proteoglykany

Proteoglykany, also known as proteoglycans, are a diverse group of complex molecules that play crucial roles in the structure and function of the Extracellular Matrix (ECM) in various tissues. They are composed of a core protein covalently attached to one or more glycosaminoglycan (GAG) chains, which are long, unbranched polysaccharides.

Proteoglycans are primarily found in connective tissues, where they contribute to the resilience, elasticity, and hydration of the ECM. Their unique structure allows them to bind water and other molecules, forming a gel-like substance that provides mechanical support to cells. This property is essential for cartilage, where proteoglycans such as aggrecan give cartilage its shock-absorbing capability.

Throughout the body, proteoglycans are involved in various biological processes, including cell proliferation, migration, adhesion, and signaling. They modulate the activity of growth factors and influence cell behavior by interacting with other ECM components and cell surface receptors.

There are several classes of proteoglycans, categorized based on their location and structure. Some are membrane-bound, like syndecans and glypicans, playing roles in cell signaling. Others are secreted into the ECM, such as aggrecan, decorin, and versican.

Alterations in proteoglycan structure or function are associated with various diseases, including osteoarthritis, cancer, and fibrosis. Due to their significance in tissue integrity and cell communication, proteoglycans are also studied as potential therapeutic targets and biomarkers for numerous conditions.

In summary, proteoglycans are vital components of the extracellular matrix, contributing to tissue structure, cellular functions, and overall organismal health.