Chemical Characterization of N-Linked Oligosaccharide As the Antigen Epitope Recognized by an Anti-Sperm Auto-Monoclonal Antibody, Ts4

摘要: Ts4, an anti-sperm auto-monoclonal antibody, possesses immunoreactivity to the acrosomal region of mouse epididymal spermatozoa. In addition, mAb shows specific reproduction-related regions such as testicular germ cells and early embryo. Our qualitative study previously showed that antigen epitope for Ts4 contained a N-linked common oligosaccharide (OS) chain on glycoproteins determined by Western blotting after treatment with several glycohydrolases. Since distribution Ts4-epitope is unique, OS in may have role(s) reproductive process. The aim this was clarify molecular structure Ts4-epitope, particularly its moiety. Using immunoprecipitation combined liquid chromatography multiple-stage mass spectrometry, candidate carbohydrate proposed be fucosylated agalacto-biantennary bisecting N-acetylglucosamine (GlcNAc) or N-acetylgalactosamine-GlcNAc motif. Further binding analyses using various lectins against Ts4-immunoprecipitants revealed Phaseolus vulgaris erythroagglutinin Pisum sativum agglutinin positive staining bands corresponding reactive proteins. Moreover, extract completely abrogated digestion β-N-acetylglucosaminidase. These results show contains N-glycan GlcNAc carrying fucose residues.