1
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Babych M, Garelja ML, Nguyen PT, Hay DL, Bourgault S. Converting the Amyloidogenic Islet Amyloid Polypeptide into a Potent Nonaggregating Peptide Ligand by Side Chain-to-Side Chain Macrocyclization. J Am Chem Soc 2024; 146:25513-25526. [PMID: 39225636 DOI: 10.1021/jacs.4c05297] [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: 09/04/2024]
Abstract
The islet amyloid polypeptide (IAPP), also known as amylin, is a hormone playing key physiological roles. However, its aggregation and deposition in the pancreatic islets are associated with type 2 diabetes. While this peptide adopts mainly a random coil structure in solution, its secondary conformational conversion into α-helix represents a critical step for receptor activation and contributes to amyloid formation and associated cytotoxicity. Considering the large conformational landscape and high amyloidogenicity of the peptide, as well as the complexity of the self-assembly process, it is challenging to delineate the delicate interplay between helical folding, peptide aggregation, and receptor activation. In the present study, we probed the roles of helical folding on the function-toxicity duality of IAPP by restricting its conformational ensemble through side chain-to-side chain stapling via azide-alkyne cycloaddition. Intramolecular macrocyclization (i; i + 4) constrained IAPP into α-helix and inhibited its aggregation into amyloid fibrils. These helical derivatives slowed down the self-assembly of unmodified IAPP. Site-specific macrocyclization modulated the capacity of IAPP to perturb lipid bilayers and cell plasma membrane and reduced, or even fully inhibited, the cytotoxicity associated with aggregation. Furthermore, the α-helical IAPP analogs showed moderate to high potency toward cognate G protein-coupled receptors. Overall, these results indicate that macrocyclization represents a promising strategy to protect an amyloidogenic peptide hormone from aggregation and associated toxicity, while maintaining high receptor activity.
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Affiliation(s)
- Margaryta Babych
- Department of Chemistry, Université du Québec à Montréal, C.P. 8888, Succursale Centre-Ville, Montréal H3C 3P8, Canada
- Quebec Network for Research on Protein Function, Engineering and Applications, PROTEO, C.P. 8888, Succursale Centre-Ville, Montréal H3C 3P8, Canada
| | - Michael L Garelja
- Department of Pharmacology and Toxicology, University of Otago, 18 Frederick Street, Dunedin 9016, New Zealand
| | - Phuong Trang Nguyen
- Department of Chemistry, Université du Québec à Montréal, C.P. 8888, Succursale Centre-Ville, Montréal H3C 3P8, Canada
- Quebec Network for Research on Protein Function, Engineering and Applications, PROTEO, C.P. 8888, Succursale Centre-Ville, Montréal H3C 3P8, Canada
| | - Debbie L Hay
- Department of Pharmacology and Toxicology, University of Otago, 18 Frederick Street, Dunedin 9016, New Zealand
- Maurice Wilkins Centre for Molecular Biodiscovery, University of Auckland, 3A Symonds Street, Auckland 92019, New Zealand
| | - Steve Bourgault
- Department of Chemistry, Université du Québec à Montréal, C.P. 8888, Succursale Centre-Ville, Montréal H3C 3P8, Canada
- Quebec Network for Research on Protein Function, Engineering and Applications, PROTEO, C.P. 8888, Succursale Centre-Ville, Montréal H3C 3P8, Canada
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2
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Kihal N, Archambault MJ, Babych M, Nazemi A, Bourgault S. Probing the molecular determinants of the activation of toll-like receptor 2/6 by amyloid nanostructures through directed peptide self-assembly. SOFT MATTER 2024. [PMID: 39225438 DOI: 10.1039/d4sm00638k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/04/2024]
Abstract
Amyloid fibrils are proteinaceous nanostructures known for their ability to activate the innate immune system, which has been recently exploited for their use as self-adjuvanted antigen delivery systems for vaccines. Among mechanisms of immunostimulation, the activation of the heterodimeric toll-like receptor 2/6 (TLR2/TLR6) by the cross-β-sheet quaternary conformation appears important. Nonetheless, the lack of control over the process of self-assembly and the polydispersity of the resulting supramolecular architectures make it challenging to elucidate the molecular basis of TLR2/TLR6 engagement by amyloid assemblies. In this context, we harnessed the effects of N- and C-terminal modifications of a short 10-mer β-peptide derived from the islet amyloid polypeptide (I10) to investigate the relationships between the morphology and physicochemical properties of amyloid assemblies and their TLR2/TLR6 activity. Chemical substitutions at the N- and C-termini of the I10 peptide, including addition of charged residues at the N-terminus and α-amidation of C-terminus, allowed the controlled formation of a diversity of architectures, including belt-like filaments, rigid nanorods as well as flat and twisted fibrils. These fully cytocompatible peptide nanostructures showed different potencies to activate TLR2/TLR6, which correlated with the charge exposed on the surface. These results further demonstrate the potent modulatory effect of N- and C-terminal electrostatic capping on the self-assembly of short synthetic β-peptides. This study also indicates that self-assembly into cross-β-sheet nanostructures is essential for the activation of the TLR2/TLR6 by amyloidogenic peptides, albeit the structural requirements of the engagement of this promiscuous immune receptor by the nanostructures remain challenging to precisely untangle.
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Affiliation(s)
- Nadjib Kihal
- Department of Chemistry, Université du Québec à Montréal. C.P.8888, Succursale Centre-Ville, Montréal, H3C 3P8, Canada.
- Quebec Network for Research on Protein Function, Engineering and Applications (PROTEO), Québec, Canada
- Quebec Centre for Advanced Materials, QCAM, Montreal, Canada
| | - Marie-Jeanne Archambault
- Department of Chemistry, Université du Québec à Montréal. C.P.8888, Succursale Centre-Ville, Montréal, H3C 3P8, Canada.
- Quebec Network for Research on Protein Function, Engineering and Applications (PROTEO), Québec, Canada
| | - Margaryta Babych
- Department of Chemistry, Université du Québec à Montréal. C.P.8888, Succursale Centre-Ville, Montréal, H3C 3P8, Canada.
- Quebec Network for Research on Protein Function, Engineering and Applications (PROTEO), Québec, Canada
| | - Ali Nazemi
- Department of Chemistry, Université du Québec à Montréal. C.P.8888, Succursale Centre-Ville, Montréal, H3C 3P8, Canada.
- Quebec Centre for Advanced Materials, QCAM, Montreal, Canada
| | - Steve Bourgault
- Department of Chemistry, Université du Québec à Montréal. C.P.8888, Succursale Centre-Ville, Montréal, H3C 3P8, Canada.
- Quebec Network for Research on Protein Function, Engineering and Applications (PROTEO), Québec, Canada
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3
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Nagy Á, Abouzayed A, Kanellopoulos P, Landmark F, Bezverkhniaia E, Tolmachev V, Orlova A, Eriksson Karlström A. Evaluation of ABD-Linked RM26 Conjugates for GRPR-Targeted Drug Delivery. ACS OMEGA 2024; 9:36122-36133. [PMID: 39220525 PMCID: PMC11359615 DOI: 10.1021/acsomega.4c00489] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/15/2024] [Revised: 05/10/2024] [Accepted: 07/31/2024] [Indexed: 09/04/2024]
Abstract
Targeting the gastrin-releasing peptide receptor (GRPR) with the bombesin analogue RM26, a 9 aa peptide, has been a promising strategy for cancer theranostics, with recent success in radionuclide imaging of prostate cancer. However, therapeutic application of the short peptide RM26 would require a longer half-life to prevent fast clearance from the circulation. Conjugation to an albumin-binding domain (ABD) is a viable strategy to extend the in vivo half-life of peptides and proteins. We previously reported an ABD-fused RM26 peptide targeting GRPR (ABD-RM26 Gen 1) that showed prolonged and stable tumor uptake over 144 h; however, the observed high kidney uptake indicated that the conjugate's binding to albumin was reduced and that this could be an obstacle for its use as a delivery system for targeted therapy, especially for radiotherapy. Here, we have designed, produced, and preclinically evaluated a series of novel ABD-RM26 conjugates with the aim of improving the conjugate's binding to albumin and decreasing the kidney uptake. We developed three second-generation constructs with varying formats, differing in the relative positions of the targeting moieties and the radionuclide chelator. The produced conjugates were radiolabeled with indium-111 and evaluated in vitro and in vivo. All constructs displayed improved biophysical characteristics, biodistribution, and lower kidney uptake compared to previously reported first-generation molecules. The ABD-RM26 Gen 2A conjugate showed the best biodistribution profile with a nearly 6-fold reduction in kidney uptake. However, the ABD-RM26 Gen 2A conjugate's binding to GRPR was compromised. This conjugate's assembly of albumin- and GRPR-binding moieties might be used for further development of drug conjugates for targeted therapy/radiotherapy of GRPR-expressing cancers.
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Affiliation(s)
- Ábel Nagy
- Department
of Protein Science, School of Engineering Sciences in Chemistry, Biotechnology
and Health, KTH Royal Institute of Technology, AlbaNova University Center, 106 91 Stockholm, Sweden
| | - Ayman Abouzayed
- Department
of Medicinal Chemistry, Uppsala University, 752 37 Uppsala, Sweden
| | | | - Fredrika Landmark
- Department
of Protein Science, School of Engineering Sciences in Chemistry, Biotechnology
and Health, KTH Royal Institute of Technology, AlbaNova University Center, 106 91 Stockholm, Sweden
| | - Ekaterina Bezverkhniaia
- Department
of Medicinal Chemistry, Uppsala University, 752 37 Uppsala, Sweden
- Research
Centrum for Oncotheranostics, Research School of Chemistry and Applied
Biomedical Sciences, Tomsk Polytechnic University, 634009 Tomsk, Russia
| | - Vladimir Tolmachev
- Department
of Immunology, Genetics and Pathology, Uppsala
University, 752 37 Uppsala, Sweden
| | - Anna Orlova
- Department
of Medicinal Chemistry, Uppsala University, 752 37 Uppsala, Sweden
- Science for
Life Laboratory, Uppsala University, 752 37 Uppsala, Sweden
| | - Amelie Eriksson Karlström
- Department
of Protein Science, School of Engineering Sciences in Chemistry, Biotechnology
and Health, KTH Royal Institute of Technology, AlbaNova University Center, 106 91 Stockholm, Sweden
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4
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Pesce G, Gondelaud F, Ptchelkine D, Bignon C, Fourquet P, Longhi S. Dissecting Henipavirus W proteins conformational and fibrillation properties: contribution of their N- and C-terminal constituent domains. FEBS J 2024. [PMID: 39180270 DOI: 10.1111/febs.17239] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2024] [Revised: 05/07/2024] [Accepted: 07/23/2024] [Indexed: 08/26/2024]
Abstract
The Nipah and Hendra viruses are severe human pathogens. In addition to the P protein, their P gene also encodes the V and W proteins that share with P their N-terminal intrinsically disordered domain (NTD) and possess distinct C-terminal domains (CTDs). The W protein is a key player in the evasion of the host innate immune response. We previously showed that the W proteins are intrinsically disordered and can form amyloid-like fibrils. However, structural information on W CTD (CTDW) and its potential contribution to the fibrillation process is lacking. In this study, we demonstrate that CTDWS are disordered and able to form dimers mediated by disulfide bridges. We also show that the NTD and the CTDW interact with each other and that this interaction triggers both a gain of secondary structure and a chain compaction within the NTD. Finally, despite the lack of intrinsic fibrillogenic properties, we show that the CTDW favors the formation of fibrils by the NTD both in cis and in trans. Altogether, the results herein presented shed light on the molecular mechanisms underlying Henipavirus pathogenesis and may thus contribute to the development of targeted therapies.
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Affiliation(s)
- Giulia Pesce
- Laboratoire Architecture et Fonction des Macromolécules Biologiques (AFMB), UMR 7257, Centre National de la Recherche Scientifique (CNRS) and Aix Marseille University, France
| | - Frank Gondelaud
- Laboratoire Architecture et Fonction des Macromolécules Biologiques (AFMB), UMR 7257, Centre National de la Recherche Scientifique (CNRS) and Aix Marseille University, France
| | - Denis Ptchelkine
- Laboratoire Architecture et Fonction des Macromolécules Biologiques (AFMB), UMR 7257, Centre National de la Recherche Scientifique (CNRS) and Aix Marseille University, France
| | - Christophe Bignon
- Laboratoire Architecture et Fonction des Macromolécules Biologiques (AFMB), UMR 7257, Centre National de la Recherche Scientifique (CNRS) and Aix Marseille University, France
| | - Patrick Fourquet
- INSERM, Centre de Recherche en Cancérologie de Marseille (CRCM), Centre National de la Recherche Scientifique (CNRS), Marseille Protéomique, Institut Paoli-Calmettes, Aix Marseille University, France
| | - Sonia Longhi
- Laboratoire Architecture et Fonction des Macromolécules Biologiques (AFMB), UMR 7257, Centre National de la Recherche Scientifique (CNRS) and Aix Marseille University, France
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5
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Andrews B, Schweitzer-Stenner R, Urbanc B. Intrinsic Conformational Dynamics of Glycine and Alanine in Polarizable Molecular Dynamics Force Fields: Comparison to Spectroscopic Data. J Phys Chem B 2024; 128:6217-6231. [PMID: 38877893 PMCID: PMC11215781 DOI: 10.1021/acs.jpcb.4c02278] [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: 04/09/2024] [Revised: 05/29/2024] [Accepted: 05/30/2024] [Indexed: 06/28/2024]
Abstract
Molecular dynamics (MD) is a great tool for elucidating conformational dynamics of proteins and peptides in water at the atomistic level that often surpasses the level of detail available experimentally. Structure predictions, however, are limited by the accuracy of the underlying MD force field. This limitation is particularly stark in the case of intrinsically disordered peptides and proteins, which are characterized by solvent-accessible and disordered peptide regions and domains. Recent studies show that most additive MD force fields, including CHARMM36m, do not reproduce the intrinsic conformational distributions of guest amino acid residues x in cationic GxG peptides in water in line with experimental data. Positing that a lack of polarizability in additive MD force fields may be the culprit for the reported discrepancies, we here examine the conformational dynamics of guest glycine and alanine residues in cationic GxG peptides in water using two polarizable MD force fields, CHARMM Drude and AMOEBA. Our results indicate that while AMOEBA captures the experimental data better than CHARMM Drude, neither of the two polarizable force fields offers an improvement of the Ramachandran distributions of glycine and alanine residues in cationic GGG and GAG peptides, respectively, over CHARMM36m.
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Affiliation(s)
- Brian Andrews
- Department
of Physics, Drexel University, Philadelphia, Pennsylvania 19104, United States
| | | | - Brigita Urbanc
- Department
of Physics, Drexel University, Philadelphia, Pennsylvania 19104, United States
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6
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Wu H, Hoare BL, Handley TNG, Akhter Hossain M, Bathgate RAD. Development of a synthetic relaxin-3/INSL5 chimeric peptide ligand for NanoBiT complementation binding assays. Biochem Pharmacol 2024; 224:116238. [PMID: 38677442 DOI: 10.1016/j.bcp.2024.116238] [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] [Received: 01/16/2024] [Revised: 04/09/2024] [Accepted: 04/25/2024] [Indexed: 04/29/2024]
Abstract
INSL5 and relaxin-3 are relaxin family peptides with important roles in gut and brain function, respectively. They mediate their actions through the class A GPCRs RXFP4 and RXFP3. RXFP4 has been proposed to be a therapeutic target for colon motility disorders whereas RXFP3 targeting could be effective for neurological conditions such as anxiety. Validation of these targets has been limited by the lack of specific ligands and the availability of robust ligand-binding assays for their development. In this study, we have utilized NanoBiT complementation to develop a SmBiT-conjugated tracer for use with LgBiT-fused RXFP3 and RXFP4. The low affinity between LgBiT:SmBiT should result in a low non-specific luminescence signal and enable the quantification of binding without the tedious separation of non-bound ligands. We used solid-phase peptide synthesis to produce a SmBiT-labelled RXFP3/4 agonist, R3/I5, where SmBiT was conjugated to the B-chain N-terminus via a PEG12 linker. Both SmBiT-R3/I5 and R3/I5 were synthesized and purified in high purity and yield. Stable HEK293T cell lines expressing LgBiT-RXFP3 and LgBiT-RXFP4 were produced and demonstrated normal signaling in response to the synthetic R3/I5 peptide. Binding was first characterized in whole-cell binding kinetic assays validating that the SmBiT-R3/I5 bound to both cell lines with nanomolar affinity with minimal non-specific binding without bound and free SmBiT-R3/I5 separation. We then optimized membrane binding assays, demonstrating easy and robust analysis of both saturation and competition binding from frozen membranes. These assays therefore provide an appropriate rigorous binding assay for the high-throughput analysis of RXFP3 and RXFP4 ligands.
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Affiliation(s)
- Hongkang Wu
- The Florey, University of Melbourne, Victoria, Australia
| | | | | | - Mohammed Akhter Hossain
- The Florey, University of Melbourne, Victoria, Australia; School of Chemistry, University of Melbourne, Victoria, Australia; Department of Biochemistry and Pharmacology, University of Melbourne, Victoria, Australia.
| | - Ross A D Bathgate
- The Florey, University of Melbourne, Victoria, Australia; Department of Biochemistry and Pharmacology, University of Melbourne, Victoria, Australia.
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7
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Mi T, Nguyen D, Gao Z, Burgess K. Bioinformatics leading to conveniently accessible, helix enforcing, bicyclic ASX motif mimics (BAMMs). Nat Commun 2024; 15:4217. [PMID: 38760359 PMCID: PMC11101637 DOI: 10.1038/s41467-024-48323-z] [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: 08/14/2023] [Accepted: 04/29/2024] [Indexed: 05/19/2024] Open
Abstract
Helix mimicry provides probes to perturb protein-protein interactions (PPIs). Helical conformations can be stabilized by joining side chains of non-terminal residues (stapling) or via capping fragments. Nature exclusively uses capping, but synthetic helical mimics are heavily biased towards stapling. This study comprises: (i) creation of a searchable database of unique helical N-caps (ASX motifs, a protein structural motif with two intramolecular hydrogen-bonds between aspartic acid/asparagine and following residues); (ii) testing trends observed in this database using linear peptides comprising only canonical L-amino acids; and, (iii) novel synthetic N-caps for helical interface mimicry. Here we show many natural ASX motifs comprise hydrophobic triangles, validate their effect in linear peptides, and further develop a biomimetic of them, Bicyclic ASX Motif Mimics (BAMMs). BAMMs are powerful helix inducing motifs. They are synthetically accessible, and potentially useful to a broad section of the community studying disruption of PPIs using secondary structure mimics.
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Affiliation(s)
- Tianxiong Mi
- Department of Chemistry, Texas A & M University, College Station, TX, 77842, USA
| | - Duyen Nguyen
- Department of Chemistry, Texas A & M University, College Station, TX, 77842, USA
| | - Zhe Gao
- Department of Chemistry, Texas A & M University, College Station, TX, 77842, USA
| | - Kevin Burgess
- Department of Chemistry, Texas A & M University, College Station, TX, 77842, USA.
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8
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Dinic J, Tirrell MV. Effects of Charge Sequence Pattern and Lysine-to-Arginine Substitution on the Structural Stability of Bioinspired Polyampholytes. Biomacromolecules 2024; 25:2838-2851. [PMID: 38567844 PMCID: PMC11094733 DOI: 10.1021/acs.biomac.4c00002] [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: 01/01/2024] [Revised: 03/17/2024] [Accepted: 03/18/2024] [Indexed: 05/14/2024]
Abstract
A comprehensive study focusing on the combined influence of the charge sequence pattern and the type of positively charged amino acids on the formation of secondary structures in sequence-specific polyampholytes is presented. The sequences of interest consisting exclusively of ionizable amino acids (lysine, K; arginine, R; and glutamic acid, E) are (EKEK)5, (EKKE)5, (ERER)5, (ERRE)5, and (EKER)5. The stability of the secondary structure was examined at three pH values in the presence of urea and NaCl. The results presented here underscore the combined prominent effects of the charge sequence pattern and the type of positively charged monomers on secondary structure formation. Additionally, (ERRE)5 readily aggregated across a wide range of pH. In contrast, sequences with the same charge pattern, (EKKE)5, as well as the sequences with the equivalent amino acid content, (ERER)5, exhibited no aggregate formation under equivalent pH and concentration conditions.
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Affiliation(s)
- Jelena Dinic
- Pritzker
School of Molecular Engineering, University
of Chicago, Chicago, Illinois 60637, United States
- Center
for Molecular Engineering and Materials Science Division, Argonne National Laboratory, Lemont, Illinois 60439, United States
| | - Matthew V. Tirrell
- Pritzker
School of Molecular Engineering, University
of Chicago, Chicago, Illinois 60637, United States
- Center
for Molecular Engineering and Materials Science Division, Argonne National Laboratory, Lemont, Illinois 60439, United States
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9
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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.
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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
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10
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Zavrtanik U, Lah J, Hadži S. Estimation of Peptide Helicity from Circular Dichroism Using the Ensemble Model. J Phys Chem B 2024; 128:2652-2663. [PMID: 38470351 PMCID: PMC10961730 DOI: 10.1021/acs.jpcb.3c07511] [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: 11/14/2023] [Revised: 02/27/2024] [Accepted: 02/28/2024] [Indexed: 03/13/2024]
Abstract
An established method for the quantitation of the helix content in peptides using circular dichroism (CD) relies on the linear spectroscopic model. This model assumes an average value of the helix-length correction for all peptide conformers, irrespective of the length of the helical segment. Here we assess the validity of this approximation and introduce a more physically realistic ensemble-based analysis of the CD signal in which the length correction is assigned specifically to each ensemble conformer. We demonstrate that the linear model underestimates peptide helicity, with the difference depending on the ensemble composition. We developed a computer program that implements the ensemble model to estimate the peptide helicity. Using this model and the CD data set covering a broad range of helicities, we recalibrate CD baseline parameters and redetermine helix-coil parameters for the alanine-rich peptide. We show that the ensemble model leverages small differences in signal between conformers to extract more information from the experimental data, enabling the determination of several poorly defined quantities, such as the nucleation constant and heat capacity change associated with helix folding. Overall, the presented ensemble-based treatment of the CD signal, together with the recalibrated values of the spectroscopic baseline parameters, provides a coherent framework for the analysis of the peptide helix content.
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Affiliation(s)
- Uroš Zavrtanik
- Department of Physical Chemistry,
Faculty of Chemistry and Chemical Technology, University of Ljubljana, 1000 Ljubljana, Slovenia
| | - Jurij Lah
- Department of Physical Chemistry,
Faculty of Chemistry and Chemical Technology, University of Ljubljana, 1000 Ljubljana, Slovenia
| | - San Hadži
- Department of Physical Chemistry,
Faculty of Chemistry and Chemical Technology, University of Ljubljana, 1000 Ljubljana, Slovenia
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11
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Lee PY, Singh O, Nanajkar N, Bermudez H, Matysiak S. Opposing roles of organic salts on mini-protein structure. Phys Chem Chem Phys 2024; 26:8973-8981. [PMID: 38436427 DOI: 10.1039/d3cp05607d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/05/2024]
Abstract
We investigated the effects of 1-ethyl-3-methylimidazolium chloride ([EMIM][Cl]) and choline chloride ([Chol][Cl]) on the local environment and conformational landscapes of Trp-cage and Trpzip4 mini-proteins using experimental and computational approaches. Fluorescence experiments and computational simulations revealed distinct behaviors of the mini-proteins in the presence of these organic salts. [EMIM][Cl] showed a strong interaction with Trp-cage, leading to fluorescence quenching and destabilization of its native structural interactions. Conversely, [Chol][Cl] had a negligible impact on Trp-cage fluorescence at low concentrations but increased it at high concentrations, indicating a stabilizing role. Computational simulations elucidated that [EMIM][Cl] disrupted the hydrophobic core packing and decreased proline-aromatic residue contacts in Trp-cage, resulting in a more exposed environment for Trp residues. In contrast, [Chol][Cl] subtly influenced the hydrophobic core packing, creating a hydrophobic environment near the tryptophan residues. Circular dichroism experiments revealed that [Chol][Cl] stabilized the secondary structure of both mini-proteins, although computational simulations did not show significant changes in secondary content at the explored concentrations. The simulations also demonstrated a more rugged free energy landscape for Trp-cage and Trpzip4 in [EMIM][Cl], suggesting destabilization of the tertiary structure for Trp-cage and secondary structure for Trpzip4. Similar fluorescence trends were observed for Trpzip4, with [EMIM][Cl] quenching fluorescence and exhibiting stronger interaction, while [Chol][Cl] increased the fluorescence at high concentrations. These findings highlight the interplay between [EMIM][Cl] and [Chol][Cl] with the mini-proteins and provide a detailed molecular-level understanding of how these organic salts impact the nearby surroundings and structural variations. Understanding such interactions is valuable for diverse applications, from biochemistry to materials science.
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Affiliation(s)
- Pei-Yin Lee
- Chemical Physics Program, Institute for Physical Science and Technology, University of Maryland, College Park, USA
| | - Onkar Singh
- Department of Polymer Science and Engineering, University of Massachusetts, Amherst, MA, USA.
| | - Neha Nanajkar
- Department of Biology, University of Maryland, College Park, USA
| | - Harry Bermudez
- Department of Polymer Science and Engineering, University of Massachusetts, Amherst, MA, USA.
| | - Silvina Matysiak
- Fischell Department of Bioengineering, University of Maryland, College Park, USA.
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12
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Takechi-Haraya Y, Ohgita T, Usui A, Nishitsuji K, Uchimura K, Abe Y, Kawano R, Konaklieva MI, Reimund M, Remaley AT, Sato Y, Izutsu KI, Saito H. Structural flexibility of apolipoprotein E-derived arginine-rich peptides improves their cell penetration capability. Sci Rep 2023; 13:19396. [PMID: 37938626 PMCID: PMC10632520 DOI: 10.1038/s41598-023-46754-0] [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: 08/17/2023] [Accepted: 11/04/2023] [Indexed: 11/09/2023] Open
Abstract
Amphipathic arginine-rich peptide, A2-17, exhibits moderate perturbation of lipid membranes and the highest cell penetration among its structural isomers. We investigated the direct cell-membrane penetration mechanism of the A2-17 peptide while focusing on structural flexibility. We designed conformationally constrained versions of A2-17, stapled (StpA2-17) and stitched (StchA2-17), whose α-helical conformations were stabilized by chemical crosslinking. Circular dichroism confirmed that StpA2-17 and StchA2-17 had higher α-helix content than A2-17 in aqueous solution. Upon liposome binding, only A2-17 exhibited a coil-to-helix transition. Confocal microscopy revealed that A2-17 had higher cell penetration efficiency than StpA2-17, whereas StchA2-17 remained on the cell membrane without cell penetration. Although the tryptophan fluorescence analysis suggested that A2-17 and its analogs had similar membrane-insertion positions between the interface and hydrophobic core, StchA2-17 exhibited a higher membrane affinity than A2-17 or StpA2-17. Atomic force microscopy demonstrated that A2-17 reduced the mechanical rigidity of liposomes to a greater extent than StpA2-17 and StchA2-17. Finally, electrophysiological analysis showed that A2-17 induced a higher charge influx through transient pores in a planer lipid bilayer than StpA2-17 and StchA2-17. These findings indicate that structural flexibility, which enables diverse conformations of A2-17, leads to a membrane perturbation mode that contributes to cell membrane penetration.
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Affiliation(s)
- Yuki Takechi-Haraya
- Division of Drugs, National Institute of Health Sciences, 3-25-26 Tonomachi, Kawasaki-ku, Kawasaki, 210-9501, Japan.
| | - Takashi Ohgita
- Center for Instrumental Analysis, Kyoto Pharmaceutical University, 1 Misasagi-Shichono-cho, Yamashina-ku, Kyoto, 607-8412, Japan
| | - Akiko Usui
- Division of Drugs, National Institute of Health Sciences, 3-25-26 Tonomachi, Kawasaki-ku, Kawasaki, 210-9501, Japan
| | - Kazuchika Nishitsuji
- Department of Biochemistry, Wakayama Medical University, 811-1 Kimiidera, Wakayama, 641-8509, Japan
- Unité de Glycobiologie Structurale et Fonctionnelle, UMR 8576 CNRS, Université de Lille, 59655, Villeneuve d'Ascq, France
| | - Kenji Uchimura
- Unité de Glycobiologie Structurale et Fonctionnelle, UMR 8576 CNRS, Université de Lille, 59655, Villeneuve d'Ascq, France
| | - Yasuhiro Abe
- Division of Drugs, National Institute of Health Sciences, 3-25-26 Tonomachi, Kawasaki-ku, Kawasaki, 210-9501, Japan
| | - Ryuji Kawano
- Department of Biotechnology and Life Science, Tokyo University of Agriculture and Technology, 2-24-6 Naka-cho, Koganei, Tokyo, 184-8588, Japan
| | - Monika I Konaklieva
- Department of Chemistry, American University, 4400 Massachusetts Avenue NW, Washington, DC, 20016-8014, USA
| | - Mart Reimund
- Lipoprotein Metabolism Laboratory, Translational Vascular Medicine Branch, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Alan T Remaley
- Lipoprotein Metabolism Laboratory, Translational Vascular Medicine Branch, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Yoji Sato
- Division of Drugs, National Institute of Health Sciences, 3-25-26 Tonomachi, Kawasaki-ku, Kawasaki, 210-9501, Japan
| | - Ken-Ichi Izutsu
- School of Pharmacy Department of Pharmaceutical Sciences, International University of Health and Welfare, 2600-1 Kitakanemaru, Otawara, Tochigi, 324-8501, Japan
| | - Hiroyuki Saito
- Department of Biophysical Chemistry, Kyoto Pharmaceutical University, 5 Misasagi-Nakauchi-cho, Yamashina-ku, Kyoto, 607-8414, Japan
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13
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Uceda AB, Frau J, Vilanova B, Adrover M. Tyrosine Nitroxidation Does Not Affect the Ability of α-Synuclein to Bind Anionic Micelles, but It Diminishes Its Ability to Bind and Assemble Synaptic-like Vesicles. Antioxidants (Basel) 2023; 12:1310. [PMID: 37372040 DOI: 10.3390/antiox12061310] [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: 05/15/2023] [Revised: 06/15/2023] [Accepted: 06/17/2023] [Indexed: 06/29/2023] Open
Abstract
Parkinson's disease (PD) is characterized by dopaminergic neuron degeneration and the accumulation of neuronal inclusions known as Lewy bodies, which are formed by aggregated and post-translationally modified α-synuclein (αS). Oxidative modifications such as the formation of 3-nitrotyrosine (3-NT) or di-tyrosine are found in αS deposits, and they could be promoted by the oxidative stress typical of PD brains. Many studies have tried to elucidate the molecular mechanism correlating nitroxidation, αS aggregation, and PD. However, it is unclear how nitroxidation affects the physiological function of αS. To clarify this matter, we synthetized an αS with its Tyr residues replaced by 3-NT. Its study revealed that Tyr nitroxidation had no effect on either the affinity of αS towards anionic micelles nor the overall structure of the micelle-bound αS, which retained its α-helical folding. Nevertheless, we observed that nitroxidation of Y39 lengthened the disordered stretch bridging the two consecutive α-helices. Conversely, the affinity of αS towards synaptic-like vesicles diminished as a result of Tyr nitroxidation. Additionally, we also proved that nitroxidation precluded αS from performing its physiological function as a catalyst of the clustering and the fusion of synaptic vesicles. Our findings represent a step forward towards the completion of the puzzle that must explain the molecular mechanism behind the link between αS-nitroxidation and PD.
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Affiliation(s)
- Ana Belén Uceda
- Health Research Institute of the Balearic Islands (IdISBa), E-07120 Palma de Mallorca, Spain
- Departament de Química, Universitat de les Illes Balears, Ctra. Valldemossa km 7.5, E-07122 Palma de Mallorca, Spain
| | - Juan Frau
- Health Research Institute of the Balearic Islands (IdISBa), E-07120 Palma de Mallorca, Spain
- Departament de Química, Universitat de les Illes Balears, Ctra. Valldemossa km 7.5, E-07122 Palma de Mallorca, Spain
| | - Bartolomé Vilanova
- Health Research Institute of the Balearic Islands (IdISBa), E-07120 Palma de Mallorca, Spain
- Departament de Química, Universitat de les Illes Balears, Ctra. Valldemossa km 7.5, E-07122 Palma de Mallorca, Spain
| | - Miquel Adrover
- Health Research Institute of the Balearic Islands (IdISBa), E-07120 Palma de Mallorca, Spain
- Departament de Química, Universitat de les Illes Balears, Ctra. Valldemossa km 7.5, E-07122 Palma de Mallorca, Spain
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14
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Yamada Y, Nishizono K, Kano M, Koreki S, Nagahora N, Nibu Y. Spectroscopic and Theoretical Studies on Conformational Stability of Benzyl Methyl Ether. J Phys Chem A 2023. [PMID: 37262017 DOI: 10.1021/acs.jpca.3c01843] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Conformer-selected electronic and vibrational spectra of benzyl methyl ether and its terminal methyl group-substituted derivative in a supersonic jet have been measured using ultraviolet (UV)-UV hole burning and fluorescence-detected infrared spectroscopy to investigate the conformational stability of flexible molecules. Various quantum chemical calculations as well as experimental observations reveal the coexistence of three conformers with different CCOC dihedral angles and side-chain orientations relative to the benzene ring plane. Vibrational analysis in the excited state with time-dependent density functional theory and IR simulations containing anharmonic coupling sufficiently reproduce the experimental results, suggesting that these three conformers can be distinguished into one gauche-conformer and two trans-ones with respect to the CCOC dihedral angle. We also observe that the gauche conformer exhibits higher-frequency CH2 modes. The natural bond orbital analysis indicates that this phenomenon is attributed to the electron delocalization from the non-bonding orbitals and the C-O orbitals associated with the neighboring oxygen atom, which leads to a conformer dependence of the methylene C-H bond strength.
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Affiliation(s)
- Yuji Yamada
- Department of Chemistry, Graduate School of Science, Fukuoka University, Jonan-ku, Fukuoka 814-0180, Japan
| | - Kohei Nishizono
- Department of Chemistry, Graduate School of Science, Fukuoka University, Jonan-ku, Fukuoka 814-0180, Japan
| | - Mai Kano
- Department of Chemistry, Graduate School of Science, Fukuoka University, Jonan-ku, Fukuoka 814-0180, Japan
| | - Satomi Koreki
- Department of Chemistry, Graduate School of Science, Fukuoka University, Jonan-ku, Fukuoka 814-0180, Japan
| | - Noriyoshi Nagahora
- Department of Chemistry, Graduate School of Science, Fukuoka University, Jonan-ku, Fukuoka 814-0180, Japan
| | - Yoshinori Nibu
- Department of Chemistry, Graduate School of Science, Fukuoka University, Jonan-ku, Fukuoka 814-0180, Japan
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15
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Hossain MA, Praveen P, Noorzi NA, Wu H, Harrison IP, Handley T, Selemidis S, Samuel CS, Bathgate RAD. Development of Novel High-Affinity Antagonists for the Relaxin Family Peptide Receptor 1. ACS Pharmacol Transl Sci 2023; 6:842-853. [PMID: 37200817 PMCID: PMC10186362 DOI: 10.1021/acsptsci.3c00053] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2023] [Indexed: 05/20/2023]
Abstract
H2 relaxin is a peptide hormone that exerts its biological actions through the G protein-coupled receptor, RXFP1. The numerous important biological functions of H2 relaxin, including potent renal, vasodilatory, cardioprotective, and anti-fibrotic actions, have resulted in considerable interest in its use as a therapeutic for various cardiovascular diseases and other fibrotic indications. Interestingly though, H2 relaxin and RXFP1 have been shown to be overexpressed in prostate cancer, allowing for the downregulation or blocking of relaxin/RXFP1 to decrease prostate tumor growth. These findings suggest the application of an RXFP1 antagonist for the treatment of prostate cancer. However, these therapeutically relevant actions are still poorly understood and have been hindered by the lack of a high-affinity antagonist. In this study, we chemically synthesized three novel H2 relaxin analogues that have complex insulin-like structures with two chains (A and B) and three disulfide bridges. We report here the structure-activity relationship studies on H2 relaxin that resulted in the development of a novel high-affinity RXFP1 antagonist, H2 B-R13HR (∼40 nM), that has only one extra methylene group in the side chain of arginine 13 in the B-chain (ArgB13) of H2 relaxin. Most notably, the synthetic peptide was shown to be active in a mouse model of prostate tumor growth in vivo where it inhibited relaxin-mediated tumor growth. Our compound H2 B-R13HR will be an important research tool to understand relaxin actions through RXFP1 and may be a potential lead compound for the treatment of prostate cancer.
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Affiliation(s)
- Mohammed Akhter Hossain
- Florey
Institute of Neuroscience and Mental Health, University of Melbourne, Parkville 3010, Victoria, Australia
- School
of Chemistry, University of Melbourne, Parkville 3010, Victoria, Australia
- Department
of Biochemistry and Pharmacology, University
of Melbourne, Parkville 3010, Victoria, Australia
| | - Praveen Praveen
- Florey
Institute of Neuroscience and Mental Health, University of Melbourne, Parkville 3010, Victoria, Australia
| | - Nurhayati Ahmad Noorzi
- Cardiovascular
Disease Program, Monash Biomedicine Discovery Institute, Monash University, Clayton 3800, Victoria, Australia
- Department
of Pharmacology, Monash University, Clayton 3800, Victoria, Australia
| | - Hongkang Wu
- Florey
Institute of Neuroscience and Mental Health, University of Melbourne, Parkville 3010, Victoria, Australia
- Department
of Biochemistry and Pharmacology, University
of Melbourne, Parkville 3010, Victoria, Australia
| | - Ian P. Harrison
- Cardiovascular
Disease Program, Monash Biomedicine Discovery Institute, Monash University, Clayton 3800, Victoria, Australia
- Department
of Pharmacology, Monash University, Clayton 3800, Victoria, Australia
| | - Thomas Handley
- Florey
Institute of Neuroscience and Mental Health, University of Melbourne, Parkville 3010, Victoria, Australia
| | - Stavros Selemidis
- School
of
Health and Biomedical Sciences, RMIT University, Bundoora 3083, Victoria, Australia
| | - Chrishan S. Samuel
- Cardiovascular
Disease Program, Monash Biomedicine Discovery Institute, Monash University, Clayton 3800, Victoria, Australia
- Department
of Pharmacology, Monash University, Clayton 3800, Victoria, Australia
| | - Ross A. D. Bathgate
- Florey
Institute of Neuroscience and Mental Health, University of Melbourne, Parkville 3010, Victoria, Australia
- Department
of Biochemistry and Pharmacology, University
of Melbourne, Parkville 3010, Victoria, Australia
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16
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Webb KR, Hess KA, Shmidt A, Segner KD, Buchanan LE. Probing local changes to α-helical structures with 2D IR spectroscopy and isotope labeling. Biophys J 2023; 122:1491-1502. [PMID: 36906800 PMCID: PMC10147839 DOI: 10.1016/j.bpj.2023.03.014] [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: 05/24/2022] [Revised: 10/13/2022] [Accepted: 03/08/2023] [Indexed: 03/12/2023] Open
Abstract
α-Helical secondary structures impart specific mechanical and physiochemical properties to peptides and proteins, enabling them to perform a vast array of molecular tasks ranging from membrane insertion to molecular allostery. Loss of α-helical content in specific regions can inhibit native protein function or induce new, potentially toxic, biological activities. Thus, identifying specific residues that exhibit loss or gain of helicity is critical for understanding the molecular basis of function. Two-dimensional infrared (2D IR) spectroscopy coupled with isotope labeling is capable of capturing detailed structural changes in polypeptides. Yet, questions remain regarding the inherent sensitivity of isotope-labeled modes to local changes in α-helicity, such as terminal fraying; the origin of spectral shifts (hydrogen-bonding versus vibrational coupling); and the ability to definitively detect coupled isotopic signals in the presence of overlapping side chains. Here, we address each of these points individually by characterizing a short, model α-helix (DPAEAAKAAAGR-NH2) with 2D IR and isotope labeling. These results demonstrate that pairs of 13C18O probes placed three residues apart can detect subtle structural changes and variations along the length of the model peptide as the α-helicity is systematically tuned. Comparison of singly and doubly labeled peptides affirm that frequency shifts arise primarily from hydrogen-bonding, while vibrational coupling between paired isotopes leads to increased peak areas that can be clearly differentiated from underlying side-chain modes or uncoupled isotope labels not participating in helical structures. These results demonstrate that 2D IR in tandem with i,i+3 isotope-labeling schemes can capture residue-specific molecular interactions within a single turn of an α-helix.
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Affiliation(s)
| | - Kayla Anne Hess
- Department of Chemistry, Vanderbilt University, Nashville, Tennessee
| | - Alisa Shmidt
- Department of Chemistry, Vanderbilt University, Nashville, Tennessee
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17
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Uceda AB, Frau J, Vilanova B, Adrover M. On the effect of methionine oxidation on the interplay between α-synuclein and synaptic-like vesicles. Int J Biol Macromol 2023; 229:92-104. [PMID: 36584779 DOI: 10.1016/j.ijbiomac.2022.12.262] [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: 09/14/2022] [Revised: 12/19/2022] [Accepted: 12/23/2022] [Indexed: 12/29/2022]
Abstract
Human alpha-synuclein (αS) is an intrinsically disordered protein highly expressed in dopaminergic neurons. Its amyloid aggregates are the major component of Lewy bodies, which are considered a hallmark of Parkinson's disease (PD). αS has four different Met, which are particularly sensitive to oxidation, as most of them are found as Met sulfoxide (MetO) in the αS deposits. Consequently, researchers have invested mounting efforts trying to elucidate the molecular mechanisms underlying the links between oxidative stress, αS aggregation and PD. However, it has not been described yet the effect of Met oxidation on the physiological function of αS. Trying to shed light on this aspect, we have here studied a synthetic αS that displayed all its Met replaced by MetO moieties (αS-MetO). Our study has allowed to prove that MetO diminishes the affinity of αS towards anionic micelles (SDS), although the micelle-bound fraction of αS-MetO still adopts an α-helical folding resembling that of the lipid-bound αS. MetO also diminishes the affinity of αS towards synaptic-like vesicles, and its hindering effect is much more pronounced than that displayed on the αS-micelle affinity. Additionally, we have also demonstrated that MetO impairs the physiological function of αS as a catalyst of the clustering and the fusion of synaptic vesicles (SVs). Our findings provide a new understanding on how Met oxidation affects one of the most relevant biological functions attributed to αS that is to bind and cluster SVs along the neurotransmission.
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Affiliation(s)
- Ana Belén Uceda
- Institut Universitari d'Investigació en Ciències de la Salut (IUNICS), Institut de Recerca en Ciències de la Salut (IdISBa), Departament de Química, Universitat de les Illes Balears, Ctra. Valldemossa km 7.5, E-07122 Palma de Mallorca, Spain
| | - Juan Frau
- Institut Universitari d'Investigació en Ciències de la Salut (IUNICS), Institut de Recerca en Ciències de la Salut (IdISBa), Departament de Química, Universitat de les Illes Balears, Ctra. Valldemossa km 7.5, E-07122 Palma de Mallorca, Spain
| | - Bartolomé Vilanova
- Institut Universitari d'Investigació en Ciències de la Salut (IUNICS), Institut de Recerca en Ciències de la Salut (IdISBa), Departament de Química, Universitat de les Illes Balears, Ctra. Valldemossa km 7.5, E-07122 Palma de Mallorca, Spain
| | - Miquel Adrover
- Institut Universitari d'Investigació en Ciències de la Salut (IUNICS), Institut de Recerca en Ciències de la Salut (IdISBa), Departament de Química, Universitat de les Illes Balears, Ctra. Valldemossa km 7.5, E-07122 Palma de Mallorca, Spain.
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18
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Mi T, Nguyen D, Burgess K. Bicyclic Schellman Loop Mimics (BSMs): Rigid Synthetic C-Caps for Enforcing Peptide Helicity. ACS CENTRAL SCIENCE 2023; 9:300-306. [PMID: 36844493 PMCID: PMC9951308 DOI: 10.1021/acscentsci.2c01265] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/25/2022] [Indexed: 06/18/2023]
Abstract
Macrocyclic peptides are the prevalent way to mimic interface helices for disruption of protein interactions, but current strategies to do this via synthetic C-cap mimics are underdeveloped and suboptimal. Bioinformatic studies described here were undertaken to better understand Schellman loops, the most common C-caps in proteins, to design superior synthetic mimics. An algorithm (Schellman Loop Finder) was developed, and data mining with this led to the discovery that these secondary structures are often stabilized by combinations of three hydrophobic side chains, most frequently from Leu, to form hydrophobic triangles. That insight facilitated design of synthetic mimics, bicyclic Schellman loop mimics (BSMs), where the hydrophobic triumvirate was replaced by 1,3,5-trimethylbenzene. We demonstrate that BSMs can be made quickly and efficiently, and are more rigid and helix-inducing than the best current C-cap mimics, which are rare and all monocycles.
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19
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Rajkovic A, Kanchugal S, Abdurakhmanov E, Howard R, Wärmländer S, Erwin J, Barrera Saldaña HA, Gräslund A, Danielson H, Flores SC. Amino acid substitutions in human growth hormone affect secondary structure and receptor binding. PLoS One 2023; 18:e0282741. [PMID: 36952491 PMCID: PMC10035860 DOI: 10.1371/journal.pone.0282741] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2022] [Accepted: 02/22/2023] [Indexed: 03/25/2023] Open
Abstract
The interaction between human Growth Hormone (hGH) and hGH Receptor (hGHR) has basic relevance to cancer and growth disorders, and hGH is the scaffold for Pegvisomant, an anti-acromegaly therapeutic. For the latter reason, hGH has been extensively engineered by early workers to improve binding and other properties. We are particularly interested in E174 which belongs to the hGH zinc-binding triad; the substitution E174A is known to significantly increase binding, but to now no explanation has been offered. We generated this and several computationally-selected single-residue substitutions at the hGHR-binding site of hGH. We find that, while many successfully slow down dissociation of the hGH-hGHR complex once bound, they also slow down the association of hGH to hGHR. The E174A substitution induces a change in the Circular Dichroism spectrum that suggests the appearance of coiled-coiling. Here we show that E174A increases affinity of hGH against hGHR because the off-rate is slowed down more than the on-rate. For E174Y (and certain mutations at other sites) the slowdown in on-rate was greater than that of the off-rate, leading to decreased affinity. The results point to a link between structure, zinc binding, and hGHR-binding affinity in hGH.
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Affiliation(s)
- Andrei Rajkovic
- Department of Cell and Molecular Biology, Uppsala University, Uppsala, Sweden
| | - Sandesh Kanchugal
- Department of Cell and Molecular Biology, Uppsala University, Uppsala, Sweden
| | | | - Rebecca Howard
- Department of Biochemistry and Biophysics, Stockholm University, Frescati, Sweden
| | - Sebastian Wärmländer
- Department of Biochemistry and Biophysics, Stockholm University, Frescati, Sweden
| | - Joseph Erwin
- Department of Biochemistry and Biophysics, Stockholm University, Frescati, Sweden
| | | | - Astrid Gräslund
- Department of Biochemistry and Biophysics, Stockholm University, Frescati, Sweden
| | | | - Samuel Coulbourn Flores
- Department of Biochemistry and Biophysics, Stockholm University, Frescati, Sweden
- Department of Animal Breeding and Genetics, Swedish University of Agricultural Sciences, Uppsala, Sweden
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20
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Yeritsyan K, Valant M, Badasyan A. Processing helix–coil transition data: Account of chain length and solvent effects. FRONTIERS IN NANOTECHNOLOGY 2022. [DOI: 10.3389/fnano.2022.982644] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
Numerous nanobiotechnologies include manipulations of short polypeptide chains. The conformational properties of these polypeptides are studied in vitro by circular dichroism and time-resolved infrared spectroscopy. To find out the interaction parameters, the measured temperature dependence of normalized helicity degree needs to be further processed by fitting to a model. Using recent advances in the Hamiltonian formulation of the classical Zimm and Bragg model, we explicitly include chain length and solvent effects in the theoretical description. The expression for the helicity degree we suggest successfully fits the experimental data and provides hydrogen bonding energies and nucleation parameter values within the standards in the field.
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21
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Dinic J, Schnorenberg MR, Tirrell MV. Sequence-Controlled Secondary Structures and Stimuli Responsiveness of Bioinspired Polyampholytes. Biomacromolecules 2022; 23:3798-3809. [PMID: 35969881 DOI: 10.1021/acs.biomac.2c00666] [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] [Indexed: 11/28/2022]
Abstract
A comprehensive study focusing on the influence of the sequence charge pattern on the secondary structure preferences of annealed polyampholytes and their responsiveness to external stimuli is presented. Two sequences are designed composed entirely of ionizable amino acids (charge fraction, f = 1) and an equal number of positive and negative charges (f+ = f- = 0.5) with distinct charge patterns consisting of lysine and glutamic acid monomers. The study reveals that the sequence charge pattern has a significant influence on the secondary structure preferences of polyampholytes at physiological pH. Furthermore, it shows that external stimuli such as pH, ionic strength, and solvent dielectric constant can be used to modulate the secondary structure of the two studied sequences. The observed secondary structure transformations for the two sequences are also substantially different from those determined for uniformly charged homo-polypeptides under matching conditions.
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Affiliation(s)
- Jelena Dinic
- Center for Molecular Engineering and Materials Science Division, Argonne National Laboratory, Lemont, Illinois 60439, United States
- Pritzker School of Molecular Engineering, University of Chicago, Chicago, Illinois 60637, United States
| | - Mathew R Schnorenberg
- Pritzker School of Molecular Engineering, University of Chicago, Chicago, Illinois 60637, United States
| | - Matthew V Tirrell
- Center for Molecular Engineering and Materials Science Division, Argonne National Laboratory, Lemont, Illinois 60439, United States
- Pritzker School of Molecular Engineering, University of Chicago, Chicago, Illinois 60637, United States
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22
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Uceda AB, Frau J, Vilanova B, Adrover M. Glycation of α-synuclein hampers its binding to synaptic-like vesicles and its driving effect on their fusion. Cell Mol Life Sci 2022; 79:342. [PMID: 35662377 PMCID: PMC9167179 DOI: 10.1007/s00018-022-04373-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2022] [Revised: 05/08/2022] [Accepted: 05/11/2022] [Indexed: 12/24/2022]
Abstract
Parkinson's disease (PD) is one of the most prevalent neurodegenerative disorders affecting the worldwide population. One of its hallmarks is the intraneuronal accumulation of insoluble Lewy bodies (LBs), which cause the death of dopaminergic neurons. α-Synuclein (αS) is the main component of these LBs and in them, it commonly contains non-enzymatic post-translational modifications, such as those resulting from its reaction with reactive carbonyl species arising as side products of the intraneuronal glycolysis (mainly methylglyoxal). Consequently, lysines of the αS found in LBs of diabetic individuals are usually carboxyethylated. A precise comprehension of the effect of Nε-(carboxyethyl)lysine (CEL) on the aggregation of αS and on its physiological function becomes crucial to fully understand the molecular mechanisms underlying the development of diabetes-induced PD. Consequently, we have here used a synthetic αS where all its Lys have been replaced by CEL moieties (αS-CEL), and we have studied how these modifications could impact on the neurotransmission mechanism. This study allows us to describe how the non-enzymatic glycosylation (glycation) affects the function of a protein like αS, involved in the pathogenesis of PD. CEL decreases the ability of αS to bind micelles, although the micelle-bound fraction of αS-CEL still displays an α-helical fold resembling that of the lipid-bound αS. However, CEL completely abolishes the affinity of αS towards synaptic-like vesicles and, consequently, it hampers its physiological function as a catalyst of the clustering and the fusion of the synaptic vesicles.
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Affiliation(s)
- Ana Belén Uceda
- Departament de Química, Institut Universitari d'Investigació en Ciències de la Salut (IUNICS), Institut de Recerca en Ciències de la Salut (IdISBa), Universitat de les Illes Balears, Ed. Mateu Orfila i Rotger, Ctra. Valldemossa km 7.5, 07122, Palma, Spain
| | - Juan Frau
- Departament de Química, Institut Universitari d'Investigació en Ciències de la Salut (IUNICS), Institut de Recerca en Ciències de la Salut (IdISBa), Universitat de les Illes Balears, Ed. Mateu Orfila i Rotger, Ctra. Valldemossa km 7.5, 07122, Palma, Spain
| | - Bartolomé Vilanova
- Departament de Química, Institut Universitari d'Investigació en Ciències de la Salut (IUNICS), Institut de Recerca en Ciències de la Salut (IdISBa), Universitat de les Illes Balears, Ed. Mateu Orfila i Rotger, Ctra. Valldemossa km 7.5, 07122, Palma, Spain
| | - Miquel Adrover
- Departament de Química, Institut Universitari d'Investigació en Ciències de la Salut (IUNICS), Institut de Recerca en Ciències de la Salut (IdISBa), Universitat de les Illes Balears, Ed. Mateu Orfila i Rotger, Ctra. Valldemossa km 7.5, 07122, Palma, Spain.
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Effect of hydrophobic moment on membrane interaction and cell penetration of apolipoprotein E-derived arginine-rich amphipathic α-helical peptides. Sci Rep 2022; 12:4959. [PMID: 35322082 PMCID: PMC8943082 DOI: 10.1038/s41598-022-08876-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2021] [Accepted: 03/14/2022] [Indexed: 12/15/2022] Open
Abstract
We previously developed an amphipathic arginine-rich peptide, A2-17, which has high ability to directly penetrate across cell membranes. To understand the mechanism of the efficient cell-penetrating ability of the A2-17 peptide, we designed three structural isomers of A2-17 having different values of the hydrophobic moment and compared their membrane interaction and direct cell penetration. Confocal fluorescence microscopy revealed that cell penetration efficiency of peptides tends to increase with their hydrophobic moment, in which A2-17 L14R/R15L, an A2-17 isomer with the highest hydrophobic moment, predominantly remains on plasma cell membranes. Consistently, Trp fluorescence analysis indicated the deepest insertion of A2-17 L14R/R15L into lipid membranes among all A2-17 isomers. Electrophysiological analysis showed that the duration and charge flux of peptide-induced pores in lipid membranes were prominent for A2-17 L14R/R15L, indicating the formation of stable membrane pores. Indeed, the A2-17 L14R/R15L peptide exhibited the strongest membrane damage to CHO-K1 cells. Atomic force microscopy quantitatively defined the peptide-induced membrane perturbation as the decrease in the stiffness of lipid vesicles, which was correlated with the hydrophobic moment of all A2-17 isomers. These results indicate that optimal membrane perturbation by amphipathic A2-17 peptide is critical for its efficient penetration into cells without inducing stabilized membrane pores.
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24
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Parks FC, Sheetz EG, Stutsman SR, Lutolli A, Debnath S, Raghavachari K, Flood AH. Revealing the Hidden Costs of Organization in Host-Guest Chemistry Using Chloride-Binding Foldamers and Their Solvent Dependence. J Am Chem Soc 2022; 144:1274-1287. [PMID: 35015538 DOI: 10.1021/jacs.1c10758] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Preorganization is a key concept in supramolecular chemistry. Preorganized receptors enhance binding by minimizing the organization costs associated with adopting the conformation needed to orient the binding sites toward the guest. Conversely, poorly organized receptors show affinities below what is possible based on the potential of their specific binding interactions. Despite the fact that the organization energy is paid each time like a tax, its value has never been measured directly, though many compounds have been developed to measure its effects. We present a method to quantify the hidden costs of receptor organization by independently measuring the contribution it makes to chloride complexation by a flexible foldameric receptor. This method uses folding energy to approximate organization energy and relies on measurement of the coil-helix equilibrium as a function of solvent. We also rely on the finding, established with rigid receptors, that affinity is inversely related to the solvent dielectric and expect the same for the foldamer's helically organized state. Increasing solvent polarity across nine dichloromethane-acetonitrile mixtures we see an unusual V-shape in affinity (decrease then increase). Quantitatively, this shape arises from weakened hydrogen-bonding interactions with solvent polarity followed by solvent-driven folding into an organized helix. We confirm that dielectric screening impacts the stability of host-guest complexes of flexible foldamers just like rigid receptors. These results experimentally verify the canonical model of binding (affinity depends on the sum of organization and noncovalent interactions). The picture of how solvent impacts complex stability and conformational organization thereby helps lay the groundwork for de novo receptor design.
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Affiliation(s)
- Fred C Parks
- Department of Chemistry, Indiana University, 800 East Kirkwood Avenue, Bloomington, Indiana 47405, United States
| | - Edward G Sheetz
- Department of Chemistry, Indiana University, 800 East Kirkwood Avenue, Bloomington, Indiana 47405, United States
| | - Sydney R Stutsman
- Department of Chemistry, Indiana University, 800 East Kirkwood Avenue, Bloomington, Indiana 47405, United States
| | - Alketa Lutolli
- Department of Chemistry, Indiana University, 800 East Kirkwood Avenue, Bloomington, Indiana 47405, United States
| | - Sibali Debnath
- Department of Chemistry, Indiana University, 800 East Kirkwood Avenue, Bloomington, Indiana 47405, United States
| | - Krishnan Raghavachari
- Department of Chemistry, Indiana University, 800 East Kirkwood Avenue, Bloomington, Indiana 47405, United States
| | - Amar H Flood
- Department of Chemistry, Indiana University, 800 East Kirkwood Avenue, Bloomington, Indiana 47405, United States
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25
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Antón Z, Weijman JF, Williams C, Moody ERR, Mantell J, Yip YY, Cross JA, Williams TA, Steiner RA, Crump MP, Woolfson DN, Dodding MP. Molecular mechanism for kinesin-1 direct membrane recognition. SCIENCE ADVANCES 2021; 7:7/31/eabg6636. [PMID: 34321209 PMCID: PMC8318374 DOI: 10.1126/sciadv.abg6636] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/20/2021] [Accepted: 06/11/2021] [Indexed: 06/13/2023]
Abstract
The cargo-binding capabilities of cytoskeletal motor proteins have expanded during evolution through both gene duplication and alternative splicing. For the light chains of the kinesin-1 family of microtubule motors, this has resulted in an array of carboxyl-terminal domain sequences of unknown molecular function. Here, combining phylogenetic analyses with biophysical, biochemical, and cell biology approaches, we identify a highly conserved membrane-induced curvature-sensitive amphipathic helix within this region of a subset of long kinesin light-chain paralogs and splice isoforms. This helix mediates the direct binding of kinesin-1 to lipid membranes. Membrane binding requires specific anionic phospholipids, and it contributes to kinesin-1-dependent lysosome positioning, a canonical activity that, until now, has been attributed exclusively the recognition of organelle-associated cargo adaptor proteins. This leads us to propose a protein-lipid coincidence detection framework for kinesin-1-mediated organelle transport.
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Affiliation(s)
- Zuriñe Antón
- School of Biochemistry, Faculty of Life Sciences, University of Bristol, Bristol BS8 1TD, UK
| | - Johannes F Weijman
- School of Biochemistry, Faculty of Life Sciences, University of Bristol, Bristol BS8 1TD, UK
| | - Christopher Williams
- School of Chemistry, Faculty of Life Sciences, University of Bristol, Bristol BS8 1TS, UK
- Bristol BioDesign Institute, University of Bristol, Life Sciences Building, Tyndall Avenue, Bristol BS8 1TQ, UK
| | - Edmund R R Moody
- School of Biological Sciences, Faculty of Life Sciences, University of Bristol, Life Sciences Building, Tyndall Avenue, Bristol BS8 1TQ, UK
| | - Judith Mantell
- School of Biochemistry, Faculty of Life Sciences, University of Bristol, Bristol BS8 1TD, UK
| | - Yan Y Yip
- Randall Centre of Cell and Molecular Biophysics, Faculty of Life Sciences and Medicine, King's College London, London, UK
| | - Jessica A Cross
- School of Biochemistry, Faculty of Life Sciences, University of Bristol, Bristol BS8 1TD, UK
- School of Chemistry, Faculty of Life Sciences, University of Bristol, Bristol BS8 1TS, UK
| | - Tom A Williams
- School of Biological Sciences, Faculty of Life Sciences, University of Bristol, Life Sciences Building, Tyndall Avenue, Bristol BS8 1TQ, UK
| | - Roberto A Steiner
- Randall Centre of Cell and Molecular Biophysics, Faculty of Life Sciences and Medicine, King's College London, London, UK
- Department of Biomedical Sciences, University of Padova, Padova, Italy
| | - Matthew P Crump
- School of Chemistry, Faculty of Life Sciences, University of Bristol, Bristol BS8 1TS, UK
- Bristol BioDesign Institute, University of Bristol, Life Sciences Building, Tyndall Avenue, Bristol BS8 1TQ, UK
| | - Derek N Woolfson
- School of Biochemistry, Faculty of Life Sciences, University of Bristol, Bristol BS8 1TD, UK
- School of Chemistry, Faculty of Life Sciences, University of Bristol, Bristol BS8 1TS, UK
- Bristol BioDesign Institute, University of Bristol, Life Sciences Building, Tyndall Avenue, Bristol BS8 1TQ, UK
| | - Mark P Dodding
- School of Biochemistry, Faculty of Life Sciences, University of Bristol, Bristol BS8 1TD, UK.
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26
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Zhuang Y, Bureau HR, Lopez C, Bucher R, Quirk S, Hernandez R. Energetics and structure of alanine-rich α-helices via adaptive steered molecular dynamics. Biophys J 2021; 120:2009-2018. [PMID: 33775636 PMCID: PMC8204395 DOI: 10.1016/j.bpj.2021.03.017] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Revised: 03/03/2021] [Accepted: 03/18/2021] [Indexed: 12/12/2022] Open
Abstract
The energetics and hydrogen bonding profiles of the helix-to-coil transition were found to be an additive property and to increase linearly with chain length, respectively, in alanine-rich α-helical peptides. A model system of polyalanine repeats was used to establish this hypothesis for the energetic trends and hydrogen bonding profiles. Numerical measurements of a synthesized polypeptide Ac-Y(AEAAKA)kF-NH2 and a natural α-helical peptide a2N (1-17) provide evidence of the hypothesis's generality. Adaptive steered molecular dynamics was employed to investigate the mechanical unfolding of all of these alanine-rich polypeptides. We found that the helix-to-coil transition is primarily dependent on the breaking of the intramolecular backbone hydrogen bonds and independent of specific side-chain interactions and chain length. The mechanical unfolding of the α-helical peptides results in a turnover mechanism in which a 310-helical structure forms during the unfolding, remaining at a near constant population and thereby maintaining additivity in the free energy. The intermediate partially unfolded structures exhibited polyproline II helical structure as previously seen by others. In summary, we found that the average force required to pull alanine-rich α-helical peptides in between the endpoints-namely the native structure and free coil-is nearly independent of the length or the specific primary structure.
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Affiliation(s)
- Yi Zhuang
- Department of Chemistry, Johns Hopkins University, Baltimore, Maryland
| | - Hailey R Bureau
- Department of Chemistry, Johns Hopkins University, Baltimore, Maryland
| | - Christine Lopez
- Department of Chemistry, Johns Hopkins University, Baltimore, Maryland
| | - Ryan Bucher
- Department of Chemistry, Johns Hopkins University, Baltimore, Maryland
| | | | - Rigoberto Hernandez
- Department of Chemistry, Johns Hopkins University, Baltimore, Maryland; Departments of Chemical and Biomolecular Engineering, and Materials Science and Engineering, Johns Hopkins University, Baltimore, Maryland.
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27
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Westerlund K, Myrhammar A, Tano H, Gestin M, Karlström AE. Stability Enhancement of a Dimeric HER2-Specific Affibody Molecule through Sortase A-Catalyzed Head-to-Tail Cyclization. Molecules 2021; 26:2874. [PMID: 34066245 PMCID: PMC8150554 DOI: 10.3390/molecules26102874] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Revised: 05/07/2021] [Accepted: 05/08/2021] [Indexed: 11/16/2022] Open
Abstract
Natural backbone-cyclized proteins have an increased thermostability and resistance towards proteases, characteristics that have sparked interest in head-to-tail cyclization as a method to stability-enhance proteins used in diagnostics and therapeutic applications, for example. In this proof-of principle study, we have produced and investigated a head-to-tail cyclized and HER2-specific ZHER2:342 Affibody dimer. The sortase A-mediated cyclization reaction is highly efficient (>95%) under optimized conditions, and renders a cyclic ZHER3:342-dimer with an apparent melting temperature, Tm, of 68 °C, which is 3 °C higher than that of its linear counterpart. Circular dichroism spectra of the linear and cyclic dimers looked very similar in the far-UV range, both before and after thermal unfolding to 90 °C, which suggests that cyclization does not negatively impact the helicity or folding of the cyclic protein. The cyclic dimer had an apparent sub-nanomolar affinity (Kd ~750 pM) to the HER2-receptor, which is a ~150-fold reduction in affinity relative to the linear dimer (Kd ~5 pM), but the anti-HER2 Affibody dimer remained a high-affinity binder even after cyclization. No apparent difference in proteolytic stability was detected in an endopeptidase degradation assay for the cyclic and linear dimers. In contrast, in an exopeptidase degradation assay, the linear dimer was shown to be completely degraded after 5 min, while the cyclic dimer showed no detectable degradation even after 60 min. We further demonstrate that a site-specifically DyLight 594-labeled cyclic dimer shows specific binding to HER2-overexpressing cells. Taken together, the results presented here demonstrate that head-to-tail cyclization can be an effective strategy to increase the stability of an Affibody dimer.
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Affiliation(s)
| | | | | | | | - Amelie Eriksson Karlström
- Department of Protein Science, School of Engineering Sciences in Chemistry, Biotechnology and Health, KTH Royal Institute of Technology, AlbaNova University Center, SE-10691 Stockholm, Sweden; (K.W.); (A.M.); (H.T.); (M.G.)
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28
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Length Dependent Folding Kinetics of Alanine-Based Helical Peptides from Optimal Dimensionality Reduction. Life (Basel) 2021; 11:life11050385. [PMID: 33923197 PMCID: PMC8170890 DOI: 10.3390/life11050385] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2021] [Revised: 04/19/2021] [Accepted: 04/21/2021] [Indexed: 01/23/2023] Open
Abstract
We present a computer simulation study of helix folding in alanine homopeptides (ALA)n of length n = 5, 8, 15, and 21 residues. Based on multi-microsecond molecular dynamics simulations at room temperature, we found helix populations and relaxation times increasing from about 6% and ~2 ns for ALA5 to about 60% and ~500 ns for ALA21, and folding free energies decreasing linearly with the increasing number of residues. The helix folding was analyzed with the Optimal Dimensionality Reduction method, yielding coarse-grained kinetic models that provided a detailed representation of the folding process. The shorter peptides, ALA5 and ALA8, tended to convert directly from coil to helix, while ALA15 and ALA21 traveled through several intermediates. Coarse-grained aggregate states representing the helix, coil, and intermediates were heterogeneous, encompassing multiple peptide conformations. The folding involved multiple pathways and interesting intermediate states were present on the folding paths, with partially formed helices, turns, and compact coils. Statistically, helix initiation was favored at both termini, and the helix was most stable in the central region. Importantly, we found the presence of underlying universal local dynamics in helical peptides with correlated transitions for neighboring hydrogen bonds. Overall, the structural and dynamical parameters extracted from the trajectories are in good agreement with experimental observables, providing microscopic insights into the complex helix folding kinetics.
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29
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Ben-Shushan S, Miller Y. Molecular Mechanisms and Aspects on the Role of Neuropeptide Y as a Zn 2+ and Cu 2+ Chelator. Inorg Chem 2021; 60:484-493. [PMID: 33320649 DOI: 10.1021/acs.inorgchem.0c03350] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The concept of metal chelation is based on simple coordination chemistry. The development of an ideal metal chelator that completely and selectively removes toxic metals from a specific metal binding site in proteins is required to prevent and or inhibit a variety of diseases, among them neurodegenerative diseases. This work examines neuropeptide Y (NPY) as a Zn2+ and Cu2+ chelator agent. NPY is a natural peptide that is produced in the human body; therefore, it is not a toxic agent and the complex that it forms is not toxic as well. Our simulations reveal that NPY has an efficient Zn2+ chelation activity but is less effective in chelating Cu2+. Moreover, while NPY demonstrates several conformations, the metal chelation occurs more efficiently in its native structure. Beyond the exploration of the activity of NPY as a Zn2+ and Cu2+ chelator agent, this work provides an insight into the molecular mechanisms of the chelation of these metals at the molecular level. The outcomes from this work may guide future experimental studies to examine NPY in metal chelation therapy for neurodegenerative diseases.
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Affiliation(s)
- Shira Ben-Shushan
- Department of Chemistry, Ben-Gurion University of the Negev, P.O. Box 653, Be'er Sheva 84105, Israel.,Ilse Katz Institute for Nanoscale Science and Technology, Ben-Gurion University of the Negev, Be'er-Sheva 84105, Israel
| | - Yifat Miller
- Department of Chemistry, Ben-Gurion University of the Negev, P.O. Box 653, Be'er Sheva 84105, Israel.,Ilse Katz Institute for Nanoscale Science and Technology, Ben-Gurion University of the Negev, Be'er-Sheva 84105, Israel
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30
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Zhang X, Bathgate RAD, Hossain MA. Human Insulin-like Peptide 5 (INSL5). Identification of a Simplified Version of Two-Chain Analog A13. ACS Med Chem Lett 2020; 11:2455-2460. [PMID: 33335667 DOI: 10.1021/acsmedchemlett.0c00435] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2020] [Accepted: 10/08/2020] [Indexed: 01/14/2023] Open
Abstract
The receptor for insulin-like peptide 5 (INSL5), RXFP4, is a potential pharma target for treating human conditions such as constipation, anorexia, and obesity. However, since INSL5 has a complex structure of two chains and three disulfide bonds, its synthesis has proven to be extremely difficult via either chemical or recombinant approaches. Previous studies led to the engineering of a high yielding simplified INSL5 analog, named analog 13 (A13), which retains native INSL5-like activity. The focus of this study is to further simplify the structure of A13 by truncating the N-terminal residues of the B-chain. We have found that the first six residues at the N-terminus of A13 are not important for RXFP4 binding and cAMP potency. The most minimized active structure of INSL5 identified in this study is A13: B7-24 which will be an important research tool to study the physiological role of RXFP4 and a template for further modification to improve its pharmacokinetic properties.
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31
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Bergues-Pupo AE, Lipowsky R, Vila Verde A. Unfolding mechanism and free energy landscape of single, stable, alpha helices at low pull speeds. SOFT MATTER 2020; 16:9917-9928. [PMID: 33030193 DOI: 10.1039/d0sm01166e] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Single alpha helices (SAHs) stable in isolated form are often found in motor proteins where they bridge functional domains. Understanding the mechanical response of SAHs is thus critical to understand their function. The quasi-static force-extension relation of a small number of SAHs is known from single-molecule experiments. Unknown, or still controversial, are the molecular scale details behind those observations. We show that the deformation mechanism of SAHs pulled from the termini at pull speeds approaching the quasi-static limit differs from that of typical helices found in proteins, which are stable only when interacting with other protein domains. Using molecular dynamics simulations with atomistic resolution at low pull speeds previously inaccessible to simulation, we show that SAHs start unfolding from the termini at all pull speeds we investigated. Unfolding proceeds residue-by-residue and hydrogen bond breaking is not the main event determining the barrier to unfolding. We use the molecular simulation data to test the cooperative sticky chain model. This model yields excellent fits of the force-extension curves and quantifies the distance, xE = 0.13 nm, to the transition state, the natural frequency of bond vibration, ν0 = 0.82 ns-1, and the height, V0 = 2.9 kcal mol-1, of the free energy barrier associated with the deformation of single residues. Our results demonstrate that the sticky chain model could advantageously be used to analyze experimental force-extension curves of SAHs and other biopolymers.
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Affiliation(s)
- Ana Elisa Bergues-Pupo
- Max Planck Institute of Colloids and Interfaces, Department of Theory & Bio-Systems, Am Mühlenberg 1, 14476 Potsdam, Germany.
| | - Reinhard Lipowsky
- Max Planck Institute of Colloids and Interfaces, Department of Theory & Bio-Systems, Am Mühlenberg 1, 14476 Potsdam, Germany.
| | - Ana Vila Verde
- Max Planck Institute of Colloids and Interfaces, Department of Theory & Bio-Systems, Am Mühlenberg 1, 14476 Potsdam, Germany.
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32
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Abouzayed A, Tano H, Nagy Á, Rinne SS, Wadeea F, Kumar S, Westerlund K, Tolmachev V, Eriksson Karlström A, Orlova A. Preclinical Evaluation of the GRPR-Targeting Antagonist RM26 Conjugated to the Albumin-Binding Domain for GRPR-Targeting Therapy of Cancer. Pharmaceutics 2020; 12:E977. [PMID: 33081166 PMCID: PMC7594083 DOI: 10.3390/pharmaceutics12100977] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Revised: 10/12/2020] [Accepted: 10/14/2020] [Indexed: 01/02/2023] Open
Abstract
The targeting of gastrin-releasing peptide receptors (GRPR) was recently proposed for targeted therapy, e.g., radiotherapy. Multiple and frequent injections of peptide-based therapeutic agents would be required due to rapid blood clearance. By conjugation of the GRPR antagonist RM26 (D-Phe-Gln-Trp-Ala-Val-Gly-His-Sta-Leu-NH2) to an ABD (albumin-binding domain), we aimed to extend the blood circulation of peptides. The synthesized conjugate DOTA-ABD-RM26 was labelled with indium-111 and evaluated in vitro and in vivo. The labelled conjugate was stable in PBS and retained specificity and its antagonistic function against GRPR. The half-maximal inhibitory concentration (IC50) of natIn-DOTA-ABD-RM26 in the presence of human serum albumin was 49 ± 5 nM. [111In]In-DOTA-ABD-RM26 had a significantly longer residence time in blood and in tumors (without a significant decrease of up to 144 h pi) than the parental RM26 peptide. We conclude that the ABD-RM26 conjugate can be used for GRPR-targeted therapy and delivery of cytotoxic drugs. However, the undesirable elevated activity uptake in kidneys abolishes its use for radionuclide therapy. This proof-of-principle study justified further optimization of the molecular design of the ABD-RM26 conjugate.
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Affiliation(s)
- Ayman Abouzayed
- Department of Medicinal Chemistry, Uppsala University, 751 83 Uppsala, Sweden; (A.A.); (S.S.R.); (F.W.)
| | - Hanna Tano
- Department of Protein Science, School of Engineering Sciences in Chemistry, Biotechnology and Health, KTH Royal Institute of Technology, AlbaNova University Center, 106 91 Stockholm, Sweden; (H.T.); (Á.N.); (S.K.); (K.W.); (A.E.K.)
| | - Ábel Nagy
- Department of Protein Science, School of Engineering Sciences in Chemistry, Biotechnology and Health, KTH Royal Institute of Technology, AlbaNova University Center, 106 91 Stockholm, Sweden; (H.T.); (Á.N.); (S.K.); (K.W.); (A.E.K.)
| | - Sara S. Rinne
- Department of Medicinal Chemistry, Uppsala University, 751 83 Uppsala, Sweden; (A.A.); (S.S.R.); (F.W.)
| | - Fadya Wadeea
- Department of Medicinal Chemistry, Uppsala University, 751 83 Uppsala, Sweden; (A.A.); (S.S.R.); (F.W.)
| | - Sharmishtaa Kumar
- Department of Protein Science, School of Engineering Sciences in Chemistry, Biotechnology and Health, KTH Royal Institute of Technology, AlbaNova University Center, 106 91 Stockholm, Sweden; (H.T.); (Á.N.); (S.K.); (K.W.); (A.E.K.)
| | - Kristina Westerlund
- Department of Protein Science, School of Engineering Sciences in Chemistry, Biotechnology and Health, KTH Royal Institute of Technology, AlbaNova University Center, 106 91 Stockholm, Sweden; (H.T.); (Á.N.); (S.K.); (K.W.); (A.E.K.)
| | - Vladimir Tolmachev
- Department of Immunology, Genetics and Pathology, Uppsala University, 751 85 Uppsala, Sweden;
- Research Centrum for Oncotheranostics, Research School of Chemistry and Applied Biomedical Sciences, Tomsk Polytechnic University, Tomsk 634050, Russia
| | - Amelie Eriksson Karlström
- Department of Protein Science, School of Engineering Sciences in Chemistry, Biotechnology and Health, KTH Royal Institute of Technology, AlbaNova University Center, 106 91 Stockholm, Sweden; (H.T.); (Á.N.); (S.K.); (K.W.); (A.E.K.)
| | - Anna Orlova
- Department of Medicinal Chemistry, Uppsala University, 751 83 Uppsala, Sweden; (A.A.); (S.S.R.); (F.W.)
- Research Centrum for Oncotheranostics, Research School of Chemistry and Applied Biomedical Sciences, Tomsk Polytechnic University, Tomsk 634050, Russia
- Science for Life Laboratory, Uppsala University, 751 05 Uppsala, Sweden
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33
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Landeck N, Strathearn KE, Ysselstein D, Buck K, Dutta S, Banerjee S, Lv Z, Hulleman JD, Hindupur J, Lin LK, Padalkar S, Stanciu LA, Lyubchenko YL, Kirik D, Rochet JC. Two C-terminal sequence variations determine differential neurotoxicity between human and mouse α-synuclein. Mol Neurodegener 2020; 15:49. [PMID: 32900375 PMCID: PMC7487555 DOI: 10.1186/s13024-020-00380-w] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2020] [Accepted: 05/18/2020] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND α-Synuclein (aSyn) aggregation is thought to play a central role in neurodegenerative disorders termed synucleinopathies, including Parkinson's disease (PD). Mouse aSyn contains a threonine residue at position 53 that mimics the human familial PD substitution A53T, yet in contrast to A53T patients, mice show no evidence of aSyn neuropathology even after aging. Here, we studied the neurotoxicity of human A53T, mouse aSyn, and various human-mouse chimeras in cellular and in vivo models, as well as their biochemical properties relevant to aSyn pathobiology. METHODS Primary midbrain cultures transduced with aSyn-encoding adenoviruses were analyzed immunocytochemically to determine relative dopaminergic neuron viability. Brain sections prepared from rats injected intranigrally with aSyn-encoding adeno-associated viruses were analyzed immunohistochemically to determine nigral dopaminergic neuron viability and striatal dopaminergic terminal density. Recombinant aSyn variants were characterized in terms of fibrillization rates by measuring thioflavin T fluorescence, fibril morphologies via electron microscopy and atomic force microscopy, and protein-lipid interactions by monitoring membrane-induced aSyn aggregation and aSyn-mediated vesicle disruption. Statistical tests consisted of ANOVA followed by Tukey's multiple comparisons post hoc test and the Kruskal-Wallis test followed by a Dunn's multiple comparisons test or a two-tailed Mann-Whitney test. RESULTS Mouse aSyn was less neurotoxic than human aSyn A53T in cell culture and in rat midbrain, and data obtained for the chimeric variants indicated that the human-to-mouse substitutions D121G and N122S were at least partially responsible for this decrease in neurotoxicity. Human aSyn A53T and a chimeric variant with the human residues D and N at positions 121 and 122 (respectively) showed a greater propensity to undergo membrane-induced aggregation and to elicit vesicle disruption. Differences in neurotoxicity among the human, mouse, and chimeric aSyn variants correlated weakly with differences in fibrillization rate or fibril morphology. CONCLUSIONS Mouse aSyn is less neurotoxic than the human A53T variant as a result of inhibitory effects of two C-terminal amino acid substitutions on membrane-induced aSyn aggregation and aSyn-mediated vesicle permeabilization. Our findings highlight the importance of membrane-induced self-assembly in aSyn neurotoxicity and suggest that inhibiting this process by targeting the C-terminal domain could slow neurodegeneration in PD and other synucleinopathy disorders.
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Affiliation(s)
- Natalie Landeck
- Brain Repair and Imaging in Neural Systems, Department of Experimental Medical Science, Lund University, Lund, Sweden
| | - Katherine E. Strathearn
- Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, IN USA
- Present address: Fujifilm Irvine Scientific, Santa Ana, CA USA
| | - Daniel Ysselstein
- Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, IN USA
- Present address: Northwestern University Feinberg School of Medicine, Chicago, IL USA
| | - Kerstin Buck
- Brain Repair and Imaging in Neural Systems, Department of Experimental Medical Science, Lund University, Lund, Sweden
- Present address: AbbVie Deutschland GmbH & Co KG, Ludwigshafen, Germany
| | - Sayan Dutta
- Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, IN USA
- Purdue Institute for Integrative Neuroscience, Purdue University, West Lafayette, IN USA
| | - Siddhartha Banerjee
- Department of Pharmaceutical Sciences, University of Nebraska Medical Center, Omaha, NE USA
| | - Zhengjian Lv
- Department of Pharmaceutical Sciences, University of Nebraska Medical Center, Omaha, NE USA
- Present address: Bruker Nanosurfaces Division, Goleta, Santa Barbara, CA USA
| | - John D. Hulleman
- Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, IN USA
- Present address: Departments of Ophthalmology and Pharmacology, University of Texas Southwestern Medical Center, Dallas, TX USA
| | - Jagadish Hindupur
- Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, IN USA
- Present address: Liveon Biolabs Pvt. Ltd., Tumakuru, Karnataka India
| | - Li-Kai Lin
- School of Materials Engineering, Purdue University, West Lafayette, IN USA
| | - Sonal Padalkar
- School of Materials Engineering, Purdue University, West Lafayette, IN USA
- Present address: Department of Mechanical Engineering, Iowa State University, Ames, IA USA
| | - Lia A. Stanciu
- School of Materials Engineering, Purdue University, West Lafayette, IN USA
| | - Yuri L. Lyubchenko
- Department of Pharmaceutical Sciences, University of Nebraska Medical Center, Omaha, NE USA
| | - Deniz Kirik
- Brain Repair and Imaging in Neural Systems, Department of Experimental Medical Science, Lund University, Lund, Sweden
| | - Jean-Christophe Rochet
- Department of Medicinal Chemistry and Molecular Pharmacology, Purdue University, West Lafayette, IN USA
- Purdue Institute for Integrative Neuroscience, Purdue University, West Lafayette, IN USA
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Adão R, Cruz PF, Vaz DC, Fonseca F, Pedersen JN, Ferreira-da-Silva F, Brito RM, Ramos CH, Otzen D, Keller S, Bastos M. DIBMA nanodiscs keep α-synuclein folded. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2020; 1862:183314. [DOI: 10.1016/j.bbamem.2020.183314] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/23/2019] [Revised: 04/10/2020] [Accepted: 04/13/2020] [Indexed: 02/08/2023]
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Sato Y, Kuwahara K, Mogami K, Takahashi K, Nishizawa S. Amphipathic helical peptide-based fluorogenic probes for a marker-free analysis of exosomes based on membrane-curvature sensing. RSC Adv 2020; 10:38323-38327. [PMID: 35517518 PMCID: PMC9057301 DOI: 10.1039/d0ra07763a] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2020] [Accepted: 10/11/2020] [Indexed: 01/08/2023] Open
Abstract
With increasing knowledge about the diverse roles of exosomes in the biological process, much attention has been paid to develop analytical methods for detection and quantification of exosomes. Immunoassays based on the recognition of exosomal protein markers by antibodies were widely used. However, considering that exosomal protein composition varies with the cell type, the protein markers should be carefully selected for a sensitive and selective analysis of target exosomes. Herein, we developed a new class of exosome-binding fluorogenic probes based on membrane curvature (MC) sensing of amphipathic helical (AH) peptides for exosome analysis without the need to use protein markers on the exosomal membranes. The C-terminal region of apolipoprotein A-I labeled with Nile red (ApoC-NR) exhibited a significant fluorescence enhancement upon selective binding to the highly curved membranes of synthetic vesicles. Circular dichroism (CD) measurements involving 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC)/1-2-dioleoyl-sn-glycerol (DOG) vesicles suggested that ApoC-NR recognizes the lipid packing defects in the surface of highly curved membranes via the hydrophobic insertion of the α-helix structure of the ApoC unit. ApoC-NR exhibited a stronger binding affinity for exosome-sized vesicles and a higher MC selectivity compared to all other previously reported peptide probes. ApoC-NR can be used in a simple and rapid “mix and read” analysis of various kinds of exosomes derived from different cell types (limit of detection: –105 particles/μL) without being influenced by the variation in the expression of the surface proteins of the exosomes, which stands in sharp contrast to immunoassays. Fluorogenic probes based on membrane curvature sensing-amphipathic helical peptides have been developed for a marker-free exosome analysis.![]()
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Affiliation(s)
- Yusuke Sato
- Department of Chemistry
- Graduate School of Science
- Tohoku University
- Sendai 980-8578
- Japan
| | - Kazuki Kuwahara
- Department of Chemistry
- Graduate School of Science
- Tohoku University
- Sendai 980-8578
- Japan
| | - Kenta Mogami
- Department of Chemistry
- Graduate School of Science
- Tohoku University
- Sendai 980-8578
- Japan
| | - Kenta Takahashi
- Department of Chemistry
- Graduate School of Science
- Tohoku University
- Sendai 980-8578
- Japan
| | - Seiichi Nishizawa
- Department of Chemistry
- Graduate School of Science
- Tohoku University
- Sendai 980-8578
- Japan
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36
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Hossain MA, Okamoto R, Karas JA, Praveen P, Liu M, Forbes BE, Wade JD, Kajihara Y. Total Chemical Synthesis of a Nonfibrillating Human Glycoinsulin. J Am Chem Soc 2019; 142:1164-1169. [DOI: 10.1021/jacs.9b11424] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Affiliation(s)
| | - Ryo Okamoto
- Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043 Japan
| | | | | | | | - Briony E. Forbes
- Discipline of Medical Biochemistry, College of Medicine and Public Health, Flinders University, Bedford Park, South Australia 5042, Australia
| | | | - Yasuhiro Kajihara
- Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043 Japan
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37
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Martínez-Carranza M, Blasco P, Gustafsson R, Dong M, Berntsson RPA, Widmalm G, Stenmark P. Synaptotagmin Binding to Botulinum Neurotoxins. Biochemistry 2019; 59:491-498. [PMID: 31809018 DOI: 10.1021/acs.biochem.9b00554] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Botulinum neurotoxins (BoNTs) are exceptionally toxic proteins that cause paralysis but are also extensively used as treatment for various medical conditions. Most BoNTs bind two receptors on neuronal cells, namely, a ganglioside and a protein receptor. Differences in the sequence between the protein receptors from different species can impact the binding affinity and toxicity of the BoNTs. Here we have investigated how BoNT/B, /DC, and /G, all three toxins that utilize synaptotagmin I and II (Syt-I and Syt-II, respectively) as their protein receptors, bind to Syt-I and -II of mouse/rat, bovine, and human origin by isothermal titration calorimetry analysis. BoNT/G had the highest affinity for human Syt-I, and BoNT/DC had the highest affinity for bovine Syt-II. As expected, BoNT/B, /DC, and /G showed very low levels of binding to human Syt-II. Furthermore, we carried out saturation transfer difference (STD) and STD-TOCSY NMR experiments that revealed the region of the Syt peptide in direct contact with BoNT/G, which demonstrate that BoNT/G recognizes the Syt peptide in a model similar to that in the established BoNT/B-Syt-II complex. Our analyses also revealed that regions outside the Syt peptide's toxin-binding region are important for the helicity of the peptide and, therefore, the binding affinity.
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Affiliation(s)
| | - Pilar Blasco
- Department of Organic Chemistry , Stockholm University , SE-106 91 Stockholm , Sweden
| | - Robert Gustafsson
- Department of Biochemistry and Biophysics , Stockholm University , SE-106 91 Stockholm , Sweden
| | - Min Dong
- Department of Urology, Boston's Children Hospital, and Department of Microbiology and Immunology and Department of Surgery , Harvard Medical School , Boston , Massachusetts 02115 , United States
| | - Ronnie Per-Arne Berntsson
- Department of Medical Biochemistry and Biophysics , Umeå University , SE-90187 Umeå , Sweden.,Wallenberg Centre for Molecular Medicine , Umeå University , SE-90187 Umeå , Sweden
| | - Göran Widmalm
- Department of Organic Chemistry , Stockholm University , SE-106 91 Stockholm , Sweden
| | - Pål Stenmark
- Department of Biochemistry and Biophysics , Stockholm University , SE-106 91 Stockholm , Sweden.,Department of Experimental Medical Science , Lund University , SE-221 00 Lund , Sweden
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Biok NA, Passow AD, Wang C, Bingman CA, Abbott NL, Gellman SH. Retention of Coiled-Coil Dimer Formation in the Absence of Ion Pairing at Positions Flanking the Hydrophobic Core. Biochemistry 2019; 58:4821-4826. [DOI: 10.1021/acs.biochem.9b00668] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Affiliation(s)
- Naomi A. Biok
- Department of Chemistry, University of Wisconsin—Madison, 1101 University Avenue, Madison, Wisconsin 53706, United States
| | - Alexander D. Passow
- Department of Chemistry, University of Wisconsin—Madison, 1101 University Avenue, Madison, Wisconsin 53706, United States
| | - Chenxuan Wang
- Department of Chemistry, University of Wisconsin—Madison, 1101 University Avenue, Madison, Wisconsin 53706, United States
- Department of Chemical and Biological Engineering, University of Wisconsin—Madison, 1415 Engineering Drive, Madison, Wisconsin 53706, United States
| | - Craig A. Bingman
- Department of Biochemistry, University of Wisconsin—Madison, 440 Henry Mall, Madison, Wisconsin 53706, United States
| | - Nicholas L. Abbott
- Department of Chemical and Biological Engineering, University of Wisconsin—Madison, 1415 Engineering Drive, Madison, Wisconsin 53706, United States
- Smith School of Chemical and Biomolecular Engineering, Cornell University, 1 Ho Plaza, Ithaca, New York 14853, United States
| | - Samuel H. Gellman
- Department of Chemistry, University of Wisconsin—Madison, 1101 University Avenue, Madison, Wisconsin 53706, United States
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39
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Chemical and Biological Characteristics of Antimicrobial α-Helical Peptides Found in Solitary Wasp Venoms and Their Interactions with Model Membranes. Toxins (Basel) 2019; 11:toxins11100559. [PMID: 31554187 PMCID: PMC6832458 DOI: 10.3390/toxins11100559] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2019] [Revised: 09/04/2019] [Accepted: 09/16/2019] [Indexed: 02/06/2023] Open
Abstract
Solitary wasps use their stinging venoms for paralyzing insect or spider prey and feeding them to their larvae. We have surveyed bioactive substances in solitary wasp venoms, and found antimicrobial peptides together with some other bioactive peptides. Eumenine mastoparan-AF (EMP-AF) was the first to be found from the venom of the solitary eumenine wasp Anterhynchium flavomarginatum micado, showing antimicrobial, histamine-releasing, and hemolytic activities, and adopting an α-helical secondary structure under appropriate conditions. Further survey of solitary wasp venom components revealed that eumenine wasp venoms contained such antimicrobial α-helical peptides as the major peptide component. This review summarizes the results obtained from the studies of these peptides in solitary wasp venoms and some analogs from the viewpoint of (1) chemical and biological characterization; (2) physicochemical properties and secondary structure; and (3) channel-like pore-forming properties.
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Activating the Intrinsic Pathway of Apoptosis Using BIM BH3 Peptides Delivered by Peptide Amphiphiles with Endosomal Release. MATERIALS 2019; 12:ma12162567. [PMID: 31408950 PMCID: PMC6719084 DOI: 10.3390/ma12162567] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/29/2019] [Revised: 08/02/2019] [Accepted: 08/05/2019] [Indexed: 12/13/2022]
Abstract
Therapeutic manipulation of the BCL-2 family using BH3 mimetics is an emerging paradigm in cancer treatment and immune modulation. For example, peptides mimicking the BIM BH3 helix can directly target the full complement of anti- and pro-apoptotic BCL-2 proteins to trigger apoptosis. This study has incorporated the potent BH3 α-helical death domain of BIM into peptide amphiphile (PA) nanostructures designed to facilitate cellular uptake and induce cell death. This study shows that these PA nanostructures are quickly incorporated into cells, are able to specifically bind BCL-2 proteins, are stable at physiologic temperatures and pH, and induce dose-dependent apoptosis in cells. The incorporation of a cathepsin B cleavable linker between the BIM BH3 peptide and the hydrophobic tail resulted in increased intracellular accumulation and mitochondrial co-localization of the BIM BH3 peptide while also improving BCL-2 family member binding and apoptotic reactivation. This PA platform represents a promising new strategy for intracellular therapeutic peptide delivery for the disruption of intracellular protein:protein interactions.
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Ohgita T, Takechi-Haraya Y, Nadai R, Kotani M, Tamura Y, Nishikiori K, Nishitsuji K, Uchimura K, Hasegawa K, Sakai-Kato K, Akaji K, Saito H. A novel amphipathic cell-penetrating peptide based on the N-terminal glycosaminoglycan binding region of human apolipoprotein E. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2019; 1861:541-549. [DOI: 10.1016/j.bbamem.2018.12.010] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/29/2018] [Revised: 11/17/2018] [Accepted: 12/13/2018] [Indexed: 11/15/2022]
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42
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Sun Y, Medina Cruz A, Hadley KC, Galant NJ, Law R, Vernon RM, Morris VK, Robertson J, Chakrabartty A. Physiologically Important Electrolytes as Regulators of TDP-43 Aggregation and Droplet-Phase Behavior. Biochemistry 2018; 58:590-607. [DOI: 10.1021/acs.biochem.8b00842] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Yulong Sun
- University Health Network, Princess Margaret Cancer Centre, University of Toronto, TMDT 4-305, 101 College Street, Toronto, ON M5G 1L7, Canada
| | - Alison Medina Cruz
- Department of Medical Biophysics, Princess Margaret Cancer Centre, University of Toronto, TMDT 4-305, 101 College Street, Toronto, ON M5G 1L7, Canada
| | - Kevin C. Hadley
- University Health Network, Princess Margaret Cancer Centre, University of Toronto, TMDT 4-305, 101 College Street, Toronto, ON M5G 1L7, Canada
| | - Natalie J. Galant
- University Health Network, Princess Margaret Cancer Centre, University of Toronto, TMDT 4-305, 101 College Street, Toronto, ON M5G 1L7, Canada
| | - Ryan Law
- Department of Medical Biophysics, Princess Margaret Cancer Centre, University of Toronto, TMDT 4-305, 101 College Street, Toronto, ON M5G 1L7, Canada
| | - Robert M. Vernon
- Program in Molecular Medicine, The Hospital for Sick Children, Toronto, ON M5G 0A4, Canada
| | - Vanessa K. Morris
- University Health Network, Princess Margaret Cancer Centre, University of Toronto, TMDT 4-305, 101 College Street, Toronto, ON M5G 1L7, Canada
- School of Biological Sciences, University of Canterbury, Ilam, Christchurch 8041, New Zealand
| | - Janice Robertson
- Tanz Centre for Research in Neurodegenerative Diseases, University of Toronto, Toronto, ON M5T 2S8, Canada
| | - Avijit Chakrabartty
- University Health Network, Princess Margaret Cancer Centre, University of Toronto, TMDT 4-305, 101 College Street, Toronto, ON M5G 1L7, Canada
- Department of Medical Biophysics, Princess Margaret Cancer Centre, University of Toronto, TMDT 4-305, 101 College Street, Toronto, ON M5G 1L7, Canada
- Department of Biochemistry, University of Toronto, TMDT 4-305, 101 College Street, Toronto, ON M5G 1L7, Canada
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Zhang J, Mao X, Xu W. Fibril Nucleation Kinetics of a Pharmaceutical Peptide: The Role of Conformation Stability, Formulation Factors, and Temperature Effect. Mol Pharm 2018; 15:5591-5601. [PMID: 30350639 DOI: 10.1021/acs.molpharmaceut.8b00769] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Peptide aggregation, such as the formation of fibrils, could pose a significant challenge for the stability of parenteral peptide drugs. To ensure a robust peptide formulation, a thorough understanding of aggregation kinetics and the development of appropriate accelerated testing conditions are necessary. The present research investigated factors that impact the fibrillation kinetics of a helical 29mer pharmaceutical peptide (peptide A) and attempts to correlate results of accelerated kinetic studies with real time kinetics. Conformational flexibility of the peptide and its potential impact on aggregation kinetics were thoroughly evaluated. Three orthogonal approaches to evaluate aggregation kinetics were assessed, thioflavin T fluorescence, turbidity, and soluble peptide concentration. The results from the methods demonstrated that peptide A showed nucleated polymerization kinetics. The lag time of the fibrillation process depends heavily on pH, ionic strength, temperature, agitation, and substrate interface. The temperature-dependent fibril nucleation kinetics follow Arrhenius behavior, despite a helical fold in the peptide structure. This finding suggests a potential opportunity to leverage accelerated testing conditions to project the long-term performance at storage temperatures. The present study provides both fundamental understanding and practical approaches to mitigate the aggregation risk for pharmaceutical peptides with a strong tendency to form fibrils.
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Affiliation(s)
- Jingtao Zhang
- Department of Pharmaceutical Sciences, MRL , Merck & Co., Inc. , West Point , Pennsylvania 19486 , United States
| | - Xinpei Mao
- Department of Pharmaceutical Sciences, MRL , Merck & Co., Inc. , West Point , Pennsylvania 19486 , United States
| | - Wei Xu
- Department of Pharmaceutical Sciences, MRL , Merck & Co., Inc. , West Point , Pennsylvania 19486 , United States
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Tsuchie R, Shimosato M, Hamasaki K. Hydrophobic Association of a Side Chains Induces Reversible Helix Folding in a Dual Aromatic Ring Tagged Short Peptide. CHEM LETT 2018. [DOI: 10.1246/cl.180601] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Ryusuke Tsuchie
- Department of Applied Chemistry, Shibaura Institute of Technology, 3-5-7 Toyosu, Koto-ku, Tokyo 135-8548, Japan
| | - Mayu Shimosato
- Department of Applied Chemistry, Shibaura Institute of Technology, 3-5-7 Toyosu, Koto-ku, Tokyo 135-8548, Japan
| | - Keita Hamasaki
- Department of Applied Chemistry, Shibaura Institute of Technology, 3-5-7 Toyosu, Koto-ku, Tokyo 135-8548, Japan
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45
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Kiskis J, Horvath I, Wittung-Stafshede P, Rocha S. [The processes of α-synuclein amyloid protein complexes involved in the pathogenesis of Parkinson's disease]. Zh Nevrol Psikhiatr Im S S Korsakova 2018; 118:75-81. [PMID: 30251982 DOI: 10.17116/jnevro201811808175] [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: 11/18/2022]
Abstract
AIM To analyze interactions between α-synuclein (αS) protein and lipids using biophysical methods. MATERIAL AND METHODS Recombinant α-synuclein synthesized in prokaryotic cells was used. To characterize the interaction of αS with negatively charged vesicles of DOPS (1,2-dioleoyl-sn-glycero-3-phospho-L-serine, sodium salt) and DOPG (1,2-dioleoyl-sn-glycero-3-phospho-(1'-rac-glycerol), sodium salt) and the consequences of such interactions on αS amyloid formation, combined circular dichroism, fluorescence and imaging methods in vitro were applied. RESULTS AND CONCLUSION Lipid head-group chemistry modulates αS interactions and also affects amyloid fiber formation. Pre-formed αS oligomers, typically present in a small amount in the αS starting material, acted as templates for linear growth of anomalous amyloid fibers in the presence of vesicles. At the same time, the remaining αS monomers were restricted from vesicle-mediated nucleation of amyloid fibers. Although not a dominant process in bulk experiments, this hidden αS aggregation pathway may be of importance in vivo.
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Affiliation(s)
- J Kiskis
- Department of Biology and Biological Engineering, Chalmers University of Technology, Gothenburg, Sweden
| | - I Horvath
- Department of Biology and Biological Engineering, Chalmers University of Technology, Gothenburg, Sweden
| | - P Wittung-Stafshede
- Department of Biology and Biological Engineering, Chalmers University of Technology, Gothenburg, Sweden
| | - S Rocha
- Department of Biology and Biological Engineering, Chalmers University of Technology, Gothenburg, Sweden
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46
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Eckhardt D, Li-Blatter X, Schönfeld HJ, Heerklotz H, Seelig J. Cooperative unfolding of apolipoprotein A-1 induced by chemical denaturation. Biophys Chem 2018; 240:42-49. [DOI: 10.1016/j.bpc.2018.05.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2018] [Revised: 05/22/2018] [Accepted: 05/22/2018] [Indexed: 12/30/2022]
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47
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Fox SJ, Lakshminarayanan R, Beuerman RW, Li J, Verma CS. Conformational Transitions of Melittin between Aqueous and Lipid Phases: Comparison of Simulations with Experiments. J Phys Chem B 2018; 122:8698-8705. [DOI: 10.1021/acs.jpcb.8b06781] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Stephen J. Fox
- Bioinformatics Institute (A*Star), 30 Biopolis Street, #07-01 Matrix, Singapore 138671, Singapore
| | - Rajamani Lakshminarayanan
- Eye ACP, Duke-NUS Graduate Medical School, Singapore 169857, Singapore
- Anti-Infectives Research Group, Singapore Eye Research Institute, Singapore 168751, Singapore
| | - Roger W. Beuerman
- Anti-Infectives Research Group, Singapore Eye Research Institute, Singapore 168751, Singapore
| | - Jianguo Li
- Bioinformatics Institute (A*Star), 30 Biopolis Street, #07-01 Matrix, Singapore 138671, Singapore
- Eye ACP, Duke-NUS Graduate Medical School, Singapore 169857, Singapore
- Anti-Infectives Research Group, Singapore Eye Research Institute, Singapore 168751, Singapore
| | - Chandra S. Verma
- Bioinformatics Institute (A*Star), 30 Biopolis Street, #07-01 Matrix, Singapore 138671, Singapore
- Department of Biological Sciences, National University of Singapore, 16 Science Drive 4, Singapore 117558, Singapore
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, 4 Singapore 637551, Singapore
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48
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Yin Z, Machius M, Nestler EJ, Rudenko G. Activator Protein-1: redox switch controlling structure and DNA-binding. Nucleic Acids Res 2017; 45:11425-11436. [PMID: 28981703 PMCID: PMC5737521 DOI: 10.1093/nar/gkx795] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2017] [Accepted: 08/31/2017] [Indexed: 01/07/2023] Open
Abstract
The transcription factor, activator protein-1 (AP-1), binds to cognate DNA under redox control; yet, the underlying mechanism has remained enigmatic. A series of crystal structures of the AP-1 FosB/JunD bZIP domains reveal ordered DNA-binding regions in both FosB and JunD even in absence DNA. However, while JunD is competent to bind DNA, the FosB bZIP domain must undergo a large conformational rearrangement that is controlled by a 'redox switch' centered on an inter-molecular disulfide bond. Solution studies confirm that FosB/JunD cannot undergo structural transition and bind DNA when the redox-switch is in the 'OFF' state, and show that the mid-point redox potential of the redox switch affords it sensitivity to cellular redox homeostasis. The molecular and structural studies presented here thus reveal the mechanism underlying redox-regulation of AP-1 Fos/Jun transcription factors and provide structural insight for therapeutic interventions targeting AP-1 proteins.
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Affiliation(s)
- Zhou Yin
- Department of Pharmacology and Toxicology, and the Sealy Center for Structural Biology, University of Texas Medical Branch, Galveston, TX 77555, USA
| | - Mischa Machius
- Department of Pharmacology and Toxicology, and the Sealy Center for Structural Biology, University of Texas Medical Branch, Galveston, TX 77555, USA
| | - Eric J. Nestler
- Fishberg Department of Neuroscience, Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, 1 Gustave L Levy Place, New York, NY 10029, USA
| | - Gabby Rudenko
- Department of Pharmacology and Toxicology, and the Sealy Center for Structural Biology, University of Texas Medical Branch, Galveston, TX 77555, USA,To whom correspondence should be addressed. Tel: +1 409 772 6292; Fax: +1 409 772 9642;
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Membrane-Bound Alpha Synuclein Clusters Induce Impaired Lipid Diffusion and Increased Lipid Packing. Biophys J 2017; 111:2440-2449. [PMID: 27926845 DOI: 10.1016/j.bpj.2016.10.016] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2016] [Revised: 10/09/2016] [Accepted: 10/13/2016] [Indexed: 12/21/2022] Open
Abstract
The aggregation of membrane-bound α-synuclein (αS) into oligomers and/or amyloid fibrils has been suggested to cause membrane damage in in vitro model phospholipid membrane systems and in vivo. In this study, we investigate how αS interactions that precede the formation of well-defined aggregates influence physical membrane properties. Using three truncated variants of αS with different aggregation propensities and comparable phospholipid membrane binding affinities we show, using fluorescence recovery after photobleaching (FRAP) and fluorescence anisotropy measurements, that formation of αS clusters on supported lipid bilayers (SLBs) impairs lateral lipid diffusion and increases lipid packing beneath the αS clusters. Formation of protein clusters starts immediately after monomer addition. The magnitudes of the changes in effective lipid diffusion and lipid order increase with the protein cluster size. Our results show that the combination of inter-αS and αS-membrane interactions can drive the formation of more ordered lipid domains. Considering the functional involvement of membrane micro-domains in biological membranes, αS-induced domain formation may be relevant for alternative disease mechanisms.
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50
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Jafarisani M, Bathaie SZ, Mousavi MF. Saffron carotenoids (crocin and crocetin) binding to human serum albumin as investigated by different spectroscopic methods and molecular docking. J Biomol Struct Dyn 2017; 36:1681-1690. [PMID: 28537197 DOI: 10.1080/07391102.2017.1331865] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Therapeutic effects of saffron ingredients were studied in some diseases. The pharmacokinetics and pharmacodynamics of these ingredients were also studied, but their transport mechanism is not clearly known. Serum albumin has been known as the most important transporter of many drugs in the body that affects their disposition, transportation, and bioavailability. Here, we investigated the interaction of crocin (Cro) with HSA, for the first time, and compared with the crocetin (Crt)-HSA interaction. UV and fluorescence spectroscopy, circular dichroism (CD), and molecular docking was applied to investigate the possibility and mechanism of binding of HSA with these natural carotenoids. The gradually addition of Cro increased HSA absorbency at 278 nm, while Crt decreased it. Both of these changes induced HSA unfolding that was confirmed by the decreased α-helix content, as determined by the CD. Both carotenoids quenched HSA fluorescence emission, but with different mechanisms. The Stern-Volmer plots indicated a dynamic quenching of intrinsic emission of HSA due to Cro addition, while Crt quenching followed both static and dynamic quenching mechanisms. Docking results indicated binding of Cro/Crt in sub-domain IIA, Sudlow site I of HSA, which accompanied with the hydrogen bonding of Cro/Crt with Tyr138. The interaction of these ligands (Cro/Crt) caused HSA unfolding and affects the hydrophobic environment of Trp241, which result in the quenching of Trp fluorescence. The UV spectroscopy and fluorescence quenching data indicated the differences in the mechanisms of interaction of Cro/Crt with HSA, which is due to the differences in the structure and hydrophobicity of these ligands.
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Affiliation(s)
- Moslem Jafarisani
- a Faculty of Medical Sciences, Department of Clinical Biochemistry , Tarbiat Modares University , Tehran , Iran
| | - S Zahra Bathaie
- a Faculty of Medical Sciences, Department of Clinical Biochemistry , Tarbiat Modares University , Tehran , Iran
| | - Mir F Mousavi
- b Department of Chemistry , Tarbiat Modares University , Tehran 14115-175 , Iran
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