Xenopus galectin-VIIa binds N-glycans of members of the cortical granule lectin family (xCGL and xCGL2)

• Published in: Glycobiology (Oxford) Vol. 15; no. 7; pp. 709 - 720
• Main Authors: Shoji, Hiroki, Ikenaka, Kazuhiro, Nakakita, Shin-ichi, Hayama, Koh, Hirabayashi, Jun, Arata, Yoichiro, Kasai, Ken-ichi, Nishi, Nozomu, Nakamura, Takanori
• Format: Journal Article
• Language: English
• Published: England Oxford University Press 01-07-2005; Oxford Publishing Limited (England)
• Subjects: 3-([3-cholamidopropyl] dimethylammonio) propanesulfonic acid; Amino Acid Sequence; Animals; base pairs; Base Sequence; Carbohydrate Conformation; carbohydrate recognition domain; CHAPS; Chromatography, Affinity; cortical granule lectin; CRD; DNA Primers; E. coli; EDTA; Escherchia coli; EST; ethylenediamine tetra-acetic acid; expressed sequence tags; FAC; frontal affinity chromatography; galectin; Galectins - metabolism; glutathione S-transferase; GST; high performance liquid chromatography; HPLC; Lectins - chemistry; Lectins - metabolism; Molecular Sequence Data; N-acetyllactosamine; N-glycan; PCR; phenylmethane sulfonyl fluoride; PMSF; polymerase chain reaction; Polysaccharides - chemistry; Polysaccharides - metabolism; Protein Binding; pyridylaminated; Reverse Transcriptase Polymerase Chain Reaction; reverse transcription-PCR; RT–PCR; SDS–PAGE; Sequence Homology, Amino Acid; sodium dodecyl sulfate-polyacrylamide gel electrophoresis; Surface Plasmon Resonance; xCGL; Xenopus; Xenopus cortical granule lectin; Xenopus laevis galectin; xgalectin; xSL galectin
• ISSN: 0959-6658; 1460-2423
• DOI: 10.1093/glycob/cwi051

We have identified members of the Xenopus cortical granule lectin (xCGL) family as candidate target glycoproteins of Xenopus galectin-VIIa (xgalectin-VIIa) in Xenopus embryos. In addition to the original xCGL, we also identified a novel member of the xCGL family, xCGL2. Expression of the mRNAs of xCGL and xCGL2, as well as that of xgalectin-VIIa, was observed throughout early embryogenesis. Two and three potential N-glycosylation sites were deduced from the amino acid sequences of xCGL and xCGL2, respectively, and xgalectin-VIIa recognizes N-glycans linked to a common site in xCGL and xCGL2 and also recognizes N-glycans linked to a site specific to xCGL2. However, interaction between xgalectin-Ia and xCGLs was not detectable. We also obtained consistent results on surface plasmon resonance analysis involving xCGLs as ligands and xgalectins as analytes. The Kd value of the interaction between xgalectin-VIIa and xCGLs was calculated to be 35.9 nM. The structures of the N-glycans of xCGLs, which were recognized by xgalectin-VIIa, were analyzed by the two-dimensional sugar map method, and three kinds of N-acetyllactosamine type, biantennary N-glycans were identified as the major neutral N-glycans. The binding specificity of oligosaccharides for xgalectin-VIIa was analyzed by frontal affinity chromatography (FAC). The oligosaccharide specificity pattern of xgalectin-VIIa was similar to that of the human homolog galectin-3, and it was also shown that the N-acetyllactosamine type, biantennary N-glycans exhibit high affinity for xgalectin-VIIa (Kd = 11 µM). These results suggest that xgalectin-VIIa interacts with xCGLs through binding to N-acetyllactosamine type N-glycans and that this interaction might make it possible to organize a lectin network involving members of different lectin families.