title: Structural and biochemical characterization of a new type of lectin isolated from carp eggs.
abstract: A previously unidentified glycoprotein present in the eggs of the carp ( Cyprinus carpio ) was isolated and structurally characterized. The protein binds to a Sepharose 4B matrix and can be eluted with 0.4 M N -acetylglucosamine. The protein has an apparent molecular mass of 26686.3 Da. On the basis of gel-filtration chromatography, the protein appears to be present in solution as a monomer. The sequence of its 238 amino acids, the position of its four disulphide bridges and the composition of its single N-linked carbohydrate chain were determined. The lectin shows a very low agglutinating activity for human A-type erythrocytes and interacts with both Gram-positive and -negative bacteria. These latter interactions are inhibited by N -acetylglucosamine. A database search shows that its amino acid sequence is similar to that of the members of an invertebrate lectin family that includes tachylectin-1. Tachylectin-1 is present in the amoebocytes of the horseshoe crab, Tachypleus tridentatus, and plays a role in the innate defence system of this species. Homologous genes are also present in other fish, having 85% identity with a gene expressed in the oocytes of the crucian carp ( Carassius auratus gibelio ) and 78% identity with a gene in the cDNA library of the zebrafish ( Danio rerio ).
authors.affiliation: Department of Biochemistry A. Castellani, University of Pavia, via Taramelli 3b, 27100 Pavia, Italy.
authors.forename: Monica
authors.initials: M
authors.lastname: Galliano
authors.forename: Lorenzo
authors.initials: L
authors.lastname: Minchiotti
authors.forename: Monica
authors.initials: M
authors.lastname: Campagnoli
authors.forename: Alberto
authors.initials: A
authors.lastname: Sala
authors.forename: Livia
authors.initials: L
authors.lastname: Visai
authors.forename: Angela
authors.initials: A
authors.lastname: Amoresano
authors.forename: Piero
authors.initials: P
authors.lastname: Pucci
authors.forename: Annarita
authors.initials: A
authors.lastname: Casbarra
authors.forename: Marco
authors.initials: M
authors.lastname: Cauci
authors.forename: Massimiliano
authors.initials: M
authors.lastname: Perduca
authors.forename: Hugo L
authors.initials: HL
authors.lastname: Monaco
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001419:Bacteria / Q000378:metabolism; D050260:Carbohydrate Metabolism; D002241:Carbohydrates / Q000032:analysis; D002347:Carps / Q000235:genetics; D002850:Chromatography, Gel; D004220:Disulfides / Q000032:analysis; D005399:Fishes / Q000235:genetics; D007448:Invertebrates / Q000737:chemistry; D037102:Lectins / Q000737:chemistry* / Q000302:isolation & purification / Q000378:metabolism*; D008969:Molecular Sequence Data; D010063:Ovum / Q000737:chemistry; D017386:Sequence Homology, Amino Acid
chemical_list: D002241:Carbohydrates; D004220:Disulfides; D037102:Lectins