The Quaternary Structures of Enamel Proteins at Interfaces Studied by Helium-ion Microscopy (HIM)
EMSL Project ID
40112
Abstract
The interactions of proteins at surfaces are of great importance to biomineralizaton processes and to the development and function of biomaterials. Amelogenin is a unique biomineralization protein because it self-assembles to form supramolecular structures called 'nanospheres' spherical aggregates of monomers that are 20-60 nm in diameter. Although the nanosphere quaternary structure has been observed in solution, the quaternary structure of amelogenin adsorbed onto surfaces is also of great interest because the surface structure is critical to its function. Although the conventional wisdom is that amelogenin nanospheres control the formation of hydroxyapatite structures in tooth enamel, we previously found that smaller monomer and oligomer-sized structures adsorbed onto self-assembled monolayer and fluoroapatite surfaces, smaller structures than the original 40 nm nanospheres found in solution. These studies suggested that smaller, subnanometer-sized quaternary structures may be critical to the function of amelogenin. We propose to study these structures using helium-ion microscopy (HIM) and develop the technique to image the ~ 4-8 nm monomers and oligomers. This work will significantly improve the resolution of protein structures compared to other methods such as atomic force microscopy (AFM), demonstrate HIM as a powerful tool for studying biological molecules at interfaces, and answer fundamental questions about the structure of amelogenin at interfaces.
Project Details
Project type
Large-Scale EMSL Research
Start Date
2010-10-12
End Date
2011-10-16
Status
Closed
Released Data Link
Team
Principal Investigator
Team Members
Related Publications
Buchko GW, G Lin, BJ Tarasevich, and WJ Shaw. 2013. "A solution NMR investigation into the impaired self-assembly properties of two murine amelogenins containing the point mutations T21?I or P41?T." Archives of Biochemistry and Biophysics 537(2):217-224. doi:10.1016/j.abb.2013.07.015