title: Purification, characterization, and cDNA cloning of a novel lectin from the green alga, Codium barbatum.
abstract: A novel lectin (CBA) was isolated from the green alga, Codium barbatum, by conventional chromatographic methods. The hemagglutination-inhibition profile with sugars and glycoproteins indicated that CBA had preferential affinity for complex type N-glycans but not for monosaccharides, unlike the other known Codium lectins specific for N-acetylgalactosamine. CBA consisted of an SS-linked homodimer of a 9257-Da polypeptide containing seven cysteine residues, all of which were involved in disulfide linkages. The cDNA of the CBA subunit coded a polypeptide (105 amino acids) including the signal peptide of 17 residues. The calculated molecular mass from the deduced sequence was 9705 Da, implying that the four C-terminal amino acids of the CBA proprotein subunit were post-translationally truncated to afford the mature subunit (84 amino acids). No significantly similar sequences were found during an in silico search, indicating CBA to be a novel protein. CBA is the first Codium lectin whose primary structure has been elucidated.
authors.affiliation: Food Science and Biofunctions Division, Graduate School of Biosphere Science, Hiroshima University, Higashi-Hiroshima, Japan.
authors.forename: Danar
authors.initials: D
authors.lastname: Praseptiangga
authors.forename: Makoto
authors.initials: M
authors.lastname: Hirayama
authors.forename: Kanji
authors.initials: K
authors.lastname: Hori
mesh_terms: D020418:Algal Proteins / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism; D000595:Amino Acid Sequence; D000460:Chlorophyta / Q000737:chemistry*; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000235:genetics; D019281:Dimerization; D004220:Disulfides / Q000737:chemistry; D004926:Escherichia coli; D006385:Hemagglutination Inhibition Tests; D037102:Lectins / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism; D008969:Molecular Sequence Data; D008970:Molecular Weight; D011134:Polysaccharides / Q000378:metabolism; D011499:Protein Processing, Post-Translational; D021382:Protein Sorting Signals; D021122:Protein Subunits / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism; D011994:Recombinant Proteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D017386:Sequence Homology, Amino Acid
chemical_list: D020418:Algal Proteins; D018076:DNA, Complementary; D004220:Disulfides; D037102:Lectins; D011134:Polysaccharides; D021382:Protein Sorting Signals; D021122:Protein Subunits; D011994:Recombinant Proteins