MMP-20 Enamelysin Function — NDEB AFK MCQ
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Correct answer: C — It is a matrix metalloproteinase that cleaves amelogenin during the secretory stage of amelogenesis, facilitating proper enamel crystal growth
MMP-20 (enamelysin) is a matrix metalloproteinase specifically expressed during the secretory stage of amelogenesis. It cleaves amelogenin proteins into smaller fragments, which is essential for the proper organisation and growth of enamel hydroxyapatite crystals. Mutations in the MMP-20 gene cause autosomal recessive hypomaturation-type amelogenesis imperfecta (thin, soft enamel with retained protein). KLK-4 (kallikrein-4) takes over during the maturation stage, further degrading amelogenin remnants for complete removal.
Reference: Nanci – Ten Cate's Oral Histology, 9th ed., 2017