Day 3 :
Keynote Forum
Cheorl-Ho Kim
Sungkyunkwan University, Korea
Keynote: Carbohydrate xenoantigens in pig to human xenotransplantation
Time : 9:15-9:45
Biography:
Cheorl-Ho Kim has completed his PhD at the age of 28 years from The University of Tokyo and was positioned as a senior scientist from Korea Research Institute of Bioscience and Biotechnology. He is a professor of Molecular Glycobiology, SungKyunKwan University, Korea, leading organization of Korea, which is cooperated with the SamSung Group. He has published more than 341 papers in reputed journals and serving as an editorial board member, executive editor and editor-in chief of the international journals. His work was contributed to the mechanisms of glycan-mediated Hepatis B viral oncogenesis and invasion, sialoglycan-mediated leukemic differentiation and vascular biology. He is being serves as an Editor-in-Chief of Journal of Glycobiology, Editor-in-Chief of Journal of Microbial and Biochemical Technology, Executive Editor of Journal of Glycomics and Lipidomics, Editor of eCAM, Editor of The Peer Journal and Editor of Current Pharmaceutical Biotechnology.
Abstract:
NeuGc is acted as an immune rejection antigen in pig to human xenotransplantation, as it is called as a non-Gal xenoantigen, a next xenoantigen to overcome after elimination of major Gal xenoantigen by knocking out the α-1,3-galactosyltransferase in the pig to human xenotransplantation. In the previous study, we isolated two promoter regions of P1 and P2, which are responsible for transcriptional regulation and located on upstream regions of the two alternative transcripts of 5’pcmah-1 and pcmah-2, respectively. Among them, promoter P2 was demonstrated to be responsible for basal house-keeping expression of the gene (BBRCì—ì •). However, since the intestine tissues is important for the selective expression of the gene in responses to the pathogenic infection in pigs, the intestine specific regulatory mechanism of the gene promoter is the best interest of the pig NeuGc biosynthesis. Then, it is in this study reported that the 5’pcmah-1 promoter containing exon 1a and common ORF region (exon 2 to exon 14) is intestine specific in the pig. From the luciferase reporter assays using serial construction of each deleted promoter, it was demonstrated that promoter P1-1600 region relative to upstream region of 5’pcmah-1 is preferentially active in IPI-2I cells than in PK15 cells, corresponding with both mRNA expression patterns. Both promoters lack TATA box, but contain two Sp1 binding sites overlapped in the P1-260. Each mutation of Sp1 binding sites resulted in the reduction of luciferase activities in P1-542, indicating that in the proximal promoter region, Sp1 binding sites are crucial to regulate the intestine specific level of pcmah expression in the IPI-2I cells. In addition, the treatment with mithramycin A (25 nM to 100 nM) decreased the luciferase activity of P1 promoter in a dose-dependent manner. EMSA analysis revealed that the probes containing each Sp1 binding site bind to Sp1 and Sp3. Taken together, the results indicate that Sp1/3, or Sp1 bind to their putative binding sites on the P1 promoter regions of pcmah gene and positively regulate the promoter activity in pig cells
- Track 9: Glyco Immunology
Track 10: Glycans in Drug Design
Location: Atlanta
Chair
Cheorl-Ho Kim
Sungkyunkwan University, Korea
Co-Chair
Nada Al-Hasawi
Kuwait University, State of Kuwait
Session Introduction
Dev P Arya
Clemson University, USA
Title: Bacterial ribosome selective aminoglycosides
Time : 09:45-10:15
Biography:
Dev Arya earned his B.Sc. (chemistry honors program) from St. Stephen's College, Delhi; and PhD (Bioorganic Chemistry) from Northeastern University, Boston. After spending his postdoctoral years in the labs of Prof. T. C. Bruice (UC Santa Barbara), he joined the faculty at Clemson University. Dr. Arya is a recipient of a National Science Foundation CAREER Award (2002) and the ACS Horace S. Isbell Award of the Division of Carbohydrate Chemistry (2007). He has served as the Program Chair (2004-2008), Chair-Elect (2009-2010) and Chair (2010-2011) of the ACS Division of Carbohydrate Chemistry.
Abstract:
Aminoglycosides inhibit bacterial growth by binding to the A-site decoding region of the bacterial 16s ribosomal RNA (rRNA) within the 30S ribosomal subunit. Previous work has shown that there is approximately a five-fold difference in the affinity of neomycin for the human A-site model and the E. coli model. We have developed a screening assay that rapidly identifies compounds that discriminate between the two model rRNA structures. This approach, coupled with a rapid solid phase synthesis method, has identified active aminoglycosides that show large differences in binding affinity for the E. coli A-site and the human A-site than that of neomycin (~30 fold). The methodology for synthesizing, screening for both ribosomal binding/selectivity and bacterial growth inhibition, and rapid analysis of the data provides a systematic method for identification of bacterial ribosome specific antibacterial that can evade bacterial resistance pathways.
Nada Al-Hasawi
Kuwait University, State of Kuwait
Title: Inhibition of polysialylation- of neural cell adhesion molecule in the kelly neuroblastoma cell line by hexane extracts of the roots of withania somnifera
Time : 10:15-10:45
Biography:
Nada Al-Hasawi graduated from the Faculty of Science at Kuwait University in 1995 with a degree of Biochemistry and subsequently an M. Sc. In 1999. She worked first as Scientific Assistant, then as Department Technician and then for 5 years as a Teaching Assistant in the Faculty of Pharmacy at Kuwait University before taking up a scholarship to study for a PhD at the Institute of Cancer Therapeutic at Bradford University, England. Following its completiion in 2008 she was appointed to her present position as Assistant Professor in Departmenmt of Pharmaceutical Chemistry, Faculty of Pharmacy at Kuwait University. Dr Al Hasawi’s current interests focus on the role of polysialic acid in metastatic cancers.
Abstract:
It has been known for several decades that alterations in glycosylation patterns play an important role in the metastasis of cancer cells but thus far few drugs have been developed specifically targeting these molecules. Polysialic acid (PSA) is a developmentally regulated cell-surface glycan consisting of sialic acid monomers attached by α-2,8-glycosidic linkages which, in mammals, is mainly expressed on neural cell adhesion molecule (NCAM). Polysialylated NCAM is abundant in embryonic tissues, and limited to areas of persistence of neuronal plasticity in adults. Up-regulation of PSA has also been reported in highly metastatic cancers where it appears to be associated with tumour progression. In this study we tested the ability of crude extracts of the Ayurvedic medicinal plants, namely Withania somnifera (ashwaghanda) and Bacopa monnieri (Brahmi), to inhibit PSA expression in several human tumour cell lines including TE671 rhabdomyosarcoma, Kelly neuroblastoma, 1321N1 brain astrocytoma and HCT colorectal carcinoma. Highest PSA signals, determined by ELISA, were observed in Kelly cells. Hexane extracts of roots of Withania somniferahttp://glycobiology.conferenceseries.com/, at doses that did not cause any cytotoxicity as determined by MTT assay, were found to cause 20-30% inhibition of PSA expression. To exclude the effect of counteracting constituents, we intend to fractionate the herbal extract to purify and characterise the compounds responsible for this inhibitory activity. We propose a therapeutic approach in which expression of glycans associated with tumour progression and metastasis could be inhibited by prolonged treatment with relatively non-toxic agents that do not target cell survival processes.
Joon Kim
Korea University, Korea
Title: Ribosomal protein S3 secreted from cancer cell lines is N-glycosylated
Biography:
Prof. Joon Kim has completed his BS and MS in Microbiology from Seoul National University, PhD in Biochemistry from the University of California at Berkeley and postdoctoral study from Harvard Medical School. He is a Professor in the Division of Life Sciences, and the Director of Radiation Safety and Management Center, Korea University, Seoul, Korea. He has published more than 150 papers in reputed journals
Abstract:
Ribosomal protein S3(rpS3) is a component of the 40S ribosomal small subunit but has multiple other extra-ribosomal functions like apoptosis, cell cycle control, DNA repair etc. It has a DNA repair endonuclease activity which is related with various cancers. Recently, we have discovered that this protein is secreted only from various cancer cell lines as a homodimer but not in normal cells. We also confirmed that rpS3 is secreted more into media from the more invasive cancer cell lines. Presently we confirmed that the secreted protein is glycosylated at the Asn 165 residue and point mutation on this site is defective for the secretion. The secretion pathway turned out to be a ER-Golgi dependent pathway. We propose that glysosylated rpS3 could be used as a useful cancer marker.
Carlos Modenutti
Universidad de Buenos Aires, Argentina
Title: From sequence to 3D-model: an efficient use of homology modeling, molecular dynamics and ligand docking techniques to predict protein-carbohydrate complexes
Time : 11:00-11:30
Biography:
Dr. Modenutti received his Bachelors of Science degree in Genetics from the National University of Misiones, Argentina in 2009. He then moved to Buenos Aires to join the working group of Dra. Silvia Hajos at Immunology Department in Faculty of Pharmacy and Biochemistry of University of Buenos Aires (UBA) for his PhD. He worked in close collaboration with Dr. Marcelo Marti at the Chemical Biology of Faculty of Exact and Natural Sciences of UBA . His Ph.D. thesis focused on Hyaluronic Acid glycomimetic drugs development. He continued his work in the Marti Lab as a postdoc. His current work focuses on the development of bioinformatics tools to prediction of protein carbohydrate complex structures.
Abstract:
Proteins that bind carbohydrates are responsible for numerous important biological functions, such as signal transduction, cell adhesion, among many others. Despite the number of reported structures of protein-carbohydrates complexes (PCCs) is constantly increasing, achieving accurate predictions of the protein-carbohydrate interaction by means of Structural Homology Models (SHM) and ligand-docking remains one of the biggest challenges in Glycobiology. This is due mainly because the residues that form the Carbohydrate Binding Site (CBS) can differ from its ideal binding rotamer in the SHM, which can thereafter significantly affect Docking algorithms performance. In addition, while generally available docking programs work reasonably well for most drug-like compounds, carbohydrates and carbohydrate-like molecules are often problematic, because Force-Fields and Scoring Functions are typically designed to reproduce structures of protein-drug complexes. In this work, we present an integrated approach that combines conformational-space sampling of SHM using Molecular Dynamics simulations (MD) and Docking experiments. In order to obtain the most plausible binding structure of receptor and ligand, clustering analysis to identify different conformations was applied. Finally, Water-Site Bias Docking Method (WSBDM, an Autodock based protocol) was performed to generate a diversity of structures and energy-population parameters are used to rank each one of them. Here, we used human Pulmonary Surfactant-associated protein D (hSP-D) as a case study. The results show that this emerges as a promising tool to build reliable 3D-models, which can then be used for rational design or optimization of glycomimetic drugs.
Ting Ting Zhao
China-Japan Friendship Hospital, P.R. China
Title: The glycosaminoglycan chain of decorin plays an important role in AMPK signaling
Time : 11:30-12:00
Biography:
Ting Ting Zhao has completed her PhD at the age of 27 years from University of Chinese Academy of Sciences. She has published 19 papers in the international journals.
Abstract:
Diabetic nephropathy (DN) is one of the major microvascular complications of diabetes. Energy metabolism is altered under diabetic conditions. Decorin is a multifunctional small leucine-rich proteoglycan involved in the autophagy and energetic homeostasis. We investigated the role of decorin and its glycosaminoglycan chain in DN. Both decorin and phosphoralated AMPK were highly expressed in the kidney of an accelerated type 1 DN induced by streptozotocin in uninephrectomized Wistar rats at week 20. In high glucose cultured HK2 cell, glycosaminoglycan-free decorin, generated by mutating Ser4 of the mature protein core into Ala (DCN-S4A), showed more significant role in promoting of AMPK phosphoralation and LC3 II compared with the decorin proteoglycan. These data provides clues that the glycosaminoglycan chain of decorin has a reducing effect on activation of AMPK signaling pathway in DN.
Choong Hwan Kwak
Sungkyunkwan University, Korea
Title: Identification of housekeeping basal promoter 5’pcmah-2 of pig CMP-N-acetylneuraminic acid hydroxylase gene
Time : 12:00-12:30
Biography:
Graduated from Food and Biotechnology Department, KyungSung University, Busan, Korea in 2010. Obtained Master of Science from the Molecular and Cellular Glycobiology Lab, Department of Biological Science, Sungkyunkwan University, Suwon, Korea in 2012 and presently Ph.D candidate at the same laboratory under supervisor Prof Cheorl-Ho Kim, Sungkyunkwan University. My research interest is Glycan structure and biosynthesis of glycoproteins, glycoconjugates and glycolipids and NeuGc synthesis by CMP-N-acetylneuraminic acid hydroxylase.
Abstract:
Sialic acid is a generic term used for neuraminic acid and its many derivatives. N-glycolylneuraminic acid (NeuGc) is one of the most common sialic acid types found in most mammals except normal humans. NeuGc is closely linked with various diseases including cancer, infections and immune rejection response during pig-to-human xenotransplantation. Biosynthesis of NeuGc is mediated by a specific hydroxylase, cytidine-5’-monophospho-N-acetylneuraminic acid hydroxylase (CMAH), that converts CMP-NeuAc to CMP-NeuGc. In the present study, we isolated pCMAH house-keeping promoter regions (Ph), which are responsible for transcriptional regulation and which are located upstream of the alternative transcript pcmah-2. Luciferase reporter assays using serial construction of each deleted promoter demonstrated that the Pc promoter was highly active in pig-derived kidney PK15. Ph promoter of pcmah lacked a TATA box, but contained three putative Sp1 binding sites. Mutations of these Sp1 binding sites always resulted in the reduction of luciferase activities in Ph-334. In addition, treatment with mithramycin A (25–100 nM) decreased the luciferase activities of the Ph promoters in a dose-dependent manner. Electrophoretic mobility shift assay analysis revealed that the probes containing each Sp1 binding site bound to Sp1. Taken together, the results indicate that Sp1 bind to their putative binding sites on the Ph promoter regions of pcmah and positively regulate the promoter activity in pig kidney cells.
Sun-Hyung Ha
Sungkyunkwan University, Korea
Title: Intestine specific regulation of pig CMP-N-acetylneuraminic acid hydroxylase gene (pcmah) is specifically controlled by Sp1 binding sites on its promoter: 5’pcmah-1 containing exon 1a and common ORF region (exon 2 to exon 14) is intestine specific
Time : 12:30-13:00
Biography:
Graduated from Biotechnology Department, DongA University, Busan, Korea in 2014. Presently master-doctor integrated coursed student at the Molecular and Cellular Glycobiology Lab, Department of Biological Science, Sungkyunkwan University, Suwon under supervisor Prof Cheorl-Ho Kim. My research interest is Glycan structure and biosynthesis of glycoproteins, glycoconjugates and glycolipids.
Abstract:
NeuGc is acted as an immune rejection antigen in pig to human xenotransplantation, as it is called as a non-Gal xenoantigen, a next xenoantigen to overcome after elimination of major Gal xenoantigen by knocking out the α-1,3-galactosyltransferase in the pig to human xenotransplantation. In the previous study, we isolated two promoter regions of P1 and P2, which are responsible for transcriptional regulation and located on upstream regions of the two alternative transcripts of 5’pcmah-1 and pcmah-2, respectively. Among them, promoter P2 was demonstrated to be responsible for basal house-keeping expression of the gene (BBRCì—ì •). However, since the intestine tissues is important for the selective expression of the gene in responses to the pathogenic infection in pigs, the intestine specific regulatory mechanism of the gene promoter is the best interest of the pig NeuGc biosynthesis. Then, it is in this study reported that the 5’pcmah-1 promoter containing exon 1a and common ORF region (exon 2 to exon 14) is intestine specific in the pig. From the luciferase reporter assays using serial construction of each deleted promoter, it was demonstrated that promoter P1-1600 region relative to upstream region of 5’pcmah-1 is preferentially active in IPI-2I cells than in PK15 cells, corresponding with both mRNA expression patterns. Both promoters lack TATA box, but contain two Sp1 binding sites overlapped in the P1-260. Each mutation of Sp1 binding sites resulted in the reduction of luciferase activities in P1-542, indicating that in the proximal promoter region, Sp1 binding sites are crucial to regulate the intestine specific level of pcmah expression in the IPI-2I cells. In addition, the treatment with mithramycin A (25 nM to 100 nM) decreased the luciferase activity of P1 promoter in a dose-dependent manner. EMSA analysis revealed that the probes containing each Sp1 binding site bind to Sp1 and Sp3. Taken together, the results indicate that Sp1/3, or Sp1 bind to their putative binding sites on the P1 promoter regions of pcmah gene and positively regulate the promoter activity in pig cells.
Jun-Young Park
Sungkyunkwan University, Korea
Title: Disialyl ST8Sia I (GD3 synthase) accumulates GD2 ganglioside and suppress ICAM-1-mediated invasiveness in human breast cancer MDA-MB231 cells
Time : 13:00-13:30
Biography:
Graduated from Biological Science Department, Myungji University, Yongin, Gyunggido, Korea in 2014. Presently master-doctor coursed student at the Molecular and Cellular Glycobiology Lab, Department of Biological Science, Sungkyunkwan University, Suwon under supervisor Prof Cheorl-Ho Kim. My research interest is Glycan structure and biosynthesis of glycoproteins, glycoconjugates, glycolipids and anti-inflammatory mrchanism
Abstract:
Gangliosides are sialylated glycosphingolipids which are ubiquitously expressed in mammalian plasma membranes and they play crucial roles in cellular interaction, adhesion, differentiation and apoptosis. To synthesize gangliosides in cells, lactosyl ceramide is processed by different pathways composed of various glycosyltransferases or sialyltranferases. One of these sialyltransferases, GD3 synthase (ST8Sia I), is a key enzyme which controls GD3 biosynthesis from its precursor ganglioside GM3. The steady state level of GD3 expression also depends on other enzymes such as GD2 synthase and GT3 synthase. Thus, the relationship between a ganglioside and its related enzymes is linked to its glycosylation pattern in the cell membrane. The GD3 is expressed weakly in normal tissues, and expressed almost exclusively during development or under pathological conditions such as neuronal disorders. In addition, GD3 promotes tumor progression by influencing cellular proliferation, adhesion and metastasis in malignant tumors. However, GD3 is also known to induce apoptosis by transiently accumulating in the cytosol to contribute to mitochondria damage in the early stages of apoptosis. Fas-mediated apoptosis was also induced by GD3 in lymphoid cells. Therefore, the significance of the biological functions of the ganglioside GD3 in cancer cells is still controversial. Although the disialoganglioside GD3 has been considered to be involved in tumor progression or suppression in various tumor cells, the significance of the biological functions of GD3 in breast cancer cells is still controversial. This prompted us to study the possible relationship(s) between GD3 expression and the metastatic potential of a breast cancer MDA-MB231 cells. The human GD3 synthase cDNA was transfected into MDA-MB231 cells, and G-418 bulk selection was used to select cells stably overexpressing the GD3 synthase. In vitro invasion potentials of the GD3 synthase over-expressing cells (pc3-GD3s) were significantly suppressed when compared with control cells. Expression of intercellular adhesion molecule-1 (ICAM-1; CD54) was down-regulated in the pc3-GD3s cells and the decrease in ICAM-I expression is directly related to the decrease in invasiveness of the pc3-GD3s cells. Then, we investigated signaling pathways known to control ICAM-1 expression. No difference was observed in the phosphorylation of ERK and p38 between the pc3-GD3s and control cells (pc3), but the activation of AKT was inhibited in pc3-GD3s, and not in the control (pc3). In addition, the composition of total gangliosides was changed between control (pc3) and pc3-GD3s cells, as confirmed by HPTLC. The pc3-GD3s cells had an accumulation of the GD2 instead of the GD3. RT-PCR results showed that not only GD3 synthase, but also GM2/GD2 synthase (β4-GalNc T) expression was increased in pc3-GD3s cells. Overexpression of GD3 synthase suppresses the invasive potential of human breast cancer MDA-MB-231 cells through down-regulation of ICAM-1, which may be influenced by accumulation of the GD2 ganglioiside.
Manuel Maestre Reyna
Academia Sinica, Taiwan
Title: RbmA: a multifunctional protein component of the Vibrio cholerae biofilm matrix
Biography:
Manuel Maestre Reyna completed his PhD in 2011 at the Philipps University Marburg, Germany, and after a one year stay as lab leader in the same University, moved to the Academia Sinica, Taiwan, to pursue postdoctoral studies in structural proteins of bacterial biofilms. In the past five year, He has published 10 papers in reputed journals and has been involved in a variety of different projects, involving advanced computational and structural biology techniques.
Abstract:
Vibrio cholerae, the causative agent of cholera, is a gram negative bacterium, which may swim freely, or grow in sessile biofilms associated with abiotic surfaces, zoo-plankton, mollusks, or crustaceans in estuarine and brackish waters. Vibrio cholerae biofilms are involved in many aspects of the pathogen's life-cycle, constituting a possible source of antibiotic resistances, and being very important for intestinal colonization. Particularly during exopolysaccharide- dependent biofilm formation, secreted proteins of the rbm gene cluster, including RbmA, RbmC, and Bap1 are key to biofilm ultrastructure, along with the vibrio polysaccharide (VPS) itself. While RbmC and Bap1 have been linked to biofilm-surface interactions , RbmA surrounds cells within the biofilm, which results in improved mechanical strength, and better biofilm accumulation by a not very well understood mechanism, but possibly involving glycan binding. Furthermore, RbmA has been linked to micro-colony formation during V. cholerae pathogenesis, significantly enhancing the infectivity of the pathogen. Here, we elucidated the RbmA crystal structure, as well as demonstrating glycan binding activity. Furthermore, we observed two distinct proteolytic pathways for RbmA. In the first one, protease mediated post-translational modification yielded a different RbmA isoform, RbmA*, involved in VPS independent cell recruitment. The second pathway, which is phosphate and magnesium dependent, possibly leads to RbmA inactivation, and may be involved in biofilm dispersal.
Jose Ignacio Ibeas
Universidad Pablo de Olavide, Spain
Title: N- and O-glycosylation are essential for Ustilago maydis virulence
Biography:
Jose Ignacio Ibeas completed a Biology degree in 1991 at Malaga University in Spain and a PhD at the same University in 1996. His PhD work was focused in studding the yeasts involved in sherry wine production. Then he moved to Purdue University in Indiana to study the antifungal properties for the plant PR protein Osmotin. Since 2003 he is Professor at Pablo de Olavide University in Spain were he is Head of the Molecular Biology Department and Principal Investigator for the Fungal Biotechnology group. He has published more than 30 papers in reputed journals and is collaborating as reviewer for many journals and for the Spanish Evaluation Agency.
Abstract:
Cell wall and secreted proteins are the vehicles for the interaction between fungi and their host. Most of these proteins are glycosylated and this posttranslational modification is essential for their localization and function. Although the role for glycoproteins in these interaction have been studied in fungal animal pathogens for many years, almost nothing is known for phytopathogens fungi. Ustilago maydis has raised as an excellent model for the study of plant-pathogen interactions, and its relation with the maize plant is one of the systems in which studies can be tackled from both plant and pathogen perspective. In the last years our group is focused on the study of the role for N- and O-glycosylation during the maize infection for this fungi. We have identified many of the proteins involved in both process, demonstrate that N- and O-glycosylation are both essential for virulence and identified mutants in different stages across the infection process. So we have shown that mutants for Pmt4 (O-mannosyltransferase) are not able to form appressorium, a structure required for plant penetration, mutants for Gls1 (glucosidase I) can not progress into the plant once the plant has been penetrated and Gas2 (glucosidase II b-subunit) mutants are unable to induce plant tumor formation after a defective progression into the plant. By applying in silico analysis we have identified Pmt4 targets which are essential to complete plant infection. Now we are using 2-D gel analysis to identify cytoplasmic, secreted and cell wall glycoproteins involved in the infection process.
Mario Waespy
University of Bremen, Germany
Title: Insight into structure and function relation of trans-sialidase from Trypanosoma congolense
Biography:
Dr. Mario Waespy has studied Chemistry and completed his PhD in Glycobiochemistry in November 2015 at the University of Bremen in the laboratory of Prof. Sørge Kelm. Currently, he is establishing his own research project on Trypanosoma trans-sialidases at the Centre for Biomolecular Interactions Bremen (CBIB).
Abstract:
Trypanosomes are protozoan parasites causing trypanosomiasis in Latin America (Chagas' disease) and Sub-Sahara Africa (sleeping sickness in humans and Nagana in livestock). African Animal Trypanosomiasis (AAT or Nagana), caused by Trypanosoma congolense is a devastating disease in domestic and wild African animals causing an annual loss in agriculture productivity of about 4.5 billion USD due to the death of more then 3 million cattle, whereas 40 millions are estimated to be threatened. Trypanosomes express unusual enzymes termed trans-sialidase (TS). TS are surface-bound enzymes, which catalyse the transfer of sialic acids (Sia) from host cell glycoconjugates to terminal galactose residues on acceptor substrates of the parasite’s surface. Since trypanosomes are unable to synthesise Sia de novo they employ TS to cover their surface with Sia to resist and even manipulate host’s innate and acquired immune system and consequently extend their survival in the different hosts. Several studies have shown that TS play important roles in the pathology of trypanosomiasis in mammalian host and are essential for survival of the parasite also in the insect vector, representing TS as a major virulence factor. Our studies on Trypanosoma congolense TS, revealed 14 active variants exhibiting significantly different enzymatic activities, although these can not be sufficiently explained by amino acid variations at the catalytic centre. Besides the catalytic domain (CD), all TS contain a lectin-like domain (LD), whose biological function still remains unknown. Structural and functional characterisation of Trypansoma congolense TS-LD provided new insight into enzymatic activities and correlated biological functions.