Glycosaminoglycan

Glycosaminoglycans (GAGs) are long unbranched polysaccharides consisting of a repeating disaccharide unit. They are highly polar and attract water. They are therefore useful to the body as a lubricant or shock absorber.

Structure

GAGs are formed from disaccharide units made up of a sugar and an amino sugar. The sugar component can be either glucose or galactose, and the amino sugar is either glucosamine or galactosamine. The disaccharide units are linked together by glycosidic bonds.

Function

GAGs are an important component of connective tissue and contribute to its structural integrity. They are also involved in the regulation of cell growth and proliferation. In addition, they play a role in the binding of growth factors and proteins to the cell surface.

Types of GAGs

There are several types of GAGs, including hyaluronic acid, chondroitin sulfate, dermatan sulfate, keratan sulfate, and heparin. Each type has a specific structure and function.

Clinical significance

Abnormalities in the structure or metabolism of GAGs can lead to a variety of diseases, including Mucopolysaccharidosis, a group of metabolic disorders caused by the absence or malfunctioning of lysosomal enzymes needed to break down molecules called glycosaminoglycans.

See also

• Proteoglycan
• Extracellular matrix
• Mucopolysaccharidoses

Glycosaminoglycan

• 
  Chondroitin Sulfate Structure
• 
  Hyaluronan