Crystal structure of MytiLec, a galactose-binding lectin from the mussel Mytilus galloprovincialis with cytotoxicity against certain cancer cell types.
MytiLec is a lectin, isolated from bivalves, with cytotoxic activity against cancer cell lines that express globotriaosyl ceramide, Galα(1,4)Galβ(1,4)Glcα1-Cer, on the cell surface. Functional analysis shows that the protein binds to the disaccharide melibiose, Galα(1,6)Glc, and the trisaccharide globotriose, Galα(1,4)Galβ(1,4)Glc. Recombinant MytiLec expressed in bacteria showed the same haemagglutinating and cytotoxic activity against Burkitt's lymphoma (Raji) cells as the native form. The crystal structure has been determined to atomic resolution, in the presence and absence of ligands, showing the protein to be a member of the β-trefoil family, but with a mode of ligand binding unique to a small group of related trefoil lectins. Each of the three pseudo-equivalent binding sites within the monomer shows ligand binding, and the protein forms a tight dimer in solution. An engineered monomer mutant lost all cytotoxic activity against Raji cells, but retained some haemagglutination activity, showing that the quaternary structure of the protein is important for its cellular effects.
Graduate School of Medical Life Science, Yokohama City University, 1-7-29 Suehiro, Yokohama, Kanagawa 230-0045, Japan.
Daiki
D
Terada
Graduate School of Medical Life Science, Yokohama City University, 1-7-29 Suehiro, Yokohama, Kanagawa 230-0045, Japan.
Fumihiro
F
Kawai
Graduate School of Medical Life Science, Yokohama City University, 1-7-29 Suehiro, Yokohama, Kanagawa 230-0045, Japan.
Hiroki
H
Noguchi
Graduate School of Medical Life Science, Yokohama City University, 1-7-29 Suehiro, Yokohama, Kanagawa 230-0045, Japan.
Satoru
S
Unzai
Laboratory of Glycobiology and Marine Biochemistry, Graduate School of NanoBio Sciences, Yokohama City University, 22-2, Seto, Yokohama, Kanagawa 236-0027, Japan.|Department of Biochemistry and Molecular Biology, Faculty of Science, University of Rajshahi, Rajshahi-6205, Bangladesh.
Imtiaj
I
Hasan
Department of Pharmacy, Graduate School of Pharmaceutical Science, Nagasaki International University, 2825-7 Huis Ten Bosch, Sasebo, Nagasaki 859-3298, Japan.
Yuki
Y
Fujii
Graduate School of Medical Life Science, Yokohama City University, 1-7-29 Suehiro, Yokohama, Kanagawa 230-0045, Japan.
Sam-Yong
SY
Park
Laboratory of Glycobiology and Marine Biochemistry, Graduate School of NanoBio Sciences, Yokohama City University, 22-2, Seto, Yokohama, Kanagawa 236-0027, Japan.
Yasuhiro
Y
Ozeki
Graduate School of Medical Life Science, Yokohama City University, 1-7-29 Suehiro, Yokohama, Kanagawa 230-0045, Japan.
Jeremy R H
JR
Tame
D000818:Animals; D001665:Binding Sites; D002051:Burkitt Lymphoma / Q000188:drug therapy / Q000378:metabolism*; D002151:Calorimetry; D045744:Cell Line, Tumor; D002470:Cell Survival; D003001:Cloning, Molecular; D018360:Crystallography, X-Ray; D006388:Hemagglutinins / Q000737:chemistry; D006801:Humans; D037102:Lectins / Q000737:chemistry*; D008024:Ligands; D008958:Models, Molecular; D049878:Mytilus / Q000737:chemistry*; D015202:Protein Engineering; D020836:Protein Structure, Quaternary; D017433:Protein Structure, Secondary; D011994:Recombinant Proteins / Q000737:chemistry; D014312:Trisaccharides / Q000737:chemistry*; D014461:Ultracentrifugation
D006388:Hemagglutinins; D037102:Lectins; D008024:Ligands; D011994:Recombinant Proteins; D014312:Trisaccharides; C113460:globotriose