title: Purification, characterization, and amino acid sequence of an embryonic lectin in perivitelline fluid of the horseshoe crab.
abstract: Hemagglutinating activity in perivitelline fluid of the horseshoe crab embryo dramatically increases during the third and fourth molt of the embryo. A 27-kDa lectin, which we named tachylectin-P (TL-P), was newly identified in perivitelline fluid of the horseshoe crab Tachypleus tridentatus. TL-P preferentially agglutinated human A-type erythrocytes, and the activity was inhibited by N-acetyl group-containing monosaccharides. The amino acid sequence analysis indicated that TL-P is almost structurally the same as a hemocyte-derived lectin with no hemagglutinating activity, tachylectin-1 (TL-1), and that 218 out of 221 amino acid residues in total were conserved between the two lectins. Despite the high sequence similarity, biological and biochemical characteristics of TL-P differed from those of TL-1: (i) unlike TL-1, TL-P agglutinates several animal-derived erythrocytes; (ii) unlike TL-1, TL-P has no significant affinity for bacterial lipopolysaccharides or antibacterial activity; (iii) Based on apparent molecular masses determined by gel filtration, TL-P forms a dimer in solution, while TL-1 is present as a monomer; (iv) and TL-P interacts with endogenous proteins of 13 and 14 kDa present in the perivitelline fluid; however, neither has any affinity for TL-1. We propose that TL-P may have an important role in completing embryonic development by interacting with endogenous glycoproteins or N-acetylhexosamines.
authors.affiliation: Department of Molecular Biology, Graduate School of Medical Science, Kyushu University, Fukuoka 812-8582, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Nagai
authors.forename: S
authors.initials: S
authors.lastname: Kawabata
authors.forename: F
authors.initials: F
authors.lastname: Shishikura
authors.forename: H
authors.initials: H
authors.lastname: Sugita
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002241:Carbohydrates / Q000494:pharmacology; D002850:Chromatography, Gel; D004247:DNA; D004591:Electrophoresis, Polyacrylamide Gel; D006386:Hemagglutination Tests; D006737:Horseshoe Crabs / Q000196:embryology*; D037102:Lectins / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification* / Q000494:pharmacology; D008070:Lipopolysaccharides / Q000378:metabolism; D008969:Molecular Sequence Data; D008970:Molecular Weight; D010449:Peptide Mapping; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: D002241:Carbohydrates; D037102:Lectins; D008070:Lipopolysaccharides; C403522:tachylectin P, Tachypleus tridentatus; D004247:DNA