Protein nanoribbons template enamel mineralization
Bai, Yushi ; Yu, Zanlin ; Ackerman, Larry ; Zhang, Yan ; Bonde, Johan LU
; Li, Wu
; Cheng, Yifan
and Habelitz, Stefan
(2020)
In Proceedings of the National Academy of Sciences of the United States of America
117(32).
p.19201-19208
- Abstract
As the hardest tissue formed by vertebrates, enamel represents nature's engineering masterpiece with complex organizations of fibrous apatite crystals at the nanometer scale. Supramolecular assemblies of enamel matrix proteins (EMPs) play a key role as the structural scaffolds for regulating mineral morphology during enamel development. However, to achieve maximum tissue hardness, most organic content in enamel is digested and removed at the maturation stage, and thus knowledge of a structural protein template that could guide enamel mineralization is limited at this date. Herein, by examining a gene-modified mouse that lacked enzymatic degradation of EMPs, we demonstrate the presence of protein nanoribbons as the structural scaffolds... (More)
As the hardest tissue formed by vertebrates, enamel represents nature's engineering masterpiece with complex organizations of fibrous apatite crystals at the nanometer scale. Supramolecular assemblies of enamel matrix proteins (EMPs) play a key role as the structural scaffolds for regulating mineral morphology during enamel development. However, to achieve maximum tissue hardness, most organic content in enamel is digested and removed at the maturation stage, and thus knowledge of a structural protein template that could guide enamel mineralization is limited at this date. Herein, by examining a gene-modified mouse that lacked enzymatic degradation of EMPs, we demonstrate the presence of protein nanoribbons as the structural scaffolds in developing enamel matrix. Using in vitro mineralization assays we showed that both recombinant and enamel-tissue-based amelogenin nanoribbons are capable of guiding fibrous apatite nanocrystal formation. In accordance with our understanding of the natural process of enamel formation, templated crystal growth was achieved by interaction of amelogenin scaffolds with acidic macromolecules that facilitate the formation of an amorphous calcium phosphate precursor which gradually transforms into oriented apatite fibers along the protein nanoribbons. Furthermore, this study elucidated that matrix metalloproteinase-20 is a critical regulator of the enamel mineralization as only a recombinant analog of a MMP20-cleavage product of amelogenin was capable of guiding apatite mineralization. This study highlights that supramolecular assembly of the scaffold protein, its enzymatic processing, and its ability to interact with acidic carrier proteins are critical steps for proper enamel development.
(Less)
- author
- Bai, Yushi
; Yu, Zanlin
; Ackerman, Larry
; Zhang, Yan
; Bonde, Johan
LU
; Li, Wu
; Cheng, Yifan
and Habelitz, Stefan
- organization
- publishing date
- 2020
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- biomineralization, enamel, hydroxyapatite, nanoribbon structure, protein assembly
- in
- Proceedings of the National Academy of Sciences of the United States of America
- volume
- 117
- issue
- 32
- pages
- 8 pages
- publisher
- National Academy of Sciences
- external identifiers
-
- scopus:85089614474
- pmid:32737162
- ISSN
- 1091-6490
- DOI
- 10.1073/pnas.2007838117
- language
- English
- LU publication?
- yes
- id
- e49c3682-edda-4493-8c46-2438e628114a
- date added to LUP
- 2020-08-27 13:00:47
- date last changed
- 2024-05-29 18:43:35
@article{e49c3682-edda-4493-8c46-2438e628114a,
abstract = {{<p>As the hardest tissue formed by vertebrates, enamel represents nature's engineering masterpiece with complex organizations of fibrous apatite crystals at the nanometer scale. Supramolecular assemblies of enamel matrix proteins (EMPs) play a key role as the structural scaffolds for regulating mineral morphology during enamel development. However, to achieve maximum tissue hardness, most organic content in enamel is digested and removed at the maturation stage, and thus knowledge of a structural protein template that could guide enamel mineralization is limited at this date. Herein, by examining a gene-modified mouse that lacked enzymatic degradation of EMPs, we demonstrate the presence of protein nanoribbons as the structural scaffolds in developing enamel matrix. Using in vitro mineralization assays we showed that both recombinant and enamel-tissue-based amelogenin nanoribbons are capable of guiding fibrous apatite nanocrystal formation. In accordance with our understanding of the natural process of enamel formation, templated crystal growth was achieved by interaction of amelogenin scaffolds with acidic macromolecules that facilitate the formation of an amorphous calcium phosphate precursor which gradually transforms into oriented apatite fibers along the protein nanoribbons. Furthermore, this study elucidated that matrix metalloproteinase-20 is a critical regulator of the enamel mineralization as only a recombinant analog of a MMP20-cleavage product of amelogenin was capable of guiding apatite mineralization. This study highlights that supramolecular assembly of the scaffold protein, its enzymatic processing, and its ability to interact with acidic carrier proteins are critical steps for proper enamel development.</p>}},
author = {{Bai, Yushi and Yu, Zanlin and Ackerman, Larry and Zhang, Yan and Bonde, Johan and Li, Wu and Cheng, Yifan and Habelitz, Stefan}},
issn = {{1091-6490}},
keywords = {{biomineralization; enamel; hydroxyapatite; nanoribbon structure; protein assembly}},
language = {{eng}},
number = {{32}},
pages = {{19201--19208}},
publisher = {{National Academy of Sciences}},
series = {{Proceedings of the National Academy of Sciences of the United States of America}},
title = {{Protein nanoribbons template enamel mineralization}},
url = {{http://dx.doi.org/10.1073/pnas.2007838117}},
doi = {{10.1073/pnas.2007838117}},
volume = {{117}},
year = {{2020}},
}