Purification and characterization of SM 37: a fucosyllactose determinant-bearing glycoprotein probed by a Biomphalaria alexandrina lectin on adult male schistosomes.
Utilizing a Biomphalaria alexandrina-derived lectin (BaSII) of proven specificity to a Schistosoma mansoni-associated fucosyllactose [(Fuc alpha 1-2)Gal beta 1-4 Glc] determinant, a 37-kDa determinant-bearing glycoprotein (Sm 37) was identified selectively on adult male schistosomes. Sm 37 was purified to homogeneity from extracts of adult male worms metabolically radiolabeled with [35S] methionine by BaSII affinity chromatography followed by separation on an HPLC column. Treatments with endoglycosidases, alkaline borohydride, as well as serial lectin affinity chromatography and analysis on 2-dimensional gels indicated that Sm 37 is synthesized as a 33-kDa polypeptide backbone that expresses the fucosyllactose determinant on the outer chain of a single N-linked complex-type glycan unit of either the biantennary or, to a lesser extent, the tri- or tetra-antennary types. The distinct structures of the complex oligosaccharides accounted for the expression of 2 isomorphs of Sm 37. the glycoprotein lacks other conventional high mannose-type or O-linked oligosaccharides and, as deduced from the N-terminal amino acid sequence, the Sm 37 polypeptide may be distinct from other schistosome polypeptides of known sequence. Based on the structural relatedness of the Sm 37-associated fucosyllactose determinant to the antigenic blood group H trisaccharide, these observations may have implications for mechanisms of these host-parasite interactions.
Mansour
M H
MH
Department of Zoology, Faculty of Science, Cairo University, Egypt.
D000595:Amino Acid Sequence; D000818:Animals; D001700:Biomphalaria / Q000737:chemistry; D002846:Chromatography, Affinity; D002851:Chromatography, High Pressure Liquid; D015180:Electrophoresis, Gel, Two-Dimensional; D004591:Electrophoresis, Polyacrylamide Gel; D005260:Female; D016650:Fluorescein-5-isothiocyanate; D006023:Glycoproteins / Q000737:chemistry / Q000302:isolation & purification*; D015801:Helminth Proteins / Q000737:chemistry / Q000302:isolation & purification*; D037102:Lectins; D008297:Male; D008856:Microscopy, Fluorescence; D008969:Molecular Sequence Data; D012550:Schistosoma mansoni / Q000737:chemistry*; D012737:Sex Factors
D006023:Glycoproteins; D015801:Helminth Proteins; D037102:Lectins; D016650:Fluorescein-5-isothiocyanate