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Co‐operative mineralization and protein self‐assembly in amelogenesis: silica mineralization and assembly of recombinant amelogenins in vitro
Author(s) -
Fowler Christabel E.,
Beniash Elia,
Yamakoshi Yasuo,
Simmer James P.,
Margolis Henry C.
Publication year - 2006
Publication title -
european journal of oral sciences
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.802
H-Index - 93
eISSN - 1600-0722
pISSN - 0909-8836
DOI - 10.1111/j.1600-0722.2006.00288.x
Subject(s) - amelogenin , amelogenesis , dispersity , chemistry , recombinant dna , mineralization (soil science) , biophysics , transmission electron microscopy , crystallography , enamel paint , chemical engineering , materials science , nanotechnology , biochemistry , polymer chemistry , organic chemistry , biology , ameloblast , composite material , nitrogen , engineering , gene
An amorphous silica mineralization technique was used to produce inorganic/protein composites to elucidate the structure and mechanism of formation of amelogenin assemblies, which may play an important role in regulating enamel structure during the initial stages of amelogenesis. Full‐length recombinant amelogenins from mouse (rM179) and pig (rP172) were investigated along with key degradation products (rM166 and native P148) lacking the hydrophilic C terminus found in parent molecules. The resulting products were examined using transmission electron microscopy and/or small‐angle X‐ray scattering. Using protein concentrations of 0.1–3 mg ml −1 , large monodisperse spheres of remarkably similar mean diameters were observed using rM179 (124 ± 4 nm) and rP172 (126 ± 7 nm). These spheres also exhibited ‘internal structure’, comprising nearly spherical monodisperse particles of ≈ 20 nm in diameter. In the presence of rM166, P148, and bovine serum albumin (control), large unstructured and randomly shaped particles (250–1000 nm) were observed. Without added protein, large dense spherical particles of silica (mean ≈ 500 nm) lacking internal structure were produced. These findings demonstrate that full‐length amelogenins have the ability to form higher‐order structures, whereas amelogenins that lack the hydrophilic C terminus do not. The results also suggest that full‐length amelogenin can guide the formation of organized mineralized structures through co‐operative interactions between assembling protein and forming mineral.