Protein conformation in rat tooth enamel

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

“…A detailed study that carefully aimed to preserve the protein native structure by a series of different fixation protocols confirmed the 4.7-Å reflection in 1986 and also reported a weaker reflection at 4.2 Å (Jodaikin et al, 1986). The d-spacing at 4.7 Å has been associated with β-sheet structures of many proteins and peptides, while the 4.2-Å reflection is not as common but has been associated with the distance between aromatic residues in β-sheets or the presence of certain lipids (Jodaikin et al, 1986;Aggeli et al, 1997;Kubelka and Keiderling, 2001;Xu, 2009). Structural Fourier transform infrared spectroscopy (FTIR) analysis of the enamel matrix has not yet been reported.…”

“…In 1965, Glimcher and co-workers performed x-ray diffraction on a calcium-depleted incisor of an embryonic calf, and found a 4.77-Å peak that they associated with the organic matrix (Glimcher et al, 1965). Numerous studies on proteins and peptides have also shown that XRD spacings around 4.7 Å are characteristic of β-sheets (Jodaikin et al, 1986;Symmons et al, 1997;von Bergen et al, 2005).…”

Nacre biomineralisation: A review on the mechanisms of crystal nucleation

“…The water-soluble fraction is composed mainly of acidic proteins that are very rich in aspartic acid and/or glutamic acid and often contain acidic polysaccharides [27,28]. These proteins, and in some cases their associated sulfated polysaccharides, interact with calcium in vitro [27], and calcium appears to facilitate formation of β-sheet structures in some of these macromolecules [29,30]. While the β-chitin and the silk-like proteins are thought to be responsible for forming a 3-A c c e p t e d M a n u s c r i p t 5 dimensional framework in which the mineral phase forms, the aspartic acid-rich proteins are thought to be involved in control over crystal nucleation, morphology and polymorph type.…”

Structure and function of enamel gene products

“…Recent experiments coupling the biochemical extrac-DEVELOPING ENAMEL: PROTEIN-CRYSTAL @Travis and Silness and Gustavsen, 1969;Glimcher, 1979;Termine et al, 1980;Hohling et al, 1982;Yanagisawa and Takuma, 1982;Daculsi et al, 1984;Deutsch et al, 1984;Warshawsky et al, 1984;Fincham and Belcourt, 1985;Robinson and Kirkham, 1985;Traub et al, 1985;Hayashi et al, 1986;Jodaikin et al, 1986;Weiner, 1986;Deutsch and Alayoff, 1987;Slavkin et al, in press. ENAMEL GENE PRODUCTS STRUCTURE AND FUNCTION 201 tion procedure for amelogenins and enamelins with freeze-fracture and electron microscope procedures (Yanagisawa and Takuma, 1982;Daculsi et al, 1984;Warshawsky et al, 1984;Bai and Warshawsky, 1985), as well as ultrastructure localization of amelogenin and enamelin in the extracellular matrix using highresolution immunocytochemistry (on demineralized and nondemineralized sections) (Hayashi et al, 19861, and studies on isolated developing enamel crystallites (Daculsi et al, 19841, have indicated that the sheet at the surface of the crystals is probably not an artifact but results from specific protein crystal interaction.…”