Glycans

Glikan je naziv za skup monosaharida međusobno povezanih glikozidnim vezama čija duljina varira ovisno o vrsti glikozidne veze i organizmu. Naziv se češće koristi za skupinu monosaharida povezanih glikozidnim vezama koji mogu biti samostalni ili vezani na protein ili lipid, pri čemu glikan zauzima veći ili manji dio konačne strukture. Glikani mogu biti vezani na različite makromolekule: proteine, lipide, čak i RNA. Prema tome razlikujemo proteoglikane, glikoproteine i glikolipide. Oni nastaju procesom glikozilacije, a sami proces ima pet varijanti: N-, O-, C- glikozilacija, fosfoglikozilacija i glipijacija. Jasno je da je proces glikozilacije izuzetno važna posttranslacijska modifikacija zbog niza uloga koje glikani obavljaju u stanici, a daljnja istraživanja će donijeti napredak u mnogim granama znanosti.Glycan is a name for a set of oligosaccharides connected with glycosidic bonds which varies in lenght depending on a type of glycosidic bond and organism. Name is more commonly used for group of monosaccharides connected with glycosidic bonds which can be independent of connected to a protein or a lipid, where glycan occupies bigger or smaller part of final structure. Glycans can be connected to different macromolecules: proteins, lipides, even RNA. According to that we recognize proteoglycans, glycoproteins and glycolipids. They are made by glycosylation, and the process has five variants: N- , O-, C-glycosylation,phosphoglycosylation and glypiation. It is clear that the glycosylation is very important posttranslational modification by many roles that glycans do in a cell, and further reaserch will bring new advances in many branches of science