The proposed research focuses on the application and development of magic angle spinning (MAS) NMR as a tool for structural investigations of peptides and proteins. The research covers two broad areas. A. Structure of Amyloid Peptides and Proteins (1) Water layer in TTR105-115 : We intend to determine the structure of a water bilayer in TTR105-115 fibers, which may be a common feature of amyloid fibrils and the """"""""glue"""""""" that binds protofibrils to form fibrils. (2) PI3-SH3: We completed spectral assignments of the fibrillar form of this 86 AA protein, and established that the strands are in a parallel in-registe (PIR) arrangement with DNP. To complete the structure we need to measure additional interstrand contacts and sidechain distances and angles. (3) Beta-2-microglobulin (?2m): Assignments for this 99 AA protein are complete and we established that the strands are PIR. We have detected some interstrand contacts. To complete the structure we require additional distances and torsion angles. We also intend to study the ?N6 construct of ?2m. (4) CsgA and CsgB - functional amyloids: Recently it has become clear that some amyloids are functional, as opposed to pathological. We plan to study one of these, CagA, that is associated with biofilms and thought to form a ?-helical structure. B. NMR methods None of the above structural studies would be possible absent NMR methods to assign spectra, measure distances and torsion angles, to enhance signal intensities, etc. We therefore plan to continue the development of the methods essential for these structural investigations. (1) Recoupling in 2H labeled proteins DNP experiments function optimally with 2H labeled proteins. We there plan to develop methods for 2H-13C/15N recoupling based on third spin assisted experiments. (2) Spin diffusion and PAR and PAIN Simulations is used extensively in ssNMR as a semiquantitative method to measure distances. Using SPINEVOLUTION software we plan to improve the accuracy of distance measurements and apply the results to proteins.

Public Health Relevance

The research proposes to determine high resolution molecular structures of amyloid peptides and proteins associated with phosphatidyl inositol-3-kinase SH3 domain, dialysis related amyloidosis (beta-2 microglobulin) CsgA as well as some model amyloid systems. In addition we propose to continue to develop the methodology to perform the structural experiments focusing on 2H recoupling and simulations of spin diffusion.

Agency
National Institute of Health (NIH)
Institute
National Institute of Biomedical Imaging and Bioengineering (NIBIB)
Type
Research Project (R01)
Project #
5R01EB003151-36
Application #
8507550
Study Section
Biochemistry and Biophysics of Membranes Study Section (BBM)
Program Officer
Sastre, Antonio
Project Start
1977-05-01
Project End
2016-06-30
Budget Start
2013-07-01
Budget End
2014-06-30
Support Year
36
Fiscal Year
2013
Total Cost
$586,331
Indirect Cost
$172,832
Name
Massachusetts Institute of Technology
Department
Type
Organized Research Units
DUNS #
001425594
City
Cambridge
State
MA
Country
United States
Zip Code
02139
Kaushik, Monu; Bahrenberg, Thorsten; Can, Thach V et al. (2016) Gd(iii) and Mn(ii) complexes for dynamic nuclear polarization: small molecular chelate polarizing agents and applications with site-directed spin labeling of proteins. Phys Chem Chem Phys 18:27205-27218
Lin, James; Griffin, R G; Nielsen, Niels Chr et al. (2016) Three pulse recoupling and phase jump matching. J Magn Reson 263:172-83
Colvin, Michael T; Silvers, Robert; Frohm, Birgitta et al. (2015) High resolution structural characterization of Aβ42 amyloid fibrils by magic angle spinning NMR. J Am Chem Soc 137:7509-18
Szczepankiewicz, Olga; Linse, Björn; Meisl, Georg et al. (2015) N-Terminal Extensions Retard Aβ42 Fibril Formation but Allow Cross-Seeding and Coaggregation with Aβ42. J Am Chem Soc 137:14673-85
Frederick, Kendra K; Michaelis, Vladimir K; Corzilius, Björn et al. (2015) Sensitivity-enhanced NMR reveals alterations in protein structure by cellular milieus. Cell 163:620-8
Can, T V; Ni, Q Z; Griffin, R G (2015) Mechanisms of dynamic nuclear polarization in insulating solids. J Magn Reson 253:23-35
Yang, Xiaochuan; Ong, Ta-Chung; Michaelis, Vladimir K et al. (2015) Formation of Organic Molecular Nanocrystals under Soft Confinement. CrystEngComm 17:6044-6052
Michaelis, Vladimir K; Keeler, Eric G; Ong, Ta-Chung et al. (2015) Structural Insights into Bound Water in Crystalline Amino Acids: Experimental and Theoretical (17)O NMR. J Phys Chem B 119:8024-36
Eddy, Matthew T; Su, Yongchao; Silvers, Robert et al. (2015) Lipid bilayer-bound conformation of an integral membrane beta barrel protein by multidimensional MAS NMR. J Biomol NMR 61:299-310
Markin, Alexey V; Markhasin, Evgeny; Sologubov, Semen S et al. (2015) Low-temperature polymorphic phase transition in a crystalline tripeptide L-Ala-L-Pro-Gly·H2O revealed by adiabatic calorimetry. J Phys Chem B 119:1787-92

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