glycosaminoglycan catabolic process

Definition

Target type: biologicalprocess

The chemical reactions and pathways resulting in the breakdown of glycosaminoglycans, any one of a group of polysaccharides that contain amino sugars. [ISBN:0192800981]

Glycosaminoglycan catabolic process is a critical biological process that involves the breakdown of glycosaminoglycans (GAGs), long, unbranched polysaccharide chains found in the extracellular matrix of various tissues. These GAGs play crucial roles in diverse physiological functions, including cell signaling, tissue development, and maintenance of tissue structure. The catabolic process ensures the proper turnover and degradation of GAGs, preventing their accumulation and potential dysfunction.

The process begins with the enzymatic degradation of GAGs by specific enzymes, primarily glycosidases. These enzymes cleave the glycosidic bonds linking the sugar monomers within the GAG chains, releasing individual sugar residues. The breakdown of GAGs can occur in different cellular compartments, including lysosomes and the extracellular matrix.

Lysosomal degradation is a major pathway for GAG catabolism. Lysosomes are cellular organelles containing various hydrolytic enzymes, including specific glycosidases. After internalization by endocytosis, GAGs are transported to lysosomes, where they are progressively degraded by lysosomal glycosidases. These enzymes cleave specific glycosidic bonds within the GAG chains, yielding smaller oligosaccharides and monosaccharides.

Extracellular degradation also contributes to GAG turnover. Some glycosidases, such as hyaluronidases, are secreted into the extracellular matrix, where they can directly degrade GAGs. This process is important for remodeling the extracellular matrix during tissue development and repair.

The breakdown products of GAG catabolism, including individual sugar residues and oligosaccharides, can be further metabolized and utilized by cells for various purposes. For example, some sugar residues can be recycled for biosynthesis of new GAGs, while others can be used as energy sources.

Defects in GAG catabolic processes can lead to a variety of diseases, collectively known as mucopolysaccharidoses. These diseases are characterized by the accumulation of undigested GAGs in various tissues, resulting in a wide range of clinical manifestations, including skeletal abnormalities, mental retardation, and organ dysfunction.

In summary, glycosaminoglycan catabolic process is an essential biological process for the breakdown and turnover of GAGs, ensuring their proper function and preventing their accumulation. This process involves the action of specific enzymes, primarily glycosidases, which cleave the glycosidic bonds within GAG chains, releasing individual sugar residues. The breakdown can occur in lysosomes and the extracellular matrix. Defects in this process can lead to various diseases, highlighting its importance for maintaining tissue homeostasis and overall health.'
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Proteins (5)

Compounds (22)