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Ghosh S, Ali R, Verma S. Aβ-oligomers: A potential therapeutic target for Alzheimer's disease. Int J Biol Macromol 2023; 239:124231. [PMID: 36996958 DOI: 10.1016/j.ijbiomac.2023.124231] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Revised: 03/22/2023] [Accepted: 03/25/2023] [Indexed: 03/30/2023]
Abstract
The cascade of amyloid formation relates to multiple complex events at the molecular level. Previous research has established amyloid plaque deposition as the leading cause of Alzheimer's disease (AD) pathogenesis, detected mainly in aged population. The primary components of the plaques are two alloforms of amyloid-beta (Aβ), Aβ1-42 and Aβ1-40 peptides. Recent studies have provided considerable evidence contrary to the previous claim indicating that amyloid-beta oligomers (AβOs) as the main culprit responsible for AD-associated neurotoxicity and pathogenesis. In this review, we have discussed the primary features of AβOs, such as assembly formation, the kinetics of oligomer formation, interactions with various membranes/membrane receptors, the origin of toxicity, and oligomer-specific detection methods. Recently, the discovery of rationally designed antibodies has opened a gateway for using synthesized peptides as a grafting component in the complementarity determining region (CDR) of antibodies. Thus, the Aβ sequence motif or the complementary peptide sequence in the opposite strand of the β-sheet (extracted from the Protein Data Bank: PDB) helps design oligomer-specific inhibitors. The microscopic event responsible for oligomer formation can be targeted, and thus prevention of the overall macroscopic behaviour of the aggregation or the associated toxicity can be achieved. We have carefully reviewed the oligomer formation kinetics and associated parameters. Besides, we have depicted a thorough understanding of how the synthesized peptide inhibitors can impede the early aggregates (oligomers), mature fibrils, monomers, or a mixture of the species. The oligomer-specific inhibitors (peptides or peptide fragments) lack in-depth chemical kinetics and optimization control-based screening. In the present review, we have proposed a hypothesis for effectively screening oligomer-specific inhibitors using the chemical kinetics (determining the kinetic parameters) and optimization control strategy (cost-dependent analysis). Further, it may be possible to implement the structure-kinetic-activity-relationship (SKAR) strategy instead of structure-activity-relationship (SAR) to improve the inhibitor's activity. The controlled optimization of the kinetic parameters and dose usage will be beneficial for narrowing the search window for the inhibitors.
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2
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Breaker peptides against amyloid-β aggregation: a potential therapeutic strategy for Alzheimer's disease. Future Med Chem 2021; 13:1767-1794. [PMID: 34498978 DOI: 10.4155/fmc-2021-0184] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Alzheimer's disease (AD) is a progressive neurodegenerative disorder, for which blocking the early steps of extracellular misfolded amyloid-β (Aβ) aggregation is a promising therapeutic approach. However, the pathological features of AD progression include the accumulation of intracellular tau protein, membrane-catalyzed cell death and the abnormal deposition of Aβ. Here, we focus on anti-amyloid breaker peptides derived from the Aβ sequence and non-Aβ-based peptides containing both natural and modified amino acids. Critical aspects of the breaker peptides include N-methylation, conformational restriction through cyclization, incorporation of unnatural amino acid, fluorinated molecules, polymeric nanoparticles and PEGylation. This review confers a general idea of such breaker peptides with in vitro and in vivo studies, which may advance our understanding of AD pathology and develop an effective treatment strategy against AD.
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Mitra A, Sarkar N. Sequence and structure-based peptides as potent amyloid inhibitors: A review. Arch Biochem Biophys 2020; 695:108614. [PMID: 33010227 DOI: 10.1016/j.abb.2020.108614] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2020] [Revised: 09/27/2020] [Accepted: 09/28/2020] [Indexed: 02/07/2023]
Abstract
Misfolded and natively disordered globular proteins tend to aggregate together in an interwoven fashion to form fibrous, proteinaceous deposits referred to as amyloid fibrils. Formation and deposition of such insoluble fibrils are the characteristic features of a broad group of diseases, known as amyloidosis. Some of these proteins are known to cause several degenerative disorders in humans, such as Amyloid-Beta (Aβ) in Alzheimer's disease (AD), human Islet Amyloid Polypeptide (hIAPP, amylin) in type 2 diabetes, α-synuclein (α-syn) in Parkinson's disease (PD) and so on. The fact that these proteins do not share any significant sequence or structural homology in their native states make therapy quite challenging. However, it is observed that aggregation-prone proteins and peptides tend to adopt a similar type of secondary structure during the formation of fibrils. Rationally designed peptides can be a potent inhibitor that has been shown to disrupt the fibril structure by binding specifically to the amyloidogenic region(s) within a protein. The following review will analyze the inhibitory potency of both sequence-based and structure-based small peptides that have been shown to inhibit amyloidogenesis of proteins such as Aβ, human amylin, and α-synuclein.
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Affiliation(s)
- Amit Mitra
- Department of Biotechnology and Medical Engineering, National Institute of Technology Rourkela, Rourkela, 769008, Odisha, India
| | - Nandini Sarkar
- Department of Biotechnology and Medical Engineering, National Institute of Technology Rourkela, Rourkela, 769008, Odisha, India.
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Ryan P, Xu MM, Davey AK, Kassiou M, Mellick GD, Rudrawar S. O-GlcNAcylation of truncated NAC segment alters peptide-dependent effects on α-synuclein aggregation. Bioorg Chem 2020; 94:103389. [DOI: 10.1016/j.bioorg.2019.103389] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2019] [Revised: 10/15/2019] [Accepted: 10/21/2019] [Indexed: 10/25/2022]
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Ryan P, Patel B, Makwana V, Jadhav HR, Kiefel M, Davey A, Reekie TA, Rudrawar S, Kassiou M. Peptides, Peptidomimetics, and Carbohydrate-Peptide Conjugates as Amyloidogenic Aggregation Inhibitors for Alzheimer's Disease. ACS Chem Neurosci 2018; 9:1530-1551. [PMID: 29782794 DOI: 10.1021/acschemneuro.8b00185] [Citation(s) in RCA: 61] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Alzheimer's disease (AD) is a progressive neurodegenerative disorder accounting for 60-80% of dementia cases. For many years, AD causality was attributed to amyloid-β (Aβ) aggregated species. Recently, multiple therapies that target Aβ aggregation have failed in clinical trials, since Aβ aggregation is found in AD and healthy patients. Attention has therefore shifted toward the aggregation of the tau protein as a major driver of AD. Numerous inhibitors of tau-based pathology have recently been developed. Diagnosis of AD has shifted from measuring late stage senile plaques to early stage biomarkers, amyloid-β and tau monomers and oligomeric assemblies. Synthetic peptides and some derivative structures are being explored for use as theranostic tools as they possess the capacity both to bind the biomarkers and to inhibit their pathological self-assembly. Several studies have demonstrated that O-linked glycoside addition can significantly alter amyloid aggregation kinetics. Furthermore, natural O-glycosylation of amyloid-forming proteins, including amyloid precursor protein (APP), tau, and α-synuclein, promotes alternative nonamyloidogenic processing pathways. As such, glycopeptides and related peptidomimetics are being investigated within the AD field. Here we review advancements made in the last 5 years, as well as the arrival of sugar-based derivatives.
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Affiliation(s)
- Philip Ryan
- School of Pharmacy and Pharmacology, Griffith University, Gold Coast 4222, Australia
| | - Bhautikkumar Patel
- School of Pharmacy and Pharmacology, Griffith University, Gold Coast 4222, Australia
| | - Vivek Makwana
- School of Pharmacy and Pharmacology, Griffith University, Gold Coast 4222, Australia
| | - Hemant R. Jadhav
- Department of Pharmacy, Birla Institute of Technology and Science, Pilani Campus, Pilani-333031, Rajasthan, India
| | - Milton Kiefel
- Institute for Glycomics, Griffith University, Gold Coast 4222, Australia
| | - Andrew Davey
- School of Pharmacy and Pharmacology, Griffith University, Gold Coast 4222, Australia
- Menzies Health Institute Queensland, Griffith University, Gold Coast 4222, Australia
- Quality Use of Medicines Network, Griffith University, Gold Coast 4222, Australia
| | | | - Santosh Rudrawar
- School of Pharmacy and Pharmacology, Griffith University, Gold Coast 4222, Australia
- Menzies Health Institute Queensland, Griffith University, Gold Coast 4222, Australia
- Quality Use of Medicines Network, Griffith University, Gold Coast 4222, Australia
- School of Chemistry, The University of Sydney, NSW 2006, Australia
| | - Michael Kassiou
- School of Chemistry, The University of Sydney, NSW 2006, Australia
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Han X, He G. Toward a Rational Design to Regulate β-Amyloid Fibrillation for Alzheimer's Disease Treatment. ACS Chem Neurosci 2018; 9:198-210. [PMID: 29251488 DOI: 10.1021/acschemneuro.7b00477] [Citation(s) in RCA: 54] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
The last decades have witnessed a growing global burden of Alzheimer's disease (AD). Evidence indicates that the onset and progression of AD is associated with β-amyloid (Aβ) peptide fibrillation. As such, there is a strong passion with discovering potent Aβ fibrillation inhibitors that can be developed into anti-amyloiddogenic agents for AD treatment. Current challenges that have arisen with this development involve with Aβ oligomer toxicity suppression and Blood Brain Barrier penetration capability. Considering most natural or biological events, one would observe that there is usually a "seed" to direct natural materials to assemble in response to a certain stimulation. Inspired by this, several materials or compounds, including nanoparticle, peptide or peptide mimics, and organic molecules, have been designed for the purpose of redirecting or impeding Aβ aggregation. Achieving these tasks requires comprehensive understanding on (1) initial Aβ assembly into insoluble deposits, (2) main concerns with fibrillation inhibition, and (3) current major methodologies to disrupt the aggregation. Herein, the objective of this review is to address these three areas, and enable the pathway for a promising therapeutic agent design for AD treatment.
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Affiliation(s)
- Xu Han
- Huston Labs, 1951 NW Seventh
Avenue, Suite 600, Miami, Florida 33136, United States
| | - Gefei He
- East China Normal University, 3663 Zhongshan N Road, Putuo District, Shanghai 200062, China
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Baig MH, Ahmad K, Rabbani G, Choi I. Use of Peptides for the Management of Alzheimer's Disease: Diagnosis and Inhibition. Front Aging Neurosci 2018; 10:21. [PMID: 29467644 PMCID: PMC5808296 DOI: 10.3389/fnagi.2018.00021] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2017] [Accepted: 01/18/2018] [Indexed: 11/13/2022] Open
Abstract
Alzheimer's disease (AD) is a form of dementia and the most common progressive neurodegenerative disease (ND). The targeting of amyloid-beta (Aβ) aggregation is one of the most widely used strategies to manage AD, and efforts are being made globally to develop peptide-based compounds for the early diagnosis and treatment of AD. Here, we briefly discuss the use of peptide-based compounds for the early diagnosis and treatment of AD and the use of peptide-based inhibitors targeting various Aβ aggregation checkpoints. In addition, we briefly discuss recent applications of peptide-based inhibitors against various AD targets including amyloid beta, β-site amyloid precursor protein cleaving enzyme 1 (BACE1), Glyceraldehyde-3-phosphate dehydrogenase (GAPDH), tyrosine phosphatase (TP) and potassium channel KV1.3.
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Affiliation(s)
- Mohammad H Baig
- Department of Medical Biotechnology, Yeungnam University, Gyeongsan, South Korea
| | - Khurshid Ahmad
- Department of Medical Biotechnology, Yeungnam University, Gyeongsan, South Korea
| | - Gulam Rabbani
- Department of Medical Biotechnology, Yeungnam University, Gyeongsan, South Korea
| | - Inho Choi
- Department of Medical Biotechnology, Yeungnam University, Gyeongsan, South Korea
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8
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Goyal D, Shuaib S, Mann S, Goyal B. Rationally Designed Peptides and Peptidomimetics as Inhibitors of Amyloid-β (Aβ) Aggregation: Potential Therapeutics of Alzheimer's Disease. ACS COMBINATORIAL SCIENCE 2017; 19:55-80. [PMID: 28045249 DOI: 10.1021/acscombsci.6b00116] [Citation(s) in RCA: 150] [Impact Index Per Article: 21.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Alzheimer's disease (AD) is a progressive neurodegenerative disease with no clinically accepted treatment to cure or halt its progression. The worldwide effort to develop peptide-based inhibitors of amyloid-β (Aβ) aggregation can be considered an unplanned combinatorial experiment. An understanding of what has been done and achieved may advance our understanding of AD pathology and the discovery of effective therapeutic agents. We review here the history of such peptide-based inhibitors, including those based on the Aβ sequence and those not derived from that sequence, containing both natural and unnatural amino acid building blocks. Peptide-based aggregation inhibitors hold significant promise for future AD therapy owing to their high selectivity, effectiveness, low toxicity, good tolerance, low accumulation in tissues, high chemical and biological diversity, possibility of rational design, and highly developed methods for analyzing their mode of action, proteolytic stability (modified peptides), and blood-brain barrier (BBB) permeability.
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Affiliation(s)
- Deepti Goyal
- Department of Chemistry,
School of Basic and Applied Sciences, Sri Guru Granth Sahib World University, Fatehgarh Sahib-140406, Punjab, India
| | - Suniba Shuaib
- Department of Chemistry,
School of Basic and Applied Sciences, Sri Guru Granth Sahib World University, Fatehgarh Sahib-140406, Punjab, India
| | - Sukhmani Mann
- Department of Chemistry,
School of Basic and Applied Sciences, Sri Guru Granth Sahib World University, Fatehgarh Sahib-140406, Punjab, India
| | - Bhupesh Goyal
- Department of Chemistry,
School of Basic and Applied Sciences, Sri Guru Granth Sahib World University, Fatehgarh Sahib-140406, Punjab, India
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9
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Crisma M, De Zotti M, Formaggio F, Peggion C, Moretto A, Toniolo C. Handedness preference and switching of peptide helices. Part II: Helices based on noncodedα-amino acids. J Pept Sci 2015; 21:148-77. [DOI: 10.1002/psc.2743] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2014] [Revised: 12/19/2014] [Accepted: 12/19/2014] [Indexed: 12/27/2022]
Affiliation(s)
| | - Marta De Zotti
- Department of Chemistry; University of Padova; Padova Italy
| | - Fernando Formaggio
- ICB; Padova Unit; CNR Padova Italy
- Department of Chemistry; University of Padova; Padova Italy
| | | | - Alessandro Moretto
- ICB; Padova Unit; CNR Padova Italy
- Department of Chemistry; University of Padova; Padova Italy
| | - Claudio Toniolo
- ICB; Padova Unit; CNR Padova Italy
- Department of Chemistry; University of Padova; Padova Italy
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10
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Giordano C, Punzi P, Lori C, Chiaraluce R, Consalvi V. β-Sheet Breaker Peptides Containing α,β-Dehydrophenylalanine: Synthesis and In Vitro Activity Studies. Chempluschem 2014. [DOI: 10.1002/cplu.201402072] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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11
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Antimisiaris S, Mourtas S, Markoutsa E, Skouras A, Papadia K. Nanoparticles for Diagnosis and/or Treatment of Alzheimer's Disease. Adv Healthc Mater 2014. [DOI: 10.1002/9781118774205.ch4] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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12
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Yang DT, Joshi G, Cho PY, Johnson JA, Murphy RM. Transthyretin as both a sensor and a scavenger of β-amyloid oligomers. Biochemistry 2013; 52:2849-61. [PMID: 23570378 DOI: 10.1021/bi4001613] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Transthyretin (TTR) is a homotetrameric transport protein, assembled from monomers that each contain two four-stranded β-sheets and a short α-helix and loop. In the tetramer, the "inner" β-sheet forms a hydrophobic pocket while the helix and loop are solvent-exposed. β-Amyloid (Aβ) aggregates bind to TTR, and the level of binding is significantly reduced in mutants L82A (on the loop) and L110A (on the inner β-sheet). Protection against Aβ toxicity was demonstrated for wild-type TTR but not L82A or L110A, providing a direct link between TTR-Aβ binding and TTR-mediated cytoprotection. Protection is afforded at substoichiometric (1:100) TTR:Aβ molar ratios, and the level of binding of Aβ to TTR is highest for partially aggregated materials and decreased for freshly prepared or heavily aggregated Aβ, suggesting that TTR binds selectively to soluble toxic Aβ aggregates. A novel technique, nanoparticle tracking, is used to show that TTR arrests Aβ aggregation by both preventing formation of new aggregates and inhibiting growth of existing aggregates. TTR tetramers are normally quite stable; tetrameric structure is necessary for the protein's transport functions, and mutations that decrease tetramer stability have been linked to TTR amyloid diseases. However, TTR monomers bind more Aβ than do tetramers, presumably because the hydrophobic inner sheet is solvent-exposed upon tetramer disassembly. Wild-type and L110A tetramers, but not L82A, were destabilized upon being co-incubated with Aβ, suggesting that binding of Aβ to L82 triggers tetramer dissociation. Taken together, these results suggest a novel mechanism of action for TTR: the EF helix/loop "senses" the presence of soluble toxic Aβ oligomers, triggering destabilization of TTR tetramers and exposure of the hydrophobic inner sheet, which then "scavenges" these toxic oligomers and prevents them from causing cell death.
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Affiliation(s)
- Dennis T Yang
- Department of Chemical and Biological Engineering, University of Wisconsin, Madison, WI 53706, USA
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13
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Planchard MS, Samel MA, Kumar A, Rangachari V. The natural product betulinic acid rapidly promotes amyloid-β fibril formation at the expense of soluble oligomers. ACS Chem Neurosci 2012; 3:900-8. [PMID: 23401880 DOI: 10.1021/cn300030a] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Affiliation(s)
- Matthew S. Planchard
- Department of Chemistry and Biochemistry, University of Southern Mississippi, 118 College Drive
#5043, Hattiesburg, Mississippi 39406, United States
| | - Michael A. Samel
- Department of Chemistry and Biochemistry, University of Southern Mississippi, 118 College Drive
#5043, Hattiesburg, Mississippi 39406, United States
| | - Amit Kumar
- Department of Chemistry and Biochemistry, University of Southern Mississippi, 118 College Drive
#5043, Hattiesburg, Mississippi 39406, United States
| | - Vijayaraghavan Rangachari
- Department of Chemistry and Biochemistry, University of Southern Mississippi, 118 College Drive
#5043, Hattiesburg, Mississippi 39406, United States
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Nieznanski K, Choi JK, Chen S, Surewicz K, Surewicz WK. Soluble prion protein inhibits amyloid-β (Aβ) fibrillization and toxicity. J Biol Chem 2012; 287:33104-8. [PMID: 22915585 DOI: 10.1074/jbc.c112.400614] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The pathogenesis of Alzheimer disease appears to be strongly linked to the aggregation of amyloid-β (Aβ) peptide and, especially, formation of soluble Aβ1-42 oligomers. It was recently demonstrated that the cellular prion protein, PrP(C), binds with high affinity to these oligomers, acting as a putative receptor that mediates at least some of their neurotoxic effects. Here we show that the soluble (i.e. glycophosphatidylinositol anchor-free) prion protein and its N-terminal fragment have a strong effect on the aggregation pathway of Aβ1-42, inhibiting its assembly into amyloid fibrils. Furthermore, the prion protein prevents formation of spherical oligomers that normally occur during Aβ fibrillogenesis, acting as a potent inhibitor of Aβ1-42 toxicity as assessed in experiments with neuronal cell culture. These findings may provide a molecular level foundation to explain the reported protective action of the physiologically released N-terminal N1 fragment of PrP(C) against Aβ neurotoxicity. They also suggest a novel approach to pharmacological intervention in Alzheimer disease.
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Affiliation(s)
- Krzysztof Nieznanski
- Department of Physiology and Biophysics, Case Western Reserve University, Cleveland, Ohio 44106, USA
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15
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Peer CJ, Younis IR, Leonard SS, Gannett PM, Minarchick VC, Kenyon AJ, Rojanasakul Y, Callery PS. Glutathione conjugation of busulfan produces a hydroxyl radical-trapping dehydroalanine metabolite. Xenobiotica 2012; 42:1170-7. [DOI: 10.3109/00498254.2012.696740] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Funke SA, Willbold D. Peptides for therapy and diagnosis of Alzheimer's disease. Curr Pharm Des 2012; 18:755-67. [PMID: 22236121 PMCID: PMC3426787 DOI: 10.2174/138161212799277752] [Citation(s) in RCA: 83] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2011] [Accepted: 12/09/2011] [Indexed: 12/21/2022]
Abstract
Alzheimer's disease (AD) is a progressive neurodegenerative disorder with devastating effects. The greatest risk factor to develop AD is age. Today, only symptomatic therapies are available. Additionally, AD can be diagnosed with certainty only post mortem, whereas the diagnosis "probable AD" can be established earliest when severe clinical symptoms appear. Specific neuropathological changes like neurofibrillary tangles and amyloid plaques define AD. Amyloid plaques are mainly composed of the amyloid-βpeptide (Aβ). Several lines of evidence suggest that the progressive concentration and subsequent aggregation and accumulation of Aβ play a fundamental role in the disease progress. Therefore, substances which bind to Aβ and influence aggregation thereof are of great interest. An enormous number of organic substances for therapeutic purposes are described. This review focuses on peptides developed for diagnosis and therapy of AD and discusses the pre- and disadvantages of peptide drugs.
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Affiliation(s)
| | - Dieter Willbold
- Forschungszentrum Jülich, ICS-6, 52425 Jülich, Germany
- Institut für Physikalische Biologie, Heinrich-Heine-Universität, 40225 Düsseldorf, Germany
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Kumar A, Moody L, Olaivar JF, Lewis NA, Khade RL, Holder AA, Zhang Y, Rangachari V. Inhibition of Aβ42 peptide aggregation by a binuclear ruthenium(II)-platinum(II) complex: Potential for multi-metal organometallics as anti-amyloid agents. ACS Chem Neurosci 2010; 2010:691-701. [PMID: 21221412 DOI: 10.1021/cn100046m] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Design of inhibitors for amyloid-β (Aβ) peptide aggregation has been widely investigated over the years towards developing viable therapeutic agents for Alzheimer's disease (AD). The biggest challenge seems to be inhibiting Aβ aggregation at the early stages of aggregation possibly at the monomeric level, as oligomers are known to be neurotoxic. In this regard, exploiting the metal chelating property of Aβ to generate molecules that can overcome this impediment presents some promise. Recently, one such metal complex containing Pt(II) ([Pt(BPS)Cl(2)]) was reported to effectively inhibit Aβ42 aggregation and toxicity (1). This complex was able bind to Aβ42 at the N-terminal part of the peptide and triggered a conformational change resulting in effective inhibition. In the current report, we have generated a mixed-binuclear metal complex containing Pt(II) and Ru(II) that inhibited Aβ42 aggregation at an early stage of aggregation and seemed to have different modes of interaction than the previously reported Pt(II) complex, suggesting an important role of the second metal center. This 'proof-of-concept' compound will help in developing more effective molecules against Aβ aggregation by modifying the two metal centers as well as their ligands, which will open doors to new rationale for Aβ inhibition.
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Affiliation(s)
- Amit Kumar
- Department of Chemistry and Biochemistry, University of Southern Mississippi, 118 College Dr No. 5043, Hattiesburg, Mississippi 39406
| | - LaMaryet Moody
- Department of Chemistry and Biochemistry, University of Southern Mississippi, 118 College Dr No. 5043, Hattiesburg, Mississippi 39406
| | - Jason F. Olaivar
- Department of Chemistry and Biochemistry, University of Southern Mississippi, 118 College Dr No. 5043, Hattiesburg, Mississippi 39406
| | - Nerissa A. Lewis
- Department of Chemistry and Biochemistry, University of Southern Mississippi, 118 College Dr No. 5043, Hattiesburg, Mississippi 39406
| | - Rahul L. Khade
- Department of Chemistry and Biochemistry, University of Southern Mississippi, 118 College Dr No. 5043, Hattiesburg, Mississippi 39406
| | - Alvin A. Holder
- Department of Chemistry and Biochemistry, University of Southern Mississippi, 118 College Dr No. 5043, Hattiesburg, Mississippi 39406
| | - Yong Zhang
- Department of Chemistry and Biochemistry, University of Southern Mississippi, 118 College Dr No. 5043, Hattiesburg, Mississippi 39406
- Department of Chemistry, Chemical Biology, and Biomedical Engineering, Stevens Institute of Technology, Castle Point on Hudson, Hoboken, New Jersey 07030
| | - Vijayaraghavan Rangachari
- Department of Chemistry and Biochemistry, University of Southern Mississippi, 118 College Dr No. 5043, Hattiesburg, Mississippi 39406
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18
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Edwin NJ, Hammer RP, McCarley RL, Russo PS. Reversibility of beta-amyloid self-assembly: effects of pH and added salts assessed by fluorescence photobleaching recovery. Biomacromolecules 2010; 11:341-7. [PMID: 20085314 PMCID: PMC2859319 DOI: 10.1021/bm900833b] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The 40-residue peptide isoform beta-amyloid (Abeta(1-40)) is associated with Alzheimer's disease. Although found in the tangles and fibrous mats that characterize the brain in advanced stages of the disease, the toxic form of Abeta is believed to be oligomers or "protofibrils". Characterization of these fairly small structures in solution, especially in the presence of the much larger assemblies they also form, is a daunting task. Additionally, little is known about the rate of Abeta assembly or whether it can be triggered easily. Perhaps most importantly, the conditions for reversing assembly are not fully understood. Fluorescence photobleaching with modulation detection of the recovery profile is a sensitive and materials-efficient way to measure diffusers over a wide range of hydrodynamic sizes. The method does require attachment of a fluorescent label. Experiments to validate the use of 5-carboxyfluorescein-labeled Abeta(1-40) as a representative of the unlabeled, naturally occurring material included variation of photobleaching time and mixture of labeled and unlabeled materials. A dialysis cell facilitated rapid in situ changes in pH and salt conditions. Multiple steps and complex protocols can be explored with relative ease. Oligomeric aggregates were found by fluorescence photobleaching recovery to respond readily to pH and salt conditions. Changing these external cues leads to formation or disassembly of aggregates smaller than 100 nm within minutes.
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Affiliation(s)
- Nadia J. Edwin
- Department of Chemistry and Macromolecular Studies Group Louisiana State University Baton Rouge, LA 70803
| | - Robert P. Hammer
- Department of Chemistry and Macromolecular Studies Group Louisiana State University Baton Rouge, LA 70803
| | - Robin L. McCarley
- Department of Chemistry and Macromolecular Studies Group Louisiana State University Baton Rouge, LA 70803
| | - Paul S. Russo
- Department of Chemistry and Macromolecular Studies Group Louisiana State University Baton Rouge, LA 70803
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