GAGtípusok

GAGtípusok, or glycosaminoglycan types, refers to a diverse group of linear polysaccharides composed of repeating disaccharide units. These disaccharides consist of an amino sugar (either N-acetylglucosamine or N-acetylgalactosamine) and a uronic acid (glucuronic acid or iduronic acid), or a neutral sugar in the case of keratan sulfate. The specific sugar composition, length of the polysaccharide chain, and degree of sulfation contribute to the distinct properties and functions of each GAG type.

There are several major classes of GAGs found in vertebrates, each with characteristic structures and locations. Hyaluronic acid is a notable exception as it is not sulfated and is found in synovial fluid, cartilage, and the extracellular matrix. Chondroitin sulfates are abundant in cartilage and bone, playing a crucial role in their structural integrity. Dermatan sulfate is found in skin, blood vessels, and heart valves, contributing to their elasticity. Heparan sulfate and heparin are widely distributed in cell surfaces and basement membranes, with heparin also acting as an anticoagulant. Keratan sulfate is a component of cartilage, cornea, and bone.

The primary functions of GAGs are related to their highly hydrated and negatively charged nature. They form a hydrated gel that provides structural support, resists compression, and lubricates joints. Their negative charges also play a role in binding cations and water, influencing the osmotic pressure of tissues. Furthermore, GAGs interact with various proteins, including growth factors and enzymes, thereby modulating a wide range of biological processes such as cell adhesion, migration, proliferation, and differentiation. Disruptions in GAG metabolism are associated with various diseases, including mucopolysaccharidoses.