What Is Matrix Metalloproteinase 3?

Matrix metalloproteinases. Matrix metalloproteinases are a large family. They are named because they require metal ions such as Ca ²⁺ and Zn ²⁺ as cofactors. Its family members have similar structures and are generally composed of five functionally different domains: (1) a hydrophobic signal peptide sequence; and (2) a propeptide region, whose main role is to maintain the stability of the zymogen. When this region is cut off by exogenous enzymes, the zymogen of MMPs is activated; (3) the catalytically active region, which has a zinc ion binding site, is essential for the enzymatic catalysis; (4) the proline-rich Hinge region; (5) carboxy-terminal region, which is related to the substrate specificity of the enzyme. The enzyme catalytic active region and the propeptide region are highly conserved. MMPs members have their own characteristics based on the above structure. There is a certain substrate specificity among various MMPs, but it is not absolute. The same MMP can degrade multiple extracellular matrix components, and a certain extracellular matrix component can be degraded by multiple MMPs, but the degradation efficiency of different enzymes can be different.

Matrix metalloproteinases

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Matrix metalloproteinases. Matrix metalloproteinases are a large family. They are named because they require metal ions such as Ca ²⁺ and Zn ²⁺ as cofactors. Its family members have similar structures and are generally composed of 5 functionally different

MMPs can almost degrade various protein components in ECM, destroy the histological barrier of tumor cell invasion, and play a key role in tumor invasion and metastasis. Therefore, its role in tumor invasion and metastasis has been increasingly valued. It is considered to be the main process in this process. Proteolytic enzyme. The MMPs family has been identified and identified 26 members, numbered MMP1 to 26. According to the substrate and fragment homology, MMPs are divided into 6 types, including collagenase, gelatinase, matrix degradin, matrix lysin, furin-activated MMP and other secreted MMPs.

Type IV collagenase is one of the important types. It mainly has two forms, one is saccharified with a molecular weight of 92kD and named as MMP-9; the other is non-saccharified with a molecular weight of 72kD and is called MMP-2. The current research on MMP-2 and MMP-9 is in-depth.

The MMP-2 gene is located on the human chromosome 16q21 and consists of 13 exons and 12 introns. The total length of the structural gene is 27 kb. Unlike other metalloproteinases, the 5 'flanking sequence of the MMP-2 gene contains promoter regions. 2 GC boxes instead of TATA boxes. Activated MMP-2 is located at the prominent part of the cell penetrating the matrix, and it is estimated that it plays a role of "drill" in enzymatically decomposing intercellular matrix components and the main component of basement membrane type IV collagen.

In addition, MMP-3 and MMP-10 have been shown to act on PG, LN, FN, type III and type IV collagen and gelatin. And MMP-3 can activate MMP-1 and other family members. MMP-7 works on gelatin and FN. MMP-1 has a wide range of production and can be produced by stromal fibroblasts, macrophages, endothelial cells, and epithelial cells. Under normal circumstances, the MMP-1 positive rate is very low, but it can be highly expressed under various stimuli. Studies have shown that high expression of MMP-1 in malignant tumors is associated with prognosis.

The activity of MMPs is regulated by three levels, namely the level of gene transcription, proteolytic activation of inactive enzyme precursors, and the role of specific inhibitors (TIMP).