1
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Ramos S, Lee JC. Raman spectroscopy in the study of amyloid formation and phase separation. Biochem Soc Trans 2024; 52:1121-1130. [PMID: 38666616 PMCID: PMC11346453 DOI: 10.1042/bst20230599] [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: 02/14/2024] [Revised: 04/11/2024] [Accepted: 04/15/2024] [Indexed: 06/27/2024]
Abstract
Neurodegenerative diseases, such as Alzheimer's and Parkinson's, share a common pathological feature of amyloid structure accumulation. However, the structure-function relationship between these well-ordered, β-sheet-rich, filamentous protein deposits and disease etiology remains to be defined. Recently, an emerging hypothesis has linked phase separation, a process involved in the formation of protein condensates, to amyloid formation, suggesting that liquid protein droplets serve as loci for amyloid initiation. To elucidate how these processes contribute to disease progression, tools that can directly report on protein secondary structural changes are needed. Here, we review recent studies that have demonstrated Raman spectroscopy as a powerful vibrational technique for interrogating amyloid structures; one that offers sensitivity from the global secondary structural level to specific residues. This probe-free technique is further enhanced via coupling to a microscope, which affords structural data with spatial resolution, known as Raman spectral imaging (RSI). In vitro and in cellulo applications of RSI are discussed, highlighting studies of protein droplet aging, cellular internalization of fibrils, and Raman imaging of intracellular water. Collectively, utilization of the myriad Raman spectroscopic methods will contribute to a deeper understanding of protein conformational dynamics in the complex cellular milieu and offer potential clinical diagnostic capabilities for protein misfolding and aggregation processes in disease states.
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Affiliation(s)
- Sashary Ramos
- Laboratory of Protein Conformation and Dynamics, Biochemistry and Biophysics Center, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, U.S.A
| | - Jennifer C. Lee
- Laboratory of Protein Conformation and Dynamics, Biochemistry and Biophysics Center, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, U.S.A
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2
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Unnikrishnan AC, Balamurugan K, Shanmugam G. Structural Insights into the Amyloid Fibril Polymorphism Using an Isotope-Edited Vibrational Circular Dichroism Study at the Amino Acid Residue Level. J Phys Chem B 2023; 127:7674-7684. [PMID: 37667494 DOI: 10.1021/acs.jpcb.3c03437] [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: 09/06/2023]
Abstract
Polymorphism is common in both in vitro and in vivo amyloid fibrils formed by the same peptide/protein. However, the differences in their self-assembled structures at the amino acid level remain poorly understood. In this study, we utilized isotope-edited vibrational circular dichroism (VCD) on a well-known amyloidogenic peptide fragment (N22FGAIL27) of human islet amyloid polypeptide (IAPf) to investigate the structural polymorphism. Two individual isotope-labeled IAPf peptides were used, with a 13C label on the carbonyl group of phenylalanine (IAPf-F) and glycine (IAPf-G). We compared the amyloid-like nanofibril of IAPf induced by solvent casting (fibril B) with our previous report on the same IAPf peptide fibril but with a different fibril morphology (fibril A) formed in an aqueous buffer solution. Fibril B consisted of entangled, laterally fused amyloid-like nanofibrils with a relatively shorter diameter (15-50 nm) and longer length (several microns), while fibril A displayed nanofibrils with a higher diameter (30-60 nm) and shorter length (500 nm-2 μm). The isotope-edited VCD analysis indicated that fibrils B consisted of anti-parallel β-sheet arrangements with glycine residues in the registry and phenylalanine residues out of the registry, which was significantly different from fibrils A, where a mixture of parallel β-sheet and turn structure with the registry at phenylalanine and glycine residues was observed. The VCD analysis, therefore, suggests that polymorphism in amyloid-like fibrils can be attributed to the difference in the packing/arrangement of the individual β-strands in the β-sheet and the difference in the amino acid registry. Our findings provide insights into the structural aspects of fibril polymorphism related to various amyloid diseases and may aid in designing amyloid fibril inhibitors for therapeutic purposes.
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Affiliation(s)
- Anagha C Unnikrishnan
- Organic & Bioorganic Chemistry Laboratory, Council of Scientific and Industrial Research (CSIR)─Central Leather Research Institute (CLRI), Adyar, Chennai 600020, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
| | - Kanagasabai Balamurugan
- Centre for High Computing, Council of Scientific and Industrial Research (CSIR)─Central Leather Research Institute (CLRI), Adyar, Chennai 600020, India
| | - Ganesh Shanmugam
- Organic & Bioorganic Chemistry Laboratory, Council of Scientific and Industrial Research (CSIR)─Central Leather Research Institute (CLRI), Adyar, Chennai 600020, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
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3
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Avni A, Joshi A, Mukhopadhyay S. Hydrogen-Deuterium Exchange Vibrational Raman Spectroscopy Distinguishes Distinct Amyloid Polymorphs Comprising Altered Core Architecture. J Phys Chem Lett 2023:5592-5601. [PMID: 37307286 DOI: 10.1021/acs.jpclett.3c01086] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Amyloid fibrils are ordered protein aggregates comprising a hydrogen-bonded central cross-β core displaying a structural diversity in their supramolecular packing arrangements within the core. Such an altered packing results in amyloid polymorphism that gives rise to morphological and biological strain diversities. Here, we show that vibrational Raman spectroscopy coupled with hydrogen/deuterium (H/D) exchange discerns the key structural features that are responsible for yielding diverse amyloid polymorphs. Such a noninvasive and label-free methodology allows us to structurally distinguish distinct amyloid polymorphs displaying altered hydrogen bonding and supramolecular packing within the cross-β structural motif. By using quantitative molecular fingerprinting and multivariate statistical analysis, we analyze key Raman bands for the protein backbone and side chains that allow us to capture the conformational heterogeneity and structural distributions within distinct amyloid polymorphs. Our results delineate the key molecular factors governing the structural diversity in amyloid polymorphs and can potentially simplify studying amyloid remodeling by small molecules.
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4
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Thursch LJ, Lima TA, O'Neill N, Ferreira FF, Schweitzer-Stenner R, Alvarez NJ. Influence of central sidechain on self-assembly of glycine-x-glycine peptides. SOFT MATTER 2023; 19:394-409. [PMID: 36454226 DOI: 10.1039/d2sm01082h] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
Low molecular weight gelators (LMWGs) are the subject of intense research for a range of biomedical and engineering applications. Peptides are a special class of LMWG, which offer infinite sequence possibilities and, therefore, engineered properties. This work examines the propensity of the GxG peptide family, where x denotes a guest residue, to self-assemble into fibril networks via changes in pH and ethanol concentration. These triggers for gelation are motivated by recent work on GHG and GAG, which unexpectedly self-assemble into centimeter long fibril networks with unique rheological properties. The propensity of GxG peptides to self-assemble, and the physical and chemical properties of the self-assembled structures are characterized by microscopy, spectroscopy, rheology, and X-ray diffraction. Interestingly, we show that the number, length, size, and morphology of the crystalline self-assembled aggregates depend significantly on the x-residue chemistry and the solution conditions, i.e. pH, temperature, peptide concentration, etc. The different x-residues allow us to probe the importance of different peptide interactions, e.g. π-π stacking, hydrogen bonding, and hydrophobicity, on the formation of fibrils. We conclude that fibril formation requires π-π stacking interactions in pure water, while hydrogen bonding can form fibrils in the presence of ethanol-water solutions. These results validate and support theoretical arguments on the propensity for self-assembly and leads to a better understanding of the relationship between peptide chemistry and fibril self-assembly. Overall, GxG peptides constitute a unique family of peptides, whose characterization will aid in advancing our understanding of self-assembly driving forces for fibril formation in peptide systems.
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Affiliation(s)
- Lavenia J Thursch
- Department of Chemical and Biological Engineering, Drexel University, Philadelphia, PA 19104, USA.
| | - Thamires A Lima
- Department of Chemical and Biological Engineering, Drexel University, Philadelphia, PA 19104, USA.
| | - Nichole O'Neill
- Department of Chemical and Biological Engineering, Drexel University, Philadelphia, PA 19104, USA.
- Department of Chemistry, Drexel University, Philadelphia, PA 19104, USA.
| | - Fabio F Ferreira
- Centro de Ciências Naturais e Humanas, Universidade Federal do ABC, Santo André, São Paulo, Brazil
| | | | - Nicolas J Alvarez
- Department of Chemical and Biological Engineering, Drexel University, Philadelphia, PA 19104, USA.
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5
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O'Neill N, Lima TA, Ferreira FF, Thursch L, Alvarez N, Schweitzer-Stenner R. Forbidden Secondary Structures Found in Gel-Forming Fibrils of Glycylphenylalanylglycine. J Phys Chem B 2022; 126:8080-8093. [PMID: 36194765 DOI: 10.1021/acs.jpcb.2c05010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The zwitterionic l-tripeptide glycylphenylalanylglycine self-assembles into very long crystalline fibrils in an aqueous solution, which causes the formation of an exceptionally strong gel phase (G' ∼ 5 × 106 Pa). The Rietveld refinement analysis of its powder X-ray diffraction (PXRD) pattern reveals a unit cell with four peptides forming a P212121 space group and adopting an inverse polyproline II conformation, that is, a right-handed helical structure that occupies the "forbidden" region of the Ramachandran plot. This unusual structure is stabilized by a plethora of intermolecular interactions facilitated by the large number of different functional groups of the unblocked tripeptide. Comparisons of simulated and experimental Fourier transform infrared and vibrational circular dichroism (VCD) amide I' profiles corroborate the PXRD structure. Our experimental setup reduces the sample to a quasi-two-dimensional network of fibrils. We exploited the influence of this reduced dimensionality on the amide I VCD to identify the main fibril axis. We demonstrate that PXRD, vibrational spectroscopy, and amide I simulations provide a powerful toolset for secondary structure and fibril axis determination.
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Affiliation(s)
- Nichole O'Neill
- Department of Chemistry, Drexel University, 3141 Chestnut Street, Philadelphia, Pennsylvania19104, United States.,Department of Chemical Engineering, Drexel University, 3141 Chestnut Street, Philadelphia, Pennsylvania19104, United States
| | - Thamires A Lima
- Department of Chemical Engineering, Drexel University, 3141 Chestnut Street, Philadelphia, Pennsylvania19104, United States
| | - Fabio Furlan Ferreira
- Center for Natural and Human Sciences (CCNH), Federal University of ABC (UFABC), Av. Dos Estados, 5001, S622-3, Santo André, São Paulo09210-580, Brazil
| | - Lavenia Thursch
- Department of Chemical Engineering, Drexel University, 3141 Chestnut Street, Philadelphia, Pennsylvania19104, United States
| | - Nicolas Alvarez
- Department of Chemical Engineering, Drexel University, 3141 Chestnut Street, Philadelphia, Pennsylvania19104, United States
| | - Reinhard Schweitzer-Stenner
- Department of Chemistry, Drexel University, 3141 Chestnut Street, Philadelphia, Pennsylvania19104, United States
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6
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Klose D, Vemulapalli SPB, Richman M, Rudnick S, Aisha V, Abayev M, Chemerovski M, Shviro M, Zitoun D, Majer K, Wili N, Goobes G, Griesinger C, Jeschke G, Rahimipour S. Cu 2+-Induced self-assembly and amyloid formation of a cyclic D,L-α-peptide: structure and function. Phys Chem Chem Phys 2022; 24:6699-6715. [PMID: 35234757 DOI: 10.1039/d1cp05415e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
In a wide spectrum of neurodegenerative diseases, self-assembly of pathogenic proteins to cytotoxic intermediates is accelerated by the presence of metal ions such as Cu2+. Only low concentrations of these early transient oligomeric intermediates are present in a mixture of species during fibril formation, and hence information on the extent of structuring of these oligomers is still largely unknown. Here, we investigate dimers as the first intermediates in the Cu2+-driven aggregation of a cyclic D,L-α-peptide architecture. The unique structural and functional properties of this model system recapitulate the self-assembling properties of amyloidogenic proteins including β-sheet conformation and cross-interaction with pathogenic amyloids. We show that a histidine-rich cyclic D,L-α-octapeptide binds Cu2+ with high affinity and selectivity to generate amyloid-like cross-β-sheet structures. By taking advantage of backbone amide methylation to arrest the self-assembly at the dimeric stage, we obtain structural information and characterize the degree of local order for the dimer. We found that, while catalytic amounts of Cu2+ promote aggregation of the peptide to fibrillar structures, higher concentrations dose-dependently reduce fibrillization and lead to formation of spherical particles, showing self-assembly to different polymorphs. For the initial self-assembly step to the dimers, we found that Cu2+ is coordinated on average by two histidines, similar to self-assembled peptides, indicating that a similar binding interface is perpetuated during Cu2+-driven oligomerization. The dimer itself is found in heterogeneous conformations that undergo dynamic exchange, leading to the formation of different polymorphs at the initial stage of the aggregation process.
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Affiliation(s)
- Daniel Klose
- Department of Chemistry and Applied Biosciences, ETH Zürich, 8093 Zürich, Switzerland.
| | - Sahithya Phani Babu Vemulapalli
- NMR-based Structural Biology, Max Planck Institute for Biophysical Chemistry, 37077 Göttingen, Germany. .,Institute for Chemistry and Biology of the Marine Environment, University of Oldenburg, 26129 Oldenburg, Germany
| | - Michal Richman
- Department of Chemistry, Bar-Ilan University, Ramat-Gan 5290002, Israel.
| | - Safra Rudnick
- Department of Chemistry, Bar-Ilan University, Ramat-Gan 5290002, Israel. .,Bar-Ilan Institute for Technology and Advanced Materials (BINA), Bar-Ilan University, Ramat-Gan 5290002, Israel
| | - Vered Aisha
- Department of Chemistry, Bar-Ilan University, Ramat-Gan 5290002, Israel.
| | - Meital Abayev
- Department of Chemistry, Bar-Ilan University, Ramat-Gan 5290002, Israel.
| | - Marina Chemerovski
- Department of Chemistry, Bar-Ilan University, Ramat-Gan 5290002, Israel.
| | - Meital Shviro
- Department of Chemistry, Bar-Ilan University, Ramat-Gan 5290002, Israel. .,Bar-Ilan Institute for Technology and Advanced Materials (BINA), Bar-Ilan University, Ramat-Gan 5290002, Israel
| | - David Zitoun
- Department of Chemistry, Bar-Ilan University, Ramat-Gan 5290002, Israel. .,Bar-Ilan Institute for Technology and Advanced Materials (BINA), Bar-Ilan University, Ramat-Gan 5290002, Israel
| | - Katharina Majer
- Department of Chemistry and Applied Biosciences, ETH Zürich, 8093 Zürich, Switzerland.
| | - Nino Wili
- Department of Chemistry and Applied Biosciences, ETH Zürich, 8093 Zürich, Switzerland.
| | - Gil Goobes
- Department of Chemistry, Bar-Ilan University, Ramat-Gan 5290002, Israel.
| | - Christian Griesinger
- NMR-based Structural Biology, Max Planck Institute for Biophysical Chemistry, 37077 Göttingen, Germany.
| | - Gunnar Jeschke
- Department of Chemistry and Applied Biosciences, ETH Zürich, 8093 Zürich, Switzerland.
| | - Shai Rahimipour
- Department of Chemistry, Bar-Ilan University, Ramat-Gan 5290002, Israel.
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7
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Schweitzer-Stenner R, Alvarez NJ. Short Peptides as Tunable, Switchable, and Strong Gelators. J Phys Chem B 2021; 125:6760-6775. [PMID: 34133176 DOI: 10.1021/acs.jpcb.1c01447] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
This Perspective outlines our current understanding of molecular gels composed of short and ultrashort peptides over the past 20 years. We discuss in detail the state of the art regarding self-assembly mechanisms, structure, thermal stability, and kinetics of fibril and/or network formation. Emphasis is put on the importance of the combined use of spectroscopy and rheology for characterizing and validating self-assembly models. While a range of peptide chemistries are reviewed, we focus our discussion on a unique new class of ultrashort peptide gelators, denoted GxG peptides (x: guest residue), which are capable of forming self-assembled fibril networks. The storage moduli of GxG gels are tunable up to 100 kPa depending on concentration, pH, and/or cosolvent. The sheet structures of the fibrils differ from canonical β-sheets. When appropriate, each section highlights opportunities for additional research and technologies that would further our understanding.
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8
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Hesser M, Thursch LJ, Lewis TR, Lima TA, Alvarez NJ, Schweitzer-Stenner R. Concentration Dependence of a Hydrogel Phase Formed by the Deprotonation of the Imidazole Side Chain of Glycylhistidylglycine. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2021; 37:6935-6946. [PMID: 34077210 DOI: 10.1021/acs.langmuir.1c00382] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Upon deprotonation of its imidazole group at ∼pH 6, the unblocked tripeptide glycylhistidylglycine (GHG) self-assembles into very long crystalline fibrils on a 10-1000 μm scale which are capable of forming a volume spanning network, that is, hydrogel. The critical peptide concentration for self-assembly at a pH of 6 lies between 50 and 60 mM. The fraction of peptides that self-assemble into fibrils depends on the concentration of deprotonated GHG. While IR spectra seem to indicate the formation of fibrils with standard amyloid fibril β-sheet structures, vibrational circular dichroism spectra show a strongly enhanced amide I' signal, suggesting that the formed fibrils exhibit significant chirality. The fibril chirality appears to be a function of peptide concentration. Rheological measurements reveal that the rate of gelation is concentration-dependent and that there is an optimum gel strength at intermediate peptide concentrations of ca. 175 mM. This paper outlines the unique properties of the GHG gel phase which is underlain by a surprisingly dense fibril network with an exceptionally strong modulus that make them potential additives for biomedical applications.
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Affiliation(s)
- Morgan Hesser
- Department of Chemistry, Drexel University, Philadelphia, Pennsylvania 19104, United States
| | - Lavenia J Thursch
- Department of Chemical and Biological Engineering, Drexel University, Philadelphia, Pennsylvania 19104, United States
| | - Todd R Lewis
- Department of Chemical and Biological Engineering, Drexel University, Philadelphia, Pennsylvania 19104, United States
| | - Thamires A Lima
- Department of Chemical and Biological Engineering, Drexel University, Philadelphia, Pennsylvania 19104, United States
| | - Nicolas J Alvarez
- Department of Chemical and Biological Engineering, Drexel University, Philadelphia, Pennsylvania 19104, United States
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9
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Krupová M, Kessler J, Bouř P. Polymorphism of Amyloid Fibrils Induced by Catalytic Seeding: A Vibrational Circular Dichroism Study. Chemphyschem 2020; 22:83-91. [DOI: 10.1002/cphc.202000797] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2020] [Revised: 10/16/2020] [Indexed: 11/11/2022]
Affiliation(s)
- Monika Krupová
- Institute of Organic Chemistry and Biochemistry Academy of Sciences Flemingovo náměstí 2 16610 Prague Czech Republic
- Faculty of Mathematics and Physics Charles University Ke Karlovu 3 12116 Prague 2 Czech Republic
| | - Jiří Kessler
- Institute of Organic Chemistry and Biochemistry Academy of Sciences Flemingovo náměstí 2 16610 Prague Czech Republic
| | - Petr Bouř
- Institute of Organic Chemistry and Biochemistry Academy of Sciences Flemingovo náměstí 2 16610 Prague Czech Republic
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10
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Levine MS, Ghosh M, Hesser M, Hennessy N, DiGuiseppi DM, Adler-Abramovich L, Schweitzer-Stenner R. Formation of peptide-based oligomers in dimethylsulfoxide: identifying the precursor of fibril formation. SOFT MATTER 2020; 16:7860-7868. [PMID: 32761042 DOI: 10.1039/d0sm00035c] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
The well-studied dipeptide fluorenylmethyloxycarbonyl-di-phenylalanine (FmocFF) forms a rigid hydrogel upon dissolving in dimethylsulfoxide (DMSO) and dilution in H2O. Here, we explored the pre-aggregation of the peptide in pure DMSO by vibrational spectroscopies, X-ray powder diffraction and dynamic light scattering. Our results show an equilibrium between a dominant population of amorphous oligomers (on a length scale of 2 nm) and a small number of protofibrils/fibrils (on a length scale of 30 nm in the centimolar and of 200 nm in the sub-molar region). To probe the mechanism underlying the formation of these protofilaments, we measured the 1H-NMR, IR and visible Raman spectra of DMSO containing different FmocFF concentrations, ranging between 10 and 300 mM. Our data reveal that interpeptide hydrogen bonding leads to the self-assembly of FmocFF in the centimolar region, while π-π stacking between Fmoc-groups is observed above 100 mM. The high 3J(HNHCα) coupling constant of the N-terminal amide proton indicates that the Fmoc end-cap of the peptide locks the N-terminal residue into a conformational ensemble centered at a φ-value of ca. -120°, which corresponds to a parallel β-sheet type conformation. The 3J(HNHCα) coupling constant of the C-terminal residue is indicative of a polyproline II (pPII)/βt mixture. Our results suggest that the gelation of FmocFF caused by the addition of a small amount of water to DMSO mixtures is facilitated by the formation of disordered protofibrils in pure DMSO.
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Affiliation(s)
- Matthew S Levine
- Department of Chemistry, Drexel University, 3141 Chestnut Street, Philadelphia, PA 19104, USA.
| | - Moumita Ghosh
- Department of Oral Biology, The Goldschleger School of Dental Medicine, Sackler Faculty of Medicine, and The Center for Nanoscience and Nanotechnology, Tel Aviv University, Tel Aviv 69978, Israel.
| | - Morgan Hesser
- Department of Chemistry, Drexel University, 3141 Chestnut Street, Philadelphia, PA 19104, USA.
| | - Nathan Hennessy
- Department of Chemistry, The University of Sheffield, Brook Hill, Sheffield S3 7HF, United Kingdom
| | - David M DiGuiseppi
- Department of Chemistry, Drexel University, 3141 Chestnut Street, Philadelphia, PA 19104, USA.
| | - Lihi Adler-Abramovich
- Department of Oral Biology, The Goldschleger School of Dental Medicine, Sackler Faculty of Medicine, and The Center for Nanoscience and Nanotechnology, Tel Aviv University, Tel Aviv 69978, Israel.
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11
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Liu J, He X. Fragment-based quantum mechanical approach to biomolecules, molecular clusters, molecular crystals and liquids. Phys Chem Chem Phys 2020; 22:12341-12367. [PMID: 32459230 DOI: 10.1039/d0cp01095b] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
To study large molecular systems beyond the system size that the current state-of-the-art ab initio electronic structure methods could handle, fragment-based quantum mechanical (QM) approaches have been developed over the past years, and proved to be efficient in dealing with large molecular systems at various ab initio levels. According to the fragmentation approach, a large molecular system can be divided into subsystems (fragments), and subsequently the property of the whole system can be approximately obtained by taking a proper combination of the corresponding terms of individual fragments. Therefore, the standard QM calculation of a large system could be circumvented by carrying out a series of calculations on small fragments, which significantly promotes computational efficiency. The electrostatically embedded generalized molecular fractionation with conjugate caps (EE-GMFCC) method is one of the fragment-based QM approaches which has been developed by our research group in recent years. This Perspective presents the theoretical framework of this fragmentation method and its applications in biomolecules, molecular clusters, molecular crystals and liquids, including total energy calculation, protein-ligand/protein binding affinity prediction, geometry optimization, vibrational spectrum simulation, ab initio molecular dynamics simulation, and prediction of excited-state properties.
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Affiliation(s)
- Jinfeng Liu
- Department of Basic Medicine and Clinical Pharmacy, China Pharmaceutical University, Nanjing, 210009, China
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12
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Hesser M, Thursch L, Lewis T, DiGuiseppi D, Alvarez NJ, Schweitzer-Stenner R. The tripeptide GHG as an unexpected hydrogelator triggered by imidazole deprotonation. SOFT MATTER 2020; 16:4110-4114. [PMID: 32322858 DOI: 10.1039/d0sm00224k] [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
The tripeptide glycyl-histidyl-glycine (GHG) self-assembles into long, crystalline fibrils forming a strong hydrogel (G'∼ 50 kPa) above a critical concentration of 40 mM upon the deprotonation of its imidazole group. Spectroscopic data reveal a mixture of helically twisted β-sheets and monomers to coexist in the gel phase.
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Affiliation(s)
- Morgan Hesser
- Department of Chemistry, Drexel University, 3141 Chestnut Street, Philadelphia, PA 19104, USA.
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13
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Koenis MAJ, Visscher L, Buma WJ, Nicu VP. Analysis of Vibrational Circular Dichroism Spectra of Peptides: A Generalized Coupled Oscillator Approach of a Small Peptide Model Using VCDtools. J Phys Chem B 2020; 124:1665-1677. [PMID: 32037822 PMCID: PMC7061330 DOI: 10.1021/acs.jpcb.9b11261] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Vibrational circular dichroism (VCD) is one of the major spectroscopic tools to study peptides. Nevertheless, a full understanding of what determines the signs and intensities of VCD bands of these compounds in the amide I and amide II spectral regions is still far from complete. In the present work, we study the origin of these VCD signals using the general coupled oscillator (GCO) analysis, a novel approach that has recently been developed. We apply this approach to the ForValNHMe model peptide in both α-helix and β-sheet configurations. We show that the intense VCD signals observed in the amide I and amide II spectral regions essentially have the same underlying mechanism, namely, the through-space coupling of electric dipoles. The crucial role played by intramolecular hydrogen bonds in determining VCD intensities is also illustrated. Moreover, we find that the contributions to the rotational strengths, considered to be insignificant in standard VCD models, may have sizable magnitudes and can thus not always be neglected. In addition, the VCD robustness of the amide I and II modes has been investigated by monitoring the variation of the rotational strength and its contributing terms during linear transit scans and by performing calculations with different computational parameters. From these studies-and in particular, the decomposition of the rotational strength made possible by the GCO analysis-it becomes clear that one should be cautious when employing measures of robustness as proposed previously.
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Affiliation(s)
- Mark A J Koenis
- Van't Hoff Institute for Molecular Sciences, University of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands
| | - Lucas Visscher
- Amsterdam Center for Multiscale Modeling, Section Theoretical Chemistry, Faculty of Sciences, Vrije Universiteit Amsterdam, De Boelelaan 1083, 1081 HV Amsterdam, The Netherlands
| | - Wybren J Buma
- Van't Hoff Institute for Molecular Sciences, University of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands.,Institute for Molecules and Materials, FELIX Laboratory, Radboud University, Toernooiveld 7c, 6525 ED Nijmegen, The Netherlands
| | - Valentin P Nicu
- Department of Environmental Science, Physics, Physical Education and Sport, Lucian Blaga University of Sibiu, loan Ratiu Street, Nr. 7-9, 550012 Sibiu, Romania
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14
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Keiderling TA. Structure of Condensed Phase Peptides: Insights from Vibrational Circular Dichroism and Raman Optical Activity Techniques. Chem Rev 2020; 120:3381-3419. [DOI: 10.1021/acs.chemrev.9b00636] [Citation(s) in RCA: 50] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Affiliation(s)
- Timothy A. Keiderling
- Department of Chemistry, University of Illinois at Chicago 845 West Taylor Street m/c 111, Chicago, Illinois 60607-7061, United States
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15
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Hosseinpour S, Roeters SJ, Bonn M, Peukert W, Woutersen S, Weidner T. Structure and Dynamics of Interfacial Peptides and Proteins from Vibrational Sum-Frequency Generation Spectroscopy. Chem Rev 2020; 120:3420-3465. [DOI: 10.1021/acs.chemrev.9b00410] [Citation(s) in RCA: 75] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Saman Hosseinpour
- Institute of Particle Technology (LFG), Friedrich-Alexander-University Erlangen-Nürnberg (FAU), 91058 Erlangen, Germany
| | | | - Mischa Bonn
- Molecular Spectroscopy Department, Max Planck Institute for Polymer Research, 55128 Mainz, Germany
| | - Wolfgang Peukert
- Institute of Particle Technology (LFG), Friedrich-Alexander-University Erlangen-Nürnberg (FAU), 91058 Erlangen, Germany
| | - Sander Woutersen
- Van’t Hoff Institute for Molecular Sciences, University of Amsterdam, 1098 EP Amsterdam, The Netherlands
| | - Tobias Weidner
- Department of Chemistry, Aarhus University, 8000 Aarhus C, Denmark
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16
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Acharyya A, DiGiuseppi D, Stinger BL, Schweitzer-Stenner R, Vaden TD. Structural Destabilization of Azurin by Imidazolium Chloride Ionic Liquids in Aqueous Solution. J Phys Chem B 2019; 123:6933-6945. [DOI: 10.1021/acs.jpcb.9b04113] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Affiliation(s)
- Arusha Acharyya
- Department of Chemistry, University of Pennsylvania, 231 S. 34 Street, Philadelphia, Pennsylvania 19104, United States
| | - David DiGiuseppi
- Department of Chemistry, Drexel University, 32 S. 32nd Street, Philadelphia, Pennsylvania 19104, United States
| | - Brittany L. Stinger
- Department of Chemistry and Biochemistry, Rowan University, 201 Mullica Hill Road, Glassboro, New Jersey 08028, United States
| | - Reinhard Schweitzer-Stenner
- Department of Chemistry, Drexel University, 32 S. 32nd Street, Philadelphia, Pennsylvania 19104, United States
| | - Timothy D. Vaden
- Department of Chemistry and Biochemistry, Rowan University, 201 Mullica Hill Road, Glassboro, New Jersey 08028, United States
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17
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DiGuiseppi D, Thursch L, Alvarez NJ, Schweitzer-Stenner R. Exploring the thermal reversibility and tunability of a low molecular weight gelator using vibrational and electronic spectroscopy and rheology. SOFT MATTER 2019; 15:3418-3431. [PMID: 30938745 DOI: 10.1039/c9sm00104b] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Cationic glycylalanylglycine (GAG) self-assembles into a gel in a 55 mol% ethanol/45 mol% water mixture. The gel exhibits a network of crystalline fibrils grown to lengths on a 10-4-10-5 m scale (Farrel et al., Soft Matter, 2016, 12, 6096-6110). Rheological data are indicative of a rather strong gel with storage moduli in the 10 kPa regime. Spectroscopic data revealed the existence of two gel phases; one forms below T = 15 °C (phase I) while the other one forms in a temperature range between 15 °C and the melting temperature of ca. 35 °C (phase II). We explored the reformation of the cationic GAG gel in 55 mol% ethanol/45 mol% water after thermal annealing by spectroscopic and rheological means. Our data reveal that even a short residence time of 5 minutes in the sol phase at 50 °C produced a delay of the gelation process and a gel of lesser strength. These observations suggest that the residence time at the annealing temperature can be used to adjust the strength of both gel phases. Our spectroscopic data show that the annealing process does not change the chirality of peptide fibrils in the two gel phases and that the initial aggregation state of the reformation process is by far more ordered for phase I than it is for phase II. In the gel phases of GAG/ethanol/water mixtures, ethanol seems to function as a sort of catalyst that enables the self-assembly of the peptide in spite of its low intrinsic propensity for aggregation.
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Affiliation(s)
- David DiGuiseppi
- Department of Chemistry, Drexel University, Philadelphia, PA 19104, USA.
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18
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Ilawe NV, Schweitzer-Stenner R, DiGuiseppi D, Wong BM. Is a cross-β-sheet structure of low molecular weight peptides necessary for the formation of fibrils and peptide hydrogels? Phys Chem Chem Phys 2019; 20:18158-18168. [PMID: 29696249 DOI: 10.1039/c8cp00691a] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Short peptides have emerged as versatile building blocks for supramolecular structures and hydrogels. In particular, the presence of aromatic amino acid residues and/or aromatic end groups is generally considered to be a prerequisite for initiating aggregation of short peptides into nanotubes or cross β-sheet type fibrils. However, the cationic GAG tripeptide surprisingly violates these rules. Specifically, in water/ethanol mixtures, GAG peptides aggregate into very long crystalline fibrils at temperatures below 35 °C where they eventually form a spanning network structure and, thus, a hydrogel. Two gel phases are formed in this network, and they differ substantially in chirality and thickness of the underlying fibrils, their rheological parameters, and the kinetics of oligomerization, fibrilization, and gel formation. The spectroscopic data strongly suggests that the observed fibrils do not exhibit canonical cross β-sheet structures and are indicative of a yet unknown secondary conformation. To complement our unusual experimental observations in this perspective article, we performed large-scale DFT calculations to probe the geometry and spectroscopic properties of these GAG oligomers. Most importantly, our experimental and computational results yield rather unconventional structures that are not reminiscent of classical cross-β-sheet structures, and we give two extremely likely candidates for oligomer structures that are consistent with experimental amide I' profiles in IR and vibrational circular dichroism (VCD) spectra of the two gel phases.
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Affiliation(s)
- Niranjan V Ilawe
- Department of Chemical & Environmental Engineering, and Materials Science & Engineering Program, University of California-Riverside, Riverside, CA 92521, USA.
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19
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Ekiz MS, Cinar G, Khalily MA, Guler MO. Self-assembled peptide nanostructures for functional materials. NANOTECHNOLOGY 2016; 27:402002. [PMID: 27578525 DOI: 10.1088/0957-4484/27/40/402002] [Citation(s) in RCA: 62] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Nature is an important inspirational source for scientists, and presents complex and elegant examples of adaptive and intelligent systems created by self-assembly. Significant effort has been devoted to understanding these sophisticated systems. The self-assembly process enables us to create supramolecular nanostructures with high order and complexity, and peptide-based self-assembling building blocks can serve as suitable platforms to construct nanostructures showing diverse features and applications. In this review, peptide-based supramolecular assemblies will be discussed in terms of their synthesis, design, characterization and application. Peptide nanostructures are categorized based on their chemical and physical properties and will be examined by rationalizing the influence of peptide design on the resulting morphology and the methods employed to characterize these high order complex systems. Moreover, the application of self-assembled peptide nanomaterials as functional materials in information technologies and environmental sciences will be reviewed by providing examples from recently published high-impact studies.
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Affiliation(s)
- Melis Sardan Ekiz
- Institute of Materials Science and Nanotechnology, National Nanotechnology Research Center (UNAM), Bilkent University, Ankara, 06800 Turkey
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20
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DiGuiseppi D, Kraus J, Toal SE, Alvarez N, Schweitzer-Stenner R. Investigating the Formation of a Repulsive Hydrogel of a Cationic 16mer Peptide at Low Ionic Strength in Water by Vibrational Spectroscopy and Rheology. J Phys Chem B 2016; 120:10079-10090. [DOI: 10.1021/acs.jpcb.6b07673] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
| | | | - Siobhan E. Toal
- Department
of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
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21
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Farrell S, DiGuiseppi D, Alvarez N, Schweitzer-Stenner R. The interplay of aggregation, fibrillization and gelation of an unexpected low molecular weight gelator: glycylalanylglycine in ethanol/water. SOFT MATTER 2016; 12:6096-6110. [PMID: 27363780 DOI: 10.1039/c6sm00879h] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Hydrogels formed by polypeptides could be much-favored tools for drug delivery because their main ingredients are generally biodegradable. However, the gelation of peptides in aqueous solution generally requires a minimal length of the peptide as well as distinct sequences of hydrophilic and hydrophobic residues. The aggregation of short peptides like tripeptides, which are relatively cheap and offer a high degree of biodegradability, are generally thought to require a high hydrophobicity of their residues. We found that contrary to this expectation cationic glycylalanylglycine in 55 mol% ethanol/45 mol% water forms a gel below a melting temperature of ca. 36 °C. A pure hydrogel state can be obtained after allowing the ethanol component to evaporate. The gel phase consists of crystalline fibrils of several 100 μm, which form a sample-spanning network. Rheological data reveal a soft elastic solid gel. We investigated the kinetics of the various processes that lead to the final gel state of the ternary mixture by a unique combination of UV circular dichroism, infrared, vibrational circular dichroism (VCD) and rheological measurements. A mathematical analysis of our data show that gelation is preceded by the formation of peptide β-sheet like tapes or ribbons, which give rise to a significant enhancement of the amide I' VCD signal, and the subsequent formation of rather thick and long fibrils. The VCD signals indicate that the tapes exhibit a right-handed helicity at temperatures above 16 °C and a left-handed helicity below. The tapes'/ribbons' helicity change occurs at a temperature where the UVCD data reflect a relatively long nucleation process. The kinetics of gel formation probed by the storage and loss moduli are composed of a fast process that follows tape/ribbon/fibril formation and is clearly identifiable in a movie that shows the gelation process and a slow process that causes an additional gel stabilization. The rheological data indicate that left-handed fibrils observed at low temperatures form a more solid-like structure than their right-handed counterparts formed at higher temperatures. Taken together our data reveal GAG as an unexpected gelator, the formation of which is underlied by a set of distinguishable kinetic processes.
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Affiliation(s)
- Stefanie Farrell
- Department of Chemistry, Drexel University, Philadelphia, PA 19104, USA.
| | - David DiGuiseppi
- Department of Chemistry, Drexel University, Philadelphia, PA 19104, USA.
| | - Nicolas Alvarez
- Department of Chemical and Biological Engineering, Drexel University, Philadelphia, PA 19104, USA
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22
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Kurouski D, Van Duyne RP, Lednev IK. Exploring the structure and formation mechanism of amyloid fibrils by Raman spectroscopy: a review. Analyst 2016; 140:4967-80. [PMID: 26042229 DOI: 10.1039/c5an00342c] [Citation(s) in RCA: 183] [Impact Index Per Article: 22.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Amyloid fibrils are β-sheet rich protein aggregates that are strongly associated with various neurodegenerative diseases. Raman spectroscopy has been broadly utilized to investigate protein aggregation and amyloid fibril formation and has been shown to be capable of revealing changes in secondary and tertiary structures at all stages of fibrillation. When coupled with atomic force (AFM) and scanning electron (SEM) microscopies, Raman spectroscopy becomes a powerful spectroscopic approach that can investigate the structural organization of amyloid fibril polymorphs. In this review, we discuss the applications of Raman spectroscopy, a unique, label-free and non-destructive technique for the structural characterization of amyloidogenic proteins, prefibrilar oligomers, and mature fibrils.
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Affiliation(s)
- Dmitry Kurouski
- Department of Chemistry, Northwestern University, 2145 Sheridan Road, Evanston, Illinois, USA.
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23
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Liu J, Zhang JZH, He X. Fragment quantum chemical approach to geometry optimization and vibrational spectrum calculation of proteins. Phys Chem Chem Phys 2016; 18:1864-75. [DOI: 10.1039/c5cp05693d] [Citation(s) in RCA: 52] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Geometry optimization and vibrational spectra (infrared and Raman spectra) calculations of proteins are carried out by a quantum chemical approach using the EE-GMFCC (electrostatically embedded generalized molecular fractionation with conjugate caps) method (J. Phys. Chem. A, 2013, 117, 7149).
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Affiliation(s)
- Jinfeng Liu
- State Key Laboratory of Precision Spectroscopy
- Institute of Theoretical and Computational Science
- College of Chemistry and Molecular Engineering
- East China Normal University
- Shanghai
| | - John Z. H. Zhang
- State Key Laboratory of Precision Spectroscopy
- Institute of Theoretical and Computational Science
- College of Chemistry and Molecular Engineering
- East China Normal University
- Shanghai
| | - Xiao He
- State Key Laboratory of Precision Spectroscopy
- Institute of Theoretical and Computational Science
- College of Chemistry and Molecular Engineering
- East China Normal University
- Shanghai
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24
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Kurouski D, Handen JD, Dukor RK, Nafie LA, Lednev IK. Supramolecular chirality in peptide microcrystals. Chem Commun (Camb) 2015; 51:89-92. [PMID: 25351531 DOI: 10.1039/c4cc05002a] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
The vibrational circular dichroism (VCD) spectra of microcrystals of fibril-forming peptides have been measured for the first time. VCD spectra were measured and compared for microcrystals and fibrils formed from the same peptide, human islet amyloid polypeptide (IAPP, amylin). Structural information related to the supramolecular chirality of both the microcrystals and the fibrils, as well as the VCD enhancement mechanisms in fibrils and microcrystals, is obtained from these spectral comparisons. It is concluded that strongly enhanced VCD does not require braiding of two or more filaments that is permitted in fibrils but not microcrystals.
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Affiliation(s)
- Dmitry Kurouski
- Department of Chemistry, University at Albany, 1400 Washington Ave., Albany, USA.
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25
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Góbi S, Magyarfalvi G, Tarczay G. VCD Robustness of the Amide-I and Amide-II Vibrational Modes of Small Peptide Models. Chirality 2015; 27:625-34. [DOI: 10.1002/chir.22475] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2015] [Revised: 04/21/2015] [Accepted: 05/08/2015] [Indexed: 12/22/2022]
Affiliation(s)
- Sándor Góbi
- Laboratory of Molecular Spectroscopy; Institute of Chemistry, Eötvös University; Budapest Hungary
| | - Gábor Magyarfalvi
- Laboratory of Molecular Spectroscopy; Institute of Chemistry, Eötvös University; Budapest Hungary
| | - György Tarczay
- Laboratory of Molecular Spectroscopy; Institute of Chemistry, Eötvös University; Budapest Hungary
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26
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Kessler J, Bouř P. Transfer of Frequency-Dependent Polarizabilities: A Tool To Simulate Absorption and Circular Dichroism Molecular Spectra. J Chem Theory Comput 2015; 11:2210-20. [DOI: 10.1021/acs.jctc.5b00136] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Jiří Kessler
- Institute
of Organic Chemistry and Biochemistry, Academy of Sciences, Flemingovo
náměstí 2, 166
10 Prague, Czech Republic
- Department
of Physical and Macromolecular Chemistry, Faculty of Science, Charles University, Hlavova 8, 128 40 Prague, Czech Republic
| | - Petr Bouř
- Institute
of Organic Chemistry and Biochemistry, Academy of Sciences, Flemingovo
náměstí 2, 166
10 Prague, Czech Republic
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27
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Marty R, Frauenrath H, Helbing J. Aggregates from Perylene Bisimide Oligopeptides as a Test Case for Giant Vibrational Circular Dichroism. J Phys Chem B 2014; 118:11152-60. [DOI: 10.1021/jp506837c] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Affiliation(s)
- Roman Marty
- Institute
of Materials, Ecole Polytechnique Federale de Lausanne (EPFL), EPFL - STI - IMX - LMOM, MXG 037, Station 12, 1015 Lausanne, Switzerland
| | - Holger Frauenrath
- Institute
of Materials, Ecole Polytechnique Federale de Lausanne (EPFL), EPFL - STI - IMX - LMOM, MXG 037, Station 12, 1015 Lausanne, Switzerland
| | - Jan Helbing
- Department
of Chemistry, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland
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28
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Sereda V, Lednev IK. Polarized Raman Spectroscopy of Aligned Insulin Fibrils. JOURNAL OF RAMAN SPECTROSCOPY : JRS 2014; 45:665-671. [PMID: 25316956 PMCID: PMC4194063 DOI: 10.1002/jrs.4523] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Amyloid fibrils are associated with many neurodegenerative diseases. The application of conventional techniques of structural biology, X-ray crystallography and solution NMR, for fibril characterization is limited because of the non-crystalline and insoluble nature of the fibrils. Here, polarized Raman spectroscopy was used to determine the orientation of selected chemical groups in aligned insulin fibrils, specifically of peptide carbonyls. The methodology is solely based on the measurement of the change in Raman scattered intensity as a function of the angle between the incident laser polarization and the aligned fibrils. The order parameters 〈 P2 〉 and 〈 P4 〉 of the orientation distribution function were obtained, and the most probable distribution of C=O group orientation was calculated. The results indicate that the peptides' carbonyl groups are oriented at an angle of 13±5° from the fibril axis, which is in consistent with previously reported qualitative descriptions of an almost parallel orientation of the C=O groups relative to the main fibril axis.
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Affiliation(s)
- Valentin Sereda
- Department of Chemistry, University at Albany, SUNY, 1400 Washington Avenue, Albany, NY 12222, USA
| | - Igor K. Lednev
- Department of Chemistry, University at Albany, SUNY, 1400 Washington Avenue, Albany, NY 12222, USA
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29
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Bhattacharya S, Pandey NK, Roy A, Dasgupta S. Effect of (-)-epigallocatechin gallate on the fibrillation of human serum albumin. Int J Biol Macromol 2014; 70:312-9. [PMID: 25017180 DOI: 10.1016/j.ijbiomac.2014.07.003] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2014] [Revised: 07/02/2014] [Accepted: 07/04/2014] [Indexed: 01/05/2023]
Abstract
Human serum albumin (HSA), the most abundant plasma protein in the human body is known to form fibrils under partial denaturing conditions. Natural polyphenols are known to interact with HSA and some polyphenols have been shown to be potent inhibitors of amyloid fibrillation. (-)-Epigallocatechin gallate (EGCG), the major component of green tea is known to inhibit amyloid fibrillation. In this report, we have investigated the effect of EGCG on native HSA as well as on the fibrillation process of HSA from amide III band analysis of their respective visible Raman spectra. The differential role of the tryptophan (Trp214) residue present in domain II of HSA in the absence and presence of EGCG has been pointed out using fluorescence anisotropy and visible Raman spectroscopy.
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Affiliation(s)
| | - Nitin K Pandey
- Department of Chemistry, Indian Institute of Technology, Kharagpur 721302, India
| | - Anushree Roy
- Department of Physics, Indian Institute of Technology, Kharagpur 721302, India.
| | - Swagata Dasgupta
- Department of Chemistry, Indian Institute of Technology, Kharagpur 721302, India.
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30
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Małolepsza E, Straub JE. Empirical maps for the calculation of amide I vibrational spectra of proteins from classical molecular dynamics simulations. J Phys Chem B 2014; 118:7848-55. [PMID: 24654732 PMCID: PMC4317051 DOI: 10.1021/jp412827s] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022]
Abstract
![]()
New sets of parameters (maps) for
calculating amide I vibrational
spectra for proteins through a vibrational exciton model are proposed.
The maps are calculated as a function of electric field and van der
Waals forces on the atoms of peptide bonds, taking into account the
full interaction between peptide bonds and the surrounding environment.
The maps are designed to be employed using data obtained from standard
all-atom molecular simulations without any additional constraints
on the system. Six proteins representing a wide range of sizes and
secondary structure complexity were chosen as a test set. Spectra
calculated for these proteins reproduce experimental data both qualitatively
and quantitatively. The proposed maps lead to spectra that capture
the weak second peak observed in proteins containing β-sheets,
allowing for clear distinction between α-helical and β-sheet
proteins. While the parametrization is specific to the CHARMM force
field, the methodology presented can be readily applied to any empirical
force field.
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Affiliation(s)
- Edyta Małolepsza
- Department of Chemistry, Boston University , 590 Commonwealth Avenue, Boston, Massachusetts 02215, United States
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31
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Ananthakrishnan SJ, Wadgaonkar PP, Somanathan N. Linearly polarized emission from self-assembled microstructures of mesogenic polythiophenes. Phys Chem Chem Phys 2014; 16:23809-18. [DOI: 10.1039/c4cp03457k] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Polarized electroluminescence from ordered mesogenic polythiophenes.
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Affiliation(s)
| | - Prakash P. Wadgaonkar
- CSIR-Network of Institutes for Solar Energy
- India
- Polymer Science and Engineering Division
- National Chemical Laboratory
- Pune 411008, India
| | - Narayanasastri Somanathan
- Polymer Division
- CSIR – Central Leather Research Institute (CLRI)
- Chennai - 600 020, India
- CSIR-Network of Institutes for Solar Energy
- India
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32
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Bhattacharya S, Ghosh S, Pandey NK, Chaudhury S, Dasgupta S, Roy A. Distribution of protein Ramachandran psi (ψ) angle using non-resonance visible raman scattering measurements. J Phys Chem B 2013; 117:13993-4000. [PMID: 24134469 DOI: 10.1021/jp408009y] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Knowing the distribution of Ramachandran angles helps in understanding peptide and protein backbone conformation. Empirical relations are proposed to correlate the spectral profile of the amide III3 band, obtained from ultraviolet resonance Raman measurements (UVRR), with the Ramachandran dihedral psi angle distribution in small peptide and protein molecules, in different environmental conditions (Mikhonin et al. J. Phys. Chem. B 2006, 110, 1928-1943). It has also been used for more complicated structures, like large globular proteins and protein fibrils. In our work here, we use visible Raman spectra and available empirical relations to obtain similar correlations for human serum albumin, hen egg white lysozyme, and human gamma crystallin. We also report the dihedral angle distribution in fibrils and a denatured protein in an ethanol environment using the same spectroscopic technique.
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33
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Bhattacharya S, Ghosh S, Dasgupta S, Roy A. Structural differences between native Hen egg white lysozyme and its fibrils under different environmental conditions. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2013; 114:368-376. [PMID: 23786978 DOI: 10.1016/j.saa.2013.05.060] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/10/2013] [Revised: 05/14/2013] [Accepted: 05/17/2013] [Indexed: 06/02/2023]
Abstract
The difference in molecular structure of native HEWL and its fibrils, grown at a pH value near physiological pH 7.4 and at a pH value just above the pI, 10.7 in presence and absence of Cu(II) ions, is discussed. We focus on differences between the molecular structure of the native protein and fibrils using principal component analysis of their Raman spectra. The overlap areas of the scores of each species are used to quantify the difference in the structure of the native HEWL and fibrils in different environments. The overall molecular structures are significantly different for fibrils grown at two pH values. However, in presence of Cu(II) ions, the fibrils have similarities in their molecular structures at these pH environments. Spectral variation within each species, as obtained from the standard deviations of the scores in PCA plots, reveals the variability in the structure within a particular species.
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34
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Welch WRW, Kubelka J, Keiderling TA. Infrared, vibrational circular dichroism, and Raman spectral simulations for β-sheet structures with various isotopic labels, interstrand, and stacking arrangements using density functional theory. J Phys Chem B 2013; 117:10343-58. [PMID: 23924300 DOI: 10.1021/jp4056126] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Infrared (IR), Raman, and vibrational circular dichroism (VCD) spectral variations for different β-sheet structures were studied using simulations based on density functional theory (DFT) force field and intensity computations. The DFT vibrational parameters were obtained for β-sheet fragments containing nine-amides and constrained to a variety of conformations and strand arrangements. These were subsequently transferred onto corresponding larger β-sheet models, normally consisting of five strands with ten amides each, for spectral simulations. Further extension to fibril models composed of multiple stacked β-sheets was achieved by combining the transfer of DFT parameters for each sheet with dipole coupling methods for interactions between sheets. IR spectra of the amide I show different splitting patterns for parallel and antiparallel β-sheets, and their VCD, in the absence of intersheet stacking, have distinct sign variations. Isotopic labeling by (13)C of selected residues yields spectral shifts and intensity changes uniquely sensitive to relative alignment of strands (registry) for antiparallel sheets. Stacking of multiple planar sheets maintains the qualitative spectral character of the single sheet but evidences some reduction in the exciton splitting of the amide I mode. Rotating sheets with respect to each other leads to a significant VCD enhancement, whose sign pattern and intensity is dependent on the handedness and degree of rotation. For twisted β-sheets, a significant VCD enhancement is computed even for sheets stacked with either the same or opposite alignments and the inter-sheet rotation, depending on the sense, can either further increase or weaken the enhanced VCD intensity. In twisted, stacked structures (without rotation), similar VCD amide I patterns (positive couplets) are predicted for both parallel and antiparallel sheets, but different IR intensity distributions still enable their differentiation. Our simulation results prove useful for interpreting experimental vibrational spectra in terms of β-sheet and fibril structure, as illustrated in the accompanying paper.
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Affiliation(s)
- William R W Welch
- Department of Chemistry, University of Wyoming , Laramie, Wyoming 82071, United States
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35
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Welch WRW, Keiderling TA, Kubelka J. Structural analyses of experimental 13C edited amide I' IR and VCD for peptide β-sheet aggregates and fibrils using DFT-based spectral simulations. J Phys Chem B 2013; 117:10359-69. [PMID: 23924239 DOI: 10.1021/jp405613r] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
In the preceding paper, computational models based on density functional theory (DFT) were presented to characterize the sensitivity of vibrational spectroscopic methods (IR, VCD, and Raman) to structural features of β-sheets. Isotopically edited amide I' IR for peptides labeled with (13)C in multiple different sites provides the most structurally distinct signatures of strand alignment, while VCD is sensitive to the sheet twist and intersheet stacking. In this report, we simulate the IR and VCD spectra for models approximating structures of four β-sheet forming peptides previously experimentally studied using these methods with (13)C isotopic editing. Various register alignments are tested. Agreement with experiment is evaluated based on frequency shifts of both the (12)C and (13)C IR amide I' signals, relative intensity patterns, and VCD spectra where available. While for the simulation of IR spectra canonical planar sheets provide a sufficient model system, for VCD simulation twisted, stacked sheets are required in order to reproduce strong couplet-like amide I' VCD. Effects of the solvent (water) and amino acid side chains are also tested by using a simplified, electrostatic solvent model and atomic partial charges for the side chains. Very good agreement with experimental spectra is obtained, particularly for the relative (12)C and (13)C band frequencies. All four peptide models are shown to be antiparallel as had previously been assumed. However, in some cases our simulations are consistent with different register alignment of strands than originally proposed.
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Affiliation(s)
- William R W Welch
- Department of Chemistry, University of Wyoming , Laramie, Wyoming 82071, United States
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Schwartz E, Liégeois V, Koepf M, Bodis P, Cornelissen JJLM, Brocorens P, Beljonne D, Nolte RJM, Rowan AE, Woutersen S, Champagne B. Beta Sheets with a Twist: The Conformation of Helical Polyisocyanopeptides Determined by Using Vibrational Circular Dichroism. Chemistry 2013; 19:13168-74. [DOI: 10.1002/chem.201300073] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2013] [Revised: 05/07/2013] [Indexed: 11/10/2022]
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Fleming S, Frederix PWJM, Ramos Sasselli I, Hunt NT, Ulijn RV, Tuttle T. Assessing the utility of infrared spectroscopy as a structural diagnostic tool for β-sheets in self-assembling aromatic peptide amphiphiles. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2013; 29:9510-5. [PMID: 23805919 DOI: 10.1021/la400994v] [Citation(s) in RCA: 73] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
β-Sheets are a commonly found structural motif in self-assembling aromatic peptide amphiphiles, and their characteristic "amide I" infrared (IR) absorption bands are routinely used to support the formation of supramolecular structure. In this paper, we assess the utility of IR spectroscopy as a structural diagnostic tool for this class of self-assembling systems. Using 9-fluorene-methyloxycarbonyl dialanine (Fmoc-AA) and the analogous 9-fluorene-methylcarbonyl dialanine (Fmc-AA) as examples, we show that the origin of the band around 1680-1695 cm(-1) in Fourier transform infrared (FTIR) spectra, which was previously assigned to an antiparallel β-sheet conformation, is in fact absorption of the stacked carbamate group in Fmoc-peptides. IR spectra from (13)C-labeled samples support our conclusions. In addition, DFT frequency calculations on small stacks of aromatic peptides help to rationalize these results in terms of the individual vibrational modes.
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Affiliation(s)
- Scott Fleming
- WestCHEM, Department of Pure and Applied Chemistry, University of Strathclyde, Glasgow G1 1XL, UK
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Schweitzer-Stenner R. Different Degrees of Disorder in Long Disordered Peptides Can Be Discriminated by Vibrational Spectroscopy. J Phys Chem B 2013; 117:6927-36. [DOI: 10.1021/jp402869k] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Affiliation(s)
- Reinhard Schweitzer-Stenner
- Department
of Chemistry, Drexel University, 3141 Chestnut
Street, Philadelphia, Pennsylvania 19104, United
States
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39
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Roeters SJ, van Dijk CN, Torres-Knoop A, Backus EHG, Campen RK, Bonn M, Woutersen S. Determining In Situ Protein Conformation and Orientation from the Amide-I Sum-Frequency Generation Spectrum: Theory and Experiment. J Phys Chem A 2013; 117:6311-22. [DOI: 10.1021/jp401159r] [Citation(s) in RCA: 70] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Affiliation(s)
- S. J. Roeters
- Van’t Hoff Institute
for Molecular Sciences, University of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands
| | - C. N. van Dijk
- Van’t Hoff Institute
for Molecular Sciences, University of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands
| | - A. Torres-Knoop
- Van’t Hoff Institute
for Molecular Sciences, University of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands
| | - E. H. G. Backus
- Max-Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz,
Germany
| | - R. K. Campen
- Department of Physical
Chemistry, Fritz Haber Institute, Faradayweg
4-6, 14195 Berlin,
Germany
| | - M. Bonn
- Max-Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz,
Germany
| | - S. Woutersen
- Van’t Hoff Institute
for Molecular Sciences, University of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands
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40
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Fabian H, Gast K, Laue M, Jetzschmann KJ, Naumann D, Ziegler A, Uchanska-Ziegler B. IR spectroscopic analyses of amyloid fibril formation of β2-microglobulin using a simplified procedure for its in vitro generation at neutral pH. Biophys Chem 2013; 179:35-46. [PMID: 23727989 DOI: 10.1016/j.bpc.2013.05.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2013] [Revised: 04/29/2013] [Accepted: 05/01/2013] [Indexed: 11/16/2022]
Abstract
β2-microglobulin (β2m) is known to be the major component of fibrillar deposits in the joints of patients suffering from dialysis-related amyloidosis. We have developed a simplified procedure to convert monomeric recombinant β2m into amyloid fibrils at physiological pH by a combination of stirring and heating, enabling us to follow conformational changes associated with the assembly by infrared spectroscopy and electron microscopy. Our studies reveal that fibrillogenesis begins with the formation of relatively large aggregates, with secondary structure not significantly altered by the stirring-induced association. In contrast, the conversion of the amorphous aggregates into amyloid fibrils is associated with a profound re-organization at the level of the secondary and tertiary structures, leading to non-native like parallel arrangements of the β-strands in the fully formed amyloid structure of β2m. This study highlights the power of an approach to investigate the formation of β2m fibrils by a combination of biophysical techniques including IR spectroscopy.
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Affiliation(s)
- Heinz Fabian
- Robert Koch-Institut, ZBS 6, Nordufer 20, D-13353 Berlin, Germany.
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41
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Ananthakrishnan SJ, Kumar BS, Somanathan N, Mandal AB. Supramolecular assembly in side-chain conjugated thiophene copolymers. RSC Adv 2013. [DOI: 10.1039/c3ra00029j] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
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42
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Ye S, Wei F, Li H, Tian K, Luo Y. Structure and Orientation of Interfacial Proteins Determined by Sum Frequency Generation Vibrational Spectroscopy. ADVANCES IN PROTEIN CHEMISTRY AND STRUCTURAL BIOLOGY 2013; 93:213-55. [DOI: 10.1016/b978-0-12-416596-0.00007-5] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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Li H, Ye S, Wei F, Ma S, Luo Y. In situ molecular-level insights into the interfacial structure changes of membrane-associated prion protein fragment [118-135] investigated by sum frequency generation vibrational spectroscopy. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2012; 28:16979-16988. [PMID: 23116165 DOI: 10.1021/la302655p] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Protein aggregation is associated with many "protein deposition diseases". A precise molecular detail of the conformational transitions of such a membrane-associated protein structure is critical to understand the disease mechanism and develop effective treatments. One potential model peptide for studying the mechanism of protein deposition diseases is prion protein fragment [118-135] (PrP118-135), which shares homology with the C-terminal domain of the Alzheimer's β-amyloid peptide. In this study, sum frequency generation vibrational spectroscopy (SFG-VS) has been applied to characterize interactions between PrP118-135 and 1-palmitoyl-2-oleoyl-sn-glycero-3-phospho-(1'-rac-glycerol) (POPG) lipid bilayer in situ. The conformation change and orientation of PrP118-135 in lipid bilayers have been determined using SFG spectra with different polarization combinations. It is found that low-concentration PrP118-135 predominantly adopts α-helical structure but with tiny β-sheet structure. With the PrP118-135 concentration increasing, the molecular number ratio of parallel β-sheet structure increases and reaches about 44% at a concentration of 0.10 mg/mL, indicating the formation of abnormally folded scrapie isoforms. The α-helical structure inserts into the lipid bilayer with a tilt angle of ~32° versus the surface normal, while the β-sheet structure lies down on the lipid bilayer with the tilt and twist angle both of 90°. The 3300 cm(-1) N-H stretching signal in psp spectra arises from α-helical structure at low PrP concentration and from the β-sheet structure at high PrP concentration. Results from this study will provide an in-depth insight into the early events in the aggregation of PrP in cell membrane.
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Affiliation(s)
- Hongchun Li
- Hefei National Laboratory for Physical Sciences at Microscale, and Department of Chemical Physics, University of Science and Technology of China, Hefei, Anhui, People's Republic of China 230026
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Shanmugam G, Polavarapu PL. Site-specific structure of Aβ(25-35) peptide: isotope-assisted vibrational circular dichroism study. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2012; 1834:308-16. [PMID: 22910376 DOI: 10.1016/j.bbapap.2012.08.010] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/17/2012] [Revised: 08/02/2012] [Accepted: 08/07/2012] [Indexed: 11/17/2022]
Abstract
We investigated the site-specific local structure of an amyloid peptide, NH(2)-GSNKGAIIGLM-COOH [Aβ(25-35)], one of the active fragments of amyloid β peptide that is known to be responsible for Alzheimer's disease, in the fibrillar aggregated state. Isotope-assisted infrared vibrational circular dichroism (VCD) and absorption (VA) spectroscopy were used for the parent Aβ(25-35) peptide, along with doubly (13)C labeled peptides at the carbonyl groups of residues 29 (Gly) and 30 (Ala) [Aβ(25-35:(13)C-29/30)] and at the carbonyl groups of residues 33 (Gly) and 34 (Leu) [Aβ(25-35:(13)C-33/34)]. The present results confirm that Aβ(25-35) peptide fibrils adopt a β-sheet structure and isotopic dilution experiments suggest a parallel β-sheet structure. The isotopic shifts suggest that the microenvironment of residues 29 (Gly) and 30 (Ala) could be different from that of residues 33 (Gly) and 34 (Leu). An unusual enhancement for the amide II' VCD intensities of Aβ(25-35:(13)C-29/30) and Aβ(25-35:(13)C-33/34) peptide fibrils, considered to originate from inter-strand coupling, was found for the first time. The structural information reported in this manuscript has important implications in understanding the role of this peptide in the development of Alzheimer's disease.
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Affiliation(s)
- Ganesh Shanmugam
- Department of Chemistry, Vanderbilt University, Nashville, TN 37235, USA
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