| external matrix | The substance occupying the space between the inner and outer membrane of any organelle (e.g., mitochondria) with a double membrane. (05 Mar 2000) |
|---|---|
| extracellular matrix | Any material produced by cells and secreted into the surrounding medium, but usually applied to the noncellular portion of animal tissues. The ecm of connective tissue is particularly extensive and the properties of the ecm determine the properties of the tissue. In broad terms there are three major components: fibrous elements particularly collagen, elastin or reticulin), link proteins (e.g. Fibronectin, laminin) and space filling molecules (usually glycosaminoglycans). The matrix may be mineralised to resist compression (as in bone) or dominated by tension resisting fibres (as in tendon). The basal lamina of epithelial cells is another commonly encountered ecm. Although ecm is produced by cells, it has recently become clear that the ecm can influence the behaviour of cells quite markedly, an important factor to consider when growing cells in vitro: removing cells from their normal environment can have far reaching effects. (18 Nov 1997) |
| extracellular matrix proteins | Macromolecular organic compounds that contain carbon, hydrogen, oxygen, nitrogen, and usually, sulfur. These macromolecules (proteins) form an intricate meshwork in which cells are embedded to construct tissues. Variations in the relative types of macromolecules and their organization determine the type of extracellular matrix, each adapted to the functional requirements of the tissue. The two main classes of macromolecules that form the extracellular matrix are: glycosaminoglycans, usually linked to proteins (proteoglycans), and fibrous proteins (e.g., collagen, elastin, fibronectins and laminin). (12 Dec 1998) |
| receptors, cell surface | Cell surface proteins that bind signalling molecules external to the cell with high affinity and convert this extracellular event into one or more intracellular signals that alter the behaviour of the target cell. Cell surface receptors, unlike enzymes, do not chemically alter their ligands. (12 Dec 1998) |
| cell surface marker | <cell biology> Any molecule characteristic of the plasma membrane of a cell or in some cases of a specific cell type. 5' nucleotidase and Na/K ATPase are often used as plasma membrane markers. (26 Mar 1998) |
| Ac1-proteinase | <enzyme> Proteolylic haemorrhagic toxin for trimeresurus flavoviridis Registry number: EC 3.4.99.- Synonym: ac1-protease (26 Jun 1999) |
| Ac2-proteinase | <enzyme> From agkistrodon acutus venom Registry number: EC 3.4.99.- Synonym: ac2-protease (26 Jun 1999) |
| Ac3-proteinase | <enzyme> Isolated from venom of agkistrodon acutus; mw 57,000 Registry number: EC 3.4.99.- Synonym: ac3-protease (26 Jun 1999) |
| Ac4-proteinase | <enzyme> One of proteinases of venom of agkistrodon acutus and has haemorrhagic activity Registry number: EC 3.4.99.- Synonym: ac4-protease (26 Jun 1999) |
| Ac5-proteinase | <enzyme> Isolated from venom of agkistrodon acutus Registry number: EC 3.4.99.- Synonym: ac5-protease (26 Jun 1999) |
| alpha-1-proteinase deficiency | Absence of a serum proteinase inhibitor that may cause nodular non-suppurative panniculitis. (05 Mar 2000) |
| Armillaria mellea neutral proteinase | <enzyme> Specific for lysine Registry number: EC 3.4.99.32 (26 Jun 1999) |
| Artemia trypsin-like proteinase | <enzyme> Cysteine proteinase involved in lipovitellin degradation Registry number: EC 3.4.22.- (26 Jun 1999) |
| Aspergillus acid proteinase | <enzyme> Included in the group of microbial carboxyl proteinases EC 3.4.23.6; has been sequenced; genbank d87681 Registry number: EC 3.4.23.- Synonym: apfap, aspergillus fumigatus acid proteinase, aspergillus niger acid proteinase, aspergillus awamori acid proteinase (26 Jun 1999) |
| Aspergillus oryzae carboxyl proteinase | <enzyme> Included in the group of microbial carboxyl proteinases EC 3.4.23.6 Registry number: EC 3.4.23.- Synonym: takadiastase (26 Jun 1999) |