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Amelogenin: Solution- and solid-state studies of a natural biomineralization process


EMSL Project ID
48235

Abstract

The protein amelogenin is the central protein controlling the formation of dental enamel, the hardest tissue in the human body. The protein orchestrates the nucleation, growth, and organization of enamel formation (amelogenesis) through the formation of large quaternary structures called nanospheres, consisting of 20-100 monomers. The structure and function of full-length amelogenin and LRAP, the latter a splice variant of amelogenin that contains only the charged N- and C- termini, are the focus of our four-year, NIH funded investigations. We request EMSL resources to accomplish three major tasks. (1) In situ-AFM and related studies will allow us to physically view the oligomeric state of amelogenin bound to hydroxyapatite (HAP) surfaces. (2) Solution-state structural studies on full-length amelogen and LRAP will enable us to characterize the structure of these proteins under the variety of conditions found during enamel growth. (3) Solid-state NMR studies will enable the quantitative structural characterization of LRAP bound to hydroxyapatite. The AFM studies will involve two naturally occurring mutant amelogenin proteins observed in amelogenesis imperfecta. The solution-state NMR structural studies will focus on a Val, Leu, and Ile (?1) methyl-protonated 15N-, 13C-, 2H-labeled amelogenin sample. Such a labeling scheme in combination with transverse relaxation-optimized spectroscopy (TROSY) experiments, will allow us to track the structural behavior of amelogenin as it self-assembles into large molecular weight complexes. The solid-state NMR studies will focus on LRAP because its smaller size allows easy incorporation of selective isotopic labels which enable the determination of site specific, molecular level protein structure, protein-surface interactions, and dynamics. Structural changes observed in solution or in the solid-state will then be correlated to differences in function.

Project Details

Start Date
2013-12-20
End Date
2014-09-30
Status
Closed

Team

Principal Investigator

Wendy Shaw
Institution
Pacific Northwest National Laboratory

Team Members

Garry Buchko
Institution
Pacific Northwest National Laboratory

Barbara Tarasevich
Institution
Pacific Northwest National Laboratory

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