title: Fraction A of armadillo submandibular glycoprotein and its desialylated product as sialyl-Tn and Tn receptors for lectins.
abstract: Fraction A of the armadillo submandibular glycoprotein (ASG-A) is one of the simplest glycoproteins among mammalian salivary mucins. The carbohydrate side chains of this mucous glycoprotein have one-third of the NeuAc alpha 2-->6GalNAc (sialyl-Tn) sequence and two thirds of Tn (GalNAc alpha-->Ser/Thr) residues. Those of the desialylated product (ASG-Tn) are almost exclusively unsubstituted GalNAc residues (Tn determinant). When the binding properties of these glycoproteins were tested by a precipitin assay with Gal, GalNAc and GlcNAc specific lectins, it was found that ASG-Tn reacted strongly with all of the Tn-active lectins and completely precipitated Vicia villosa (VVL both B4 and mixture of A and B), Maclura pomifera (MPA), and Artocarpus integrifolia (jacalin) lectins. However, it precipitated poorly or negligibly with Ricinus communis (RCA1); Dolichos biflorus (DBA); Viscum album, ML-I; Arachis hypogaea (PNA), and Triticum vulgaris (WGA). The reactivity of ASG-A (sialyl-Tn) was as active as that of ASG-Tn with MPA and less or slightly less active than that of ASG-Tn with VVL-A+B, VVL-B4, HPA, WFA, and jacalin, as one-third of its Tn was sialylated. These findings indicate that ASG-A and its desialylated product (ASG-Tn) are highly useful reagents for the differentiation of Tn, T (Gal beta 1-->3GalNAc), A (GalNAc alpha 1-->3Gal) or Gal specific lectins and monoclonal antibodies against such epitopes.
authors.affiliation: Glyco-Immunochemistry Research Laboratory, Chang-Gung Medical College, Tao-yuan, Taiwan.
authors.forename: A M
authors.initials: AM
authors.lastname: Wu
authors.forename: F
authors.initials: F
authors.lastname: Shen
authors.forename: A
authors.initials: A
authors.lastname: Herp
authors.forename: S C
authors.initials: SC
authors.lastname: Song
authors.forename: J H
authors.initials: JH
authors.lastname: Wu
mesh_terms: D000818:Animals; D001135:Armadillos; D001212:Asialoglycoproteins / Q000737:chemistry*; D006224:Cricetinae; D006023:Glycoproteins / Q000737:chemistry*; D066298:In Vitro Techniques; D037102:Lectins / Q000378:metabolism*; D008024:Ligands; D011485:Protein Binding; D011975:Receptors, Mitogen / Q000378:metabolism*; D012471:Salivary Proteins and Peptides / Q000737:chemistry*
chemical_list: D001212:Asialoglycoproteins; D006023:Glycoproteins; D037102:Lectins; D008024:Ligands; D011975:Receptors, Mitogen; D012471:Salivary Proteins and Peptides