title: The positions of the disulfide bonds and the glycosylation site in a lectin of the acorn barnacle Megabalanus rosa.
abstract: The positions of the interchain and intrachain disulfide bonds and the glycosylation site in a lectin of the acorn barnacle Megabalanus rosa were determined. The lectin (Mr 140,000) is composed of the same subunit (Mr 22,000) which is cross-linked by disulfide bonds to form a dimer. Intact lectin yielded two fragments, CB1 and CB2, by cleavage with cyanogen bromide. One intrachain and two interchain disulfide bonds were identified as Cys-53-Cys-61, Cys-14-Cys-50' and Cys-50-Cys-14', respectively, by enzymatic digestion and Edman degradation of CB1. Two intrachain disulfide bonds were determined as Cys-78-Cys-168 and Cys-144-Cys-160 by enzymatic digestion of CB2. The two intrachain disulfide bonds are well conserved through all invertebrate lectins and calcium-dependent animal lectins. S-Carboxamidomethylated lectin was digested with Staphylococcus aureus V8 proteinase and separated by reversed-phase HPLC. Glycopeptides were detected by the 4-N,N-dimethylamino-4'-azobenzene sulfonyl hyrazide method. Sequence analyses of the glycopeptides showed that a carbohydrate chain attached to Asn-39.
authors.affiliation: School of Fisheries Sciences, Kitasato University, Sanriku, Iwate, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Muramoto
authors.forename: H
authors.initials: H
authors.lastname: Kamiya
mesh_terms: D000595:Amino Acid Sequence; D000596:Amino Acids / Q000032:analysis; D000818:Animals; D002851:Chromatography, High Pressure Liquid; D003488:Cyanogen Bromide; D004220:Disulfides / Q000032:analysis*; D004591:Electrophoresis, Polyacrylamide Gel; D006020:Glycopeptides / Q000032:analysis; D006031:Glycosylation; D037102:Lectins / Q000032:analysis* / Q000378:metabolism; D046911:Macromolecular Substances; D008969:Molecular Sequence Data; D008970:Molecular Weight; D010446:Peptide Fragments; D037121:Plant Lectins; D012697:Serine Endopeptidases; D001468:Thoracica / Q000032:analysis*
chemical_list: D000596:Amino Acids; D004220:Disulfides; D006020:Glycopeptides; D037102:Lectins; D046911:Macromolecular Substances; C064593:Megabalanus rosa lectin; D010446:Peptide Fragments; D037121:Plant Lectins; D012697:Serine Endopeptidases; C028344:glutamyl endopeptidase; D003488:Cyanogen Bromide