Highlights 2014 on glycoscience; glycosyltransferases and glycobiomarkers.

Abstract

The field of glycobiology has continued to grow and mature, establishing the role of glycans in a myriad of biological processes. Many new functions of glycans have emerged from studies on different eukaryotic and prokaryotic organisms. The development of new analytical tools and techniques have fuelled the generation of a lot of information on the structure of glycans, factors determining their structure and their derangement in several pathological conditions. One of the major themes of the recently held International Symposium on Carbohydrates in Bangalore, India was glycoconjugates and glycobiology, in which scientists working at the forefront of research in these areas reported their findings on different aspects of glycans in physiology and pathology. Selected contributions from these sessions are presented in this special issue of the journal. These contributions comprise short critical reviews or original research papers focusing on (a) glycosyl transferases in physiology and pathology (b) glycobiomarkers and (c) structural analysis of glycans. Critical information embedded within the oligosaccharides on the glycoconjugates as represented by the structural features of the glycans are important in specific biological processes however alterations in glycan structures occur during development of diseases such as cancer. Glycosyl transferases, which constitute a large family of enzymes displaying exquisite specificity for both glycosyl donor and the acceptor, are largely responsible for glycosyl transfer reactions that generate a diversity of glycan structures on glycoconjugates. Many substances including natural compounds are known to affect the activity of these enzymes, making them potential drug targets. At least six articles in the ensuing pages describe the biological importance and features of glycosyl transferases. These include data relating to (a) resiliency to mutagenicity of glycosyltransferases involved in bloodgroup antigen synthesis (b) role of O-linked glycans and protein –O-glycosylation in protein folding (c) microbial cell wall biosynthesis as well as formation of GPI anchors (d) characterisation of glycosyltransferases from new sources (e) glycosyl transferasebased assays to demonstrate glycan changes in cancer tissues. A number of changes can occur in glycan expression during the development of pathological conditions. Identification and validation of these glycan changes in disease conditions make them useful surrogate markers for the disease or drug response. A strategy for developing glycobiomarkers for disease has been described in one of the contributions while another paper reports the potential of 9-O-acylated sialic acids in differentiating normal haematopoietic stem cells from leukemic stem cells. Further, changes in cell surface proteoglycans in tumor cells and the potential of cell surface molecules such as receptor for advanced glycation end-products in recognising such molecules and development of glycomimetics based on these, have been discussed. P. R. Sudhakaran (*) Department of Computational Biology and Bioinformatics, University of Kerala, Karyavattom, Trivandrum, Kerala, India e-mail: prslab@gmail.com