Recent advances in biotechnology made proteins and proteases of the extra cellular matrix of enamel available and facilitate the study of their function in-vitro as well as allowing the first attempts to synthesize this calcified tissue in an artificial environment. The overall objective of the current proposal is to determine the physical-chemical conditions required for a protein-guided development of a material that is comparable to the composition, structure and properties of human enamel. This work should lead to an improved understanding of how amelogenin proteins, the spliced variant LRAP+ and two proteases function in the biomineralization process on an ionic and molecular level and how this information can be used to synthesize enamel in-vitro. The hypothesis to be tested is that a biomimetic synthesis of thin layers of an enamel-like material, including composition, microstructure and properties is feasible by the use of full-length and spliced human amelogenins, when combined with selected proteases in mineralizing solutions at specific physical-chemical conditions. This hypothesis will be tested by the following three specific aims: (1) To determine the physical-chemical conditions that promote biomineralization mediated by full-length amelogenin and the spliced variant LRAP+; (2) To determine if amelogenin-induced biomineralization depends on the crystallographic orientation of the apatite substrate; and (3) To synthesize an enamel-like material by gradually degrading the amelogenin matrix using recombinant MMP-20 and serine proteinase while mineralization proceeds.

Agency
National Institute of Health (NIH)
Institute
National Institute of Dental & Craniofacial Research (NIDCR)
Type
Exploratory/Developmental Grants (R21)
Project #
5R21DE015416-02
Application #
6787132
Study Section
Special Emphasis Panel (ZDE1-PZ (37))
Program Officer
Kousvelari, Eleni
Project Start
2003-08-04
Project End
2006-05-31
Budget Start
2004-06-01
Budget End
2006-05-31
Support Year
2
Fiscal Year
2004
Total Cost
$189,375
Indirect Cost
Name
University of California San Francisco
Department
Dentistry
Type
Schools of Dentistry
DUNS #
094878337
City
San Francisco
State
CA
Country
United States
Zip Code
94143
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Habelitz, Stefan; DenBesten, Pamela K; Marshall, Sally J et al. (2006) Self-assembly and effect on crystal growth of the leucine-rich amelogenin peptide. Eur J Oral Sci 114 Suppl 1:315-9; discussion 327-9, 382
Habelitz, S; Denbesten, P K; Marshall, S J et al. (2005) Amelogenin control over apatite crystal growth is affected by the pH and degree of ionic saturation. Orthod Craniofac Res 8:232-8
Habelitz, S; Kullar, A; Marshall, S J et al. (2004) Amelogenin-guided crystal growth on fluoroapatite glass-ceramics. J Dent Res 83:698-702