Protein aggregation is frequently observed in neurodegenerative diseases, including the most common adult motor neuron disease, Amyotrophic Lateral Sclerosis (ALS). In familial ALS (FALS), 20% of patients inherit mutations in the dimeric enzyme Cu, Zn superoxide dismutase (SOD1) associated with increased formation of SOD1 aggregates that contribute to the cytotoxicity responsible for motor neuron cell death and underlying FALS. Our goal is to understand the mechanism of SOD1 aggregation. Accomplishing this goal may be a key step for the development of new FALS therapies, and will impact our understanding of over 60 additional aggregation-associated diseases. Our central hypothesis is that SOD1 aggregation is caused by the increased formation of unfolded/misfolded monomeric species, and/or defects in chaperone-mediated refolding. Specifically, we postulate that mutations (in case of FALS), fluctuations in cell environment and expression levels increase SOD1 dimer dissociation, loss of zinc, and/or the rate of formation of aggregates. We will therefore determine effects of FALS mutations, metals, on the mechanism of SOD1 aggregation. We will characterize the large-scale dynamics of a single SOD1 dimer in rapid computer simulations. We will assess the impact of FALS-associated mutations on SOD1 aggregation by examining the dynamics of mutant and wild type SOD1 molecules using novel multi-scale protein models for studies of large-scale protein conformational dynamics. We will also characterize the large-scale oligomerization dynamics of multiple SOD1 molecules in computer simulations of multiple SOD1 molecules and follow their oligomerization. We will assess the impact of FALS-associated mutations on SOD1 aggregation by examining the dynamics of mutant and wild type SOD1 molecules. For each step of aggregation reaction sequence we will experimentally determine rate and equilibrium constants using size exclusion chromatography, surface plasmon resonance, analytical ultracentrifugation, dynamic light scattering, electron microscopy, and computation. Results from experimental studies will be fed back to computational studies for validating and refining computational models. In turn, computational modeling will guide experimental work.

Public Health Relevance

Mechanistic understanding of SOD1 agggregation will provide a framework for understanding the origin and for developing treatments for this and other neurodegenerative diseases.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
5R01GM080742-04
Application #
7799866
Study Section
Modeling and Analysis of Biological Systems Study Section (MABS)
Program Officer
Wehrle, Janna P
Project Start
2007-04-01
Project End
2012-03-31
Budget Start
2010-04-01
Budget End
2011-03-31
Support Year
4
Fiscal Year
2010
Total Cost
$259,317
Indirect Cost
Name
University of North Carolina Chapel Hill
Department
Biochemistry
Type
Schools of Medicine
DUNS #
608195277
City
Chapel Hill
State
NC
Country
United States
Zip Code
27599
Williams 2nd, Benfeard; Convertino, Marino; Das, Jhuma et al. (2017) Molecular Mechanisms of the R61T Mutation in Apolipoprotein E4: A Dynamic Rescue. Biophys J 113:2192-2198
Woods, Chanin T; Lackey, Lela; Williams, Benfeard et al. (2017) Comparative Visualization of the RNA Suboptimal Conformational Ensemble In Vivo. Biophys J 113:290-301
Brodie, Nicholas I; Popov, Konstantin I; Petrotchenko, Evgeniy V et al. (2017) Solving protein structures using short-distance cross-linking constraints as a guide for discrete molecular dynamics simulations. Sci Adv 3:e1700479
Convertino, Marino; Dokholyan, Nikolay V (2016) Computational Modeling of Small Molecule Ligand Binding Interactions and Affinities. Methods Mol Biol 1414:23-32
Redler, Rachel L; Das, Jhuma; Diaz, Juan R et al. (2016) Protein Destabilization as a Common Factor in Diverse Inherited Disorders. J Mol Evol 82:11-6
Dokholyan, Nikolay V (2016) Controlling Allosteric Networks in Proteins. Chem Rev 116:6463-87
Convertino, Marino; Das, Jhuma; Dokholyan, Nikolay V (2016) Pharmacological Chaperones: Design and Development of New Therapeutic Strategies for the Treatment of Conformational Diseases. ACS Chem Biol 11:1471-89
Fay, James M; Zhu, Cheng; Proctor, Elizabeth A et al. (2016) A Phosphomimetic Mutation Stabilizes SOD1 and Rescues Cell Viability in the Context of an ALS-Associated Mutation. Structure 24:1898-1906
Proctor, Elizabeth A; Fee, Lanette; Tao, Yazhong et al. (2016) Nonnative SOD1 trimer is toxic to motor neurons in a model of amyotrophic lateral sclerosis. Proc Natl Acad Sci U S A 113:614-9
Dagliyan, Onur; Tarnawski, Miroslaw; Chu, Pei-Hsuan et al. (2016) Engineering extrinsic disorder to control protein activity in living cells. Science 354:1441-1444

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