previously reported in pig organs. Here, we report the first instance of the identification of α1,3 galactosylated O-glycans from pig kidney and endothelial cells by using MALDI-TOF MS and nano-ESI MS/MS. The MALDI profile showed 28 O-glycans from miniature pig kidney and 18 O-glycans from pig endothelial cells. Among them, three potential α-galactosylated glycans considered as immunogenic antigens were identified by CID using ESI-MS/MS; Hexα1,3Hex-HexNAc-HexNAc, Hexα1,3Hex-Hex-HexNAc-HexNAc, and Hexα1,3Hex-Hex-Hex-Hex-HexNAc. This structural information on glycans will provide significant information to clinical studies regarding immune rejection responses induced by carbohydrate antigens during xenotransplantation.