title: Halilectin 1 (H-1) and Halilectin 2 (H-2): two new lectins isolated from the marine sponge Haliclona caerulea.
abstract: Two new lectins named Halilectin 1 (H-1) and Halilectin 2 (H-2) were isolated from the marine sponge Haliclona caerulea using a combination of affinity chromatography on stroma fixed onto Sephadex G-25 and cation and anion exchange chromatography. H-1 is a monomeric protein with a molecular mass of 40 kDa estimated using sodium dodecyl sulfate polyacrylamide gel electrophoresis and 15 kDa estimated using a TSK gel. Conversely, H-2 is a homodimeric protein with 15 kDa monomers linked via weak interactions. H-1 more effectively agglutinates trypsinized rabbit erythrocytes, whereas H-2 more effectively agglutinates native rabbit erythrocytes. The hemagglutinating activity of H-1 could be not inhibited by any tested sugars, but H-2 was inhibited by orosomucoid and porcine stomach mucin. Neither lectin was dependent on divalent ions. H-1 was stable at basic pH range and temperatures up to 50 °C, whereas H-2 was stable at acid pH range and temperatures up to 80 °C. The H. caerulea lectins exhibited dose-dependent toxicity against Artemia nauplii. Additionally, 76% of the primary structure of H-2 was determined using tandem mass spectrometry to contain a unique amino acid sequence with no similarity to any members of the animal lectin family.
authors.affiliation: Laboratório de Moléculas Biologicamente Ativas-BioMol-Lab, Departamento de Bioquímica e Biologia Molecular, Universidade Federal do Ceará, Campus do Pici, s/n Bloco 907, 60440-970 Fortaleza, Ceará, Brazil.
authors.forename: Rômulo Farias
authors.initials: RF
authors.lastname: Carneiro
authors.forename: Arthur Alves
authors.initials: AA
authors.lastname: de Melo
authors.forename: Fernando Edson Pessoa do
authors.initials: FE
authors.lastname: Nascimento
authors.forename: Clareane Avelino
authors.initials: CA
authors.lastname: Simplicio
authors.forename: Kyria Santiago do
authors.initials: KS
authors.lastname: Nascimento
authors.forename: Bruno Anderson Matias da
authors.initials: BA
authors.lastname: Rocha
authors.forename: Silvana
authors.initials: S
authors.lastname: Saker-Sampaio
authors.forename: Raniere da Mata
authors.initials: Rda M
authors.lastname: Moura
authors.forename: Sula Salani
authors.initials: SS
authors.lastname: Mota
authors.forename: Benildo Sousa
authors.initials: BS
authors.lastname: Cavada
authors.forename: Celso Shiniti
authors.initials: CS
authors.lastname: Nagano
authors.forename: Alexandre Holanda
authors.initials: AH
authors.lastname: Sampaio
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001156:Artemia / Q000187:drug effects; D001483:Base Sequence; D002845:Chromatography / Q000379:methods; D004912:Erythrocytes / Q000187:drug effects; D047129:Haliclona / Q000737:chemistry*; D006384:Hemagglutination / Q000187:drug effects; D006386:Hemagglutination Tests / Q000379:methods; D006863:Hydrogen-Ion Concentration; D037102:Lectins / Q000737:chemistry* / Q000494:pharmacology*; D008969:Molecular Sequence Data; D008970:Molecular Weight; D011161:Porifera / Q000737:chemistry*; D011817:Rabbits; D053719:Tandem Mass Spectrometry / Q000379:methods; D013696:Temperature
chemical_list: D037102:Lectins