The role of glycosylation in protein antigenic properties

Abstract

Glycosylation of proteins is a common event and contributes to protein antigenic properties. Most data have been obtained from model studies on glycoprotens with well-defined structure or synthetic glycopeptides and their respective monoclonal antibodies. Antibodies raised against glycoprotein antigens may be specific for their carbohydrate units which are recognized irrespective of the protein carrier (carbohydrate epitopes), or in the context of the adjacent amino acid residues (glycopeptidic epitopes). Conformation or proper exposure of peptidic epitopes of glycoproteins is also frequently modulated by glycosylation due to intramolecular carbohydrate-protein interactions. The effects of glycosylation are broad: glycosylation may 'inactivate' the peptidic epitope or may be required for its reactivity with the antibody, depending on the structure of the antigenic site and antibody fine specificity. Evidence is increasing that similar effects of glycosylation pertain to T cell-dependent cellular immune responses. Glycosylated peptides can be bound and presented by MHC class I or II molecules and elicit glycopeptide-specific T cell clones.

Evaluation of the Impact of Codon Optimization and N-Linked Glycosylation on Functional Immunogenicity of Pfs25 DNA Vaccines Delivered by In Vivo Electroporation in Preclinical Studies in Mice

“…In addition, the amino acid sequence of Pfs25 contains three putative asparagine N-linked glycosylation sites. Posttranslational modifications such as N-glycosylation have been known to play a crucial role in the folding, stability, and functional integrity of proteins (18,19). Glycosylation of proteins in Plasmodium has remained highly controversial (20), and a recent study has suggested formation of severely truncated N-glycan side chains due to the absence of glycosyltransferases required for precursor side chain generation (21).…”

Efficiency of ascorbic acid against oxidative stress-induced dimethoate toxicity in fish, Capoeta capoeta [Guldenstaedt, 1773]

“…Ascorbic acid has important functions, such as lymphocyte transformation, preventing oxidation of molecules used in the metabolic pathways, increasing chemotactic activity in neutrophils, collagen synthesis, hydrogen transport, regular growth and nucleic acid synthesis (Wang et al, 2003). The type of collagen which increased in fish exposed to ascorbic acid were identified as glycoproteins containing sialic acid groups (Lisowska, 2002;Yavuz, 2001). Dubey et al (2014) reported that Clarias batrachus -1 exposed to 0.45 µgl dimethoate increased the level of the hepatic glutamate oxaloacetate transaminase, glutamate pyrophosphate transaminase, acid phosphatase, and alkaline phosphatase enzymes were increased after 30 and 60 days compared to control fish, however protein content of the fish decreased.…”

Glycoproteins of erythrocyte membranes and the structure of their carbohydrate determinants

“…Великий вугле вод ний компо нент, експонований на зовнішньому боці клітинної мембрани, робить гліко форини го лов ними імунологічними детермінантами поверхні еритро цитів. У глікофоринах міс тяться детермінанти груп крові MN, Ss, Ge, рецептори, які взаємо діють з поверх нею бактерій, вірусів (вірус грипу, реовірус), паразитів (малярійний плазмо дій) [13,24,32,34,38,41,56,63]. Стан вуглеводного компонента глікофоринів є сигналом для розпізна вання старіючих або пошкоджених еритроцитів для по даль шого вида лення їх із кров'яного русла [8,17].…”