Heparansulfát

Heparansulfát is a complex glycosaminoglycan found on the surface of many cells and in the extracellular matrix. It is a linear polysaccharide composed of repeating disaccharide units. Each disaccharide consists of an uronic acid (either glucuronic acid or iduronic acid) and a glucosamine residue. These glucosamine residues are extensively modified with sulfate groups, and the uronic acid residues can also be sulfated. The pattern and position of these sulfate groups are highly variable and contribute to the diverse biological functions of heparansulfát.

Heparansulfát plays a crucial role in a wide array of biological processes. It is involved in cell adhesion, cell growth and differentiation, and the regulation of protein activity. Many growth factors and signaling molecules bind to heparansulfát, which helps to concentrate them at the cell surface and presents them to their receptors. This interaction is essential for mediating various cellular responses. Heparansulfát also contributes to the structural integrity of tissues and acts as a barrier to the passage of certain molecules. Its anticoagulant properties are also well-known, though unfractionated heparin, a related molecule with a higher degree of sulfation, is more potent in this regard. Defects in heparansulfát synthesis or structure can lead to various genetic disorders, highlighting its importance in normal physiological function.