Matrix metalloproteinase-12 (MMP-12) also known as macrophage metalloelastase (MME) or macrophage elastase (ME) is an
enzyme
An enzyme () is a protein that acts as a biological catalyst by accelerating chemical reactions. The molecules upon which enzymes may act are called substrate (chemistry), substrates, and the enzyme converts the substrates into different mol ...
that in humans is encoded by the ''MMP12''
gene
In biology, the word gene has two meanings. The Mendelian gene is a basic unit of heredity. The molecular gene is a sequence of nucleotides in DNA that is transcribed to produce a functional RNA. There are two types of molecular genes: protei ...
.
Function
Proteins of the
matrix metalloproteinase
Matrix metalloproteinases (MMPs), also known as matrix metallopeptidases or matrixins, are metalloproteinases that are calcium-dependent zinc-containing endopeptidases; other family members are adamalysins, serralysins, and astacins. The MMPs be ...
(MMP) family are involved in the breakdown of
extracellular matrix
In biology, the extracellular matrix (ECM), also called intercellular matrix (ICM), is a network consisting of extracellular macromolecules and minerals, such as collagen, enzymes, glycoproteins and hydroxyapatite that provide structural and bio ...
in normal physiological processes, such as
embryonic development, reproduction, and tissue remodeling, as well as in disease processes, such as arthritis and metastasis. Most MMP's are secreted as inactive proproteins. The prodomain is cleaved by extracellular proteinases when the enzyme is activated. The active enzyme is constituted by two domains, the catalytic domain responsible for its enzymatic activity and the hemopexin-like domain that in some MMPs plays a role in substrate recognition and can contribute to increasing catalytic efficiency. It is thought that the protein encoded by this gene is cleaved at both ends to yield the active enzyme, but this processing has not been fully described. The enzyme degrades soluble and insoluble
elastin
Elastin is a protein encoded by the ''ELN'' gene in humans and several other animals. Elastin is a key component in the extracellular matrix of gnathostomes (jawed vertebrates). It is highly Elasticity (physics), elastic and present in connective ...
. The gene is part of a cluster of MMP genes which localize to chromosome 11q22.3.
Clinical significance
MMP12 may play a role in
aneurysm
An aneurysm is an outward :wikt:bulge, bulging, likened to a bubble or balloon, caused by a localized, abnormal, weak spot on a blood vessel wall. Aneurysms may be a result of a hereditary condition or an acquired disease. Aneurysms can also b ...
formation
and studies in mice and humans suggest a role in the development of
emphysema
Emphysema is any air-filled enlargement in the body's tissues. Most commonly emphysema refers to the permanent enlargement of air spaces (alveoli) in the lungs, and is also known as pulmonary emphysema.
Emphysema is a lower respiratory tract di ...
.
References
Further reading
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
External links
* The
MEROPS
MEROPS is an online database for peptidases (also known as proteases, proteinases and proteolytic enzymes) and their inhibitors. The classification scheme for peptidases was published by Rawlings & Barrett in 1993, and that for protein inhibito ...
online database for peptidases and their inhibitors
M10.009PDBe-KBprovides an overview of all the structure information available in the PDB for Human Macrophage metalloelastase (MMP12)
Matrix metalloproteinases
Human proteins
EC 3.4.24
{{gene-11-stub