Isolation of the receptor for the Amaranthus leucocarpus lectin from human T lymphocytes.
Amaranthus leucocarpus lectin (ALL) is specific for GalNAc, and recognizes human T cells. The receptor for ALL was purified from T cells using biotin-labeled lectin and avidin-agarose as affinity matrix. It is a 70-kDa glycoprotein, constituted mainly by serine, glycine, and glutamic acid; its glycosidic portion contains mainly GalNAc; galactose, sialic acid, mannose, and GlcNAc were identified at a lower proportion. By ionic strength chromatography, as well as double dimension electrophoresis, we identified four isoforms of the ALL-receptor. N-terminal amino acid was blocked both in the ALL-receptor and its isoforms, therefore, tryptic peptides of ALL-receptor, analyzed through MALDI-TOF, were compared with the relative values obtained from the NCBInr (ProFound 2004/06/01) database. Our results indicated that the tryptic peptides obtained showed 54% homology with a DnaK-core molecular chaperone, 47% with human KIAA protein, and 44% with heat shock protein 8. The most frequent phenotype of the CD4 or CD8 ALL+ T cells was CD45RA+ CD27+; 26% of ALL+ T cells were CD25+ and 13% were CD69+, indicating that the glycoprotein recognized by ALL is present mainly on naive or quiescent T cells.
Porras
Flor
F
Departamento de Bioquímica, Instituto Nacional de Enfermedades Respiratorias, Calzada de Tlalpan 4502, 01040, Mexico.
Urrea
Francisco
F
Ortiz
Blanca
B
Martínez-Cairo
Salvador
S
Bouquelet
Stéphane
S
Martínez
Gisela
G
Lascurain
Ricardo
R
Zenteno
Edgar
E
D027721:Amaranthus / Q000378:metabolism; D000595:Amino Acid Sequence; D015703:Antigens, CD / Q000032:analysis; D006023:Glycoproteins / Q000737:chemistry* / Q000378:metabolism; D006801:Humans; D008562:Membrane Glycoproteins / Q000737:chemistry* / Q000302:isolation & purification*; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000737:chemistry; D010641:Phenotype; D037121:Plant Lectins / Q000737:chemistry* / Q000378:metabolism; D020033:Protein Isoforms / Q000737:chemistry / Q000302:isolation & purification; D011975:Receptors, Mitogen / Q000737:chemistry* / Q000302:isolation & purification*; D013601:T-Lymphocytes / Q000276:immunology / Q000378:metabolism*
C121359:Amaranthus leucocarpus lectin; C503573:Amaranthus leucocarpus lectin receptor, human; D015703:Antigens, CD; D006023:Glycoproteins; D008562:Membrane Glycoproteins; D010446:Peptide Fragments; D037121:Plant Lectins; D020033:Protein Isoforms; D011975:Receptors, Mitogen