Contributions of Matrix Metalloproteinases to Neural Plasticity, Habituation, Associative Learning and Drug Addiction

Table 1

Matrix metalloproteinases (MMPs), tissue inhibitors of metalloproteinases (TIMPs), and their preferred substrates.

Group	Members	Abbrev.	Substrate
Collagenases	Fibroblast collag.	MMP-1	fibrillar collagens
	Neutrophil collag.	MMP-8	fibrillar collagens
	Collagenase-3	MMP-13	fibrillar collagens
	Collagenase-4	𝜒Col 4	collagens
Gelatinases	Gelatinase A	MMP-2	gelatin, elastin fibronectin, types IV–VI collagens
	Gelatinase B	MMP-9	gelatin, elastin, fibronectin, types I, IV & V collagens
Membrane-type	MT 1-MMP	MMP-14	pro-MMP-2, collagens, gelatin, elastin, casein, fibronectin, vitronectin, aggrecan
	MT 2-MMP	MMP-15	pro-MMP-2, collagens, gelatin, fibronectin, laminin, nidogen, tenascin
	MT 3-MMP	MMP-16	pro-MMP-2, collagens, gelatin
	MT 4-MMP	MMP-17	pro-MMP-2, collagens, gelatin
Stromelysins	Stromelysin-1	MMP-3	fibronectin, collagens, laminin, non-fibrillar
	Stromelysin-2	MMP-10	fibronectin, collagens, laminin, non-fibrillar collagens
	Stromelysin-3	MMP-11	gelatin, fibrillar collagens, 𝛼1 proteinase inhibitor (serpin)
	Macrophage	MMP-12	elastin
	Metalloelastase
	Matrilysin	MMP-7	fibronectin, collagens, laminin, non-fibrillar collagens, aggrecan, casein, decorin, insulin
Others	Enamelysin	MMP-20	amelogenin
	Xenopus collag.	MMP-18	unknown
	?	MMP-19	aggrecan, gelatin, tenascin C
		XMMP	unknown
TIMPs		TIMP-1	all MMPs except MT1-MMP
		TIMP-2	all MMPs
		TIMP-3	all MMPs
		TIMP-4	all MMPs

Adapted from Wright and Harding [23].