February 15, 2005
Dental enamel arises from a complex developmental process that begins with the formation of an organic, protein-rich matrix in the tooth bud. Gradually, the matrix crystalizes into the hard, white, interwoven structure that we recognize as tooth enamel. While studying the process of enamel formation, scientists previously discovered that the primary protein of the organic matrix, called amelogenin, is almost completely hydrophobic, or water avoiding, except for a conspicuous 13 amino-acid region. As published in the Feburary 18 issue of the Journal of Structural Biology, a team of NIDCR-supported scientists have determined why this might be so. The group found that the hydrophobic region plays a role in inhibiting crystal growth, while the 13-amino-acid region is critical in aligning the crystals in structurally correct parallel arrays. The authors concluded that their results "point toward the possibility that the nascent enamel structure forms as a result of cooperative interactions between forming crystals and assembling proteins and not via mechanism of templated crystal growth on a pre-formed organic matrix framework," as is the case with bone and other mineralized tissues.
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