Endopeptidase that degrades various components of the extracellular matrix, such as aggrecan and cartilage oligomeric matrix protein (comp), during development, haemostasis and pathological conditions (arthritic disease). May also play a role in neovascularization or angiogenesis. Hydrolyzes collagen type IV, laminin, nidogen, nascin-C isoform, fibronectin, and type I gelatin. Binds 1 zinc ion per subunit. Strongly inhibited by TIMP-2, TIMP-3 and TIMP-4, while TIMP-1 is less efficient. Expressed in mammary gland, placenta, lung, pancreas, ovary, small intestine, spleen, thymus, prostate, testis colon, heart and blood vessel walls. Not detected in brain and peripheral blood leukocytes. Also expressed in the synovial fluid of normal and rheumatoid patients (PubMed:8920941). The conserved cysteine present in the cysteine-switch motif binds the catalytic zinc ion, thus inhibiting the enzyme. The dissociation of the cysteine from the zinc ion upon the activation-peptide release activates the enzyme. Activated by autolytic cleavage after Lys-97. Tyrosine phosphorylated by PKDCC/VLK. The disease is caused by variants affecting the gene represented in this entry. Autoantigen anti-MMP19 are frequent in RA patients. May be produced at very low levels due to a premature stop codon in the mRNA, leading to nonsense-mediated mRNA decay. Belongs to the peptidase M10A family. Wrong choice of CDS.