Purification, Characterization, and cDNA Cloning of a Novel Lectin from the Green Alga, Codium barbatum

• Published in: Bioscience, biotechnology, and biochemistry Vol. 76; no. 4; pp. 805 - 811
• Main Authors: PRASEPTIANGGA, Danar, HIRAYAMA, Makoto, HORI, Kanji
• Format: Journal Article
• Language: English
• Published: Tokyo Japan Society for Bioscience, Biotechnology, and Agrochemistry 2012; Japan Society for Bioscience Biotechnology and Agrochemistry; Oxford University Press
• Subjects: Algal Proteins - genetics; Algal Proteins - isolation & purification; Algal Proteins - metabolism; Amino Acid Sequence; Amino acids; Biological and medical sciences; carbohydrate-binding specificity; cDNA cloning; Chlorophyta - chemistry; Cloning; Cloning, Molecular; Codium barbatum; Cysteine; Dimerization; Disulfides - chemistry; DNA, Complementary - genetics; Escherichia coli; Fundamental and applied biological sciences. Psychology; Hemagglutination Inhibition Tests; lectin; Lectins; Lectins - genetics; Lectins - isolation & purification; Lectins - metabolism; Molecular Sequence Data; Molecular Weight; Peptides; Polypeptides; Polysaccharides - metabolism; primary structure; Protein Processing, Post-Translational; Protein Sorting Signals; Protein Subunits - genetics; Protein Subunits - isolation & purification; Protein Subunits - metabolism; Recombinant Proteins - genetics; Recombinant Proteins - isolation & purification; Recombinant Proteins - metabolism; Residues; Searching; Sequence Homology, Amino Acid; Lectin; Purification; carbohydrate-binding specificity; Algae; Primary structure; Characterization; Specificity; cDNA cloning; Chlorophyta; Ulvophyceae; Codium; Codium barbatum; Carbohydrate; Molecular cloning
• ISSN: 0916-8451; 1347-6947
• DOI: 10.1271/bbb.110944

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.