CDNA cloning and characterization of a rhamnose-binding lectin SUL-I from the toxopneustid sea urchin Toxopneustes pileolus venom. (February 2015)

• Record Type: Journal Article
• Authors: Hatakeyama, Tomomitsu; Ichise, Ayaka; Yonekura, Tomokazu; Unno, Hideaki; Goda, Shuichiro; Nakagawa, Hideyuki
• Is Part Of: Toxicon. Volume 94(2015)
• Page Start: 8
• Page End: 15
• Publication Date: 2015-02
• Subjects: Sea urchin -- Toxopneustes pileolus -- cDNA cloning -- Rhamnose -- Lectin -- Carbohydrate-binding; CRD carbohydrate-recognition domain -- SUEL sea urchin egg lectin -- SUL-I sea urchin lectin-I -- PD polyamidoamine dendrimer -- RACE rapid amplification of cDNA ends -- RBL rhamnose-binding lectin -- TBS Tris-buffered saline; Toxins -- Periodicals; Venom -- Periodicals; 615.9
• DOI: 10.1016/j.toxicon.2014.11.236
• Languages: English
• ISSNs: 0041-0101

Abstract

Abstract: The globiferous pedicellariae of the venomous sea urchin Toxopneustes pileolus contain several biologically active proteins. Among these, a galactose-binding lectin SUL-I isolated from the venom in the large globiferous pedicellariae shows several activities such as mitogenic, chemotactic, and cytotoxic activities through binding to the carbohydrate chains on the cells. We cloned cDNA encoding SUL-I by reverse transcription-PCR using the degenerate primers designed on the basis of the N-terminal amino acid sequence of the protein and expressed the recombinant SUL-I (rSUL-I) in Escherichia coli cells. The SUL-I gene contains an open reading frame of 927 nucleotides corresponding to 308 amino acid residues, including 24 residues of a putative signal sequence. The mature protein with 284 residues is composed of three homologous regions, each showing similarity with the carbohydrate-recognition domains of the rhamnose-binding lectins, which have been mostly found in fish eggs. While rSUL-I exhibited binding activity for several galactose-related sugars, the highest affinity was found forl -rhamnose among carbohydrates tested, confirming that SUL-I is a rhamnose-binding lectin. rSUL-I also showed hemagglutinating activity toward rabbit erythrocytes, indicating the existence of more than one carbohydrate-binding site to cross-link the carbohydrate chains on the cell surface, which may be closely related to its biological activities. Highlights: cDNA of a lectin SUL-I in the venom of Toxopneustes pileolus was cloned. The primary structure of SUL-I showed the homology with the rhamnose-binding lectins. The recombinant SUL-I showed the binding affinity forl -rhamnose. Homology model of SUL-I suggested the importance of the C-terminal region.