ORIGINAL ARTICLE Exquisite specificity of mitogenic lectin from Cephalosporium curvulum to core fucosylated N-glycans Shashikala R. Inamdar 1 & Sachin M. Eligar 1 & Suhas Ballal 1 & Shivakumar Belur 1 & Rajiv D. Kalraiya 2 & Bale M. Swamy 1 Received: 23 May 2015 /Revised: 11 October 2015 /Accepted: 12 October 2015 # Springer Science+Business Media New York 2015 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 gly- can array analysis. The results revealed that CSL has exqui- site 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 gly- cans. 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 ex- plored for its application in the diagnosis of gastrointestinal cancer. Keywords Cephalosporium curvulum lectin . Glycan array analysis . Core fucosylated glycans . FUT8 siRNA . Cancer diagnostics Introduction Many key biological processes including cell adhesion, mo- lecular trafficking and clearance, receptor activation, signal transduction and endocytosis involve the active participation of glycans. Understanding the diversity of these glycans expressed on the mammalian glycoconjugates provides useful information in deciphering the cellular-molecular recognitions and underlying signaling mechanisms. Lectins are the carbo- hydrate binding proteins of non immune origin, and are known to recognize such glycans that are specifically either expressed on cell surface or free in solutions. This glycan recognition property of lectins has made them a useful tool in different fields of life sciences. Some lectins recognize tu- mor associated glycans and therefore have the potential to serve as biomarkers for malignant tumors and also assist in the study of changes in the glycosylation motif in cancer line [1].The alteration/expression of specific glycans has been ob- served in many pathophysiological conditions including can- cer. Many of these specific glycans are considered as disease markers and are targets for diagnosis as well as for therapeu- tics. The role of glycans has been well established in the can- cer progression and glycans are known to be involved in tumour proliferation, invasion, haematogenous metastasis * Shashikala R. Inamdar srinamdar2009@gmail.com; pinkisri2001@yahoo.co.in 1 Department of Studies in Biochemistry, Karnatak University, Dharwad -580 003, India 2 Advanced Centre for Treatment, Research and Education in Cancer, Kharghar, Navi Mumbai 410210, India Glycoconj J DOI 10.1007/s10719-015-9628-0