Self-assembly of proteins and peptides into nanoaggregates of various sizes and morphologies is a widespread phenomenon reported for a large number of proteins and synthetic peptides. Misfolding and aggregation of proteins are associated with a wide range of human pathologies termed protein misfolding or deposition neurodegenerative disorders such as Alzheimer's, Parkinson's, and Huntington's diseases. Despite the important contribution of protein misfolding and spontaneous aggregation to disease pathology, very little is known about the molecular mechanisms underlying these processes. It has been shown that oligomeric species rather long filaments are neurotoxic, but the nature of these species remains unknown. The objective of this application is to characterize the nano-oligomers formed at the early stages of self-assembly and identify the species critically involved in aggregation. The oligomers are formed transiently during the aggregation process, and their characterization requires special approaches capable of probing such species. This application proposes a set of such approaches to attain our objective. Based on preliminary data, the central hypothesis is that formation of dimers is the key step for promoting aggregation and that the lifetimes of dimeric complexes define the misfolding-aggregation paths. The rationale for the proposed research is that understanding fundamental mechanisms of protein misfolding and aggregation has the potential to translate into specific approaches to control the aggregation process. These advances will lead to the development of new and innovative preventions and treatments of protein misfolding diseases. Guided by strong preliminary data, our major hypothesis will be tested by pursuing three specific aims: 1) Identify key nuclei for the aggregation kinetic;2) Image directly early stages of the self-assembly process;and 3) Develop novel linkers and tethers for AFM experiments. Under the first aim, the characterization of oligomeric states will be performed. A novel nanoapproach capable of probing transiently formed oligomeric species will be developed. Under the second aim, the assembly of oligomers of each size starting from dimers will be visualized directly. We will be able to measure directly the time-dependent change of the concentration of each oligomer and to identify which species play a role of building blocks for the growth of aggregates. It is hypothesized that the fibrilization requires formation of oligomers of a defined size. We will be able to directly test this hypothesis. A novel nanoimaging approach capable of unambiguous visualizing each oligomer according to its size and quantitative analysis of the kinetics of their formation will be developed. Under the third aim, a novel type of polymer linker will be developed to facilitate completion of the previous aims. The approach is innovative, because it presents a novel model for the protein aggregation process and develops a set of novel nanotechnology methods with broad biomedical applications to test this model. The proposed research is significant because the findings will lay the foundation for developing efficient treatments of protein misfolding diseases at the very early stages.

Public Health Relevance

The work proposed is relevant to public health because the discovery of critical species triggering protein aggregation is expected to increase the understanding of molecular mechanisms of Alzheimer's, Parkinson's and other protein misfolding diseases. The proposed research will provide knowledge on how pathologies related to protein misfolding develop as well as how to control the aggregation process. Thus, the proposed research is relevant to the part of NIH's mission that pertains to developing fundamental knowledge that will improve preventive and therapeutic treatments for diseases.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
5R01GM096039-02
Application #
8310197
Study Section
Nanotechnology Study Section (NANO)
Program Officer
Lewis, Catherine D
Project Start
2011-08-01
Project End
2015-07-31
Budget Start
2012-08-01
Budget End
2013-07-31
Support Year
2
Fiscal Year
2012
Total Cost
$282,150
Indirect Cost
$92,150
Name
University of Nebraska Medical Center
Department
Other Basic Sciences
Type
Schools of Pharmacy
DUNS #
168559177
City
Omaha
State
NE
Country
United States
Zip Code
68198
Lv, Zhengjian; Banerjee, Siddhartha; Zagorski, Karen et al. (2018) Supported Lipid Bilayers for Atomic Force Microscopy Studies. Methods Mol Biol 1814:129-143
Lyubchenko, Yuri L (2018) Direct AFM Visualization of the Nanoscale Dynamics of Biomolecular Complexes. J Phys D Appl Phys 51:
Maity, Sibaprasad; Viazovkina, Ekaterina; Gall, Alexander et al. (2018) Polymer Nanoarray Approach for the Characterization of Biomolecular Interactions. Methods Mol Biol 1814:63-74
Pan, Yangang; Zagorski, Karen; Shlyakhtenko, Luda S et al. (2018) The Enzymatic Activity of APOBE3G Multimers. Sci Rep 8:17953
Maity, Sibaprasad; Pramanik, Apurba; Lyubchenko, Yuri L (2018) Probing Intermolecular Interactions within the Amyloid ? Trimer Using a Tethered Polymer Nanoarray. Bioconjug Chem 29:2755-2762
Sun, Zhiqiang; Hashemi, Mohtadin; Warren, Galina et al. (2018) Dynamics of the Interaction of RecG Protein with Stalled Replication Forks. Biochemistry 57:1967-1976
Zhang, Yuliang; Hashemi, Mohtadin; Lv, Zhengjian et al. (2018) High-speed atomic force microscopy reveals structural dynamics of ?-synuclein monomers and dimers. J Chem Phys 148:123322
Banerjee, Siddhartha; Hashemi, Mohtadin; Lv, Zhengjian et al. (2017) A novel pathway for amyloids self-assembly in aggregates at nanomolar concentration mediated by the interaction with surfaces. Sci Rep 7:45592
Pan, Yangang; Sun, Zhiqiang; Maiti, Atanu et al. (2017) Nanoscale Characterization of Interaction of APOBEC3G with RNA. Biochemistry 56:1473-1481
Banerjee, Siddhartha; Sun, Zhiqiang; Hayden, Eric Y et al. (2017) Nanoscale Dynamics of Amyloid ?-42 Oligomers As Revealed by High-Speed Atomic Force Microscopy. ACS Nano 11:12202-12209

Showing the most recent 10 out of 48 publications