Matching 4.7-angstrom XRD Spacing in Amelogenin Nanoribbons and Enamel Matrix

作者：Sanii B; Martinez Avila O; Simpliciano C; Zuckermann R N; Habelitz S^*

来源：Journal of Dental Research, 2014, 93(9): 918-922.

DOI：10.1177/0022034514544216

• self-assembly
• structure
• development
• powder diffraction
• Fourier transform infrared spectroscopy
• secondary protein structure

The recent discovery of conditions that induce nanoribbon structures of amelogenin protein in vitro raises questions about their role in enamel formation. Nanoribbons of recombinant human full-length amelogenin (rH174) are about 17 nm wide and self-align into parallel bundles; thus, they could act as templates for crystallization of nanofibrous apatite comprising dental enamel. Here we analyzed the secondary structures of nanoribbon amelogenin by x-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR) and tested if the structural motif matches previous data on the organic matrix of enamel. XRD analysis showed that a peak corresponding to 4.7 angstrom is present in nanoribbons of amelogenin. In addition, FTIR analysis showed that amelogenin in the form of nanoribbons was comprised of -sheets by up to 75%, while amelogenin nanospheres had predominantly random-coil structure. The observation of a 4.7-angstrom XRD spacing confirms the presence of -sheets and illustrates structural parallels between the in vitro assemblies and structural motifs in developing enamel.

• 出版日期2014-9