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Principal Investigator: MICHAEL L GROSS
Organization: WASHINGTON UNIVERSITY
Fiscal Year: 2024
Award: $748,641
Funding agency: National Institute on Aging
The “amyloid hypothesis” posits that Amyloid β (Aβ) misfolds, oligomerizes to soluble species, and thereby
contributes to neurodegenerative Alzheimer’s disease (AD). Recent support for the hypothesis comes from a
new antibody, Lecanemab, that targets Aβ and its aggregation and significantly reduces clinical decline. Still, the
aggregation is not understood, leaving a weak foundation for building new therapeutics. In the transition from
monomer to fibril, Aβ exists in soluble, putatively neurotoxic species in mixtures of varied sizes and morphologies.
Complicating matters further is the unknown molecular role of apolipoprotein E (ApoE), a family of partially
disordered proteins including an isoform, ApoE4, that is one of few biomarkers for AD. The aggregate mixture
and the interactions of Aβ with apoE4 and with lipids constituting cell membranes are too complex for many
structural characterization techniques. Protein footprinting coupled with mass spectrometry, however, can
provide a measure of solvent accessibility, local dynamics and structure, hydrogen bonding, sites of ligand-
binding, and oligomerization, with spatial resolution at the peptide and amino-acid residue levels. Considerable
preliminary data establish that this technique can provide structural details not obtainable by other methods. This
footprinting technique has not yet been systematically or rigorously applied to characterize the soluble
intermediates formed in amyloidogenic protein aggregation, and this is our goal. We will chemically footprint Aβ
and ApoE alone or together by using both pulsed hydrogen/deuterium exchange (HDX) and irreversible
modification by highly reactive species (free radicals, carbenes, carbocations). For the latter, we will utilize the
“Fast Photochemical Oxidation of Proteins” or “FPOP” platform, which we invented. Both HDX and FPOP are
used in a differential mode where changes in structure are determined as a function of aggregation time or
increasing media complexity. Utilization of optimized reagents will be coupled with separation and kinetic
modeling to reduce heterogeneity and analyze the aggregation pathways and the varied structures or
morphologies of the oligomers. We will then apply these optimized footprinting approaches in complex media
containing lipids, small molecules, and other proteins including antibodies to reveal how aggregation changes
upon perturbation with these substances. We will be guided by powerful Density Functional Theory that can
probe small molecule/Aβ interactions Once the footprinting and data processing pass rigorous validation, we will
apply them to Aβ and ApoE in a system of reprogrammed neurons that recapitulate the pathophysiology of AD
patients. This system succeeds where pluripotent stem cells and mouse models do not because they don’t carry
age information, and age correlates strongly with AD. The proposed research will bring new understanding of
Aβ aggregation and of ApoE interactions with regional and amino acid resolution in relevant media. It will also
define and characterize a novel and potentially informative approach for gaining insight on neurodegenerative
diseases.
Terms: <21+ years old><AD dementia><AD prevention><APOE e4><APOE-ε4><APOEε4><Adult><Adult Human><Age><Alzheimer Type Dementia><Alzheimer beta-Protein><Alzheimer disease dementia><Alzheimer disease prevention><Alzheimer prevention><Alzheimer sclerosis><Alzheimer syndrome><Alzheimer's><Alzheimer's Amyloid beta-Protein><Alzheimer's Disease><Alzheimer's amyloid><Alzheimer's biomarker><Alzheimer's disease biological marker><Alzheimer's disease patient><Alzheimer's patient><Alzheimers Dementia><Alzheimer’s biological marker><Alzheimer’s disease biomarker><American><Amino Acids><Amyloid><Amyloid Alzheimer's Dementia Amyloid Protein><Amyloid Beta-Peptide><Amyloid Protein A4><Amyloid Proteins><Amyloid Substance><Amyloid beta-Protein><Amyloid β><Amyloid β-Peptide><Amyloid β-Protein><Animals><Antibodies><Apo-E><ApoE><ApoE protein><Apolipoprotein E><Aβ><Binding><Cell Body><Cell membrane><Cells><Chemicals><Chemistry><Clinical><Collaborations><Complement><Complement Proteins><Complex><Coupled><Cryo-electron Microscopy><Cryoelectron Microscopy><Cytoplasmic Membrane><Data><Degenerative Neurologic Disorders><Dependence><Deuterium><Development><Device or Instrument Development><Disease><Disorder><Dysfunction><Electron Cryomicroscopy><Entropy><Family><Fibroblasts><Field Flow Fractionation><Filament><Foundations><Free Radicals><Functional disorder><Goals><Grant><H element><H-bond><H2 isotope><Heterogeneity><Human><Hydrogen><Hydrogen Bonding><In Vitro><Individual><Isoforms><Kinetics><Label><Laboratories><Ligand Binding><Lipids><Mass Photometry/Spectrum Analysis><Mass Spectrometry><Mass Spectroscopy><Mass Spectrum><Mass Spectrum Analyses><Mass Spectrum Analysis><Math Models><Measures><Membrane><Methods><Modeling><Modern Man><Modification><Molecular><Molecular Interaction><Molecular Sieve Chromatography><Morphology><NIH><National Institutes of Health><Nature><Nerve Cells><Nerve Degeneration><Nerve Unit><Nervous System Degenerative Diseases><Neural Cell><Neural Degenerative Diseases><Neural degenerative Disorders><Neurocyte><Neurodegenerative Diseases><Neurodegenerative Disorders><Neurologic Degenerative Conditions><Neuron Degeneration><Neurons><Outcome><Paralysis Agitans><Parkinson><Parkinson Disease><Pathogenesis><Patients><Peptides><Physiologic pulse><Physiopathology><Plasma Membrane><Pluripotent Stem Cells><Population><Preventive><Primary Parkinsonism><Primary Senile Degenerative Dementia><Protein Footprinting><Protein Isoforms><Proteins><Proteomics><Protocol><Protocols documentation><Pulse><Qualifying><Rationalization><Reagent><Research><Resolution><Role><SSNMR><Site><Size Exclusion Chromatography><Solvents><Specificity><Structure><System><Techniques><Testing><Therapeutic><Thinking><Time><United States National Institutes of Health><Validation><a beta peptide><abeta><abeta accumulation><abeta aggregation><adulthood><age associated><age correlated><age dependent><age linked><age related><age specific><ages><aggregation pathway><aminoacid><amyloid beta><amyloid beta accumulation><amyloid beta aggregation><amyloid β accumulation><amyloid β aggregation><amyloid-b protein><apo E-4><apo E4><apo epsilon4><apoE epsilon 4><apoE-4><apoE4><apolipoprotein E epsilon 4><apolipoprotein E-4><apolipoprotein E4><aβ accumulation><aβ aggregation><beta amyloid fibril><carbene><complementation><computerized data processing><cryo-EM><cryoEM><cryogenic electron microscopy><data processing><degenerative diseases of motor and sensory neurons><degenerative neurological diseases><density><developmental><device development><disease prevention><disorder prevention><experience><experiment><experimental research><experimental study><experiments><in vivo><inhibitor><insight><insoluble aggregate><instrument development><instrumentation><invention><kinetic model><mathematic model><mathematical model><mathematical modeling><membrane structure><method development><methylene><monomer><mouse model><murine model><neural degeneration><neurodegeneration><neurodegenerative><neurodegenerative illness><neurological degeneration><neuronal><neuronal degeneration><neurotoxic><new approaches><new drug treatments><new drugs><new pharmacological therapeutic><new therapeutics><new therapy><next generation therapeutics><novel><novel approaches><novel drug treatments><novel drugs><novel pharmaco-therapeutic><novel pharmacological therapeutic><novel strategies><novel strategy><novel therapeutics><novel therapy><oxidation><pathophysiology><patient living with Alzheimer's disease><patient suffering from Alzheimer's disease><patient with Alzheimer's><patient with Alzheimer's disease><plasmalemma><pluripotent progenitor><primary degenerative dementia><progenitor cell model><progenitor model><protein aggregate><protein aggregation><resolutions><senile dementia of the Alzheimer type><sensor><small molecular inhibitor><small molecule><small molecule inhibitor><social role><solid state><solid state NMR><solid state nuclear magnetic resonance><soluble amyloid precursor protein><stem><stem and progenitor cell model><stem cell based model><stem cell derived model><stem cell model><theories><thoughts><tool><validations>