Purification and partial characterization of a lectin protein complex, the clathrilectin, from the calcareous sponge Clathrina clathrus.
Carbohydrate-binding proteins were purified from the marine calcareous sponge Clathrina clathrus via affinity chromatography on lactose and N-acetyl glucosamine-agarose resins. Proteomic analysis of acrylamide gel separated protein subunits obtained in reducing conditions pointed out several candidates for lectins. Based on amino-acid sequence similarity, two peptides displayed homology with the jack bean lectin Concanavalin A, including a conserved domain shared by proteins in the L-type lectin superfamily. An N-acetyl glucosamine - binding protein complex, named clathrilectin, was further purified via gel filtration chromatography, bioguided with a diagnostic rabbit erythrocyte haemagglutination assay, and its activity was found to be calcium dependent. Clathrilectin, a protein complex of 3200kDa estimated by gel filtration, is composed of monomers with apparent molecular masses of 208 and 180kDa estimated on 10% SDS-PAGE. Nine internal peptides were identified using proteomic analyses, and compared to protein libraries from the demosponge Amphimedon queenslandica and a calcareous sponge Sycon sp. from the Adriatic Sea. The clathrilectin is the first lectin isolated from a calcareous sponge and displays homologies with predicted sponge proteins potentially involved in cell aggregation and interaction with bacteria.
Unité Molécules de Communication et Adaptation des Microorganismes, UMR 7245 CNRS-MNHN, Sorbonne Universités, Muséum National d'Histoire Naturelle, CP 54, 57 rue Cuvier, 75005 Paris, France; Laboratory for Marine Molecular Biology, Center for Marine Research, Ruđer Bošković Institute, G. Paliaga 5, 52210 Rovinj, Croatia.
Johan
J
Gardères
Unité Molécules de Communication et Adaptation des Microorganismes, UMR 7245 CNRS-MNHN, Sorbonne Universités, Muséum National d'Histoire Naturelle, CP 54, 57 rue Cuvier, 75005 Paris, France.
Isabelle
I
Domart-Coulon
Unité Molécules de Communication et Adaptation des Microorganismes, UMR 7245 CNRS-MNHN, Sorbonne Universités, Muséum National d'Histoire Naturelle, CP 54, 57 rue Cuvier, 75005 Paris, France.
Arul
A
Marie
Laboratory for Marine Molecular Biology, Center for Marine Research, Ruđer Bošković Institute, G. Paliaga 5, 52210 Rovinj, Croatia.
Bojan
B
Hamer
Laboratory for Marine Molecular Biology, Center for Marine Research, Ruđer Bošković Institute, G. Paliaga 5, 52210 Rovinj, Croatia.
Renato
R
Batel
ERC Advanced Investigator Grant Research Group at Institute for Physiological Chemistry, University Medical Center of Johannes Gutenberg University Mainz, Duesbergweg 6, 55128 Mainz, Germany.
Werner E G
WE
Müller
Unité Molécules de Communication et Adaptation des Microorganismes, UMR 7245 CNRS-MNHN, Sorbonne Universités, Muséum National d'Histoire Naturelle, CP 54, 57 rue Cuvier, 75005 Paris, France. Electronic address: bourguet@mnhn.fr.
Marie-Lise
ML
Bourguet-Kondracki
D000818:Animals; D050260:Carbohydrate Metabolism; D005260:Female; D006384:Hemagglutination / Q000187:drug effects; D037102:Lectins / Q000302:isolation & purification* / Q000378:metabolism* / Q000494:pharmacology; D011161:Porifera / Q000378:metabolism*; D059748:Proteolysis; D040901:Proteomics; D011817:Rabbits; D014357:Trypsin / Q000378:metabolism
D037102:Lectins; D014357:Trypsin
Cell aggregation; Clathrina clathrus; Lectin; N-acetyl-glucosamine; Porifera; Proteomics