1
|
Wagner WJ, Gross ML. Using mass spectrometry-based methods to understand amyloid formation and inhibition of alpha-synuclein and amyloid beta. MASS SPECTROMETRY REVIEWS 2024; 43:782-825. [PMID: 36224716 PMCID: PMC10090239 DOI: 10.1002/mas.21814] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
Amyloid fibrils, insoluble β-sheets structures that arise from protein misfolding, are associated with several neurodegenerative disorders. Many small molecules have been investigated to prevent amyloid fibrils from forming; however, there are currently no therapeutics to combat these diseases. Mass spectrometry (MS) is proving to be effective for studying the high order structure (HOS) of aggregating proteins and for determining structural changes accompanying protein-inhibitor interactions. When combined with native MS (nMS), gas-phase ion mobility, protein footprinting, and chemical cross-linking, MS can afford regional and sometimes amino acid spatial resolution of the aggregating protein. The spatial resolution is greater than typical low-resolution spectroscopic, calorimetric, and the traditional ThT fluorescence methods used in amyloid research today. High-resolution approaches can struggle when investigating protein aggregation, as the proteins exist as complex oligomeric mixtures of many sizes and several conformations or polymorphs. Thus, MS is positioned to complement both high- and low-resolution approaches to studying amyloid fibril formation and protein-inhibitor interactions. This review covers basics in MS paired with ion mobility, continuous hydrogen-deuterium exchange (continuous HDX), pulsed hydrogen-deuterium exchange (pulsed HDX), fast photochemical oxidation of proteins (FPOP) and other irreversible labeling methods, and chemical cross-linking. We then review the applications of these approaches to studying amyloid-prone proteins with a focus on amyloid beta and alpha-synuclein. Another focus is the determination of protein-inhibitor interactions. The expectation is that MS will bring new insights to amyloid formation and thereby play an important role to prevent their formation.
Collapse
Affiliation(s)
- Wesley J Wagner
- Department of Chemistry, Washington University in St. Louis, St. Louis, Missouri, USA
| | - Michael L Gross
- Department of Chemistry, Washington University in St. Louis, St. Louis, Missouri, USA
| |
Collapse
|
2
|
Renawala HK, Chandrababu KB, Smith KJ, D'Addio SM, Topp EM. A Model Study to Assess Fibrillation and Product Stability to Support Peptide Drug Design. Mol Pharm 2024; 21:2223-2237. [PMID: 38552144 DOI: 10.1021/acs.molpharmaceut.3c00996] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/07/2024]
Abstract
The fibrillation of therapeutic peptides can present significant quality concerns and poses challenges for manufacturing and storage. A fundamental understanding of the mechanisms of fibrillation is critical for the rational design of fibrillation-resistant peptide drugs and can accelerate product development by guiding the selection of solution-stable candidates and formulations. The studies reported here investigated the effects of structural modifications on the fibrillation of a 29-residue peptide (PepA) and two sequence modified variants (PepB, PepC). The C-terminus of PepA was amidated, whereas both PepB and PepC retained the carboxylate, and Ser16 in PepA and PepB was substituted with a helix-stabilizing residue, α-aminoisobutyric acid (Aib), in PepC. In thermal denaturation studies by far-UV CD spectroscopy and fibrillation kinetic studies by fluorescence and turbidity measurements, PepA and PepB showed heat-induced conformational changes and were found to form fibrils, whereas PepC did not fibrillate and showed only minor changes in the CD signal. Pulsed hydrogen-deuterium exchange mass spectrometry (HDX-MS) showed a high degree of protection from HD exchange in mature PepA fibrils and its proteolytic fragments, indicating that most of the sequence had been incorporated into the fibril structure and occurred nearly simultaneously throughout the sequence. The effects of the net peptide charge and formulation pH on fibrillation kinetics were investigated. In real-time stability studies of two formulations of PepA at pH's 7.4 and 8.0, analytical methods detected significant changes in the stability of the formulations at different time points during the study, which were not observed during accelerated studies. Additionally, PepA samples were withdrawn from real-time stability and subjected to additional stress (40 °C, continuous shaking) to induce fibrillation; an approach that successfully amplified oligomers or prefibrillar species previously undetected in a thioflavin T assay. Taken together, these studies present an approach to differentiate and characterize fibrillation risk in structurally related peptides under accelerated and real-time conditions, providing a model for rapid, iterative structural design to optimize the stability of therapeutic peptides.
Collapse
Affiliation(s)
- Harshil K Renawala
- Department of Industrial and Molecular Pharmaceutics, College of Pharmacy, Purdue University, West Lafayette, Indiana 47907, United States
| | - Karthik B Chandrababu
- Department of Industrial and Molecular Pharmaceutics, College of Pharmacy, Purdue University, West Lafayette, Indiana 47907, United States
| | - Katelyn J Smith
- Pharmaceutical Sciences and Clinical Supply, Merck & Co., Inc., Rahway, New Jersey 07065, United States
| | - Suzanne M D'Addio
- Pharmaceutical Sciences and Clinical Supply, Merck & Co., Inc., Rahway, New Jersey 07065, United States
| | - Elizabeth M Topp
- Department of Industrial and Molecular Pharmaceutics, College of Pharmacy, Purdue University, West Lafayette, Indiana 47907, United States
- Davidson School of Chemical Engineering, College of Engineering, Purdue University, West Lafayette, Indiana 47907, United States
- National Institute for Bioprocessing Research and Training, Belfield, Blackrock, Co. Dublin A94 X099, Ireland
| |
Collapse
|
3
|
Ng YK, Konermann L. Mechanism of Protein Aggregation Inhibition by Arginine: Blockage of Anionic Side Chains Favors Unproductive Encounter Complexes. J Am Chem Soc 2024; 146:8394-8406. [PMID: 38477601 DOI: 10.1021/jacs.3c14180] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/14/2024]
Abstract
Aggregation refers to the assembly of proteins into nonphysiological higher order structures. While amyloid has been studied extensively, much less is known about amorphous aggregation, a process that interferes with protein expression and storage. Free arginine (Arg+) is a widely used aggregation inhibitor, but its mechanism remains elusive. Focusing on myoglobin (Mb), we recently applied atomistic molecular dynamics (MD) simulations for gaining detailed insights into amorphous aggregation (Ng J. Phys. Chem. B 2021, 125, 13099). Building on that approach, the current work for the first time demonstrates that MD simulations can directly elucidate aggregation inhibition mechanisms. Comparative simulations with and without Arg+ reproduced the experimental finding that Arg+ significantly decreased the Mb aggregation propensity. Our data reveal that, without Arg+, protein-protein encounter complexes readily form salt bridges and hydrophobic contacts, culminating in firmly linked dimeric aggregation nuclei. Arg+ promotes the dissociation of encounter complexes. These "unproductive" encounter complexes are favored because Arg+ binding to D- and E- lowers the tendency of these anionic residues to form interprotein salt bridges. Side chain blockage is mediated largely by the guanidinium group of Arg+, which binds carboxylates through H-bond-reinforced ionic contacts. Our MD data revealed Arg+ self-association into a dynamic quasi-infinite network, but we found no evidence that this self-association is important for protein aggregation inhibition. Instead, aggregation inhibition by Arg+ is similar to that mediated by free guanidinium ions. The computational strategy used here should be suitable for the rational design of aggregation inhibitors with enhanced potency.
Collapse
Affiliation(s)
- Yuen Ki Ng
- Department of Chemistry, The University of Western Ontario, London, Ontario N6A 5B7, Canada
| | - Lars Konermann
- Department of Chemistry, The University of Western Ontario, London, Ontario N6A 5B7, Canada
| |
Collapse
|
4
|
Illes-Toth E, Rempel DL, Gross ML. Exploration of Resveratrol as a Potent Modulator of α-Synuclein Fibril Formation. ACS Chem Neurosci 2024; 15:503-516. [PMID: 38194353 PMCID: PMC10922803 DOI: 10.1021/acschemneuro.3c00571] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2024] Open
Abstract
The molecular determinants of amyloid protein misfolding and aggregation are key for the development of therapeutic interventions in neurodegenerative disease. Although small synthetic molecules, bifunctional molecules, and natural products offer a potentially advantageous approach to therapeutics to remodel aggregation, their evaluation requires new platforms that are informed at the molecular level. To that end, we chose pulsed hydrogen/deuterium exchange mass spectrometry (HDX-MS) to discern the phenomena of aggregation modulation for a model system of alpha synuclein (αS) and resveratrol, an antiamyloid compound. We invoked, as a complement to HDX, advanced kinetic modeling described here to illuminate the details of aggregation and to determine the number of oligomeric populations by kinetically fitting the experimental data under conditions of limited proteolysis. The misfolding of αS is most evident within and nearby the nonamyloid-β component region, and resveratrol significantly remodels that aggregation. HDX distinguishes readily a less solvent-accessible, more structured oligomer that coexists with a solvent-accessible, more disordered oligomer during aggregation. A view of the misfolding emerges from time-dependent changes in the fractional species across the protein with or without resveratrol, while details were determined through kinetic modeling of the protected species. A detailed picture of the inhibitory action of resveratrol with time and regional specificity emerges, a picture that can be obtained for other inhibitors and amyloid proteins. Moreover, the model reveals that new states of aggregation are sampled, providing new insights on amyloid formation. The findings were corroborated by circular dichroism and transmission electron microscopy.
Collapse
Affiliation(s)
- Eva Illes-Toth
- Department of Chemistry, Washington University in St Louis, St Louis, Missouri 63130, United States
| | - Don L Rempel
- Department of Chemistry, Washington University in St Louis, St Louis, Missouri 63130, United States
| | - Michael L Gross
- Department of Chemistry, Washington University in St Louis, St Louis, Missouri 63130, United States
| |
Collapse
|
5
|
Sunda AP, Sharma AK. Molecular Insights into Cu/Zn Metal Response to the Amyloid β-Peptide (1-42). ACS PHYSICAL CHEMISTRY AU 2024; 4:57-66. [PMID: 38283784 PMCID: PMC10811771 DOI: 10.1021/acsphyschemau.3c00041] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/11/2023] [Revised: 10/03/2023] [Accepted: 10/04/2023] [Indexed: 01/30/2024]
Abstract
Aβ1-40 peptide and Aβ1-42 peptide are the building units of beta-amyloid plaques present in Alzheimer's disease (AD)-affected brain. The binding affinity of various divalent metal ions such as Cu and Zn present in AD-affected brain with different amino acids available in Aβ-peptide became the focus to explore their role in soluble neurotoxic oligomer formation. Cu2+ metal ions are known to enhance the neurotoxicity of the Aβ1-42 peptide by catalyzing the formation of soluble neurotoxic oligomers. The competitive preference of both Cu2+ and Zn2+ simultaneously to interact with the Aβ-peptide is unknown. The divalent Cu and Zn ions were inserted in explicit aqueous Aβ1-42 peptide configurations to get insights into the binding competence of these metal ions with peptides using classical molecular dynamics (MD) simulations. The metal-ion interactions reveal that competitive binding preferences of various peptide sites become metal-ion-specific and differ significantly. For Cu2+, interactions are found to be more significant with respect to those of Asp-7, His-6, Glu-11, and His-14. Asp-1, Glu-3, Asp-7, His-6, Glu-11, and His-13 amino acid residues show higher affinity toward Zn2+ ions. MD simulations show notable variation in the solvent-accessible surface area in the hydrophobic region of the peptide. Infinitesimal mobility was obtained for Zn2+ compared to Cu2+ in an aqueous solution and Cu2+ diffusivity deviated significantly at different time scales, proving its labile features in aqueous Aβ1-42 peptides.
Collapse
Affiliation(s)
- Anurag Prakash Sunda
- Department
of Chemistry, J. C. Bose University of Science
and Technology, YMCA, Faridabad 121006, India
| | - Anuj Kumar Sharma
- Department
of Chemistry, School of Chemical Sciences and Pharmacy, Central University of Rajasthan, Ajmer 305817, India
| |
Collapse
|
6
|
Guan Y, Li Y, Gao W, Mei J, Xu W, Wang C, Ai H. Aggregation Dynamics Characteristics of Seven Different Aβ Oligomeric Isoforms-Dependence on the Interfacial Interaction. ACS Chem Neurosci 2024; 15:155-168. [PMID: 38109178 DOI: 10.1021/acschemneuro.3c00585] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2023] Open
Abstract
The aggregation of β-amyloid (Aβ) peptides has been confirmed to be associated with the onset of Alzheimer's disease (AD). Among the three phases of Aβ aggregation, the lag phase has been considered to be the best time for early Aβ pathological deposition clinical intervention and prevention for potential patients with normal cognition. Aβ peptide exists in various lengths in vivo, and Aβ oligomer in the early lag phase is neurotoxic but polymorphous and metastable, depending on Aβ length (isoform), molecular weight, and specific phase, and therefore hardly characterized experimentally. To cope with the problem, molecular dynamics simulation was used to investigate the aggregation process of five monomers for each of the seven common Aβ isoforms during the lag phase. Results showed that Aβ(1-40) and Aβ(1-38) monomers aggregated faster than their truncated analogues Aβ(4-40) and Aβ(4-38), respectively. However, the aggregation rate of Aβ(1-42) was slower than that of its truncated analogues Aβ(4-42) rather than that of Aβpe(3-42). More importantly, Aβ(1-38) is first predicted as more likely to form stable hexamer than the remaining five Aβ isoforms, as Aβ(1-42) does. It is hydrophobic interaction mainly (>50%) from the interfacial β1 and β2 regions of two reactants, pentamer and monomer, aggregated by Aβ(1-38)/Aβ(1-42) rather than by other Aβ isoforms, that drives the hexamer stably as a result of the formation of the effective hydrophobic collapse. This paper provides new insights into the aggregation characteristics of Aβ with different lengths and the conditions necessary for Aβ to form oligomers with a high molecular weight in the early lag phase, revealing the dependence of Aβ hexamer formation on the specific interfacial interaction.
Collapse
Affiliation(s)
- Yvning Guan
- School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, P. R. China
| | - Ye Li
- School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, P. R. China
| | - Wenqi Gao
- School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, P. R. China
| | - Jinfei Mei
- School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, P. R. China
| | - Wen Xu
- School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, P. R. China
| | - Chuanbo Wang
- School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, P. R. China
| | - Hongqi Ai
- School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, P. R. China
| |
Collapse
|
7
|
Yu TG, Lee J, Yoon J, Choi JM, Kim DG, Heo WD, Song JJ, Kim HS. Engineering of a Fluorescent Protein for a Sensing of an Intrinsically Disordered Protein through Transition in the Chromophore State. JACS AU 2023; 3:3055-3065. [PMID: 38034956 PMCID: PMC10685427 DOI: 10.1021/jacsau.3c00445] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/05/2023] [Revised: 09/18/2023] [Accepted: 10/02/2023] [Indexed: 12/02/2023]
Abstract
Intrinsically disordered proteins (IDPs) not only play important roles in biological processes but are also linked with the pathogenesis of various human diseases. Specific and reliable sensing of IDPs is crucial for exploring their roles but remains elusive due to structural plasticity. Here, we present the development of a new type of fluorescent protein for the ratiometric sensing and tracking of an IDP. A β-strand of green fluorescent protein (GFP) was truncated, and the resulting GFP was further engineered to undergo the transition in the absorption maximum upon binding of a target motif within amyloid-β (Aβ) as a model IDP through rational design and directed evolution. Spectroscopic and structural analyses of the engineered truncated GFP demonstrated that a shift in the absorption maximum is driven by the change in the chromophore state from an anionic (460 nm) state into a neutral (390 nm) state as the Aβ binds, allowing a ratiometric detection of Aβ. The utility of the developed GFP was shown by the efficient and specific detection of an Aβ and the tracking of its conformational change and localization in astrocytes.
Collapse
Affiliation(s)
- Tae-Geun Yu
- Departement
of Biological Sciences, Korea Advanced Institute
of Science and Technology (KAIST), Daejeon 34141, Korea
| | - Jinsu Lee
- Departement
of Biological Sciences, Korea Advanced Institute
of Science and Technology (KAIST), Daejeon 34141, Korea
| | - Jungmin Yoon
- Departement
of Biological Sciences, Korea Advanced Institute
of Science and Technology (KAIST), Daejeon 34141, Korea
| | - Jung Min Choi
- School
of Food Biotechnology and Nutrition, Kyungsung
University, Busan 48434, Korea
| | - Dong-Gun Kim
- Departement
of Biological Sciences, Korea Advanced Institute
of Science and Technology (KAIST), Daejeon 34141, Korea
| | - Won Do Heo
- Departement
of Biological Sciences, Korea Advanced Institute
of Science and Technology (KAIST), Daejeon 34141, Korea
| | - Ji-Joon Song
- Departement
of Biological Sciences, Korea Advanced Institute
of Science and Technology (KAIST), Daejeon 34141, Korea
| | - Hak-Sung Kim
- Departement
of Biological Sciences, Korea Advanced Institute
of Science and Technology (KAIST), Daejeon 34141, Korea
| |
Collapse
|
8
|
Bai Y, Zhang S, Dong H, Liu Y, Liu C, Zhang X. Advanced Techniques for Detecting Protein Misfolding and Aggregation in Cellular Environments. Chem Rev 2023; 123:12254-12311. [PMID: 37874548 DOI: 10.1021/acs.chemrev.3c00494] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2023]
Abstract
Protein misfolding and aggregation, a key contributor to the progression of numerous neurodegenerative diseases, results in functional deficiencies and the creation of harmful intermediates. Detailed visualization of this misfolding process is of paramount importance for improving our understanding of disease mechanisms and for the development of potential therapeutic strategies. While in vitro studies using purified proteins have been instrumental in delivering significant insights into protein misfolding, the behavior of these proteins in the complex milieu of living cells often diverges significantly from such simplified environments. Biomedical imaging performed in cell provides cellular-level information with high physiological and pathological relevance, often surpassing the depth of information attainable through in vitro methods. This review highlights a variety of methodologies used to scrutinize protein misfolding within biological systems. This includes optical-based methods, strategies leaning on mass spectrometry, in-cell nuclear magnetic resonance, and cryo-electron microscopy. Recent advancements in these techniques have notably deepened our understanding of protein misfolding processes and the features of the resulting misfolded species within living cells. The progression in these fields promises to catalyze further breakthroughs in our comprehension of neurodegenerative disease mechanisms and potential therapeutic interventions.
Collapse
Affiliation(s)
- Yulong Bai
- Department of Chemistry, Research Center for Industries of the Future, Westlake University, 600 Dunyu Road, Hangzhou 310030, Zhejiang Province, China
- CAS Key Laboratory of Separation Science for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, Liaoning 116023, China
| | - Shengnan Zhang
- Interdisciplinary Research Center on Biology and Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai 201210, China
| | - Hui Dong
- Interdisciplinary Research Center on Biology and Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai 201210, China
- University of the Chinese Academy of Sciences, 19 A Yuquan Road, Shijingshan District, Beijing 100049, China
| | - Yu Liu
- CAS Key Laboratory of Separation Science for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, Liaoning 116023, China
| | - Cong Liu
- Interdisciplinary Research Center on Biology and Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai 201210, China
- State Key Laboratory of Chemical Biology, Shanghai Institute of Organic Chemistry, University of Chinese Academy of Sciences, Shanghai 200032, China
| | - Xin Zhang
- Department of Chemistry, Research Center for Industries of the Future, Westlake University, 600 Dunyu Road, Hangzhou 310030, Zhejiang Province, China
- Westlake Laboratory of Life Sciences and Biomedicine, 18 Shilongshan Road, Hangzhou 310024, Zhejiang Province, China
| |
Collapse
|
9
|
Xu W, Mei J, Wang C, Yang H, Ma X, Gao W, Ahmad S, Ai H. Origin of stronger binding of ionic pair (IP) inhibitor to Aβ42 than the equimolar neutral counterparts: synergy mechanism of IP in disrupting Aβ42 protofibril and inhibiting Aβ42 aggregation under two pH conditions. Phys Chem Chem Phys 2023; 25:21612-21630. [PMID: 37551434 DOI: 10.1039/d3cp01683h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/09/2023]
Abstract
Fibrous aggregates of beta-amyloid (Aβ) is a hallmark of Alzheimer's disease (AD). Several major strategies of drugs or inhibitors, including neutral molecules, positive or negative ions, and dual-inhibitor, are used to inhibit the misfolding or aggregation of Aβ42, among which a kind of dual-inhibitor composed of a pair of positive and negative ions is emerging as the most powerful candidate. This knowledge lacks the origin of the strong inhibitory effect and synergy mechanisms blocking the development and application of such inhibitors. To this end, we employed 1 : 1 ionic pairs (IP) of oppositely charged benzothiazole molecules (+)BAM1-EG6 (Pos) and (-)BAM1-EG6 (Neg) as well as equimolar neutral BAM1-EG6 (Neu) counterpart at two pH conditions (5.5 and 7.0) to bind Aβ42 targets, Aβ42 monomer (AβM), soluble pentamer (AβP), and pentameric protofibril (AβF) models, respectively, corresponding to the products of three toxic Aβ42 development pathways, lag, exponential and fibrillation phases. Simulated results illustrated the details of the inhibitory mechanisms of IP and Neu for the AβY (Y = M, P, or F) in the three different phases, characterizing the roles of Pos and Neg of IP as well as their charged, hydrophobic groups and linker playing in the synergistic interaction, and elucidated a previously unknown molecular mechanism governing the IP-Aβ42 interaction. Most importantly, we first revealed the origin of the stronger binding of IP inhibitors to Aβ42 than that of the equimolar neutral counterparts, observing a perplexing phenomenon that the physiological condition (pH = 7.0) than the acidic one (pH = 5.5) is more favorable to the enhancement of IP binding, and finally disclosed that solvation is responsible to the enhancement because at pH 7.0, AβP and AβF act as anionic membranes, where solvation plays a critical role in the chemoelectromechanics. The result not only provides a new dimension in dual-inhibitor/drug design and development but also a new perspective for uncovering charged protein disaggregation under IP-like inhibitors.
Collapse
Affiliation(s)
- Wen Xu
- School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, P. R. China.
| | - Jinfei Mei
- School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, P. R. China.
| | - Chuanbo Wang
- School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, P. R. China.
| | - Huijuan Yang
- School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, P. R. China.
| | - Xiaohong Ma
- School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, P. R. China.
| | - Wenqi Gao
- School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, P. R. China.
| | - Sajjad Ahmad
- School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, P. R. China.
| | - Hongqi Ai
- School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, P. R. China.
| |
Collapse
|
10
|
A label-free electrochemical immunosensor based on PtCoCu PNPs/NB-rGO as a dual signal amplification platform for sensitive detection of β-Amyloid 1-42. Bioelectrochemistry 2023; 152:108405. [PMID: 36898344 DOI: 10.1016/j.bioelechem.2023.108405] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2022] [Revised: 02/03/2023] [Accepted: 02/21/2023] [Indexed: 03/07/2023]
Abstract
In this work, a label-free electrochemical immunosensor based on popcorn-shaped PtCoCu nanoparticles supported on N- and B-codoped reduced graphene oxide (PtCoCu PNPs/NB-rGO) was constructed to sensitively detect concentration level of β-Amyloid1-42 oligomers (Aβ). The PtCoCu PNPs exhibits excellent catalytic ability due to its popcorn structure which improves the specific surface area and porosity, resulting in more active sites being exposed and fast transport paths for ion/electron. NB-rGO with large surface area and unique pleated structure could disperse PtCoCu PNPs through electrostatic adsorption and formation of d-p dative bonds between the metal ion and pyridinic N of NB-rGO. In addition, the doping of B atoms enhances the catalytic ability of GO enormously and achieves further signal amplification. Besides, both PtCoCu PNPs and NB-rGO are able to fix abundant antibodies through M(Pt, Co, Cu)-N bonds and amide bonds respectively without any other complex processing procedures such as carboxylation, ect. The designed platform achieved the dual amplification of electrocatalytic signal and effectively immobilization of antibodies. Under the optimum conditions, the designed electrochemical immunosensor presented wide linear rang (50.0 fg/mL ∼ 100 ng/mL) and low detection limits (3.5 fg/mL). The results demonstrated that the prepared immunosensor will be promising in sensitive detection of AD biomarkers.
Collapse
|
11
|
Depraz Depland A, Stroganova I, Wootton CA, Rijs AM. Developments in Trapped Ion Mobility Mass Spectrometry to Probe the Early Stages of Peptide Aggregation. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2023; 34:193-204. [PMID: 36633834 PMCID: PMC9896548 DOI: 10.1021/jasms.2c00253] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/07/2022] [Revised: 11/15/2022] [Accepted: 12/16/2022] [Indexed: 06/17/2023]
Abstract
Ion mobility mass spectrometry (IM-MS) has proven to be an excellent method to characterize the structure of amyloidogenic protein and peptide aggregates, which are formed in coincidence with the development of neurodegenerative diseases. However, it remains a challenge to obtain detailed structural information on all conformational intermediates, originating from the early onset of those pathologies, due to their complex and heterogeneous environment. One way to enhance the insights and the identification of these early stage oligomers is by employing high resolution ion mobility mass spectrometry experiments. This would allow us to enhance the mobility separation and MS characterization. Trapped ion mobility spectrometry (TIMS) is an ion mobility technique known for its inherently high resolution and has successfully been applied to the analysis of protein conformations among others. To obtain conformational information on fragile peptide aggregates, the instrumental parameters of the TIMS-Quadrupole-Time-of-Flight mass spectrometer (TIMS-qToF-MS) have to be optimized to allow the study of intact aggregates and ensure their transmission toward the detector. Here, we investigate the suitability and application of TIMS to probe the aggregation process, targeting the well-characterized M307-N319 peptide segment of the TDP-43 protein, which is involved in the development of amyotrophic lateral sclerosis. By studying the influence of key parameters over the full mass spectrometer, such as source temperature, applied voltages or RFs among others, we demonstrate that by using an optimized instrumental method TIMS can be used to probe peptide aggregation.
Collapse
Affiliation(s)
- Agathe Depraz Depland
- Division
of Bioanalytical Chemistry, Amsterdam Institute of Molecular and Life
Sciences, Vrije Universiteit Amsterdam, De Boelelaan 1105, 1081 HV Amsterdam, The Netherlands
| | - Iuliia Stroganova
- Division
of Bioanalytical Chemistry, Amsterdam Institute of Molecular and Life
Sciences, Vrije Universiteit Amsterdam, De Boelelaan 1105, 1081 HV Amsterdam, The Netherlands
| | | | - Anouk M. Rijs
- Division
of Bioanalytical Chemistry, Amsterdam Institute of Molecular and Life
Sciences, Vrije Universiteit Amsterdam, De Boelelaan 1105, 1081 HV Amsterdam, The Netherlands
| |
Collapse
|
12
|
Mass spectrometric insights into protein aggregation. Essays Biochem 2023; 67:243-253. [PMID: 36636963 PMCID: PMC10070474 DOI: 10.1042/ebc20220103] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2022] [Revised: 12/11/2022] [Accepted: 12/14/2022] [Indexed: 01/14/2023]
Abstract
Protein aggregation is now recognized as a generic and significant component of the protein energy landscape. Occurring through a complex and dynamic pathway of structural interconversion, the assembly of misfolded proteins to form soluble oligomers and insoluble aggregates remains a challenging topic of study, both in vitro and in vivo. Since the etiology of numerous human diseases has been associated with protein aggregation, and it has become a field of increasing importance in the biopharmaceutical industry, the biophysical characterization of protein misfolded states and their aggregation mechanisms continues to receive increased attention. Mass spectrometry (MS) has firmly established itself as a powerful analytical tool capable of both detection and characterization of proteins at all levels of structure. Given inherent advantages of biological MS, including high sensitivity, rapid timescales of analysis, and the ability to distinguish individual components from complex mixtures with unrivalled specificity, it has found widespread use in the study of protein aggregation, importantly, where traditional structural biology approaches are often not amenable. The present review aims to provide a brief overview of selected MS-based approaches that can provide a range of biophysical descriptors associated with protein conformation and the aggregation pathway. Recent examples highlight where this technology has provided unique structural and mechanistic understanding of protein aggregation.
Collapse
|
13
|
Illuminating Intrinsically Disordered Proteins with Integrative Structural Biology. Biomolecules 2023; 13:biom13010124. [PMID: 36671509 PMCID: PMC9856150 DOI: 10.3390/biom13010124] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2022] [Revised: 01/01/2023] [Accepted: 01/04/2023] [Indexed: 01/11/2023] Open
Abstract
Intense study of intrinsically disordered proteins (IDPs) did not begin in earnest until the late 1990s when a few groups, working independently, convinced the community that these 'weird' proteins could have important functions. Over the past two decades, it has become clear that IDPs play critical roles in a multitude of biological phenomena with prominent examples including coordination in signaling hubs, enabling gene regulation, and regulating ion channels, just to name a few. One contributing factor that delayed appreciation of IDP functional significance is the experimental difficulty in characterizing their dynamic conformations. The combined application of multiple methods, termed integrative structural biology, has emerged as an essential approach to understanding IDP phenomena. Here, we review some of the recent applications of the integrative structural biology philosophy to study IDPs.
Collapse
|
14
|
Renawala HK, Topp EM. Fibrillation of human insulin B-chain by pulsed hydrogen-deuterium exchange mass spectrometry. Biophys J 2022; 121:4505-4516. [PMID: 36325616 PMCID: PMC9748358 DOI: 10.1016/j.bpj.2022.10.042] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2022] [Revised: 08/15/2022] [Accepted: 10/28/2022] [Indexed: 11/13/2022] Open
Abstract
Insulin forms amyloid fibrils under slightly destabilizing conditions, and B-chain residues are thought to play an important role in insulin fibrillation. Here, pulsed hydrogen-deuterium exchange mass spectrometry (HDX-MS), far-UV circular dichroism spectroscopy, thioflavin T (ThioT) fluorescence, turbidity, and soluble fraction measurements were used to monitor the kinetics and mechanisms of fibrillation of human insulin B-chain (INSB) in acidic solution (1 mg/mL, pH 4.5) under stressed conditions (40°C, continuous shaking). Initially, INSB rapidly formed β-sheet-rich oligomers that were protected from HD exchange and showed weak ThioT binding. Subsequent fibril growth and maturation was accompanied by even greater protection from HD exchange and stronger ThioT binding. With peptic digestion of deuterated INSB, HDX-MS suggested early involvement of the N-terminal (1-11, 1-15) and central (12-15, 16-25) fragments in fibril-forming interactions, whereas the C-terminal fragment (25-30) showed limited involvement. The results provide mechanistic understanding of the intermolecular interactions and structural changes during INSB fibrillation under stressed conditions and demonstrate the application of pulsed HDX-MS to probe peptide fibrillation.
Collapse
Affiliation(s)
- Harshil K Renawala
- Department of Industrial and Physical Pharmacy, College of Pharmacy, Purdue University, West Lafayette, Indiana
| | - Elizabeth M Topp
- Department of Industrial and Physical Pharmacy, College of Pharmacy, Purdue University, West Lafayette, Indiana; National Institute for Bioprocessing Research and Training, Dublin, Ireland.
| |
Collapse
|
15
|
Gupta S, Raskatov JA, Ralston CY. A Hybrid Structural Method for Investigating Low Molecular Weight Oligomeric Structures of Amyloid Beta. Chembiochem 2022; 23:e202200333. [PMID: 35980391 PMCID: PMC9729406 DOI: 10.1002/cbic.202200333] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2022] [Revised: 08/16/2022] [Indexed: 01/25/2023]
Abstract
Spurred in part by the failure of recent therapeutics targeting amyloid β plaques in Alzheimer's Disease (AD), attention is increasingly turning to the oligomeric forms of this peptide that form early in the aggregation process. However, while numerous amyloid β fibril structures have been characterized, primarily by NMR spectroscopy and cryo-EM, obtaining structural information on the low molecular weight forms of amyloid β that presumably precede and/or seed fibril formation has proved challenging. These transient forms are heterogeneous, and depend heavily on experimental conditions such as buffer, temperature, concentration, and degree of quiescence during measurement. Here, we present the concept for a new approach to delineating structural features of early-stage low molecular weight amyloid β oligomers, using a solvent accessibility assay in conjunction with simultaneous fluorescence measurements.
Collapse
Affiliation(s)
- Sayan Gupta
- Molecular Foundry Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley CA 94720 (USA)
| | - Jevgenij A. Raskatov
- Department of Chemistry and Biochemistry, University of California Santa Cruz, Physical Science Building 356, 1156 High Street, Santa Cruz, CA 95064 (USA)
| | - Corie Y. Ralston
- Molecular Foundry Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley CA 94720 (USA)
| |
Collapse
|
16
|
Huang Y, Sun L, Mirica LM. Turn-on fluorescent sensors for Cu-rich amyloid β peptide aggregates. SENSORS & DIAGNOSTICS 2022; 1:709-713. [PMID: 35923774 PMCID: PMC9280444 DOI: 10.1039/d2sd00028h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/17/2022] [Accepted: 05/09/2022] [Indexed: 01/12/2023]
Abstract
Protein misfolding and metal dishomeostasis are two key pathological factors of Alzheimer's disease. Previous studies have shown that Cu-mediated amyloid β (Aβ) peptide aggregation leads to the formation of neurotoxic Aβ oligomers. Herein, we report a series of picolinic acid-based Cu-activatable sensors, which can be used for the fluorescence imaging of Cu-rich Aβ aggregates.
Collapse
Affiliation(s)
- Yiran Huang
- Department of Chemistry, University of Illinois at Urbana-Champaign 600 S. Mathews Avenue Urbana IL 61801 USA
| | - Liang Sun
- Department of Chemistry, University of Illinois at Urbana-Champaign 600 S. Mathews Avenue Urbana IL 61801 USA
| | - Liviu M Mirica
- Department of Chemistry, University of Illinois at Urbana-Champaign 600 S. Mathews Avenue Urbana IL 61801 USA
| |
Collapse
|
17
|
Mei J, Yang H, Ahmad S, Ma X, Xu W, Gao W, Li Y, Wang C, Ai H. Toxicity Mechanism of Aβ42 Oligomer in the Binding between the GABA BR1a sushi1 Domain and Amyloid Precursor Protein 9mer: A Mechanism like Substitution Reaction. ACS Chem Neurosci 2022; 13:2048-2059. [PMID: 35737468 DOI: 10.1021/acschemneuro.2c00311] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Amyloid-β peptide (Aβ), characterized by its abnormal folding into neurotoxic aggregates, impairs synaptic plasticity and causes synaptic loss associated with Alzheimer's disease (AD). The neurotoxicity of Aβ oligomers via the binding to various cell-surface receptors was frequently observed experimentally; however, the toxic mechanism still remains unknown. In this paper, we study the intervention of Aβ oligomers to the receptor-peptide binding in the GABABR1a sushi1-APP 9mer complex, a key node in increasing short-term synaptic facilitation in the mouse hippocampus and decreasing neuronal activity by inhibiting neurotransmitter release by molecular dynamics simulations. The residue types of Aβ42 oligomers involved in the intervention and core contact areas of the receptor were first identified, by which an unprecedented toxicity mechanism of Aβ42 oligomers is proposed. These involved residues of Aβ42 oligomers are positively charged residues Asp and Glu, and the core area of GABABR1a sushi1 domain is the Coil one, sharing the rich negatively charged residues R19/R21/R25/R45 with the pocket, in which APP 9mer is locked. The presence of an Aβ42 oligomer rather than of a monomer stretches these key residues in the core area and consequently "unlocks and releases" the APP 9mer from its initial pocket, unsteadying the sushi1 domain and taking into toxic effect. It looks like a chemical "substitution" reaction, Aβ42 oligomer + GABABR1a sushi1-APP 9mer complex → Aβ42 oligomer-GABABR1a sushi1 complex + APP 9mer. Further analysis reveals that the toxicity of Aβ42 oligomer to GABABR1a sushi1 domain stability depends on the residue number of the contact area and the size of Aβ42 oligomer, in which semi-extended trimeric Aβ42 oligomer is identified as the most toxic one. This work provides a novel insight into the mechanism of Aβ oligomeric toxicity to neuroreceptors and sets an important precedent for dealing with Aβ oligomeric toxicity to other receptors at the molecular level.
Collapse
Affiliation(s)
- Jinfei Mei
- School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, P.R. China
| | - Huijuan Yang
- School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, P.R. China
| | - Sajjad Ahmad
- School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, P.R. China
| | - Xiaohong Ma
- School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, P.R. China
| | - Wen Xu
- School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, P.R. China
| | - Wenqi Gao
- School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, P.R. China
| | - Ye Li
- School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, P.R. China
| | - Chuanbo Wang
- School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, P.R. China
| | - Hongqi Ai
- School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, P.R. China
| |
Collapse
|
18
|
Zhou Y, Hua J, Ding D, Tang Y. Interrogating amyloid aggregation with aggregation-induced emission fluorescence probes. Biomaterials 2022; 286:121605. [DOI: 10.1016/j.biomaterials.2022.121605] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2022] [Revised: 05/22/2022] [Accepted: 05/24/2022] [Indexed: 12/26/2022]
|
19
|
Vallejo DD, Rojas Ramírez C, Parson KF, Han Y, Gadkari VV, Ruotolo BT. Mass Spectrometry Methods for Measuring Protein Stability. Chem Rev 2022; 122:7690-7719. [PMID: 35316030 DOI: 10.1021/acs.chemrev.1c00857] [Citation(s) in RCA: 34] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Mass spectrometry is a central technology in the life sciences, providing our most comprehensive account of the molecular inventory of the cell. In parallel with developments in mass spectrometry technologies targeting such assessments of cellular composition, mass spectrometry tools have emerged as versatile probes of biomolecular stability. In this review, we cover recent advancements in this branch of mass spectrometry that target proteins, a centrally important class of macromolecules that accounts for most biochemical functions and drug targets. Our efforts cover tools such as hydrogen-deuterium exchange, chemical cross-linking, ion mobility, collision induced unfolding, and other techniques capable of stability assessments on a proteomic scale. In addition, we focus on a range of application areas where mass spectrometry-driven protein stability measurements have made notable impacts, including studies of membrane proteins, heat shock proteins, amyloidogenic proteins, and biotherapeutics. We conclude by briefly discussing the future of this vibrant and fast-moving area of research.
Collapse
Affiliation(s)
- Daniel D Vallejo
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Carolina Rojas Ramírez
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Kristine F Parson
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Yilin Han
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Varun V Gadkari
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Brandon T Ruotolo
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan 48109, United States
| |
Collapse
|
20
|
Sciacca MF, Naletova I, Giuffrida ML, Attanasio F. Semax, a Synthetic Regulatory Peptide, Affects Copper-Induced Abeta Aggregation and Amyloid Formation in Artificial Membrane Models. ACS Chem Neurosci 2022; 13:486-496. [PMID: 35080861 PMCID: PMC8855339 DOI: 10.1021/acschemneuro.1c00707] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
Abstract
![]()
Alzheimer’s
disease, the most common form of dementia, is
characterized by the aggregation of amyloid beta protein (Aβ).
The aggregation and toxicity of Aβ are strongly modulated by
metal ions and phospholipidic membranes. In particular, Cu2+ ions play a pivotal role in modulating Aβ aggregation. Although
in the last decades several natural or synthetic compounds were evaluated
as candidate drugs, to date, no treatments are available for the pathology.
Multifunctional compounds able to both inhibit fibrillogenesis, and
in particular the formation of oligomeric species, and prevent the
formation of the Aβ:Cu2+ complex are of particular
interest. Here we tested the anti-aggregating properties of a heptapeptide,
Semax, an ACTH-like peptide, which is known to form a stable complex
with Cu2+ ions and has been proven to have neuroprotective
and nootropic effects. We demonstrated through a combination of spectrofluorometric,
calorimetric, and MTT assays that Semax not only is able to prevent
the formation of Aβ:Cu2+ complexes but also has anti-aggregating
and protective properties especially in the presence of Cu2+. The results suggest that Semax inhibits fiber formation by interfering
with the fibrillogenesis of Aβ:Cu2+ complexes.
Collapse
Affiliation(s)
- Michele F.M. Sciacca
- Consiglio Nazionale delle Ricerche, Istituto di Cristallografia, Via Paolo Gaifami, 18, Catania 95126, Italy
| | - Irina Naletova
- Consiglio Nazionale delle Ricerche, Istituto di Cristallografia, Via Paolo Gaifami, 18, Catania 95126, Italy
| | - Maria Laura Giuffrida
- Consiglio Nazionale delle Ricerche, Istituto di Cristallografia, Via Paolo Gaifami, 18, Catania 95126, Italy
| | - Francesco Attanasio
- Consiglio Nazionale delle Ricerche, Istituto di Cristallografia, Via Paolo Gaifami, 18, Catania 95126, Italy
| |
Collapse
|
21
|
Lin Y, Gross ML. Mass Spectrometry-Based Structural Proteomics for Metal Ion/Protein Binding Studies. Biomolecules 2022; 12:135. [PMID: 35053283 PMCID: PMC8773722 DOI: 10.3390/biom12010135] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2021] [Revised: 01/13/2022] [Accepted: 01/13/2022] [Indexed: 01/01/2023] Open
Abstract
Metal ions are critical for the biological and physiological functions of many proteins. Mass spectrometry (MS)-based structural proteomics is an ever-growing field that has been adopted to study protein and metal ion interactions. Native MS offers information on metal binding and its stoichiometry. Footprinting approaches coupled with MS, including hydrogen/deuterium exchange (HDX), "fast photochemical oxidation of proteins" (FPOP) and targeted amino-acid labeling, identify binding sites and regions undergoing conformational changes. MS-based titration methods, including "protein-ligand interactions by mass spectrometry, titration and HD exchange" (PLIMSTEX) and "ligand titration, fast photochemical oxidation of proteins and mass spectrometry" (LITPOMS), afford binding stoichiometry, binding affinity, and binding order. These MS-based structural proteomics approaches, their applications to answer questions regarding metal ion protein interactions, their limitations, and recent and potential improvements are discussed here. This review serves as a demonstration of the capabilities of these tools and as an introduction to wider applications to solve other questions.
Collapse
Affiliation(s)
- Yanchun Lin
- Department of Chemistry, Washington University in St. Louis, St. Louis, MO 63130, USA
| | - Michael L Gross
- Department of Chemistry, Washington University in St. Louis, St. Louis, MO 63130, USA
| |
Collapse
|
22
|
Ng YK, Tajoddin NN, Scrosati PM, Konermann L. Mechanism of Thermal Protein Aggregation: Experiments and Molecular Dynamics Simulations on the High-Temperature Behavior of Myoglobin. J Phys Chem B 2021; 125:13099-13110. [PMID: 34808050 DOI: 10.1021/acs.jpcb.1c07210] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Proteins that encounter unfavorable solvent conditions are prone to aggregation, a phenomenon that remains poorly understood. This work focuses on myoglobin (Mb) as a model protein. Upon heating, Mb produces amorphous aggregates. Thermal unfolding experiments at low concentration (where aggregation is negligible), along with centrifugation assays, imply that Mb aggregation proceeds via globally unfolded conformers. This contrasts studies on other proteins that emphasized the role of partially folded structures as aggregate precursors. Molecular dynamics (MD) simulations were performed to gain insights into the mechanism by which heat-unfolded Mb molecules associate with one another. A prerequisite for these simulations was the development of a method for generating monomeric starting structures. Periodic boundary condition artifacts necessitated the implementation of a partially immobilized water layer lining the walls of the simulation box. Aggregation simulations were performed at 370 K to track the assembly of monomeric Mb into pentameric species. Binding events were preceded by multiple unsuccessful encounters. Even after association, protein-protein contacts remained in flux. Binding was mediated by hydrophobic contacts, along with salt bridges that involved hydrophobically embedded Lys residues. Overall, this work illustrates that atomistic MD simulations are well suited for garnering insights into protein aggregation mechanisms.
Collapse
Affiliation(s)
- Yuen Ki Ng
- Department of Chemistry, The University of Western Ontario, London, Ontario N6A 5B7, Canada
| | - Nastaran N Tajoddin
- Department of Chemistry, The University of Western Ontario, London, Ontario N6A 5B7, Canada
| | - Pablo M Scrosati
- Department of Chemistry, The University of Western Ontario, London, Ontario N6A 5B7, Canada
| | - Lars Konermann
- Department of Chemistry, The University of Western Ontario, London, Ontario N6A 5B7, Canada
| |
Collapse
|
23
|
Lambeth T, Julian RR. Proteolysis of Amyloid β by Lysosomal Enzymes as a Function of Fibril Morphology. ACS OMEGA 2021; 6:31520-31527. [PMID: 34869978 PMCID: PMC8637590 DOI: 10.1021/acsomega.1c03915] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/22/2021] [Accepted: 11/08/2021] [Indexed: 05/27/2023]
Abstract
Aggregation of amyloid-β (Aβ) into extracellular plaques is a well-known hallmark of Alzheimer's disease (AD). Similarly, autophagic vacuoles, autophagosomes, and other residual bodies within dystrophic neurites, though more difficult to detect, are characteristic features of AD. To explore the potential intersection between these observations, we conducted experiments to assess whether Aβ fibril formation disrupts proteolysis by lysosomal enzymes. Fibrils constituted by either Aβ 1-40 or Aβ 1-42 were grown under both neutral and acidic pH. The extent of proteolysis by individual cathepsins (L, D, B, and H) was monitored by both thioflavin T fluorescence and liquid chromatography combined with mass spectrometry. The results show that all Aβ fibril morphologies are resistant to cathepsin digestion, with significant amounts of the undigested material remaining for samples grown in either neutral or acidic pH. Further analysis revealed that the neutral-grown fibrils are proteolytically resistant throughout the sequence, while the acid-grown fibrils prevented digestion primarily in the C-terminal portion of the sequence. Fibrils grown from Aβ 1-42 are generally more resistant to degradation compared to Aβ 1-40. Overall, the results indicate that Aβ fibrils formed in the neutral pH environments found in intracellular or extracellular spaces may pose the greatest difficulty for complete digestion by the lysosome, particularly when the fibrils are comprised of Aβ 1-42.
Collapse
|
24
|
Matuszyk MM, Garwood CJ, Ferraiuolo L, Simpson JE, Staniforth RA, Wharton SB. Biological and methodological complexities of beta-amyloid peptide: Implications for Alzheimer's disease research. J Neurochem 2021; 160:434-453. [PMID: 34767256 DOI: 10.1111/jnc.15538] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Revised: 10/29/2021] [Accepted: 11/09/2021] [Indexed: 01/01/2023]
Abstract
Although controversial, the amyloid cascade hypothesis remains central to the Alzheimer's disease (AD) field and posits amyloid-beta (Aβ) as the central factor initiating disease onset. In recent years, there has been an increase in emphasis on studying the role of low molecular weight aggregates, such as oligomers, which are suggested to be more neurotoxic than fibrillary Aβ. Other Aβ isoforms, such as truncated Aβ, have also been implicated in disease. However, developing a clear understanding of AD pathogenesis has been hampered by the complexity of Aβ biochemistry in vitro and in vivo. This review explores factors contributing to the lack of consistency in experimental approaches taken to model Aβ aggregation and toxicity and provides an overview of the different techniques available to analyse Aβ, such as electron and atomic force microscopy, nuclear magnetic resonance spectroscopy, dye-based assays, size exclusion chromatography, mass spectrometry and SDS-PAGE. The review also explores how different types of Aβ can influence Aβ aggregation and toxicity, leading to variation in experimental outcomes, further highlighting the need for standardisation in Aβ preparations and methods used in current research.
Collapse
Affiliation(s)
- Martyna M Matuszyk
- Sheffield Institute for Translational Neuroscience, University of Sheffield, Sheffield, UK
| | - Claire J Garwood
- Sheffield Institute for Translational Neuroscience, University of Sheffield, Sheffield, UK
| | - Laura Ferraiuolo
- Sheffield Institute for Translational Neuroscience, University of Sheffield, Sheffield, UK
| | - Julie E Simpson
- Sheffield Institute for Translational Neuroscience, University of Sheffield, Sheffield, UK
| | | | - Stephen B Wharton
- Sheffield Institute for Translational Neuroscience, University of Sheffield, Sheffield, UK
| |
Collapse
|
25
|
Illes-Toth E, Meisl G, Rempel DL, Knowles TPJ, Gross ML. Pulsed Hydrogen-Deuterium Exchange Reveals Altered Structures and Mechanisms in the Aggregation of Familial Alzheimer's Disease Mutants. ACS Chem Neurosci 2021; 12:1972-1982. [PMID: 33988976 DOI: 10.1021/acschemneuro.1c00072] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Mutations of the Amyloid Precursor Protein, from which the amyloid β peptide Aβ42 is cleaved, are associated with familial Alzheimer's disease. The disease-relevant familial mutations include the Arctic (E22G), Iowa (D23N), Italian (E22K), Dutch (E22Q), Japanese (D7N), English (D6R), and Flemish (A21G) variants. A detailed mechanistic understanding of the aggregation behavior of the mutant peptides at the residue level is, however, still lacking. We report here a study of the aggregation kinetics of these mutants in vitro by pulsed hydrogen-deuterium exchange mass spectrometry (HDX-MS) to obtain a temporally and sequence resolved picture of their self-assembly. For all variants, HDX occurs to give a bimodal distribution representing two soluble classes of aggregates, one protected and one solvent-exposed. There is no evidence of other classes of structural intermediates within the detection limits of the HDX approach. The fractional changes in the bimodal exchange profiles for several regions of Aβ42 reveal that the central and C-terminal peptides gain protection upon fibril formation, whereas the N-terminal regions remain largely solvent-accessible. For these mutants, all peptide fragments follow the same kinetics, acquiring solvent protection at the same time, further supporting that there are no significant populations of intermediate species under our experimental conditions. The results demonstrate the potential of pulsed HDX-MS for resolving the region-specific aggregation behavior of Aβ42 isoforms in solution where X-ray crystallography and solid-state NMR (ssNMR) are challenged.
Collapse
Affiliation(s)
- Eva Illes-Toth
- Washington University in St. Louis, Department of Chemistry, St. Louis, Missouri 63130, United States
| | - Georg Meisl
- University of Cambridge, Department of Chemistry, Lensfield Road, Cambridge CB2 1EW, UK
| | - Don L. Rempel
- Washington University in St. Louis, Department of Chemistry, St. Louis, Missouri 63130, United States
| | - Tuomas P. J. Knowles
- University of Cambridge, Department of Chemistry, Lensfield Road, Cambridge CB2 1EW, UK
| | - Michael L. Gross
- Washington University in St. Louis, Department of Chemistry, St. Louis, Missouri 63130, United States
| |
Collapse
|
26
|
Lu J, Lu Z, Liu L, Li X, Yu W, Lu X. Identification of Crocin as a New hIAPP Amyloid Inhibitor via a Simple Yet Highly Biospecific Screening System. Chem Biodivers 2021; 18:e2100270. [PMID: 33890414 DOI: 10.1002/cbdv.202100270] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2021] [Accepted: 04/20/2021] [Indexed: 11/07/2022]
Abstract
Amylin (hIAPP) amyloid formation plays an important role in the pathogenesis of type 2 diabetes (T2D), which makes it a promising therapeutic target for T2D. In this study, we established a screening tool for identifying chemicals affecting hIAPP amyloid formation based on a reported genetic tool, which constantly tracks protein aggregates in Saccharomyces cerevisiae. In order to obtain the hIAPP with better aggregation ability, the gene of hIAPP was tandemly ligated to create 1×, 2×, 4× or 6×-hIAPP expressing strains. By measuring the cell density and fluorescence intensity of green fluorescent protein (GFP) regulated by the aggregation status of hIAPP, it was found that four intramolecular ligated hIAPP (4×hIAPP) could form obvious amyloids with mild toxicity. The validity and reliability of the screening tool were verified by testing six reported hIAPP inhibitors, including curcumin, epigallocatechin gallate and so on. Combined with surface plasmon resonance (SPR) and the screening tool, which could be a screening system for hIAPP inhibitors, we found that crocin specifically binds to hIAPP and acts inhibit amyloid formation of hIAPP. The effect of crocin was further confirmed by Thioflavin T (ThT) fluorescence and transmission electron microscopy (TEM) analysis. Thus, a screening system for hIAPP amyloid inhibitors and a new mechanism of crocin on anti-T2D were obtained as a result of this study.
Collapse
Affiliation(s)
- Jingxuan Lu
- Key Laboratory of Marine Drugs, Ministry of Education, School of Medicine and Pharmacy, Ocean University of China, Qingdao, 266003, P. R. China
| | - Zhongxia Lu
- Key Laboratory of Marine Drugs, Ministry of Education, School of Medicine and Pharmacy, Ocean University of China, Qingdao, 266003, P. R. China
| | - Luxin Liu
- Key Laboratory of Marine Drugs, Ministry of Education, School of Medicine and Pharmacy, Ocean University of China, Qingdao, 266003, P. R. China
| | - Xinyu Li
- Key Laboratory of Marine Drugs, Ministry of Education, School of Medicine and Pharmacy, Ocean University of China, Qingdao, 266003, P. R. China
| | - Wengong Yu
- Key Laboratory of Marine Drugs, Ministry of Education, School of Medicine and Pharmacy, Ocean University of China, Qingdao, 266003, P. R. China
- Laboratory for Marine Drugs and Bioproducts of Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266003, P. R. China
| | - Xinzhi Lu
- Key Laboratory of Marine Drugs, Ministry of Education, School of Medicine and Pharmacy, Ocean University of China, Qingdao, 266003, P. R. China
| |
Collapse
|
27
|
McKenzie-Coe A, Shortt R, Jones LM. THE MAKING OF A FOOTPRINT IN PROTEIN FOOTPRINTING: A REVIEW IN HONOR OF MICHAEL L. GROSS. MASS SPECTROMETRY REVIEWS 2021; 40:177-200. [PMID: 32400038 PMCID: PMC7849054 DOI: 10.1002/mas.21632] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/18/2020] [Revised: 04/17/2020] [Accepted: 04/23/2020] [Indexed: 06/11/2023]
Abstract
Within the past decade protein footprinting in conjunction with mass spectrometry has become a powerful and versatile means to unravel the higher order structure of proteins. Footprinting-based approaches has demonstrated the capacity to inform on interaction sites and dynamic regions that participate in conformational changes. These findings when set in a biological perspective inform on protein folding/unfolding, protein-protein interactions, and protein-ligand interactions. In this review, we will look at the contribution of Dr. Michael L. Gross to protein footprinting approaches such as hydrogen deuterium exchange mass spectrometry and hydroxyl radical protein footprinting. This review details the development of novel footprinting methods as well as their applications to study higher order protein structure. © 2020 The Authors. Mass Spectrometry Reviews published by John Wiley & Sons Ltd. Mass Spec Rev.
Collapse
Affiliation(s)
- Alan McKenzie-Coe
- Department of Pharmaceutical Sciences, University of Maryland Baltimore, Baltimore, Maryland, 21201
| | - Raquel Shortt
- Department of Pharmaceutical Sciences, University of Maryland Baltimore, Baltimore, Maryland, 21201
| | - Lisa M Jones
- Department of Pharmaceutical Sciences, University of Maryland Baltimore, Baltimore, Maryland, 21201
| |
Collapse
|
28
|
Beveridge R, Calabrese AN. Structural Proteomics Methods to Interrogate the Conformations and Dynamics of Intrinsically Disordered Proteins. Front Chem 2021; 9:603639. [PMID: 33791275 PMCID: PMC8006314 DOI: 10.3389/fchem.2021.603639] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2020] [Accepted: 01/19/2021] [Indexed: 12/21/2022] Open
Abstract
Intrinsically disordered proteins (IDPs) and regions of intrinsic disorder (IDRs) are abundant in proteomes and are essential for many biological processes. Thus, they are often implicated in disease mechanisms, including neurodegeneration and cancer. The flexible nature of IDPs and IDRs provides many advantages, including (but not limited to) overcoming steric restrictions in binding, facilitating posttranslational modifications, and achieving high binding specificity with low affinity. IDPs adopt a heterogeneous structural ensemble, in contrast to typical folded proteins, making it challenging to interrogate their structure using conventional tools. Structural mass spectrometry (MS) methods are playing an increasingly important role in characterizing the structure and function of IDPs and IDRs, enabled by advances in the design of instrumentation and the development of new workflows, including in native MS, ion mobility MS, top-down MS, hydrogen-deuterium exchange MS, crosslinking MS, and covalent labeling. Here, we describe the advantages of these methods that make them ideal to study IDPs and highlight recent applications where these tools have underpinned new insights into IDP structure and function that would be difficult to elucidate using other methods.
Collapse
Affiliation(s)
- Rebecca Beveridge
- Department of Pure and Applied Chemistry, University of Strathclyde, Glasgow, United Kingdom
| | - Antonio N. Calabrese
- Astbury Centre for Structural Molecular Biology, School of Molecular and Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds, United Kingdom
| |
Collapse
|
29
|
Noor A, Zafar S, Zerr I. Neurodegenerative Proteinopathies in the Proteoform Spectrum-Tools and Challenges. Int J Mol Sci 2021; 22:1085. [PMID: 33499319 PMCID: PMC7865347 DOI: 10.3390/ijms22031085] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2020] [Revised: 01/18/2021] [Accepted: 01/19/2021] [Indexed: 12/11/2022] Open
Abstract
Proteinopathy refers to a group of disorders defined by depositions of amyloids within living tissue. Neurodegenerative proteinopathies, including Alzheimer's disease, Parkinson's disease, Creutzfeldt-Jakob disease, and others, constitute a large fraction of these disorders. Amyloids are highly insoluble, ordered, stable, beta-sheet rich proteins. The emerging theory about the pathophysiology of neurodegenerative proteinopathies suggests that the primary amyloid-forming proteins, also known as the prion-like proteins, may exist as multiple proteoforms that contribute differentially towards the disease prognosis. It is therefore necessary to resolve these disorders on the level of proteoforms rather than the proteome. The transient and hydrophobic nature of amyloid-forming proteins and the minor post-translational alterations that lead to the formation of proteoforms require the use of highly sensitive and specialized techniques. Several conventional techniques, like gel electrophoresis and conventional mass spectrometry, have been modified to accommodate the proteoform theory and prion-like proteins. Several new ones, like imaging mass spectrometry, have also emerged. This review aims to discuss the proteoform theory of neurodegenerative disorders along with the utility of these proteomic techniques for the study of highly insoluble proteins and their associated proteoforms.
Collapse
Affiliation(s)
- Aneeqa Noor
- Department of Neurology, University Medical Center Göttingen, 37075 Göttingen, Germany; (A.N.); (I.Z.)
- German Center for Neurodegenerative Diseases (DZNE), 37075 Göttingen, Germany
| | - Saima Zafar
- Department of Neurology, University Medical Center Göttingen, 37075 Göttingen, Germany; (A.N.); (I.Z.)
- German Center for Neurodegenerative Diseases (DZNE), 37075 Göttingen, Germany
- Biomedical Engineering and Sciences Department, School of Mechanical and Manufacturing Engineering (SMME), National University of Sciences and Technology (NUST), Bolan Road, H-12, 44000 Islamabad, Pakistan
| | - Inga Zerr
- Department of Neurology, University Medical Center Göttingen, 37075 Göttingen, Germany; (A.N.); (I.Z.)
- German Center for Neurodegenerative Diseases (DZNE), 37075 Göttingen, Germany
| |
Collapse
|
30
|
The Aggregation Pattern of Aβ
1–40
is Altered by the Presence of
N
‐Truncated Aβ
4–40
and/or Cu
II
in a Similar Way through Ionic Interactions. Chemistry 2021; 27:2798-2809. [DOI: 10.1002/chem.202004484] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2020] [Indexed: 12/19/2022]
|
31
|
Cawood EE, Karamanos TK, Wilson AJ, Radford SE. Visualizing and trapping transient oligomers in amyloid assembly pathways. Biophys Chem 2021; 268:106505. [PMID: 33220582 PMCID: PMC8188297 DOI: 10.1016/j.bpc.2020.106505] [Citation(s) in RCA: 81] [Impact Index Per Article: 27.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2020] [Revised: 10/29/2020] [Accepted: 11/01/2020] [Indexed: 12/31/2022]
Abstract
Oligomers which form during amyloid fibril assembly are considered to be key contributors towards amyloid disease. However, understanding how such intermediates form, their structure, and mechanisms of toxicity presents significant challenges due to their transient and heterogeneous nature. Here, we discuss two different strategies for addressing these challenges: use of (1) methods capable of detecting lowly-populated species within complex mixtures, such as NMR, single particle methods (including fluorescence and force spectroscopy), and mass spectrometry; and (2) chemical and biological tools to bias the amyloid energy landscape towards specific oligomeric states. While the former methods are well suited to following the kinetics of amyloid assembly and obtaining low-resolution structural information, the latter are capable of producing oligomer samples for high-resolution structural studies and inferring structure-toxicity relationships. Together, these different approaches should enable a clearer picture to be gained of the nature and role of oligomeric intermediates in amyloid formation and disease.
Collapse
Affiliation(s)
- Emma E Cawood
- Astbury Centre for Structural Molecular Biology, School of Chemistry, University of Leeds, LS2 9JT, UK; Astbury Centre for Structural Molecular Biology, School of Molecular and Cellular Biology, University of Leeds, LS2 9JT, UK
| | - Theodoros K Karamanos
- Astbury Centre for Structural Molecular Biology, School of Molecular and Cellular Biology, University of Leeds, LS2 9JT, UK; Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Andrew J Wilson
- Astbury Centre for Structural Molecular Biology, School of Chemistry, University of Leeds, LS2 9JT, UK.
| | - Sheena E Radford
- Astbury Centre for Structural Molecular Biology, School of Molecular and Cellular Biology, University of Leeds, LS2 9JT, UK.
| |
Collapse
|
32
|
Renawala HK, Chandrababu KB, Topp EM. Fibrillation of Human Calcitonin and Its Analogs: Effects of Phosphorylation and Disulfide Reduction. Biophys J 2020; 120:86-100. [PMID: 33220304 DOI: 10.1016/j.bpj.2020.11.009] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2020] [Revised: 10/24/2020] [Accepted: 11/10/2020] [Indexed: 11/16/2022] Open
Abstract
Some therapeutic peptides self-assemble in solution to form ordered, insoluble, β-sheet-rich amyloid fibrils. This physical instability can result in reduced potency, cause immunogenic side effects, and limit options for formulation. Understanding the mechanisms of fibrillation is key to developing rational mitigation strategies. Here, amide hydrogen-deuterium exchange with mass spectrometric analysis (HDX-MS) coupled with proteolytic digestion was used to identify the early stage interactions leading to fibrillation of human calcitonin (hCT), a peptide hormone important in calcium metabolism. hCT fibrillation kinetics was sigmoidal, with lag, growth, and plateau phases as shown by thioflavin T and turbidity measurements. HDX-MS of fibrillating hCT (pH 7.4; 25°C) suggested early involvement of the N-terminal (1-11) and central (12-19) fragments in interactions during the lag phase, whereas C-terminal fragments (20-32 and 26-32) showed limited involvement during this period. The residue-level information was used to develop phosphorylated hCT analogs that showed modified fibrillation that depended on phosphorylation site. Phosphorylation in the central region resulted in complete inhibition of fibrillation for the phospho-Thr-13 hCT analog, whereas phosphorylation in the N-terminal and C-terminal regions inhibited but did not prevent fibrillation. Reduction of the Cys1-Cys7 disulfide bond resulted in faster fibrillation with involvement of different hCT residues as indicated by pulsed HDX-MS. Together, the results demonstrate that small structural changes have significant effects on hCT fibrillation and that understanding these effects can inform the rational development of fibrillation-resistant hCT analogs.
Collapse
Affiliation(s)
- Harshil K Renawala
- Department of Industrial and Physical Pharmacy, College of Pharmacy, Purdue University, West Lafayette, Indiana
| | - Karthik B Chandrababu
- Department of Industrial and Physical Pharmacy, College of Pharmacy, Purdue University, West Lafayette, Indiana
| | - Elizabeth M Topp
- Department of Industrial and Physical Pharmacy, College of Pharmacy, Purdue University, West Lafayette, Indiana; National Institute for Bioprocessing Research and Training, Dublin, Ireland.
| |
Collapse
|
33
|
Niu B, Mackness BC, Zitzewitz JA, Matthews CR, Gross ML. Trifluoroethanol Partially Unfolds G93A SOD1 Leading to Protein Aggregation: A Study by Native Mass Spectrometry and FPOP Protein Footprinting. Biochemistry 2020; 59:3650-3659. [PMID: 32924445 DOI: 10.1021/acs.biochem.0c00425] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Misfolding of Cu, Zn superoxide dismutase (SOD1) variants may lead to protein aggregation and ultimately amyotrophic lateral sclerosis (ALS). The mechanism and protein conformational changes during this process are complex and remain unclear. To study SOD1 variant aggregation at the molecular level and in solution, we chemically induced aggregation of a mutant variant (G93A SOD1) with trifluoroethanol (TFE) and used both native mass spectrometry (MS) to analyze the intact protein and fast photochemical oxidation of proteins (FPOP) to characterize the structural changes induced by TFE. We found partially unfolded G93A SOD1 monomers prior to oligomerization and identified regions of the N-terminus, C-terminus, and strands β5, β6 accountable for the partial unfolding. We propose that exposure of hydrophobic interfaces of these unstructured regions serves as a precursor to aggregation. Our results provide a possible mechanism and molecular basis for ALS-linked SOD1 misfolding and aggregation.
Collapse
Affiliation(s)
- Ben Niu
- Department of Chemistry, Washington University in St. Louis, St. Louis, Missouri 63130, United States
| | - Brian C Mackness
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, Massachusetts 01655, United States
| | - Jill A Zitzewitz
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, Massachusetts 01655, United States
| | - C Robert Matthews
- Department of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, Massachusetts 01655, United States
| | - Michael L Gross
- Department of Chemistry, Washington University in St. Louis, St. Louis, Missouri 63130, United States
| |
Collapse
|
34
|
Sun L, Sharma AK, Han BH, Mirica LM. Amentoflavone: A Bifunctional Metal Chelator that Controls the Formation of Neurotoxic Soluble Aβ 42 Oligomers. ACS Chem Neurosci 2020; 11:2741-2752. [PMID: 32786307 DOI: 10.1021/acschemneuro.0c00376] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Alzheimer's disease (AD) is the most common neurodegenerative disorder, yet the cause and progression of this disorder are not completely understood. While the main hallmark of AD is the deposition of amyloid plaques consisting of the β-amyloid (Aβ) peptide, transition metal ions are also known to play a significant role in disease pathology by expediting the formation of neurotoxic soluble β-amyloid (Aβ) oligomers, reactive oxygen species (ROS), and oxidative stress. Thus, bifunctional metal chelators that can control these deleterious properties are highly desirable. Herein, we show that amentoflavone (AMF), a natural biflavonoid compound, exhibits good metal-chelating properties, especially for chelating Cu2+ with very high affinity (pCu7.4 = 10.44). In addition, AMF binds to Aβ fibrils with a high affinity (Ki = 287 ± 20 nM), as revealed by a competition thioflavin T (ThT) assay, and specifically labels the amyloid plaques ex vivo in the brain sections of transgenic AD mice, as confirmed via immunostaining with an Aβ antibody. The effect of AMF on Aβ42 aggregation and disaggregation of Aβ42 fibrils was also investigated and revealed that AMF can control the formation of neurotoxic soluble Aβ42 oligomers, both in the absence and presence of metal ions, as confirmed via cell toxicity studies. Furthermore, an ascorbate consumption assay shows that AMF exhibits potent antioxidant properties and can chelate Cu2+ and significantly diminish the Cu2+-ascorbate redox cycling and reactive oxygen species (ROS) formation. Overall, these studies strongly suggest that AMF acts as a bifunctional chelator that can interact with various Aβ aggregates and reduce their neurotoxicity and can also bind Cu2+ and mediate its deleterious redox properties. Thus AMF has the potential to be a lead compound for further therapeutic agent development for AD.
Collapse
Affiliation(s)
- Liang Sun
- Department of Chemistry, University of Illinois at Urbana−Champaign, 600 S. Mathews Avenue, Urbana, Illinois 61801, United States
| | - Anuj K. Sharma
- Department of Chemistry, Central University of Rajasthan, Bandarsindari, Distt. Ajmer-305801, Rajasthan, India
| | - Byung-Hee Han
- Department of Pharmacology, A.T. Still University of Health Sciences, Kirksville, Missouri 63501, United States
| | - Liviu M. Mirica
- Department of Chemistry, University of Illinois at Urbana−Champaign, 600 S. Mathews Avenue, Urbana, Illinois 61801, United States
- Hope Center for Neurological Disorders, Washington University School of Medicine, St. Louis, Missouri 63110, United States
| |
Collapse
|
35
|
Palla G, Malecka K, Dehaen W, Radecki J, Radecka H. Immunosensor incorporating half-antibody fragment for electrochemical monitoring of amyloid-β fibrils in artificial blood plasma. Bioelectrochemistry 2020; 137:107643. [PMID: 32891964 DOI: 10.1016/j.bioelechem.2020.107643] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2020] [Revised: 08/25/2020] [Accepted: 08/25/2020] [Indexed: 02/06/2023]
Abstract
In this report, an electrochemical immunosensor for the selective and sensitive monitoring of Aβ1-42 fibrils is presented. The sensing platform was prepared by the formation of a 4,4'-thiobisbenzenethiol (TBBT) self-assembled monolayer on a clean gold surface followed by the covalent entrapment of gold nanoparticles (AuNPs). The half-antibody fragments of the Anti-Amyloid Fibrils antibody were immobilized on AuNPs via S-Au covalent bonds. Each step of immunosensor fabrication was characterized with cyclic voltammetry and electrochemical impedance spectroscopy. The biosensor was successfully used for the sensing of Aβ1-42 fibrils in both phosphate saline buffer (PBS) and artificial blood plasma (ABP). The immunosensor sensitivity estimated based on calibration slopes was better in the presence of APP in the comparison to PBS. The LOD values obtained for both measuring media were of 0.6 pM level. The moderate response towards Aβ1-42 oligomers demonstrated the immunosensor selectivity.
Collapse
Affiliation(s)
- Gopal Palla
- Institute of Animal Reproduction and Food Research, Polish Academy of Sciences, Tuwima Str. 10, 10-748 Olsztyn, Poland
| | - Kamila Malecka
- Institute of Animal Reproduction and Food Research, Polish Academy of Sciences, Tuwima Str. 10, 10-748 Olsztyn, Poland
| | - Wim Dehaen
- University of Leuven, Department of Chemistry, Celestijnenlaan 200f - box 2404, 3001 Leuven, Belgium
| | - Jerzy Radecki
- Institute of Animal Reproduction and Food Research, Polish Academy of Sciences, Tuwima Str. 10, 10-748 Olsztyn, Poland
| | - Hanna Radecka
- Institute of Animal Reproduction and Food Research, Polish Academy of Sciences, Tuwima Str. 10, 10-748 Olsztyn, Poland.
| |
Collapse
|
36
|
Collagen hydrogel confinement of Amyloid-β (Aβ) accelerates aggregation and reduces cytotoxic effects. Acta Biomater 2020; 112:164-173. [PMID: 32464268 DOI: 10.1016/j.actbio.2020.05.030] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2019] [Revised: 05/18/2020] [Accepted: 05/19/2020] [Indexed: 01/09/2023]
Abstract
Alzheimer's disease (AD) is the most common form of dementia and is associated with the accumulation of amyloid-β (Aβ), a peptide whose aggregation has been associated with neurotoxicity. Drugs targeting Aβ have shown great promise in 2D in vitro models and mouse models, yet preclinical and clinical trials for AD have been highly disappointing. We propose that current in vitro culture systems for discovering and developing AD drugs have significant limitations; specifically, that Aβ aggregation is vastly different in these 2D cultures carried out on flat plastic or glass substrates vs. in a 3D environment, such as brain tissue, where Aβ confinement alters aggregation kinetics and thermodynamics. In this work, we identified attenuation of Aβ cytotoxicity in 3D hydrogel culture compared to 2D cell culture. We investigated Aβ structure and aggregation in solution vs. hydrogel using Transmission Electron Microscopy (TEM), Fluorescence Correlation Spectroscopy (FCS), and Thioflavin T (ThT) assays. Our results reveal that the equilibrium is shifted to stable extended β-sheet (ThT positive) aggregates in hydrogels and away from the relatively unstable/unstructured presumed toxic oligomeric Aβ species in solution. Volume exclusion imparted by hydrogel confinement stabilizes unfolded, presumably toxic species, promoting stable extended β-sheet fibrils. STATEMENT OF SIGNIFICANCE: Alzheimer's disease (AD) is a devastating disease and has been studied for over 100 years. Yet, no cure exists and only 5 prescription drugs are FDA-approved to temporarily treat the AD symptoms of declining brain functions related to thinking and memory. Why don't we have more effective treatments to cure AD or relieve AD symptoms? We propose that current culture methods based upon cells cultured on flat, stiff substrates have significant limitations for discovering and developing AD drugs. This study provides strong evidence that AD drugs should be tested in 3D culture systems as a step along the development pathway towards new, more effective drugs to treat AD.
Collapse
|
37
|
Huang Y, Cho HJ, Bandara N, Sun L, Tran D, Rogers BE, Mirica LM. Metal-chelating benzothiazole multifunctional compounds for the modulation and 64Cu PET imaging of Aβ aggregation. Chem Sci 2020; 11:7789-7799. [PMID: 34094152 PMCID: PMC8163150 DOI: 10.1039/d0sc02641g] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Accepted: 07/07/2020] [Indexed: 12/14/2022] Open
Abstract
While Alzheimer's Disease (AD) is the most common neurodegenerative disease, there is still a dearth of efficient therapeutic and diagnostic agents for this disorder. Reported herein are a series of new multifunctional compounds (MFCs) with appreciable affinity for amyloid aggregates that can be potentially used for both the modulation of Aβ aggregation and its toxicity, as well as positron emission tomography (PET) imaging of Aβ aggregates. Firstly, among the six compounds tested HYR-16 is shown to be capable to reroute the toxic Cu-mediated Aβ oligomerization into the formation of less toxic amyloid fibrils. In addition, HYR-16 can also alleviate the formation of reactive oxygen species (ROS) caused by Cu2+ ions through Fenton-like reactions. Secondly, these MFCs can be easily converted to PET imaging agents by pre-chelation with the 64Cu radioisotope, and the Cu complexes of HYR-4 and HYR-17 exhibit good fluorescent staining and radiolabeling of amyloid plaques both in vitro and ex vivo. Importantly, the 64Cu-labeled HYR-17 is shown to have a significant brain uptake of up to 0.99 ± 0.04 %ID per g. Overall, by evaluating the various properties of these MFCs valuable structure-activity relationships were obtained that should aid the design of improved therapeutic and diagnostic agents for AD.
Collapse
Affiliation(s)
- Yiran Huang
- Department of Chemistry, University of Illinois at Urbana-Champaign 600 S. Mathews Avenue Urbana Illinois 61801 USA
| | - Hong-Jun Cho
- Department of Chemistry, University of Illinois at Urbana-Champaign 600 S. Mathews Avenue Urbana Illinois 61801 USA
| | - Nilantha Bandara
- Department of Radiation Oncology, Washington University School of Medicine St. Louis Missouri 63108 USA
| | - Liang Sun
- Department of Chemistry, University of Illinois at Urbana-Champaign 600 S. Mathews Avenue Urbana Illinois 61801 USA
| | - Diana Tran
- Department of Radiation Oncology, Washington University School of Medicine St. Louis Missouri 63108 USA
| | - Buck E Rogers
- Department of Radiation Oncology, Washington University School of Medicine St. Louis Missouri 63108 USA
| | - Liviu M Mirica
- Department of Chemistry, University of Illinois at Urbana-Champaign 600 S. Mathews Avenue Urbana Illinois 61801 USA
- Hope Center for Neurological Disorders, Washington University School of Medicine St. Louis MO 63110 USA
| |
Collapse
|
38
|
Espino JA, Zhang Z, Jones LM. Chemical Penetration Enhancers Increase Hydrogen Peroxide Uptake in C. elegans for In Vivo Fast Photochemical Oxidation of Proteins. J Proteome Res 2020; 19:3708-3715. [PMID: 32506919 PMCID: PMC7861136 DOI: 10.1021/acs.jproteome.0c00245] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
![]()
Fast photochemical oxidation of proteins (FPOP) is a hydroxyl radical protein
footprinting method that covalently labels solvent-accessible amino acids by photolysis
of hydrogen peroxide. Recently, we expanded the use of FPOP for in vivo
(IV-FPOP) covalent labeling in C. elegans. In initial IV-FPOP studies,
545 proteins were oxidatively modified in all body systems within the worm. Here, with
the use of chemical penetration enhancers (CPEs), we increased the number of modified
proteins as well as the number of modifications per protein to gain more structural
information. CPEs aid in the delivery of hydrogen peroxide inside C.
elegans by disturbing the highly ordered lipid bilayer of the worm cuticle
without affecting worm viability. IV-FPOP experiments performed using the CPE azone
showed an increase in oxidatively modified proteins and peptides. This increase
correlated with greater hydrogen peroxide uptake by C. elegans
quantified using a chemical fluorophore demonstrating the efficacy of using CPEs with
IV-FPOP. Mass spectrometry proteomics data are available via ProteomeXchange with
identifier PXD019290.
Collapse
Affiliation(s)
- Jessica A Espino
- Department of Pharmaceutical Sciences, University of Maryland, Baltimore, Maryland 21202, United States
| | - Zhihui Zhang
- Department of Pharmaceutical Sciences, University of Maryland, Baltimore, Maryland 21202, United States
| | - Lisa M Jones
- Department of Pharmaceutical Sciences, University of Maryland, Baltimore, Maryland 21202, United States
| |
Collapse
|
39
|
Liu XR, Zhang MM, Gross ML. Mass Spectrometry-Based Protein Footprinting for Higher-Order Structure Analysis: Fundamentals and Applications. Chem Rev 2020; 120:4355-4454. [PMID: 32319757 PMCID: PMC7531764 DOI: 10.1021/acs.chemrev.9b00815] [Citation(s) in RCA: 130] [Impact Index Per Article: 32.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Proteins adopt different higher-order structures (HOS) to enable their unique biological functions. Understanding the complexities of protein higher-order structures and dynamics requires integrated approaches, where mass spectrometry (MS) is now positioned to play a key role. One of those approaches is protein footprinting. Although the initial demonstration of footprinting was for the HOS determination of protein/nucleic acid binding, the concept was later adapted to MS-based protein HOS analysis, through which different covalent labeling approaches "mark" the solvent accessible surface area (SASA) of proteins to reflect protein HOS. Hydrogen-deuterium exchange (HDX), where deuterium in D2O replaces hydrogen of the backbone amides, is the most common example of footprinting. Its advantage is that the footprint reflects SASA and hydrogen bonding, whereas one drawback is the labeling is reversible. Another example of footprinting is slow irreversible labeling of functional groups on amino acid side chains by targeted reagents with high specificity, probing structural changes at selected sites. A third footprinting approach is by reactions with fast, irreversible labeling species that are highly reactive and footprint broadly several amino acid residue side chains on the time scale of submilliseconds. All of these covalent labeling approaches combine to constitute a problem-solving toolbox that enables mass spectrometry as a valuable tool for HOS elucidation. As there has been a growing need for MS-based protein footprinting in both academia and industry owing to its high throughput capability, prompt availability, and high spatial resolution, we present a summary of the history, descriptions, principles, mechanisms, and applications of these covalent labeling approaches. Moreover, their applications are highlighted according to the biological questions they can answer. This review is intended as a tutorial for MS-based protein HOS elucidation and as a reference for investigators seeking a MS-based tool to address structural questions in protein science.
Collapse
Affiliation(s)
| | | | - Michael L. Gross
- Department of Chemistry, Washington University in St. Louis, St. Louis, MO, USA, 63130
| |
Collapse
|
40
|
Cho HJ, Sharma AK, Zhang Y, Gross ML, Mirica LM. A Multifunctional Chemical Agent as an Attenuator of Amyloid Burden and Neuroinflammation in Alzheimer's Disease. ACS Chem Neurosci 2020; 11:1471-1481. [PMID: 32310630 PMCID: PMC7732605 DOI: 10.1021/acschemneuro.0c00114] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Alzheimer's disease (AD) is the most common neurodegenerative disease, and its main hallmark is the deposition of amyloid beta (Aβ) peptides. However, several clinical trials focusing on Aβ-targeting agents have failed recently, and thus new therapeutic leads are focusing on alternate targets such as tau protein pathology, Aβ-metal induced oxidative stress, and neuroinflammation. To address these different pathological aspects of AD, we have employed a multifunctional compound, L1 [4-(benzo[d]thiazol-2-yl)-2-((4,7-dimethyl-1,4,7-triazonan-1-yl)methyl)-6-methoxyphenol], that integrates Aβ-interacting and metal-binding fragments in a single molecular framework, exhibits significant antioxidant activity and metal chelating ability, and also rescues neuroblastoma N2A cells from Cu2+-induced Aβ neurotoxicity. Along with demonstrating in vivo Aβ-binding and favorable brain uptake properties, L1 treatment of transgenic 5xFAD mice significantly reduces the amount of both amyloid plaques and associated phosphorylated tau (p-tau) aggregates in the brain by 40-50% versus the vehicle-treated 5xFAD mice. Moreover, L1 mitigates the neuroinflammatory response of the activated microglia during the Aβ-induced inflammation process. Overall, these multifunctional properties of L1 to attenuate the formation of amyloid plaques and associated p-tau aggregates while also reducing the microglia-mediated neuroinflammatory response are quite uncommon among the previously reported amyloid-targeting chemical agents, and thus L1 could be envisioned as a lead compound for the development of novel AD therapeutics.
Collapse
Affiliation(s)
- Hong-Jun Cho
- Department of Chemistry, University of Illinois at Urbana-Champaign, 600 S. Mathews Avenue, Urbana, Illinois 61801, United States
| | - Anuj K Sharma
- Department of Chemistry, Central University of Rajasthan, NH-8, Bandarsindri, Ajmer, Rajasthan 305817, India
| | - Ying Zhang
- Department of Chemistry, Washington University, One Brookings Drive, St. Louis, Missouri 63130, United States
| | - Michael L Gross
- Department of Chemistry, Washington University, One Brookings Drive, St. Louis, Missouri 63130, United States
| | - Liviu M Mirica
- Department of Chemistry, University of Illinois at Urbana-Champaign, 600 S. Mathews Avenue, Urbana, Illinois 61801, United States
- Hope Center for Neurological Disorders, Washington University School of Medicine, St. Louis, Missouri 63110, United States
| |
Collapse
|
41
|
Hu J, Zheng Q. Applications of Mass Spectrometry in the Onset of Amyloid Fibril Formation: Focus on the Analysis of Early-Stage Oligomers. Front Chem 2020; 8:324. [PMID: 32432078 PMCID: PMC7215083 DOI: 10.3389/fchem.2020.00324] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2019] [Accepted: 03/30/2020] [Indexed: 02/05/2023] Open
Abstract
Amyloid fibril formation is a hallmark of diverse neurodegenerative and metabolic diseases, such as Alzheimer's disease (AD), Parkinson's disease (PD), and type 2 diabetes mellitus (T2DM). Conventional diagnosis is based on the appearance of fibrils or plaques, while neglects the role of early-stage oligomers in the disease progression. Recent studies have uncovered that it is the early-stage oligomer, rather than the mature fibril, that greatly contributes cytotoxicity. The formation of oligomers involves complicate structural conversions and it is essential to investigate their conformational changes for a better understanding of aggregation mechanism. The coexistence of soluble early-stage oligomers, intermediates, and pre-fibril species makes it difficult to be differentiate by morphological methods, and only average structural information is provided as they lack the ability of separation. Therefore, mass spectrometry (MS) becomes an alternative technique that presents new and complementary insights into the onset of amyloid fibrils. This review highlights the hotspots and important achievements by MS in the field of amyloid formation mechanism, including the direct detection and differentiation of soluble oligomers (native MS), unambiguous identification of interacted sites involved in the onset of aggregation [hydrogen/deuterium exchange (HDX) and chemical cross-linking (CX)], and conformational switch that leads to fibrilization [collision cross section (CCS) regularity by ion mobility (IM)].
Collapse
Affiliation(s)
- Jiaojiao Hu
- Key Laboratory of Drug Metabolism and Pharmacokinetics, State Key Laboratory of Natural Medicines, Department of Pharmaceutical Analysis, School of Pharmacy, China Pharmaceutical University, Nanjing, China
| | - Qiuling Zheng
- Key Laboratory of Drug Metabolism and Pharmacokinetics, State Key Laboratory of Natural Medicines, Department of Pharmaceutical Analysis, School of Pharmacy, China Pharmaceutical University, Nanjing, China
| |
Collapse
|
42
|
Hodge EA, Benhaim MA, Lee KK. Bridging protein structure, dynamics, and function using hydrogen/deuterium-exchange mass spectrometry. Protein Sci 2020; 29:843-855. [PMID: 31721348 PMCID: PMC7096709 DOI: 10.1002/pro.3790] [Citation(s) in RCA: 66] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2019] [Revised: 11/08/2019] [Accepted: 11/11/2019] [Indexed: 12/21/2022]
Abstract
Much of our understanding of protein structure and mechanistic function has been derived from static high-resolution structures. As structural biology has continued to evolve it has become clear that high-resolution structures alone are unable to fully capture the mechanistic basis for protein structure and function in solution. Recently Hydrogen/Deuterium-exchange Mass Spectrometry (HDX-MS) has developed into a powerful and versatile tool for structural biologists that provides novel insights into protein structure and function. HDX-MS enables direct monitoring of a protein's structural fluctuations and conformational changes under native conditions in solution even as it is carrying out its functions. In this review, we focus on the use of HDX-MS to monitor these dynamic changes in proteins. We examine how HDX-MS has been applied to study protein structure and function in systems ranging from large, complex assemblies to intrinsically disordered proteins, and we discuss its use in probing conformational changes during protein folding and catalytic function. STATEMENT FOR A BROAD AUDIENCE: The biophysical and structural characterization of proteins provides novel insight into their functionalities. Protein motions, ranging from small scale local fluctuations to larger concerted structural rearrangements, often determine protein function. Hydrogen/Deuterium-exchange Mass Spectrometry (HDX-MS) has proven a powerful biophysical tool capable of probing changes in protein structure and dynamic protein motions that are often invisible to most other techniques.
Collapse
Affiliation(s)
- Edgar A. Hodge
- Department of Medicinal ChemistryUniversity of WashingtonSeattleWashington
| | - Mark A. Benhaim
- Department of Medicinal ChemistryUniversity of WashingtonSeattleWashington
| | - Kelly K. Lee
- Department of Medicinal ChemistryUniversity of WashingtonSeattleWashington
| |
Collapse
|
43
|
Choi EY, Kang SS, Lee SK, Han BH. Polyphenolic Biflavonoids Inhibit Amyloid-Beta Fibrillation and Disaggregate Preformed Amyloid-Beta Fibrils. Biomol Ther (Seoul) 2020; 28:145-151. [PMID: 31697876 PMCID: PMC7059817 DOI: 10.4062/biomolther.2019.113] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2019] [Revised: 09/14/2019] [Accepted: 09/16/2019] [Indexed: 12/18/2022] Open
Abstract
Alzheimer’s disease (AD) is a devastating neurodegenerative disease and a major cause of dementia in elderly individuals world-wide. Increased deposition of insoluble amyloid β (Aβ) fibrils in the brain is thought be a key neuropathological hallmark of AD. Many recent studies show that natural products such as polyphenolic flavonoids inhibit the formation of insoluble Aβ fibrils and/or destabilize β-sheet-rich Aβ fibrils to form non-cytotoxic aggregates. In the present study, we explored the structure-activity relationship of naturally-occurring biflavonoids on Aβ amyloidogenesis utilizing an in vitro thioflavin T assay with Aβ1–42 peptide which is prone to aggregate more rapidly to fibrils than Aβ1–40 peptide. Among the biflavonoids we tested, we found amentoflavone revealed the most potent effects on inhibiting Aβ1–42 fibrillization (IC50: 0.26 μM), as well as on disassembling preformed Aβ1–42 fibrils (EC50: 0.59 μM). Our structure-activity relationship study suggests that the hydroxyl groups of biflavonoid compounds play an essential role in their molecular interaction with the dynamic process of Aβ1–42 fibrillization. Our atomic force microscopic imaging analysis demonstrates that amentoflavone directly disrupts the fibrillar structure of preformed Aβ1–42 fibrils, resulting in conversion of those fibrils to amorphous Aβ1–42 aggregates. These results indicate that amentoflavone affords the most potent anti-amyloidogenic effects on both inhibition of Aβ1–42 fibrillization and disaggregation of preformed mature Aβ1–42 fibrils.
Collapse
Affiliation(s)
- Erika Y Choi
- Department of Pharmacology, A.T. Still University of Health Sciences, Kirksville, MO 63501, USA
| | - Sam Sik Kang
- School of Pharmacy, Seoul National University, Seoul 08826, Republic of Korea
| | - Sang Kook Lee
- School of Pharmacy, Seoul National University, Seoul 08826, Republic of Korea
| | - Byung Hee Han
- Department of Pharmacology, A.T. Still University of Health Sciences, Kirksville, MO 63501, USA
| |
Collapse
|
44
|
Xing X, Liu C, Yang H, Nouman MF, Ai H. Folding dynamics of Aβ42 monomer at pH 4.0–7.5 with and without physiological salt conditions – does the β1 or β2 region fold first? NEW J CHEM 2020. [DOI: 10.1039/d0nj01090a] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
The seeding region of Aβ42 monomer is jointly affected by the solution acidity, ionic distribution of the salt, and charged residues.
Collapse
Affiliation(s)
- Xiaofeng Xing
- School of Chemistry and Chemical Engineering
- University of Jinan
- Jinan
- China
| | - Chengqiang Liu
- School of Chemistry and Chemical Engineering
- University of Jinan
- Jinan
- China
| | - Huijuan Yang
- School of Chemistry and Chemical Engineering
- University of Jinan
- Jinan
- China
| | | | - Hongqi Ai
- School of Chemistry and Chemical Engineering
- University of Jinan
- Jinan
- China
| |
Collapse
|
45
|
Niu B, Appleby TC, Wang R, Morar M, Voight J, Villaseñor AG, Clancy S, Wise S, Belzile JP, Papalia G, Wong M, Brendza KM, Lad L, Gross ML. Protein Footprinting and X-ray Crystallography Reveal the Interaction of PD-L1 and a Macrocyclic Peptide. Biochemistry 2019; 59:541-551. [PMID: 31841311 DOI: 10.1021/acs.biochem.9b00822] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Blocking interactions between PD-1 and PD-L1 opens a new era of cancer treatment involving immunity modulation. Although most immunotherapies use monoclonal antibodies, small-molecule inhibitors offer advantages. To facilitate development of small-molecule therapeutics, we implemented a rapid approach to characterize the binding interfaces of small-molecule inhibitors with PD-L1. We determined its interaction with a synthetic macrocyclic peptide by using two mass spectrometry-based approaches, hydrogen-deuterium exchange and fast photochemical oxidation of proteins (FPOP), and corroborated the findings with our X-ray structure of the PD-L1/macrocycle complex. Although all three approaches show that the macrocycle binds directly to PD-L1 over the regions of residues 46-87 and 114-125, the two protein footprinting approaches show additional binding at the N-terminus of PD-L1, and FPOP reveals some critical binding residues. The outcomes not only show the binding regions but also demonstrate the utility of MS-based footprinting in probing protein/ligand inhibitory interactions in cancer immunotherapy.
Collapse
Affiliation(s)
- Ben Niu
- Department of Chemistry , Washington University in St. Louis , St. Louis , Missouri 63130 , United States
| | - Todd C Appleby
- Gilead Sciences, Inc. , 333 Lakeside Drive , Foster City , California 94404 , United States
| | - Ruth Wang
- Gilead Sciences, Inc. , 333 Lakeside Drive , Foster City , California 94404 , United States
| | - Mariya Morar
- Gilead Sciences, Inc. , 333 Lakeside Drive , Foster City , California 94404 , United States
| | - Johannes Voight
- Gilead Sciences, Inc. , 333 Lakeside Drive , Foster City , California 94404 , United States
| | - Armando G Villaseñor
- Gilead Sciences, Inc. , 333 Lakeside Drive , Foster City , California 94404 , United States
| | - Sheila Clancy
- Gilead Sciences, Inc. , 333 Lakeside Drive , Foster City , California 94404 , United States
| | - Sarah Wise
- Gilead Sciences, Inc. , 333 Lakeside Drive , Foster City , California 94404 , United States
| | - Jean-Philippe Belzile
- Gilead Sciences, Inc. , 333 Lakeside Drive , Foster City , California 94404 , United States
| | - Giuseppe Papalia
- Gilead Sciences, Inc. , 333 Lakeside Drive , Foster City , California 94404 , United States
| | - Melanie Wong
- Gilead Sciences, Inc. , 333 Lakeside Drive , Foster City , California 94404 , United States
| | - Katherine M Brendza
- Gilead Sciences, Inc. , 333 Lakeside Drive , Foster City , California 94404 , United States
| | - Latesh Lad
- Gilead Sciences, Inc. , 333 Lakeside Drive , Foster City , California 94404 , United States
| | - Michael L Gross
- Department of Chemistry , Washington University in St. Louis , St. Louis , Missouri 63130 , United States
| |
Collapse
|
46
|
Effects of Cu(II) on the aggregation of amyloid-β. J Biol Inorg Chem 2019; 24:1197-1215. [PMID: 31602542 DOI: 10.1007/s00775-019-01727-5] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2019] [Accepted: 10/01/2019] [Indexed: 12/27/2022]
Abstract
Aberrant aggregation of the Aβ protein is a hallmark of Alzheimer's disease (AD), but no complete characterization of the molecular level pathogenesis has been achieved. A promising hypothesis is that dysfunction of metal ion homeostasis, and consequently, the undesired interaction of metal ions with Aβ, may be central to the development of AD. Qualitatively, most data indicate that Cu(II) induces rapid self-assembly of both Aβ40 and Aβ42 during the initial phase of the aggregation, while at longer time scales fibrillation may occur, depending on the experimental conditions. For Aβ40 and Cu(II):Aβ ≤ 1, most data imply that low concentration of Aβ40 favors nucleation and rapid fibril elongation, while high concentration of Aβ40 favors formation of amorphous aggregates. However, there are conflicting reports on this issue. For Aβ42 and Cu(II):Aβ ≤ 1, there is consensus that the lag time is extended upon addition of Cu(II). For Cu(II):Aβ > 1, the lag time is increased upon interaction with Cu(II), and in most cases fibrillation is not observed, presumably because Cu(II) occupies a second more solvent-exposed binding site, which is more prone to form metal ion-bridged species and cause rapid formation of non-fibrillar aggregates. The interesting N-terminally truncated Aβ11-40 with high affinity for Cu(II), exhibits delay of fibrillation upon addition of 0.4 eq. Cu(II). In our view, there are still problems achieving reproducible results in this field, and we provide a shortlist of some of the pitfalls. Finally, we propose a consensus model for the effects of Cu(II) on the aggregation kinetics of Aβ.
Collapse
|
47
|
Iadanza MG, Jackson MP, Hewitt EW, Ranson NA, Radford SE. A new era for understanding amyloid structures and disease. Nat Rev Mol Cell Biol 2019; 19:755-773. [PMID: 30237470 DOI: 10.1038/s41580-018-0060-8] [Citation(s) in RCA: 568] [Impact Index Per Article: 113.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The aggregation of proteins into amyloid fibrils and their deposition into plaques and intracellular inclusions is the hallmark of amyloid disease. The accumulation and deposition of amyloid fibrils, collectively known as amyloidosis, is associated with many pathological conditions that can be associated with ageing, such as Alzheimer disease, Parkinson disease, type II diabetes and dialysis-related amyloidosis. However, elucidation of the atomic structure of amyloid fibrils formed from their intact protein precursors and how fibril formation relates to disease has remained elusive. Recent advances in structural biology techniques, including cryo-electron microscopy and solid-state NMR spectroscopy, have finally broken this impasse. The first near-atomic-resolution structures of amyloid fibrils formed in vitro, seeded from plaque material and analysed directly ex vivo are now available. The results reveal cross-β structures that are far more intricate than anticipated. Here, we describe these structures, highlighting their similarities and differences, and the basis for their toxicity. We discuss how amyloid structure may affect the ability of fibrils to spread to different sites in the cell and between organisms in a prion-like manner, along with their roles in disease. These molecular insights will aid in understanding the development and spread of amyloid diseases and are inspiring new strategies for therapeutic intervention.
Collapse
Affiliation(s)
- Matthew G Iadanza
- Astbury Centre for Structural Molecular Biology, School of Molecular and Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds, UK
| | - Matthew P Jackson
- Astbury Centre for Structural Molecular Biology, School of Molecular and Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds, UK
| | - Eric W Hewitt
- Astbury Centre for Structural Molecular Biology, School of Molecular and Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds, UK
| | - Neil A Ranson
- Astbury Centre for Structural Molecular Biology, School of Molecular and Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds, UK
| | - Sheena E Radford
- Astbury Centre for Structural Molecular Biology, School of Molecular and Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds, UK.
| |
Collapse
|
48
|
Liu C, Zhao W, Xing X, Shi H, Kang B, Liu H, Li P, Ai H. An Original Monomer Sampling from a Ready‐Made Aβ
42
NMR Fibril Suggests a Turn‐β‐Strand Synergetic Seeding Mechanism. Chemphyschem 2019; 20:1649-1660. [DOI: 10.1002/cphc.201801137] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2018] [Indexed: 01/15/2023]
Affiliation(s)
- Chengqiang Liu
- School of Chemistry and Chemical EngineeringUniversity of Jinan Jinan 250022 China
| | - Wei Zhao
- School of Chemistry and Chemical EngineeringUniversity of Jinan Jinan 250022 China
| | - Xiaofeng Xing
- School of Chemistry and Chemical EngineeringUniversity of Jinan Jinan 250022 China
| | - Hu Shi
- School of Chemistry and Chemical EngineeringShanxi University Taiyuan 030006 China
| | - Baotao Kang
- School of Chemistry and Chemical EngineeringUniversity of Jinan Jinan 250022 China
| | - Haiying Liu
- School of PhysicsUniversity of Jinan Jinan 250022 China
| | - Ping Li
- Key Laboratory of Life-Organic Analysis, School of Chemistry and Chemical EngineeringQufu Normal University Qufu 273165 China
| | - Hongqi Ai
- School of Chemistry and Chemical EngineeringUniversity of Jinan Jinan 250022 China
| |
Collapse
|
49
|
Schiavone NM, Pirrone GF, Guetschow ED, Mangion I, Makarov AA. Combination of circular dichroism spectroscopy and size-exclusion chromatography coupled with HDX-MS for studying global conformational structures of peptides in solution. Talanta 2019; 194:177-182. [DOI: 10.1016/j.talanta.2018.09.077] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2018] [Revised: 09/19/2018] [Accepted: 09/20/2018] [Indexed: 01/10/2023]
|
50
|
Benhaim M, Lee KK, Guttman M. Tracking Higher Order Protein Structure by Hydrogen-Deuterium Exchange Mass Spectrometry. Protein Pept Lett 2019; 26:16-26. [PMID: 30543159 PMCID: PMC6386625 DOI: 10.2174/0929866526666181212165037] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2018] [Revised: 08/30/2018] [Accepted: 11/17/2018] [Indexed: 12/27/2022]
Abstract
BACKGROUND Structural biology has provided a fundamental understanding of protein structure and mechanistic insight into their function. However, high-resolution structures alone are insufficient for a complete understanding of protein behavior. Higher energy conformations, conformational changes, and subtle structural fluctuations that underlie the proper function of proteins are often difficult to probe using traditional structural approaches. Hydrogen/Deuterium Exchange with Mass Spectrometry (HDX-MS) provides a way to probe the accessibility of backbone amide protons under native conditions, which reports on local structural dynamics of solution protein structure that can be used to track complex structural rearrangements that occur in the course of a protein's function. CONCLUSION In the last 20 years the advances in labeling techniques, sample preparation, instrumentation, and data analysis have enabled HDX to gain insights into very complex biological systems. Analysis of challenging targets such as membrane protein complexes is now feasible and the field is paving the way to the analysis of more and more complex systems.
Collapse
Affiliation(s)
- Mark Benhaim
- Department of Medicinal Chemistry, University of Washington, Seattle, WA 98195 USA
| | - Kelly K. Lee
- Department of Medicinal Chemistry, University of Washington, Seattle, WA 98195 USA
| | - Miklos Guttman
- Department of Medicinal Chemistry, University of Washington, Seattle, WA 98195 USA
| |
Collapse
|