Structural analysis of α‐Gal and new non‐Gal carbohydrate epitopes from specific pathogen‐free miniature pig kidney

Authors:
Publisher website
Google Scholar
Abstract
The major barrier in transplantation of pig organs into humans is the presence of surface carbohydrate antigens (e.g., the Galα1‐3Galβ1‐4GlcNAc‐R (α‐Gal) epitope) expressed on pig endothelial cells. In this study, total N‐glycans from membrane glycoproteins derived from specific pathogen‐free miniature pig kidney are identified by MALDI‐TOF, negative ion ESI MS/MS and normal‐phase HPLC (NP‐HPLC) combined with exoglycosidase digestion. Over 100 N‐glycans, including sialylated and neutral types, were identified. As well as the known α‐Gal antigens, some of these glycans contained novel non‐Gal carbohydrate antigens such as (Neu5Gc‐Gal‐GlcNAc) and Galα1‐3Lewisx (Gal‐Gal‐(Fuc)GlcNAc) which have not been reported before in N‐glycans from pig organs. The ability of MALDI, ESI, and HPLC to measure the relative proportions of the glycans was evaluated. The HPLC resolution was insufficient for accurate work and some minor differences were noted in the ionization efficiencies of different glycan groups when measured by the two mass spectrometric techniques. However, the results indicated that the relative quantity of α‐Gal epitope was in the region of 50% of the complex glycans. High‐mannose type glycans were also abundant (35–43%) but appeared to be ionized more efficiently than the complex glycans by ESI than by MALDI.

This publication has 31 references indexed in Scilit: