Aggrecan
| Aggrecan | ||
|---|---|---|
| Properties of human protein | ||
| Mass / length primary structure | 2023 amino acids | |
| Isoforms | 3 | |
| Identifier | ||
| Gene name | ACAN | |
| External IDs | ||
| Occurrence | ||
| Homology family | Aggrecan Core Protein | |
| Parent taxon | Euteleostomi | |
| Orthologue | ||
| human | House mouse | |
| Entrez | 176 | 11595 |
| Ensemble | ENSG00000157766 | ENSMUSG00000030607 |
| UniProt | P16112 | Q61282 |
| Refseq (mRNA) | NM_001135 | NM_007424 |
| Refseq (protein) | NP_001126 | NP_031450 |
| Gene locus | Chr 15: 88.8 - 88.88 Mb | Chr 7: 79.05 - 79.12 Mb |
| PubMed search | 176 |
11595
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Aggrecan (also: Aggrekan ) is a protein found in vertebrates . Aggrecan is mainly found in hyaline cartilage (10% of the cartilage weight). Here it fulfills elasticity tasks together with collagenous fibrils. This is u. a. due to the high water absorption capacity. Several aggrecan molecules are usually attached to a long hyaluronic acid thread via a connecting protein. The protein forms the basic thread to which chondroitin sulfate or dermatan sulfate disaccharides are attached . Keratan sulfate disaccharide subunits are also found closer to hyaluronic acid . Mutations of the ACAN - gene can be rare hereditary spondyloepiphysärer dysplasia lead.
Pathological aggrecan degradation
Human cartilage tissue consists of a combination of hyaluronic acid and the cartilage protein aggrecan. Aggrecan consists of the two macromolecules keratan sulfate and chondroitin sulfate. The compression of the sulfate groups within the aggrecan leads to an electrostatic repulsion of the side chains from one another. This intramolecular interaction is responsible for the total compression resistance of the cartilage. Aggrecanases are proteolytic enzymes that break down aggrecans in connective tissues. A pathological overexpression of these enzymes in the cartilage tissue leads to increased decomposition of the aggrecan and thus to the decompensation of keratan sulfate and chondroitin sulfate. This results in the loss of compression resistance, which leads to osteoarthritis. The aggrecanases ADAMTS-4 and ADAMTS-5 are primarily responsible for the breakdown of aggrecan in cartilage tissue.