Gelatinase B

Gelatinase B (EC 3.4.24.35, 92-kDa gelatinase, matrix metalloproteinase 9, type V collagenase, 92-kDa type IV collagenase, macrophage gelatinase, 95 kDa type IV collagenase/gelatinase, collagenase IV, collagenase type IV, gelatinase MMP 9, MMP 9, type IV collagen metalloproteinase) is an enzyme. This enzyme catalyses the following chemical reaction

This enzyme is similar to gelatinase A, but possesses a further domain. Regarding its structure, Gelatinase B has domains which can bind with gelatin, laminin, and collagens type I and IV- collagenases do not possess these binding domains.

Function

Due to its role in cleaving collagen in the extracellular matrix, gelatinase B has multiple functional roles in normal physiology.

Neutrophil action

Gelatinase B, along with elastase, appears to be a regulatory factor in neutrophil migration across the basement membrane. Gelatinase B plays several important functions within neutrophil action, such as degrading extracellular matrix, activation of IL-1β, and cleavage of several chemokines. In a mouse model, Gelatinase B deficiency resulted in resistance to endotoxin shock, suggesting that Gelatinase B is important in sepsis.

MMP9

Matrix metallopeptidase 9 (MMP-9), also known as 92 kDa type IV collagenase, 92 kDa gelatinase or gelatinase B (GELB), is a matrixin, a class of enzymes that belong to the zinc-metalloproteinases family involved in the degradation of the extracellular matrix. In humans the MMP9 gene encodes for a signal peptide, a propeptide, a catalytic domain with inserted three repeats of fibronectin type II domain followed by a C-terminal hemopexin-like domain.

Function

Proteins of the matrix metalloproteinase (MMP) family are involved in the breakdown of extracellular matrix in normal physiological processes, such as embryonic development, reproduction, angiogenesis, bone development, wound healing, cell migration, learning and memory, as well as in pathological processes, such as arthritis, intracerebral hemorrhage, and metastasis. Most MMPs are secreted as inactive proproteins which are activated when cleaved by extracellular proteinases. The enzyme encoded by this gene degrades type IV and V collagens and other extracellular matrix proteins. Studies in rhesus monkeys suggest that the enzyme is involved in IL-8-induced mobilization of hematopoietic progenitor cells from bone marrow, and murine studies suggest a role in tumor-associated tissue remodeling.