title: Purification and characterization of four Ca(2+)-dependent lectins from the marine invertebrate, Cucumaria echinata.
abstract: Four Ca(2+)-dependent, N-acetylgalactosamine/galactose-specific lectins were purified from the marine invertebrate, Cucumaria echinata (Holothuroidea), by column chromatography on lactosyl-Sepharose 4B, Sephacryl S-200, and Q-Sepharose. The molecular masses of these lectins were estimated to be 27 kDa (CEL-I), 35 kDa (CEL-II), 45 kDa (CEL-III), and 68 kDa (CEL-IV) on SDS-PAGE under nonreducing conditions. Among these lectins, CEL-I and CEL-IV strongly agglutinated rabbit and human erythrocytes, and were found to recognize N-acetylgalactosamine and galactose-containing carbohydrates from the results of a hemagglutination inhibition assay. In contrast, CEL-II failed to agglutinate any erythrocytes tested, although its carbohydrate-binding ability was confirmed by a carbohydrate-binding assay involving asialofetuin-horseradish peroxidase. Interestingly, CEL-III caused hemolysis of rabbit and human erythrocytes, while it showed only hemagglutination of chicken and horse erythrocytes at relatively high concentrations. The hemolytic activity of CEL-III was also dependent on the Ca(2+)-concentration, and inhibited by N-acetylgalactosamine and galactose-containing carbohydrates, suggesting that the hemolysis was caused by Ca(2+)-dependent binding of CEL-III to specific carbohydrate chains on the erythrocyte surface and the following partial destruction of the membrane.
authors.affiliation: Laboratory of Biochemistry, Faculty of Agriculture, Kyushu University, Fukuoka.
authors.forename: T
authors.initials: T
authors.lastname: Hatakeyama
authors.forename: H
authors.initials: H
authors.lastname: Kohzaki
authors.forename: H
authors.initials: H
authors.lastname: Nagatomo
authors.forename: N
authors.initials: N
authors.lastname: Yamasaki
mesh_terms: D000818:Animals; D002118:Calcium / Q000494:pharmacology*; D002241:Carbohydrates / Q000494:pharmacology; D004912:Erythrocytes / Q000378:metabolism; D006386:Hemagglutination Tests; D006801:Humans; D037102:Lectins / Q000302:isolation & purification*; D008970:Molecular Weight; D012616:Sea Cucumbers / Q000737:chemistry*
chemical_list: D002241:Carbohydrates; D037102:Lectins; D002118:Calcium