title: Homology between ABH-carrier alpha2-seminoglycoprotein and Mac-2 binding protein.
abstract: alpha2-seminoglycoprotein (alpha2-SGP), purified from human seminal plasma, is a carrier of glycoprotein for the ABO blood grouping. The alpha2-SGP exists in the secretions of the seminal vesicle and various glands. However, the function of alpha2-SGP is, as yet, unknown. In this study, we determined that two internal amino acid sequences of 8 and 12 residues of alpha2-SGP were Ala-Val-Asp-Thr-Trp-Ser-Trp-Gly and Thr-Leu-Gln-Ala-Leu-Glu-Phe-His-Thr-Val-Pro-Phe. These sequences were completely coincident with the domain 3 of human Mac-2 binding protein (M2BP), which was identified as a tumor-associated antigen. In addition, we also confirmed an alpha2-SGP binding activity to galectin-3 that was one of a ligand for M2BP, and the immunological cross-reactivity between alpha2-SGP and M2BP. These findings strongly suggested that alpha2-SGP was identical with M2BP.
authors.affiliation: Division of Forensic Pathology and Science, Department of Translational Medical Science, Course of Medical and Dental Science, Graduate School of Biomedical Science, Nagasaki University, Japan.
authors.forename: Shinichiro
authors.initials: S
authors.lastname: Tsuruya
authors.forename: Ryouichi
authors.initials: R
authors.lastname: Tsuda
authors.forename: Kazuya
authors.initials: K
authors.lastname: Ikematsu
authors.forename: Hideki
authors.initials: H
authors.lastname: Matsumoto
authors.forename: Shinichiro
authors.initials: S
authors.lastname: Kagawa
authors.forename: Ichiro
authors.initials: I
authors.lastname: Nakasono
mesh_terms: D000017:ABO Blood-Group System / Q000378:metabolism; D000595:Amino Acid Sequence; D000951:Antigens, Neoplasm / Q000737:chemistry* / Q000276:immunology; D015153:Blotting, Western; D002352:Carrier Proteins / Q000378:metabolism; D003429:Cross Reactions; D037502:Galectin 3 / Q000378:metabolism; D006801:Humans; D007150:Immunohistochemistry; D008024:Ligands; D008297:Male; D008562:Membrane Glycoproteins / Q000737:chemistry* / Q000276:immunology; D012661:Semen / Q000737:chemistry; D029589:Seminal Plasma Proteins / Q000737:chemistry* / Q000276:immunology; D020539:Sequence Analysis, Protein; D000090203:Zn-Alpha-2-Glycoprotein
chemical_list: D000017:ABO Blood-Group System; D000951:Antigens, Neoplasm; D002352:Carrier Proteins; D037502:Galectin 3; D008024:Ligands; D008562:Membrane Glycoproteins; D029589:Seminal Plasma Proteins; C114782:TAA90K protein, human; D000090203:Zn-Alpha-2-Glycoprotein