Inhibition of Seeded Growth of Enamel Apatite Crystals by Amelogenin and Enamelin Proteins in vitro

Doi, Yutaka; Eanes, E. D.; Shimokawa, Hitoyata; Termine, John D.

doi:10.1177/00220345840630021801

Cited by 87 publications

(41 citation statements)

References 30 publications

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“…The earlier fi nding that amelogenin can 'slightly' inhibit the seeded crystal growth of apatite in solution has indicated that amelogenin proteins actually interact with apatite crystals [Doi et al, 1984]. The strong adsorption affi nity of porcine amelogenin and its proteolytic products on hydroxyapatite crystals were fi rst reported by Aoba et al [1989] using native amelogenins.…”

Section: Amelogenin As a Temporary Template For Controlled Crystal Grmentioning

confidence: 99%

Amelogenin Supra-Molecular Assembly in vitro Compared with the Architecture of the Forming Enamel Matrix

Moradian‐Oldak

Goldberg

2005

Cells Tissues Organs

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Tooth enamel is formed in the extracellular space within an organic matrix enriched in amelogenin proteins. Amelogenin nanosphere assembly is a key factor in controlling the oriented and organized growth of enamel apatite crystals. Recently, we have reported the formation of higher ordered structures resulting from organized association and self-orientation of amelogenin nanospheres in vitro. This remarkable hierarchical organization includes self-assembly of amelogenin molecules into subunits of 4–6 nm in diameter followed by their assembly to form nanospheres of 15–25 nm in radii. Chains of >100 nm length are then formed as the result of nanosphere association. These linear arrays of nanospheres assemble to form the microribbons that are hundreds of microns in length, tens of microns in width, and a few microns in thickness. Here, we review the step by step process of amelogenin self-assembly during the formation of microribbon structures in vitro. Assembly properties of selected amelogenins lacking the hydrophilic C terminus will then be reviewed. We will consider amelogenin as a template for the organized growth of crystals in vitro. Finally, we will compare the structures formed in vitro with globular and periodic structures observed earlier, in vivo, by different sample preparation conditions. We propose that the alignment of amelogenin nanospheres into long chains is evident in vivo, and is an important indication for the function of this protein in controlling the oriented and elongated growth of apatite crystals during enamel biomineralization.

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Section: Amelogenin As a Temporary Template For Controlled Crystal Grmentioning

confidence: 99%

Amelogenin Supra-Molecular Assembly in vitro Compared with the Architecture of the Forming Enamel Matrix

Moradian‐Oldak

Goldberg

2005

Cells Tissues Organs

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“…In vitro these nanospheres locate adjacent to the a-and b-surfaces of the Hap crystallites, theoretically favoring crystallite elongation along the c-axis [Kirkham et al, 2000;Paine et al, 2001]. Such a scheme for supramolecular assembly in vivo would result in long and thin crystals arranged in parallel [Doi et al, 1984;Paine et al, 2001], which is apparent in enamel rod architecture. As enamel mineralization proceeds, the organic matrix is progressively removed allowing for the crystallites to grow in thickness [Fincham et al, 1995].…”

Section: Abbreviations Used In This Papermentioning

confidence: 99%

Overexpression of TRAP in the Enamel Matrix Does Not Alter the Enamel Structural Hierarchy

Paine

Zhu²,

Luo³

et al. 2004

Cells Tissues Organs

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The secreted, full-length amelogenin is the dominant protein of the forming enamel organ. As enamel mineralization progresses, amelogenin is quickly subjected to proteolytic activity, and eliminated from the enamel environment. Mature enamel contains only traces of structural proteins, including enamelin and the sheath protein ameloblastin. In addition, a proteolytic fragment of amelogenin, known as the tyrosine-rich amelogenin peptide or TRAP, is present in low but isolatable quantities. By overexpressing TRAP during enamel development we sought to determine if such overexpression would result in structural alterations to the mature enamel. We reasoned that overexpressing a protein associated with enamel maturation, at an inappropriate developmental stage, would result in alterations to the enamel protein assembly and hence, alterations in enamel structure and morphology. As judged by transmission and scanning electron microscopy, the enamel formed by overexpressing TRAP showed little morphological differences when compared to the enamel of normal nontransgenic animals. Based on scanning electron-microscopic images, there was modest hypomineralization evident in the interrod enamel of the TRAP-overexpressing animals. However, this finding was inconsistent and inconsequential from a structural and functional perspective. From these results it appears that additional amounts of TRAP protein in the immature enamel matrix are not sufficient to alter the properties of the enamel extracellular matrix to an extent that the hierarchical structure of mature enamel is altered.

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“…14-16 Doi et al 14 have speculated that mainly the central portion of the amelogenin molecule inhibits the seeded enamel crystal growth. Their report was based on their study of a series of bovine amelogenins of different molecular weights, from 5000 to 27,000 Da.…”

Section: Introductionmentioning

confidence: 99%

Modification of calcium–phosphate coatings on titanium by recombinant amelogenin

Wen

Moradian‐Oldak

2003

J Biomedical Materials Res

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Amelogenin proteins, the principal components of the developing dental enamel extracellular matrix, have been postulated to facilitate the elongated and oriented growth of the carbonated apatite crystals during enamel formation. We previously reported that amelogenin caused modulation of apatite crystals nucleated on a bioactive glass (Bioglass(R)) in vitro. Here, the effects of amelogenin on the growth morphology of calcium-phosphate crystals nucleated on a titanium surface were investigated in order to gain a better understanding of the role of amelogenins during enamel biomineralization and to explore their potential application in the design and development of novel biomaterials. The dose-dependent effects of a recombinant mouse amelogenin (rM179) were found to be different from those of bovine serum albumin, which significantly inhibited apatite crystal growth and caused the octacalcium phosphate (OCP) crystals to change from a plate-like shape to a curved shape, indicating a general inhibitory effect. The effects of rM179 on the crystal growth of OCP at 12.5-100 microg/mL and of apatite at 50 microg/mL were insignificant while the apatite crystals were remarkably elongated along their c-axes upon the use of 100 microg/mL of rM179. The unique modulation of the calcium-phosphate coatings on titanium by rM179 supports the view that amelogenins have a great potential for applications designed to develop novel biomimetic materials.

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Inhibition of Seeded Growth of Enamel Apatite Crystals by Amelogenin and Enamelin Proteins in vitro

Cited by 87 publications

References 30 publications

Amelogenin Supra-Molecular Assembly in vitro Compared with the Architecture of the Forming Enamel Matrix

Amelogenin Supra-Molecular Assembly in vitro Compared with the Architecture of the Forming Enamel Matrix

Overexpression of TRAP in the Enamel Matrix Does Not Alter the Enamel Structural Hierarchy

Modification of calcium–phosphate coatings on titanium by recombinant amelogenin

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