title: The mushroom Marasmius oreades lectin is a blood group type B agglutinin that recognizes the Galalpha 1,3Gal and Galalpha 1,3Galbeta 1,4GlcNAc porcine xenotransplantation epitopes with high affinity.
abstract: A blood group B-specific lectin from the mushroom Marasmius oreades (MOA) was investigated with respect to its molecular structure and carbohydrate binding properties. SDS-PAGE mass spectrometric analysis showed it to consist of an intact (H; 33 kDa) and truncated (L; 23 kDa) subunit in addition to a small polypeptide (P; 10 kDa). Isolation in the presence of EDTA produced only the H subunits, indicating that the latter two are formed by metalloprotease cleavage of the intact H subunit. Tryptic digestion of the H, L, and P polypeptide chains followed by mass spectral analysis supports this view. The lectin strongly precipitated blood group type B substance, was nonreactive with type A substance, and reacted weakly with type H substance. Carbohydrate binding studies reveal a high affinity for Galalpha1,3Gal (but not for the isomeric alpha1,2-, alpha1,4-, and alpha1,6-disaccharides); Galalpha1,3Galbeta1,4GlcNAc; and the type B branched trisaccharide. MOA also reacts strongly with murine laminin from the Engelbreth-Holm-Swarm sarcoma and bovine thyroglobulin, both of which contain multiple Galalpha1,3Galbeta1,4GlcNAc end groups. This linear B trisaccharide is a component of porcine tissues and organs, preventing their transplantation into humans. MOA also shares carbohydrate recognition of this trisaccharide with toxin A elaborated by Clostridium difficile.
authors.affiliation: Department of Biological Chemistry, University of Michigan, Medical School, Ann Arbor, Michigan 48109-0606, USA.
authors.forename: Harry C
authors.initials: HC
authors.lastname: Winter
authors.forename: Kazem
authors.initials: K
authors.lastname: Mostafapour
authors.forename: Irwin J
authors.initials: IJ
authors.lastname: Goldstein
mesh_terms: D000363:Agaricales / Q000737:chemistry*; D000373:Agglutinins / Q000737:chemistry / Q000276:immunology*; D000818:Animals; D002240:Carbohydrate Sequence; D002241:Carbohydrates / Q000276:immunology*; D002850:Chromatography, Gel; D002851:Chromatography, High Pressure Liquid; D004591:Electrophoresis, Polyacrylamide Gel; D000939:Epitopes / Q000737:chemistry / Q000276:immunology*; D037102:Lectins / Q000378:metabolism*; D008969:Molecular Sequence Data; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D013552:Swine; D014183:Transplantation, Heterologous
chemical_list: D000373:Agglutinins; D002241:Carbohydrates; D000939:Epitopes; D037102:Lectins