Matrix metalloproteinase-20 (MMP-20) also known as enamel metalloproteinase or enamelysin is an enzyme that in humans is encoded by the MMP20gene.[5][6]
Proteins of the matrix metalloproteinase (MMP) family are involved in the breakdown of extracellular matrix 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 which are activated when cleaved by extracellular proteinases.
MMP-20, also known as enamelysin, appears to be the only MMP that is tooth-specific and it is expressed by cells of different developmental origin (i.e. epithelial ameloblasts and mesenchymal odontoblasts).
The human MMP-20 gene contains 10 exons and is part of a cluster of matrix metalloproteinase genes that localize to human chromosome 11q22.3.[6] A mutation in this gene, which alters the normal splice pattern and results in premature termination of the encoded protein, has been associated with amelogenesis imperfecta. Enamel in the absence of MMP-20 is hypoplastic (thin), contains less mineral (only one-third as much total mineral as wild type), and contains more protein and water. In general, MMP-20 functions in enamel are to cleave enamel matrix proteins at specific cleavage sites.[7]
^"Human PubMed Reference:". National Center for Biotechnology Information, U.S. National Library of Medicine.
^"Mouse PubMed Reference:". National Center for Biotechnology Information, U.S. National Library of Medicine.
^Llano E, Pendas AM, Knauper V, Sorsa T, Salo T, Salido E, Murphy G, Simmer JP, Bartlett JD, Lopez-Otin C (Jan 1998). "Identification and structural and functional characterization of human enamelysin (MMP-20)". Biochemistry. 36 (49): 15101–15108. doi:10.1021/bi972120y. PMID9398237.
Pendás AM, Santamaría I, Alvarez MV, et al. (1997). "Fine physical mapping of the human matrix metalloproteinase genes clustered on chromosome 11q22.3". Genomics. 37 (2): 266–269. doi:10.1006/geno.1996.0557. PMID8921407.
Terp GE, Christensen IT, Jørgensen FS (2000). "Structural differences of matrix metalloproteinases. Homology modeling and energy minimization of enzyme-substrate complexes". J. Biomol. Struct. Dyn. 17 (6): 933–46. doi:10.1080/07391102.2000.10506582. PMID10949161. S2CID1270176.
Väänänen A, Tjäderhane L, Eklund L, et al. (2005). "Expression of collagen XVIII and MMP-20 in developing teeth and odontogenic tumors". Matrix Biol. 23 (3): 153–161. doi:10.1016/j.matbio.2004.04.003. PMID15296943.
