| Popis: |
The mistaken idea that biologically important molecules belong to mutually exclusive four categories has been inhibiting glycoconjugate research for many years. We are aware now that the great majority of secrtory and membrane bound proteins are glycosylated. So are many mambrane bound lipids. Recent advances in glycobiology have demonstrated that glycosylation is not limited to surface and extracellular proteins only, but is widespread also in the nucleus and the cytoplasm of the cell. Different sizes, chemical, physical and antigenic properties of glycans determine the variety of biological functions which are now slowly being unravelled. The overwhelming body of evidence indicates that the carbohydrates attached to glycoconjugates at the surface of cells play pivotal roles in the early stages of infection by pathogenic invaders, such as bacteria and viruses. They are important for defence and inflammation, for fertilization and development, for memory consolidation and rejection of xenografts. They explained many storage deseases and are of primary importance in the progression of cancer and metastasis thus providing a gauge of malignancy. Immunologists and physicians have begun to realise that the absence of the normal saccharide portions from recombinant therapeutics and adjuvants provokes an immune response from some patients during trials. Thus sugars are laying claim to important physiological and pharmaceutical properties, and can no longer be ignored. |
