glikozaminoglikánok

Glikozaminoglikánok, often abbreviated as GAGs, are long, unbranched polysaccharides consisting of repeating disaccharide units. These disaccharides are composed of an amino sugar (either N-acetylglucosamine or N-acetylgalactosamine) and a uronic sugar (either glucuronic acid or iduronic acid). The only exception to this pattern is keratan sulfate, which contains galactose instead of a uronic sugar. GAGs are highly negatively charged due to the presence of sulfate and carboxyl groups, which allows them to attract and retain large amounts of water. This property makes them crucial components of the extracellular matrix, where they provide structural support, lubrication, and shock absorption.

In the body, GAGs are found in various connective tissues, including cartilage, bone, tendons, skin, and the vitreous humor of the eye. They play vital roles in maintaining tissue hydration, elasticity, and integrity. Specific GAGs have specialized functions. For instance, hyaluronic acid, the largest and most abundant GAG, is essential for joint lubrication and skin hydration. Chondroitin sulfate is a major component of cartilage, contributing to its tensile strength and ability to withstand compression. Dermatan sulfate is found in skin and blood vessels, influencing their elasticity. Heparan sulfate and heparin are involved in cell signaling, blood clotting, and inflammatory responses. The structure and composition of GAGs can vary, influencing their specific biological activities and interactions with other molecules.