Glükosaminoglükaanide

Glükosaminoglükaanid, also known as glycosaminoglycans (GAGs) or mucopolysaccharides, are long, unbranched polysaccharide chains composed of repeating disaccharide units. The disaccharides typically consist of a hexosamine (either glucosamine or galactosamine) and a uronic acid (either glucuronic acid or iduronic acid). These molecules are highly negatively charged due to the presence of sulfate and carboxyl groups, which allows them to bind large amounts of water and cations. This property is crucial for their diverse biological functions.

GAGs are a major component of the extracellular matrix in connective tissues, playing vital roles in maintaining tissue structure, elasticity, and hydration. They are found in cartilage, tendons, ligaments, skin, and the vitreous humor of the eye. Different types of GAGs exist, including hyaluronic acid, chondroitin sulfate, dermatan sulfate, heparin, heparan sulfate, and keratan sulfate. Each type has a distinct structure and distribution within the body, contributing to specific functions. For example, hyaluronic acid provides lubrication and shock absorption in joints and skin, while heparin acts as an anticoagulant.

In addition to their structural roles, GAGs are involved in cell signaling, cell adhesion, and regulating the activity of various growth factors and enzymes. Deficiencies or mutations in the enzymes responsible for GAG synthesis or degradation can lead to a group of rare genetic disorders known as mucopolysaccharidoses, which are characterized by the accumulation of GAGs in lysosomes and can result in severe multisystem abnormalities.