| Summary: | 1 Charles University in Prague Faculty of Science Department of Biochemistry α-N-Acetylgalactosaminidase as a tools in the synthesis of complex oligosaccharide immune stimulators Summary of Ph. D. Thesis Mgr. Hynek Mrázek Supervisor: Prof. RNDr. Karel Bezouška, Dsc. Prague 2011 2 Introduction Glycoproteins Glycoproteins consist of proteins to which carbohydrate are covalently linked. The distinction between proteoglycans and glycoproteins residues is in the level and types of carbohydrate modification. Carbohydrates are linked to the protein component through either O-glycosidic or N-glycosidic bonds. The N-glycosidic linkage is through the amide group of asparagine. The O- glycosidic linkage is to the hydroxyl of serine, threonine or hydroxylysine. The predominant carbohydrate attachment in glycoproteins of mammalian cells is via N-glycosidic linkage. The site of carbohydrate attachment to N- linked glycoproteins is found within a consensus sequence of amino acids, N-X- S(T), where X is any amino acid except proline. While the N-glycosylation is governed by the above rules, no exact rules were found for glycosylation of O- type. This process is the step-wise addition of the sugar residues directly onto the polypeptide chain. Biosynthesis of glycoproteins occurs via protein glycosylation (the addition of...
|
|---|
