Post-translational modifications (PTMs) are crucial biological processes implicated in multiple physiological and pathological pathways. Glycosylation is one such PTM that results in the attachment of glycans, which are chain-like structures of single sugar molecules to lipids or proteins such as lectins. Glycosylation influences the physicochemical stability and efficient folding of translated proteins, and is thus crucial for accurate biological functioning of proteins. In addition to physiological roles such as cell-to-cell adhesion, glycosylation is also an important mediator of several pathological processes such as immune evasion by pathogens.
Lectins, proteins that bind glycans, are known to mediate the suppression of cancer cell proliferation, tumour growth, and B and T cell activation, and are therefore crucial for inhibiting malignancies and autoimmune disorders. Immune modulation by lymphocyte mitogenesis induction and macrophage activation by lectins inhibits several pathogenic invasions. Thus, modifications introduced by interaction with glycans significantly influence these immunological and pathological roles.
Alterations in glycosylation processes are often implicated in the formation of cryptic non-physiological structures that are perceived as foreign by the immune system. Aberrant mucin-type O-glycosylation resulting in the expression of Thomsen-Friedenreich (TF) and Thomsen-nouveau (Tn) antigens on malignant cell surfaces and in autoimmune conditions is an example of pathological implications of rogue glycosylation processes. Protein glycosylation analysis has, therefore, captured the broader attention of biomedical and biopharmaceutical research. The challenges involved in the analysis of glycopeptides obtained by glycosylation warrant the need for glycoanalytical workflows reliant on advanced proteomic techniques.
Ganatra et al use IonOpticks Aurora Series columns in UPLC-MS to develop a glycoproteomics workflow using recombinant Boletopsis grisea lectin (rBGL) and mutant rBGL proteins. This study contributes to better understanding of clinically significant glycan binding and crosslinking mechanisms, and also identifies rBGL proteins as novel high specificity glycoproteomic tools.
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A bi-specific lectin from the mushroom Boletopsis grisea and its application in glycoanalytical workflows.
Sci Rep. 2021;11(1):160. Published 2021 Jan 8. doi:10.1038/s41598-020-80488-7
Ganatra MB, Potapov V, Vainauskas S, et al.
Commentary by Pialy Ghanekar, PhD.
About the author
Pialy is a virologist, with special interests in immunology and molecular biology. She has studied the immuno-pathologies of several human viral diseases using molecular biology and proteomic based techniques.