Polyvalency of Tn (GalNAcα1→Ser/Thr) glycotope as a critical factor for Vicia villosa B4 and glycoprotein interactions

FEBS Letters

Wu, Albert M.¹ 

[1] Glyco-Immunochemistry Research Laboratory, Institute of Molecular and Cellular Biology, College of Medicine, Chang-Gung University, Kwei-San, Tao-Yuan 333, Taiwan

关键词: Polyvalency;    Multivalent effect;    Carbohydrate specificity;    Glycoprotein binding;    Lectin;    Vicia villosa B4;    Sugars: Gal;    D-galactopyranose;    Glc;    D-glucopyranose;    D-Fuc;    D-fucopyranose;    L-Ara;    L-arabinose;    GalNAc;    2-acetamido-2-deoxy-D-galactopyranose;    GlcNAc;    2-acetamido-2-deoxy-D-glucopyranose;    Man;    D-mannopyranose;    NeuNAc/Sialic acid;    N-acetylneuraminic acid;    Glycoproteins (gp): HSM;    hamster submaxillary sialyl Tn gp;    ASG-Tn;    native Tn glycoprotein from armadillo salivary gland;    OSM;    ovine submandibular glycoprotein-major;    BSM;    bovine submandibular glycoprotein-major;    HOC;    human ovarian cyst fluid;    PSM;    porcine salivary glycoprotein;    THGP;    Tamm–Horsfall glycoprotein;    Lectin: VVL-B4;    Tn-specific lectin from seeds of Vicia villosa;    The mammalian carbohydrate structural units in glycans used to define binding properties of VVL-B4 and expressed in parentheses after glycoproteins are listed in Table 2;    II;    Galβ1→4GlcNAc;    mII;    poly (multi) valent II;    ELLSA;    enzyme-linked lectinosorbent assay;    Reagent: TBS-T;    Tris–HCl-buffered saline containing 0.05% Tween 20;   

DOI  :  10.1016/S0014-5793(04)00180-2

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Vicia villosa B₄ (VVL-B₄) is an important lectin for detecting exposed Tn (GalNAcα1-Ser/Thr) determinants on cancer cells. In order to elucidate the binding factors involved in VVL-B₄ and glycotope interaction, the binding properties of this lectin were analyzed by enzyme-linked lectinosorbent and inhibition assays. From the results, it is concluded that the most critical factor affecting VVL-B₄ binding is polyvalency at the α anomer of Gal with –NH CH₃CO at carbon-2 (Tn epitope), which enhances the reactivity by 3.3×10⁵ times over monovalent Gal. The reactivities of glycotopes can be ranked as follows: high density Tn cluster≫Tn glycopeptides (MW<3.0×10³)≫monomeric Tn to tri- Tn glycopeptides⋙other GalNAcα/β-related structural units>Gal and Galα- or β-linked ligands, demonstrating the essential role of the polyvalency of Tn glycotopes in the enhancement of the binding.

【 授权许可】

Unknown