title: Lebecetin, a C-lectin protein from the venom of Macrovipera lebetina that inhibits platelet aggregation and adhesion of cancerous cells.
abstract: A novel C-lectin protein, lebecetin, was purified and characterized from the venom of Macrovipera lebetina. It is a disulfide-linked heterodimer of 15 and 16 kD. The subunits are homologous to each other and to the other snake venom proteins of the C-type (Ca(2+)-dependent) lectin superfamily. Lebecetin shows a potent inhibitory effect on whole blood and washed platelets induced by different agonists. It inhibits the agglutination of human fixed platelets in the presence of ristocetin. Lebecetin also interferes with the adhesion of IGR39 melanoma and HT29D4 adenocarcinoma cells. These two lines adhere to lebecetin used as matrix. Lebecetin is also able to strongly reduce IGR39 and HT29D4 cell adhesion to fibrinogen and laminin, but not to fibronectin and collagen types I and IV, respectively. Adhesion properties of lebecetin may thus involve integrin receptors.
authors.affiliation: Laboratoire des Venins et Toxines, Institut Pasteur de Tunis, 13 Place Pasteur, BP 74, 1001 Tunis-Belvédère, Tunisia. sameh_sarray@voila.fr
authors.forename: S
authors.initials: S
authors.lastname: Sarray
authors.forename: N
authors.initials: N
authors.lastname: Srairi
authors.forename: J
authors.initials: J
authors.lastname: Luis
authors.forename: J
authors.initials: J
authors.lastname: Marvaldi
authors.forename: M
authors.initials: M
authors.lastname: El Ayeb
authors.forename: N
authors.initials: N
authors.lastname: Marrakchi
mesh_terms: D000818:Animals; D002448:Cell Adhesion / Q000187:drug effects; D016326:Extracellular Matrix Proteins / Q000378:metabolism; D005340:Fibrinogen / Q000378:metabolism; D006801:Humans; D007797:Laminin / Q000378:metabolism; D037181:Lectins, C-Type / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism; D009369:Neoplasms / Q000473:pathology*; D010974:Platelet Aggregation / Q000187:drug effects*; D010975:Platelet Aggregation Inhibitors / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology; D011485:Protein Binding / Q000187:drug effects; D011817:Rabbits; D014407:Tumor Cells, Cultured / Q000187:drug effects; D014757:Viper Venoms / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*
chemical_list: D016326:Extracellular Matrix Proteins; D007797:Laminin; D037181:Lectins, C-Type; D010975:Platelet Aggregation Inhibitors; D014757:Viper Venoms; D005340:Fibrinogen