title: Exquisite specificity of mitogenic lectin from Cephalosporium curvulum to core fucosylated N-glycans.
abstract: Lectins are carbohydrate binding proteins that are gaining attention as important tools for the identification of specific glycan markers expressed during different stages of the cancer. We earlier reported the purification of a mitogenic lectin from human pathogenic fungus Cephalosporium curvulum (CSL) that has complex sugar specificity when analysed by hapten inhibition assay. In the present study, we report the fine sugar specificity of CSL as determined by glycan array analysis. The results revealed that CSL has exquisite specificity towards core fucosylated N-glycans. Fucosylated trimannosyl core is the basic structure required for the binding of CSL. The presence of fucose in the side chain further enhances the avidity of CSL towards such glycans. The affinity of CSL is drastically reduced towards the non-core fucosylated glycans, in spite of their side chain fucosylation. CSL showed no binding to the tested O-glycans and monosaccharides. These observations suggest the unique specificity of CSL towards core fucosylated N-glycans, which was further validated by binding of CSL to human colon cancer epithelial and hepatocarcinoma cell lines namely HT29 and HepG2, respectively, that are known to express core fucosylated N-glycans, using AOL and LCA as positive controls. LCA and AOL are fucose specific lectins that are currently being used clinically for the diagnosis of hepatocellular carcinomas. Most of the gastrointestinal markers express core fucosylated N-glycans. The high affinity and exclusive specificity of CSL towards α1-6 linkage of core fucosylated glycans compared to other fucose specific lectins, makes it a promising molecule that needs to be further explored for its application in the diagnosis of gastrointestinal cancer.
authors.affiliation: Department of Studies in Biochemistry, Karnatak University, Dharwad, -580 003, India. srinamdar2009@gmail.com.
authors.forename: Shashikala R
authors.initials: SR
authors.lastname: Inamdar
authors.affiliation: Department of Studies in Biochemistry, Karnatak University, Dharwad, -580 003, India.
authors.forename: Sachin M
authors.initials: SM
authors.lastname: Eligar
authors.affiliation: Department of Studies in Biochemistry, Karnatak University, Dharwad, -580 003, India.
authors.forename: Suhas
authors.initials: S
authors.lastname: Ballal
authors.affiliation: Department of Studies in Biochemistry, Karnatak University, Dharwad, -580 003, India.
authors.forename: Shivakumar
authors.initials: S
authors.lastname: Belur
authors.affiliation: Advanced Centre for Treatment, Research and Education in Cancer, Kharghar, Navi Mumbai, 410210, India.
authors.forename: Rajiv D
authors.initials: RD
authors.lastname: Kalraiya
authors.affiliation: Department of Studies in Biochemistry, Karnatak University, Dharwad, -580 003, India.
authors.forename: Bale M
authors.initials: BM
authors.lastname: Swamy
mesh_terms: D000164:Acremonium / Q000737:chemistry*; D002240:Carbohydrate Sequence; D005643:Fucose / Q000031:analogs & derivatives*; D005936:Glucans / Q000737:chemistry / Q000378:metabolism*; D019073:HT29 Cells; D056945:Hep G2 Cells; D006801:Humans; D037102:Lectins / Q000378:metabolism*; D008969:Molecular Sequence Data; D011485:Protein Binding
chemical_list: D005936:Glucans; D037102:Lectins; D005643:Fucose
keywords: Cancer diagnostics; Cephalosporium curvulum lectin; Core fucosylated glycans; FUT8 siRNA; Glycan array analysis