1
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Madden SK, Brennan A, Mason JM. A library-derived peptide inhibitor of the BZLF1 transcription factor. J Pept Sci 2024; 30:e3557. [PMID: 38041527 DOI: 10.1002/psc.3557] [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] [Received: 04/19/2023] [Revised: 11/12/2023] [Accepted: 11/13/2023] [Indexed: 12/03/2023]
Abstract
Transcription factor dysregulation is associated with many diseases, including cancer. Peptide-based molecules are increasingly recognised as important modulators of difficult intracellular protein-protein interaction targets, with peptide library screening consequently proven to be a viable strategy in developing inhibitors against a wide range of transcription factors (TFs). However, current strategies simply select the highest affinity of binding to a target TF rather than the ability to inhibit TF function. Here, we utilise our Transcription Block Survival (TBS) screening platform to enable high-throughput identification of peptides that inhibit TFs from binding to cognate DNA sites, hence inhibiting functionality. In this study, we explore whether the TBS can be expanded to derive a potent and functional peptide inhibitor of the BZLF1 transcription factor. The library-derived peptide, AcidicW, is shown to form a more stable dimer with BZLF1 than the BZLF1 homodimer, with a thermal denaturation temperature exceeding 80°C. AcidicW can also functionally inhibit the BZLF1:TRE DNA interaction with high potency and an IC50 of 612 nM.
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Affiliation(s)
- Sarah K Madden
- Department of Life Sciences, University of Bath, Bath, UK
- Yusuf Hamied Department of Chemistry, University of Cambridge, Cambridge, UK
- Cancer Research UK Cambridge Institute, Cambridge, UK
| | - Andrew Brennan
- Department of Life Sciences, University of Bath, Bath, UK
| | - Jody M Mason
- Department of Life Sciences, University of Bath, Bath, UK
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2
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Raghavan SS, Iqbal S, Ayyadurai N, Gunasekaran K. Insights in the structural understanding of amyloidogenicity and mutation-led conformational dynamics of amyloid beta (Aβ) through molecular dynamics simulations and principal component analysis. J Biomol Struct Dyn 2021; 40:5577-5587. [PMID: 33438527 DOI: 10.1080/07391102.2021.1871955] [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: 10/22/2022]
Abstract
Abnormal protein aggregation in the nervous tissue leads to several neurodegenerative disorders like Alzheimer's disease (AD). In AD, accumulation of the amyloid beta (Aβ) peptide is proposed to be an early important event in pathogenesis. Significant research efforts are devoted so as to understand the Aβ misfolding and aggregation. Molecular dynamics (MD) simulations complement experiments and provide structural information at the atomic level with dynamics without facing the same experimental limitations. Artificial missense mutations are employed experimentally and computationally for providing insights into the structure-function relationships of amyloid-β in relation to the pathologies of AD. Present work describes the MD simulations for 100 ns so as to probe the structural and conformational dynamics of Aβ1-42 assemblies and its mutants. Essential dynamics analysis with respect to conformational deviation of Cα was evaluated to identify the largest residual fluctuation of Cα. Conformational stability of all Aβ mutants was analyzed by computing RMSD, deciphering the convergence is reached in the last 20 ns in all replicas. To highlight the low frequency mode of motion corresponding to the highest amplitude, atomic displacements seen in trajectory, distance pair principal component analysis (dpPCA) was performed, which adumbrated mutations strongly affect the conformational dynamics of investigated model when compared with wild type. Dynamic cross correlation matrix (DCCM) also suggests the conserved interactions of wild Aβ and imply mutations in β3-β4 loop region induce deformity and residual fluctuations as observed from simulation. Present study indicate the mutational energy landscape which induces deformation leading to fibrillation.Communicated by Ramaswamy H. Sarma.
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Affiliation(s)
- Sriram Srinivasa Raghavan
- Department of Crystallography and Biophysics, University of Madras, Chennai, India.,Molecular Biophysics Unit, Indian Institute of Science, Bangalore, India.,Division of Biotechnology, Council of Scientific and Industrial Research-Central Leather Research Institute (CSIR-CLRI), Chennai, India
| | - Saleem Iqbal
- Department of Crystallography and Biophysics, University of Madras, Chennai, India.,Department of Computational and Data Sciences, Indian Institute of Science, Bangalore, India
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3
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Madden SK, de Araujo AD, Gerhardt M, Fairlie DP, Mason JM. Taking the Myc out of cancer: toward therapeutic strategies to directly inhibit c-Myc. Mol Cancer 2021; 20:3. [PMID: 33397405 PMCID: PMC7780693 DOI: 10.1186/s12943-020-01291-6] [Citation(s) in RCA: 172] [Impact Index Per Article: 57.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2020] [Accepted: 11/29/2020] [Indexed: 02/07/2023] Open
Abstract
c-Myc is a transcription factor that is constitutively and aberrantly expressed in over 70% of human cancers. Its direct inhibition has been shown to trigger rapid tumor regression in mice with only mild and fully reversible side effects, suggesting this to be a viable therapeutic strategy. Here we reassess the challenges of directly targeting c-Myc, evaluate lessons learned from current inhibitors, and explore how future strategies such as miniaturisation of Omomyc and targeting E-box binding could facilitate translation of c-Myc inhibitors into the clinic.
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Affiliation(s)
- Sarah K Madden
- Department of Biology & Biochemistry, University of Bath, Claverton Down, Bath, BA2 7AY, UK.
| | - Aline Dantas de Araujo
- Division of Chemistry and Structural Biology and ARC 1066 Centre of Excellence for Innovations in Peptide and Protein Science, Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD, 4072, Australia
| | - Mara Gerhardt
- Department of Biology & Biochemistry, University of Bath, Claverton Down, Bath, BA2 7AY, UK
| | - David P Fairlie
- Division of Chemistry and Structural Biology and ARC 1066 Centre of Excellence for Innovations in Peptide and Protein Science, Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD, 4072, Australia
| | - Jody M Mason
- Department of Biology & Biochemistry, University of Bath, Claverton Down, Bath, BA2 7AY, UK.
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4
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Meade RM, Morris KJ, Watt KJC, Williams RJ, Mason JM. The Library Derived 4554W Peptide Inhibits Primary Nucleation of α-Synuclein. J Mol Biol 2020; 432:166706. [PMID: 33186583 DOI: 10.1016/j.jmb.2020.11.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2020] [Revised: 11/02/2020] [Accepted: 11/05/2020] [Indexed: 11/28/2022]
Abstract
Aggregation of α-Synuclein (αS) is widely regarded as a key factor in neuronal cell death, leading to a wide range of synucleinopathies, including Parkinson's Disease. Development of therapeutics has therefore focused on inhibiting aggregation of αS into toxic forms. One such inhibitor, based on the preNAC region αS45-54 (4554W), was identified using an intracellular peptide library screen, and subsequently shown to both inhibit formation of αS aggregates while simultaneously lowering toxicity. Subsequent efforts have sought to determine the mode of 4554W action. In particular, and consistent with the fact that both target and peptide are co-produced during library screening, we find that the peptide inhibits primary nucleation of αS, but does not modulate downstream elongation or secondary nucleation events. These findings hold significant promise towards mechanistic understanding and development of molecules that can module the first steps in αS aggregation towards novel treatments for Parkinson's disease and related synucleinopathies.
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Affiliation(s)
- Richard M Meade
- Depart of Biology and Biochemistry, University of Bath, Claverton Down, BA2 7AY, United Kingdom
| | - Kimberley J Morris
- Depart of Biology and Biochemistry, University of Bath, Claverton Down, BA2 7AY, United Kingdom
| | - Kathryn J C Watt
- Depart of Biology and Biochemistry, University of Bath, Claverton Down, BA2 7AY, United Kingdom
| | - Robert J Williams
- Depart of Biology and Biochemistry, University of Bath, Claverton Down, BA2 7AY, United Kingdom
| | - Jody M Mason
- Depart of Biology and Biochemistry, University of Bath, Claverton Down, BA2 7AY, United Kingdom.
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5
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Li P, Wang L, Di LJ. Applications of Protein Fragment Complementation Assays for Analyzing Biomolecular Interactions and Biochemical Networks in Living Cells. J Proteome Res 2019; 18:2987-2998. [PMID: 31274323 DOI: 10.1021/acs.jproteome.9b00154] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Protein-protein interactions (PPIs) are indispensable for the dynamic assembly of multiprotein complexes that are central players of nearly all of the intracellular biological processes, such as signaling pathways, metabolic pathways, formation of intracellular organelles, establishment of cytoplasmic skeletons, etc. Numerous approaches have been invented to study PPIs both in vivo and in vitro, including the protein-fragment complementation assay (PCA), which is a widely applied technology to study PPIs and biomolecular interactions. PCA is a technology based on the expression of the bait and prey proteins in fusion with two complementary reporter protein fragments, respectively, that will reassemble when in close proximity. The reporter protein can be the enzymes or fluorescent proteins. Recovery of the enzymatic activity or fluorescent signal can be the indicator of PPI between the bait and prey proteins. Significant effort has been invested in developing many derivatives of PCA, along with various applications, in order to address specific questions. Therefore, a prompt review of these applications is important. In this review, we will categorize these applications according to the scenarios that the PCAs were applied and expect to provide a reference guideline for the future selection of PCA methods in solving a specific problem.
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Affiliation(s)
- Peipei Li
- Cancer Center, Faculty of Health Sciences , University of Macau , Macau , SAR of China
| | - Li Wang
- Cancer Center, Faculty of Health Sciences , University of Macau , Macau , SAR of China.,Metabolomics Core, Faculty of Health Sciences , University of Macau , Macau , SAR of China
| | - Li-Jun Di
- Cancer Center, Faculty of Health Sciences , University of Macau , Macau , SAR of China
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6
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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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7
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Xie H, Peng J, Liu C, Fang X, Duan H, Zou Y, Yang Y, Wang C. Aromatic-interaction-mediated inhibition of β-amyloid assembly structures and cytotoxicity. J Pept Sci 2017; 23:679-684. [DOI: 10.1002/psc.3011] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2017] [Revised: 04/24/2017] [Accepted: 04/26/2017] [Indexed: 12/19/2022]
Affiliation(s)
- Hanyi Xie
- CAS Key Laboratory of Biological Effects of Nanomaterials and Nanosafety, CAS Key Laboratory of Standardization and Measurement for Nanotechnology of Nanomaterials and Nanosafety; CAS Center for Excellence in Nanoscience, CAS Center for Excellence in Brain Science, National Center for Nanoscience and Technology; Beijing 100190 PR China
- Academy for Advanced Interdisciplinary Studies; Peking University; Beijing 100871 PR China
| | - Jiaxi Peng
- CAS Key Laboratory of Biological Effects of Nanomaterials and Nanosafety, CAS Key Laboratory of Standardization and Measurement for Nanotechnology of Nanomaterials and Nanosafety; CAS Center for Excellence in Nanoscience, CAS Center for Excellence in Brain Science, National Center for Nanoscience and Technology; Beijing 100190 PR China
| | - Changliang Liu
- CAS Key Laboratory of Biological Effects of Nanomaterials and Nanosafety, CAS Key Laboratory of Standardization and Measurement for Nanotechnology of Nanomaterials and Nanosafety; CAS Center for Excellence in Nanoscience, CAS Center for Excellence in Brain Science, National Center for Nanoscience and Technology; Beijing 100190 PR China
| | - Xiaocui Fang
- CAS Key Laboratory of Biological Effects of Nanomaterials and Nanosafety, CAS Key Laboratory of Standardization and Measurement for Nanotechnology of Nanomaterials and Nanosafety; CAS Center for Excellence in Nanoscience, CAS Center for Excellence in Brain Science, National Center for Nanoscience and Technology; Beijing 100190 PR China
| | - Hongyang Duan
- CAS Key Laboratory of Biological Effects of Nanomaterials and Nanosafety, CAS Key Laboratory of Standardization and Measurement for Nanotechnology of Nanomaterials and Nanosafety; CAS Center for Excellence in Nanoscience, CAS Center for Excellence in Brain Science, National Center for Nanoscience and Technology; Beijing 100190 PR China
- Academy for Advanced Interdisciplinary Studies; Peking University; Beijing 100871 PR China
| | - Yimin Zou
- CAS Key Laboratory of Biological Effects of Nanomaterials and Nanosafety, CAS Key Laboratory of Standardization and Measurement for Nanotechnology of Nanomaterials and Nanosafety; CAS Center for Excellence in Nanoscience, CAS Center for Excellence in Brain Science, National Center for Nanoscience and Technology; Beijing 100190 PR China
| | - Yanlian Yang
- CAS Key Laboratory of Biological Effects of Nanomaterials and Nanosafety, CAS Key Laboratory of Standardization and Measurement for Nanotechnology of Nanomaterials and Nanosafety; CAS Center for Excellence in Nanoscience, CAS Center for Excellence in Brain Science, National Center for Nanoscience and Technology; Beijing 100190 PR China
| | - Chen Wang
- CAS Key Laboratory of Biological Effects of Nanomaterials and Nanosafety, CAS Key Laboratory of Standardization and Measurement for Nanotechnology of Nanomaterials and Nanosafety; CAS Center for Excellence in Nanoscience, CAS Center for Excellence in Brain Science, National Center for Nanoscience and Technology; Beijing 100190 PR China
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8
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β-Sheet interfering molecules acting against β-amyloid aggregation and fibrillogenesis. Bioorg Med Chem 2015; 23:1671-83. [DOI: 10.1016/j.bmc.2015.02.041] [Citation(s) in RCA: 56] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2014] [Revised: 02/09/2015] [Accepted: 02/18/2015] [Indexed: 12/17/2022]
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9
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Cheruvara H, Allen-Baume VL, Kad NM, Mason JM. Intracellular screening of a peptide library to derive a potent peptide inhibitor of α-synuclein aggregation. J Biol Chem 2015; 290:7426-35. [PMID: 25616660 DOI: 10.1074/jbc.m114.620484] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Aggregation of α-synuclein (α-syn) into toxic fibrils is a pathogenic hallmark of Parkinson disease (PD). Studies have focused largely on residues 71-82, yet most early-onset mutations are located between residues 46 and 53. A semirationally designed 209,952-member library based entirely on this region was constructed, containing all wild-type residues and changes associated with early-onset PD. Intracellular cell survival screening and growth competition isolated a 10-residue peptide antagonist that potently inhibits α-syn aggregation and associated toxicity at a 1:1 stoichiometry. This was verified using continuous growth measurements and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide cytotoxicity studies. Atomic force microscopy and circular dichroism on the same samples showed a random-coil structure and no oligomers. A new region of α-syn for inhibitor targeting has been highlighted, together with the approach of using a semirational design and intracellular screening. The peptides can then be used as candidates for modification in drugs capable of slowing or even preventing the onset of PD.
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Affiliation(s)
- Harish Cheruvara
- From the School of Biological Sciences, University of Essex, Wivenhoe Park, Colchester, Essex CO4 3SQ
| | - Victoria L Allen-Baume
- From the School of Biological Sciences, University of Essex, Wivenhoe Park, Colchester, Essex CO4 3SQ
| | - Neil M Kad
- the School of Biosciences, University of Kent, Canterbury, Kent CT2 7NJ, and
| | - Jody M Mason
- the Department of Biology and Biochemistry, University of Bath, Claverton Down, Bath BA2 7AY, United Kingdom
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10
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Rajasekhar K, Chakrabarti M, Govindaraju T. Function and toxicity of amyloid beta and recent therapeutic interventions targeting amyloid beta in Alzheimer's disease. Chem Commun (Camb) 2015; 51:13434-50. [DOI: 10.1039/c5cc05264e] [Citation(s) in RCA: 149] [Impact Index Per Article: 16.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Our Feature Article details the physiological role of amyloid beta (Aβ), elaborates its toxic effects and outlines therapeutic molecules designed in the last two years targeting different aspects of Aβ for preventing AD.
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Affiliation(s)
- K. Rajasekhar
- Bioorganic Chemistry Laboratory
- New Chemistry Unit
- Jawaharlal Nehru Centre for Advanced Scientific Research
- Bengaluru 560064
- India
| | - Malabika Chakrabarti
- Bioorganic Chemistry Laboratory
- New Chemistry Unit
- Jawaharlal Nehru Centre for Advanced Scientific Research
- Bengaluru 560064
- India
| | - T. Govindaraju
- Bioorganic Chemistry Laboratory
- New Chemistry Unit
- Jawaharlal Nehru Centre for Advanced Scientific Research
- Bengaluru 560064
- India
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11
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Cho PY, Joshi G, Johnson JA, Murphy RM. Transthyretin-derived peptides as β-amyloid inhibitors. ACS Chem Neurosci 2014; 5:542-51. [PMID: 24689444 DOI: 10.1021/cn500014u] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Self-association of β-amyloid (Aβ) into soluble oligomers and fibrillar aggregates is associated with Alzheimer's disease pathology, motivating the search for compounds that selectively bind to and inhibit Aβ oligomerization and/or neurotoxicity. Numerous small-molecule inhibitors of Aβ aggregation or toxicity have been reported in the literature. However, because of their greater size and complexity, peptides and peptidomimetics may afford improved specificity and affinity as Aβ aggregation modulators compared to small molecules. Two divergent strategies have been employed in the search for peptides that bind Aβ: (i) using recognition domains corresponding to sequences in Aβ itself (such as KLVFF) and (ii) screening random peptide-based libraries. In this study, we propose a third strategy, specifically, designing peptides that mimic binding domains of Aβ-binding proteins. Transthyretin, a plasma transport protein that is also relatively abundant in cerebrospinal fluid, has been shown to bind to Aβ, inhibit aggregation, and reduce its toxicity. Previously, we identified strand G of transthyretin as a specific Aβ binding domain. In this work we further explore and define the necessary features of this binding domain. We demonstrate that peptides derived from transthyretin bind Aβ and inhibit its toxicity. We also show that, although both transthyretin and transthyretin-derived peptides bind Aβ and inhibit toxicity, they differ significantly in their effect on Aβ aggregation.
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Affiliation(s)
- Patricia Y. Cho
- Department of Chemical and Biological
Engineering, and ‡School of Pharmacy, University of Wisconsin—Madison, Madison, Wisconsin 53706, United States
| | - Gururaj Joshi
- Department of Chemical and Biological
Engineering, and ‡School of Pharmacy, University of Wisconsin—Madison, Madison, Wisconsin 53706, United States
| | - Jeffrey A. Johnson
- Department of Chemical and Biological
Engineering, and ‡School of Pharmacy, University of Wisconsin—Madison, Madison, Wisconsin 53706, United States
| | - Regina M. Murphy
- Department of Chemical and Biological
Engineering, and ‡School of Pharmacy, University of Wisconsin—Madison, Madison, Wisconsin 53706, United States
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12
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Acerra N, Kad NM, Cheruvara H, Mason JM. Intracellular selection of peptide inhibitors that target disulphide-bridged Aβ42 oligomers. Protein Sci 2014; 23:1262-74. [PMID: 24947815 DOI: 10.1002/pro.2509] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2014] [Revised: 06/16/2014] [Accepted: 06/18/2014] [Indexed: 12/31/2022]
Abstract
The β-amyloid (Aβ) peptide aggregates into a number of soluble and insoluble forms, with soluble oligomers thought to be the primary factor implicated in Alzheimer's disease pathology. As a result, a wide range of potential aggregation inhibitors have been developed. However, in addition to problems with solubility and protease susceptibility, many have inadvertently raised the concentration of these soluble neurotoxic species. Sandberg et al. previously reported a β-hairpin stabilized variant of Aβ42 that results from an intramolecular disulphide bridge (A21C/A31C; Aβ42cc), which generates highly toxic oligomeric species incapable of converting into mature fibrils. Using an intracellular protein-fragment complementation (PCA) approach, we have screened peptide libraries using E. coli that harbor an oxidizing environment to permit cytoplasmic disulphide bond formation. Peptides designed to target either the first or second β-strand have been demonstrated to bind to Aβ42cc, lower amyloid cytotoxicity, and confer bacterial cell survival. Peptides have consequently been tested using wild-type Aβ42 via ThT binding assays, circular dichroism, MTT cytotoxicity assays, fluorescence microscopy, and atomic force microscopy. Results demonstrate that amyloid-PCA selected peptides function by both removing amyloid oligomers as well as inhibiting their formation. These data further support the use of semirational design combined with intracellular PCA methodology to develop Aβ antagonists as candidates for modification into drugs capable of slowing or even preventing the onset of AD.
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Affiliation(s)
- Nicola Acerra
- School of Biological Sciences, University of Essex, Wivenhoe Park, Colchester, Essex, CO4 3SQ, United Kingdom
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13
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Acerra N, Kad NM, Griffith DA, Ott S, Crowther DC, Mason JM. Retro-inversal of Intracellular Selected β-Amyloid-Interacting Peptides: Implications for a Novel Alzheimer’s Disease Treatment. Biochemistry 2014; 53:2101-11. [DOI: 10.1021/bi5001257] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Affiliation(s)
- Nicola Acerra
- School
of Biological Sciences, University of Essex, Wivenhoe Park, Colchester CO4 3SQ, U.K
| | - Neil M. Kad
- School
of Biological Sciences, University of Essex, Wivenhoe Park, Colchester CO4 3SQ, U.K
| | - Douglas A. Griffith
- Department
of Genetics, University of Cambridge, Downing Site, Cambridge CB2 3EH, U.K
| | - Stanislav Ott
- Department
of Genetics, University of Cambridge, Downing Site, Cambridge CB2 3EH, U.K
| | - Damian C. Crowther
- Department
of Genetics, University of Cambridge, Downing Site, Cambridge CB2 3EH, U.K
| | - Jody M. Mason
- School
of Biological Sciences, University of Essex, Wivenhoe Park, Colchester CO4 3SQ, U.K
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