title: Use of monoclonal anti-light subunit antibodies to study the structure and function of the Entamoeba histolytica Gal/GalNAc adherence lectin.
abstract: Adherence of Entamoeba histolytica trophozoites to host cells is mediated by a galactose (Gal) and N-acetylgalactosamine (GalNAc)-specific surface lectin. The lectin is a heterodimeric protein composed of heavy (170 kDa) and light (35-31 kDa) subunits linked by disulfide bonds. Polyclonal and monoclonal antibodies (mAb) raised against a light subunit-glutathione-S-transferase fusion protein were used to probe its structure and function. Four light subunit-specific mAb were produced which recognized distinct epitopes on five different light subunit isoforms. Immunoblots with these mAb demonstrated co-migration of light and heavy subunits when nonreduced trophozoite proteins were analysed by SDS-PAGE, indicating that the subunits do not exist free of the heterodimer in significant quantities. While anti-heavy subunit antibodies had previously been shown to alter adherence, anti-light subunit antibodies did not, suggesting that the heavy subunit contains the carbohydrate recognition domain.
authors.affiliation: Department of Medicine, University of Virginia School of Medicine, Charlottesville 22908.
authors.forename: J J
authors.initials: JJ
authors.lastname: McCoy
authors.forename: A M
authors.initials: AM
authors.lastname: Weaver
authors.forename: W A
authors.initials: WA
authors.lastname: Petri
mesh_terms: D000116:Acetylgalactosamine / Q000378:metabolism*; D000595:Amino Acid Sequence; D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology; D015153:Blotting, Western; D016466:CHO Cells; D002846:Chromatography, Affinity; D006224:Cricetinae; D004748:Entamoeba histolytica / Q000737:chemistry*; D005690:Galactose / Q000378:metabolism*; D037102:Lectins / Q000737:chemistry* / Q000276:immunology / Q000302:isolation & purification / Q000378:metabolism; D008562:Membrane Glycoproteins / Q000737:chemistry* / Q000276:immunology / Q000302:isolation & purification; D008969:Molecular Sequence Data; D011485:Protein Binding; D015800:Protozoan Proteins / Q000737:chemistry* / Q000276:immunology / Q000302:isolation & purification; D013329:Structure-Activity Relationship
chemical_list: D000911:Antibodies, Monoclonal; D037102:Lectins; D008562:Membrane Glycoproteins; D015800:Protozoan Proteins; C052452:galactose inhibitable adherence protein, Entamoeba histolytica; D000116:Acetylgalactosamine; D005690:Galactose