glycoprotein

• a glycoprotein is a molecule that consists of a protein covalently bonded to one or more carbohydrate chains. glycoproteins are found throughout the body, especially on cell surfaces and in plasma, where they play essential roles in cell signaling, immune response, coagulation, and cell–cell recognition. they are synthesized in the endoplasmic reticulum and golgi apparatus of cells.

  • chemical properties

    • structure: composed of a polypeptide backbone with covalently attached oligosaccharide chains
    • bond type: n-linked (to asparagine) or o-linked (to serine/threonine) glycosidic bonds
    • solubility: varies widely; many are membrane-bound or secreted
    • examples: fibrinogen, immunoglobulins, hormones (like erythropoietin), mucins

  • usefulness in biology and medicine

    • glycoproteins are essential in immune defense, especially antibodies and major histocompatibility complex (mhc) proteins.
    • they function as hormones, enzymes, clotting factors, and cell receptors.
    • changes in glycoprotein structure or levels are associated with diseases such as cancer, autoimmune disorders, and viral infections.
    • used in medicine as biologic drugs, diagnostic markers, and vaccine components.

  • antibacterial and antimicrobial activity

    • many glycoproteins, especially in mucosal tissues, help trap and neutralize pathogens.
    • mucins, a type of glycoprotein, form a protective barrier and inhibit microbial invasion.
    • antibodies (immunoglobulins), which are glycoproteins, play a direct role in recognizing and neutralizing bacteria and viruses.
    • research highlights:
      • immune glycoproteins:
        • immunoglobulin g research link
        • mucins research link

• research links

  • glycoproteins in cell signaling
  • glycoproteins and immunity
  • glycoproteins and disease biomarkers