1
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Bhatt MR, Ganguly HK, Zondlo NJ. Acyl Capping Group Identity Effects on α-Helicity: On the Importance of Amide·Water Hydrogen Bonds to α-Helix Stability. Biochemistry 2024; 63:1118-1130. [PMID: 38623827 DOI: 10.1021/acs.biochem.3c00646] [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: 04/17/2024]
Abstract
Acyl capping groups stabilize α-helices relative to free N-termini by providing one additional C═Oi···Hi+4-N hydrogen bond. The electronic properties of acyl capping groups might also directly modulate α-helix stability: electron-rich N-terminal acyl groups could stabilize the α-helix by strengthening both i/i + 4 hydrogen bonds and i/i + 1 n → π* interactions. This hypothesis was tested in peptides X-AKAAAAKAAAAKAAGY-NH2, where X = different acyl groups. Surprisingly, the most electron-rich acyl groups (pivaloyl and iso-butyryl) strongly destabilized the α-helix. Moreover, the formyl group induced nearly identical α-helicity to that of the acetyl group, despite being a weaker electron donor for hydrogen bonds and for n → π* interactions. Other acyl groups exhibited intermediate α-helicity. These results indicate that the electronic properties of the acyl carbonyl do not directly determine the α-helicity in peptides in water. In order to understand these effects, DFT calculations were conducted on α-helical peptides. Using implicit solvation, α-helix stability correlated with acyl group electronics, with the pivaloyl group exhibiting closer hydrogen bonds and n → π* interactions, in contrast to the experimental results. However, DFT and MD calculations with explicit water solvation revealed that hydrogen bonding to water was impacted by the sterics of the acyl capping group. Formyl capping groups exhibited the closest water-amide hydrogen bonds, while pivaloyl groups exhibited the longest. In α-helices in the PDB, the highest frequency of close amide-water hydrogen bonds is observed when the N-cap residue is Gly. The combination of experimental and computational results indicates that solvation (hydrogen bonding of water) to the N-terminal amide groups is a central determinant of α-helix stability.
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Affiliation(s)
- Megh R Bhatt
- Department of Chemistry and Biochemistry, University of Delaware Newark, Delaware 19716, United States
| | - Himal K Ganguly
- Department of Chemistry and Biochemistry, University of Delaware Newark, Delaware 19716, United States
| | - Neal J Zondlo
- Department of Chemistry and Biochemistry, University of Delaware Newark, Delaware 19716, United States
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2
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Hossain M, Huda N, Bhuyan AK. A three-state mechanism for trifluoroethanol denaturation of an intrinsically disordered protein (IDP). J Biochem 2023; 174:519-531. [PMID: 37709541 DOI: 10.1093/jb/mvad067] [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: 04/27/2023] [Revised: 09/05/2023] [Accepted: 09/13/2023] [Indexed: 09/16/2023] Open
Abstract
Relating the amino acid composition and sequence to chain folding and binding preferences of intrinsically disordered proteins (IDPs) has emerged as a huge challenge. While globular proteins have respective 3D structures that are unique to their individual functions, IDPs violate this structure-function paradigm because rather than having a well-defined structure an ensemble of rapidly interconverting disordered structures characterize an IDP. This work measures 2,2,2-trifluoroethanol (TFE)-induced equilibrium transitions of an IDP called AtPP16-1 (Arabidopsis thaliana phloem protein type 16-1) by using fluorescence, circular dichroism, infrared and nuclear magnetic resonance (NMR) methods at pH 4, 298 K. Low TFE reversibly removes the tertiary structure to produce an ensemble of obligate intermediate ($\mathrm{I}$) retaining the native-state ($\mathrm{N}$) secondary structure. The intermediate $\mathrm{I}$ is preceded by a non-obligate tryptophan-specific intermediate ${\mathrm{I}}_{\mathrm{w}}$ whose population is detectable for AtPP16-1 specifically. Accumulation of such non-obligate intermediates is discriminated according to the sequence composition of the protein. In all cases, however, a tertiary structure-unfolded general obligate intermediate $\mathrm{I}$ is indispensable. The $\mathrm{I}$ ensemble has higher helical propensity conducive to the acquisition of an exceedingly large level of α-helices by a reversible denaturation transition of $\mathrm{I}$ to the denatured state $\mathrm{D}$ as the TFE level is increased. Strikingly, it is the same $\mathrm{N}\rightleftharpoons \mathrm{I}\rightleftharpoons \mathrm{D}$ scheme typifying the TFE transitions of globular proteins. The high-energy state $\mathrm{I}$ characterized by increased helical propensity is called a universal intermediate encountered in both genera of globular and disordered proteins. Neither $\mathrm{I}$ nor $\mathrm{D}$ strictly show molten globule (MG)-like properties, dismissing the belief that TFE promotes MGs.
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Affiliation(s)
- Mujahid Hossain
- School of Chemistry, University of Hyderabad, Hyderabad 500046, India
| | - Noorul Huda
- School of Chemistry, University of Hyderabad, Hyderabad 500046, India
| | - Abani K Bhuyan
- School of Chemistry, University of Hyderabad, Hyderabad 500046, India
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3
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Pérez-Trejo I, Dominguez L. GaMD simulations as an alternative in the TFE-water mixture description. J Mol Model 2023; 29:352. [PMID: 37906368 PMCID: PMC10618327 DOI: 10.1007/s00894-023-05749-4] [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: 05/30/2023] [Accepted: 10/04/2023] [Indexed: 11/02/2023]
Abstract
CONTEXT 2,2,2-Trifluoroethanol has been widely used to study the structure and dynamic properties of intrinsically disordered proteins. Experimentally, it is known that TFE-water mixtures stabilize secondary structures of IDPs, and therefore, it allows the studying of conformational ensembles of these proteins. In the last decades, molecular dynamic simulations have helped study the IDPs' conformational ensemble. Unfortunately, conventional MD requires very long simulation times to describe the properties of IDPs. Therefore, a variety of accelerated sampling techniques have been developed and employed. The TFE-water mixture arrangement description through MD has faced substantial difficulties since emulating the TFE nanocrowding at certain TFE:H[Formula: see text]O ratios (around 15-40% of TFE). In this work, we determine the most suitable conditions that reproduce experimentally reported properties of TFE-water mixtures. We compared the employment of conventional MD and GaMD simulations and various water parameters. Our results show that the combination of parameters that better reproduce the experimental information is the combination of the TIP4PD water model and GaMD simulations. Therefore, these conditions help accurately describe the structural ensemble of IDPs in TFE-water mixtures. METHODS Conventional MD and GaMD simulations were performed under AMBER 18 software. The TFE and water molecules were described using GAFF2 and a variety of water models, such as TIP3P, TIP4P2005, TIP4PD, and TIP5P, respectively. The systems were simulated a 100 ns at 298 K.
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Affiliation(s)
- Itzel Pérez-Trejo
- Departamento de Fisicoquímica, Facultad de Química, Universidad Nacional Autónoma de México, Mexico City, 04510, Mexico
| | - Laura Dominguez
- Departamento de Fisicoquímica, Facultad de Química, Universidad Nacional Autónoma de México, Mexico City, 04510, Mexico.
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4
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Nedvedova S, Guillière F, Miele AE, Cantrelle FX, Dvorak J, Walker O, Hologne M. Divide, conquer and reconstruct: How to solve the 3D structure of recalcitrant Micro-Exon Gene (MEG) protein from Schistosoma mansoni. PLoS One 2023; 18:e0289444. [PMID: 37535563 PMCID: PMC10399815 DOI: 10.1371/journal.pone.0289444] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2023] [Accepted: 07/19/2023] [Indexed: 08/05/2023] Open
Abstract
Micro-Exon Genes are a widespread class of genes known for their high variability, widespread in the genome of parasitic trematodes such as Schistosoma mansoni. In this study, we present a strategy that allowed us to solve the structures of three alternatively spliced isoforms from the Schistoma mansoni MEG 2.1 family for the first time. All isoforms are hydrophobic, intrinsically disordered, and recalcitrant to be expressed in high yield in heterologous hosts. We resorted to the chemical synthesis of shorter pieces, before reconstructing the entire sequence. Here, we show that isoform 1 partially folds in a-helix in the presence of trifluoroethanol while isoform 2 features two rigid elbows, that maintain the peptide as disordered, preventing any structuring. Finally, isoform 3 is dominated by the signal peptide, which folds into a-helix. We demonstrated that combining biophysical techniques, like circular dichroism and nuclear magnetic resonance at natural abundance, with in silico molecular dynamics simulation for isoform 1 only, was the key to solve the structure of MEG 2.1. Our results provide a crucial piece to the puzzle of this elusive and highly variable class of proteins.
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Affiliation(s)
- Stepanka Nedvedova
- Université de Lyon, CNRS, UCB Lyon1, Institut des Sciences Analytiques, UMR5280, 5 rue de la Doua, Villeurbanne, France
- Department of Chemistry, Faculty of Agrobiology, Food and Natural Resources, Czech University of Life Sciences Prague, Prague, Czech Republic
- Department of Zoology and Fisheries, Center of Infectious Animal Diseases, Czech University of Life Sciences Prague, Prague, Czech Republic
| | - Florence Guillière
- Université de Lyon, CNRS, UCB Lyon1, Institut des Sciences Analytiques, UMR5280, 5 rue de la Doua, Villeurbanne, France
| | - Adriana Erica Miele
- Université de Lyon, CNRS, UCB Lyon1, Institut des Sciences Analytiques, UMR5280, 5 rue de la Doua, Villeurbanne, France
- Department of Biochemical Sciences, Sapienza University of Rome, Rome, Italy
| | - François-Xavier Cantrelle
- Université de Lille, CNRS, UMR8576 -UGSF-Unité de Glycobiologie Structurale et Fonctionnelle, Lille, France
| | - Jan Dvorak
- Department of Zoology and Fisheries, Center of Infectious Animal Diseases, Czech University of Life Sciences Prague, Prague, Czech Republic
- Institute of Organic Chemistry and Biochemistry, Czech Academy of Sciences, Prague, Czechia
- Faculty of Environmental Sciences, Center of Infectious Animal Diseases, Czech University of Life Sciences in Prague, Prague, Czech Republic
| | - Olivier Walker
- Université de Lyon, CNRS, UCB Lyon1, Institut des Sciences Analytiques, UMR5280, 5 rue de la Doua, Villeurbanne, France
| | - Maggy Hologne
- Université de Lyon, CNRS, UCB Lyon1, Institut des Sciences Analytiques, UMR5280, 5 rue de la Doua, Villeurbanne, France
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5
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Jones S, Matos B, Dennison S, Fardilha M, Howl J. Stem Cell Bioengineering with Bioportides: Inhibition of Planarian Head Regeneration with Peptide Mimetics of Eyes Absent Proteins. Pharmaceutics 2023; 15:2018. [PMID: 37631231 PMCID: PMC10458859 DOI: 10.3390/pharmaceutics15082018] [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: 06/15/2023] [Revised: 07/17/2023] [Accepted: 07/24/2023] [Indexed: 08/27/2023] Open
Abstract
Djeya1 (RKLAFRYRRIKELYNSYR) is a very effective cell penetrating peptide (CPP) that mimics the α5 helix of the highly conserved Eya domain (ED) of eyes absent (Eya) proteins. The objective of this study was to bioengineer analogues of Djeya1 that, following effective translocation into planarian tissues, would reduce the ability of neoblasts (totipotent stem cells) and their progeny to regenerate the anterior pole in decapitated S. mediterranea. As a strategy to increase the propensity for helix formation, molecular bioengineering of Djeya1 was achieved by the mono-substitution of the helicogenic aminoisobutyric acid (Aib) at three species-variable sites: 10, 13, and 16. CD analyses indicated that Djeya1 is highly helical, and that Aib-substitution had subtle influences upon the secondary structures of bioengineered analogues. Aib-substituted Djeya1 analogues are highly efficient CPPs, devoid of influence upon cell viability or proliferation. All three peptides increase the migration of PC-3 cells, a prostate cancer line that expresses high concentrations of Eya. Two peptides, [Aib13]Djeya1 and [Aib16]Djeya1, are bioportides which delay planarian head regeneration. As neoblasts are the only cell population capable of division in planaria, these data indicate that bioportide technologies could be utilised to directly manipulate other stem cells in situ, thus negating any requirement for genetic manipulation.
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Affiliation(s)
- Sarah Jones
- Research Institute in Healthcare Science, Faculty of Science & Engineering, University of Wolverhampton, Wulfruna Street, Wolverhampton WV1 1LY, UK;
| | - Bárbara Matos
- Laboratory of Signal Transduction, Department of Medical Sciences, Institute of Biomedicine—iBiMED, University of Aveiro, 3810-193 Aveiro, Portugal; (B.M.); (M.F.)
| | - Sarah Dennison
- School of Pharmacy and Biomedical Sciences, University of Central Lancashire, Preston PR1 2HE, UK;
| | - Margarida Fardilha
- Laboratory of Signal Transduction, Department of Medical Sciences, Institute of Biomedicine—iBiMED, University of Aveiro, 3810-193 Aveiro, Portugal; (B.M.); (M.F.)
| | - John Howl
- Research Institute in Healthcare Science, Faculty of Science & Engineering, University of Wolverhampton, Wulfruna Street, Wolverhampton WV1 1LY, UK;
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6
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Del Giudice A, Gurrieri L, Galantini L, Fanti S, Trost P, Sparla F, Fermani S. Conformational Disorder Analysis of the Conditionally Disordered Protein CP12 from Arabidopsis thaliana in Its Different Redox States. Int J Mol Sci 2023; 24:ijms24119308. [PMID: 37298260 DOI: 10.3390/ijms24119308] [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: 04/10/2023] [Revised: 05/18/2023] [Accepted: 05/24/2023] [Indexed: 06/12/2023] Open
Abstract
CP12 is a redox-dependent conditionally disordered protein universally distributed in oxygenic photosynthetic organisms. It is primarily known as a light-dependent redox switch regulating the reductive step of the metabolic phase of photosynthesis. In the present study, a small angle X-ray scattering (SAXS) analysis of recombinant Arabidopsis CP12 (AtCP12) in a reduced and oxidized form confirmed the highly disordered nature of this regulatory protein. However, it clearly pointed out a decrease in the average size and a lower level of conformational disorder upon oxidation. We compared the experimental data with the theoretical profiles of pools of conformers generated with different assumptions and show that the reduced form is fully disordered, whereas the oxidized form is better described by conformers comprising both the circular motif around the C-terminal disulfide bond detected in previous structural analysis and the N-terminal disulfide bond. Despite the fact that disulfide bridges are usually thought to confer rigidity to protein structures, in the oxidized AtCP12, their presence coexists with a disordered nature. Our results rule out the existence of significant amounts of structured and compact conformations of free AtCP12 in a solution, even in its oxidized form, thereby highlighting the importance of recruiting partner proteins to complete its structured final folding.
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Affiliation(s)
| | - Libero Gurrieri
- Department of Pharmacy and Biotechnology, University of Bologna, 40126 Bologna, Italy
| | - Luciano Galantini
- Department of Chemistry, Sapienza University of Rome, 00185 Rome, Italy
| | - Silvia Fanti
- Department of Chemistry "G. Ciamician", University of Bologna, 40126 Bologna, Italy
| | - Paolo Trost
- Department of Pharmacy and Biotechnology, University of Bologna, 40126 Bologna, Italy
| | - Francesca Sparla
- Department of Pharmacy and Biotechnology, University of Bologna, 40126 Bologna, Italy
| | - Simona Fermani
- Department of Chemistry "G. Ciamician", University of Bologna, 40126 Bologna, Italy
- Interdepartmental Centre for Industrial Research Health Sciences & Technologies, University of Bologna, 40064 Bologna, Italy
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7
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Hossain M, Huda N, Bhuyan AK. A surprisingly simple three-state generic process for reversible protein denaturation by trifluoroethanol. Biophys Chem 2022; 291:106895. [PMID: 36182744 DOI: 10.1016/j.bpc.2022.106895] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2022] [Revised: 09/12/2022] [Accepted: 09/14/2022] [Indexed: 12/30/2022]
Abstract
Despite the rich knowledge of the influence of 2,2,2-trifluoroethanol (TFE) on the structure and conformation of peptides and proteins, the mode(s) of TFE-protein interactions and the mechanism by which TFE reversibly denatures a globular protein remain elusive. This study systematically examines TFE-induced equilibrium transition curves for six paradigmatic globular proteins by using basic fluorescence and circular dichroism measurements under neutral pH conditions. The results are remarkably simple. Low TFE invariably unfolds the tertiary structure of all proteins to produce the obligate intermediate (I) which retains nearly all of native-state secondary structure, but enables the formation of extra α-helices as the level of TFE is raised higher. Inspection of the transitions at once reveals that the tertiary structure unfolding is always a distinct process, necessitating the inclusion of at least one obligate intermediate in the TFE-induced protein denaturation. It appears that the intermediate in the minimal unfolding mechanism N⇌I⇌D somehow acquires higher α-helical propensity to generate α-helices in excess of that in the native state to produce the denatured state (D), also called the TFE state. The low TFE-populated intermediate I may be called a universal intermediate by virtue of its α-helical propensity. Contrary to many earlier suggestions, this study dismisses molten globule (MG)-like attribute of I or D.
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Affiliation(s)
- Mujahid Hossain
- School of Chemistry, University of Hyderabad, Hyderabad 500046, India
| | - Noorul Huda
- School of Chemistry, University of Hyderabad, Hyderabad 500046, India
| | - Abani K Bhuyan
- School of Chemistry, University of Hyderabad, Hyderabad 500046, India.
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8
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Pereira AF, Piccoli V, Martínez L. Trifluoroethanol direct interactions with protein backbones destabilize α-helices. J Mol Liq 2022. [DOI: 10.1016/j.molliq.2022.120209] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
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9
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Lopes JLS, Araujo CCF, Neves RC, Bürck J, Couto SG. Structural analysis of the peptides temporin-Ra and temporin-Rb and interactions with model membranes. EUROPEAN BIOPHYSICS JOURNAL : EBJ 2022; 51:493-502. [PMID: 35978176 DOI: 10.1007/s00249-022-01615-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/08/2022] [Revised: 07/27/2022] [Accepted: 07/31/2022] [Indexed: 06/15/2023]
Abstract
The skin of amphibians is widely exploited as rich sources of membrane active peptides that differ in chain size, polypeptide net charge, secondary structure, target selectivity and toxicity. In this study, two small antimicrobial peptides, temporin-Ra and temporin-Rb, originally isolated from the skin of the European marsh frog (Rana ridibunda), described as active against pathogen bacteria and presenting low toxicity to eukaryotic cells were synthesized and had their physicochemical properties and mechanism of action investigated. The temporin peptides were examined in aqueous solution and in the presence of membrane models (lipid monolayers, micelles, lipid bilayers and vesicles). A combined approach of bioinformatics analyses, biological activity assays, surface pressure measurements, synchrotron radiation circular dichroism spectroscopy, and oriented circular dichroism spectroscopy were employed. Both peptides were able to adsorb at a lipid-air interface with a negative surface charge density, and efficiently disturb the lipid surface packing. A disorder-to-helix transition was observed on the secondary structure of both peptides when either in a non-polar environment or interacting with model membranes containing a negative net charge density. The binding of both temporin-Ra and temporin-Rb to membrane models is modulated by the presence of negatively charged lipids in the membrane. The amphipathic helix induced in temporin-Ra is oriented parallel to the membrane surface in negatively charged or in zwitterionic lipid bilayers, with no tendency for realignment after binding. Temporin-Rb, instead, assumes a β-sheet conformation when deposited into oriented stacked lipid bilayers. Due to their short size and simple composition, both peptides are quite attractive for the development of new classes of peptide-based anti-infective drugs.
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Affiliation(s)
- José L S Lopes
- Instituto de Física, Universidade de São Paulo, São Paulo, SP, 05080-900, Brazil
| | - Caio C F Araujo
- Faculdade de Medicina, Universidade Federal de Goiás, Goiânia, GO, 74690-900, Brazil
| | - Rogério C Neves
- Instituto de Patologia Tropical E Saúde Pública, Universidade Federal de Goiás, Goiânia, GO, 74605050, Brazil
| | - Jochen Bürck
- Institute of Biological Interfaces (IBG-2), Karlsruhe Institute of Technology (KIT), POB 3640, 76021, Karlsruhe, Germany
| | - Sheila G Couto
- Instituto de Física, Universidade Federal de Goiás, Av. Esperança, s/n - Campus Samambaia, Goiânia, GO, 74690-900, Brazil.
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10
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Koszinowski K, Rahrt R. Anionic Dimers of Fluorinated Alcohols. JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY 2022; 33:1411-1418. [PMID: 35609237 DOI: 10.1021/jasms.2c00070] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Negative-ion mode electrospray ionization of solutions of ethanol (RF0OH), 2-fluoroethanol (RF1OH), 2,2-difluoroethanol (RF2OH), and/or 2,2,2-trifluoroethanol (RF3OH) produces anionic dimers of the types (RFnO)2H- and (RFnO)(RFn+1O)H-. The exchange reactions of these anionic dimers with the neutral alcohols are examined in a quadrupole-ion trap to extract kinetic data, from which the reaction Gibbs energies are obtained. In all cases, the formation of anionic dimers containing the more highly fluorinated alcohols is favored. Quantum chemical calculations confirm this trend and, besides affording structural data, also determine the dissociation energies of the anionic dimers. These dissociation energies are much higher than those of the corresponding neutral dimers and increase further for the more highly fluorinated alcohols due to the stronger hydrogen-bond donor ability of the latter. The present results on the interaction of individual alkoxide anions and neutral alcohol molecules contribute to a better understanding of the association of the fluorinated alcohols in solution.
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Affiliation(s)
- Konrad Koszinowski
- Universität Göttingen, Institut für Organische und Biomolekulare Chemie, Tammannstr. 2, 37077 Göttingen, Germany
| | - Rene Rahrt
- Universität Göttingen, Institut für Organische und Biomolekulare Chemie, Tammannstr. 2, 37077 Göttingen, Germany
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11
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Das A, Vishvakarma V, Dey A, Dey S, Gupta A, Das M, Vishwakarma KK, Roy DS, Yadav S, Kesarwani S, Venkatramani R, Maiti S. Biophysical properties of the isolated spike protein binding helix of human ACE2. Biophys J 2021; 120:2785-2792. [PMID: 34214538 PMCID: PMC8241576 DOI: 10.1016/j.bpj.2021.06.017] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2020] [Revised: 04/22/2021] [Accepted: 06/17/2021] [Indexed: 12/13/2022] Open
Abstract
The entry of the severe acute respiratory syndrome coronavirus 2 virus in human cells is mediated by the binding of its surface spike protein to the human angiotensin-converting enzyme 2 (ACE2) receptor. A 23-residue long helical segment (SBP1) at the binding interface of human ACE2 interacts with viral spike protein and therefore has generated considerable interest as a recognition element for virus detection. Unfortunately, emerging reports indicate that the affinity of SBP1 to the receptor-binding domain of the spike protein is much lower than that of the ACE2 receptor itself. Here, we examine the biophysical properties of SBP1 to reveal factors leading to its low affinity for the spike protein. Whereas SBP1 shows good solubility (solubility > 0.8 mM), circular dichroism spectroscopy shows that it is mostly disordered with some antiparallel β-sheet content and no helicity. The helicity is substantial (>20%) only upon adding high concentrations (≥20% v/v) of 2,2,2-trifluoroethanol, a helix promoter. Fluorescence correlation spectroscopy and single-molecule photobleaching studies show that the peptide oligomerizes at concentrations >50 nM. We hypothesized that mutating the hydrophobic residues (F28, F32, and F40) of SBP1, which do not directly interact with the spike protein, to alanine would reduce peptide oligomerization without affecting its spike binding affinity. Whereas the mutant peptide (SBP1mod) shows substantially reduced oligomerization propensity, it does not show improved helicity. Our study shows that the failure of efforts, so far, to produce a short SBP1 mimic with a high affinity for the spike protein is not only due to the lack of helicity but is also due to the heretofore unrecognized problem of oligomerization.
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Affiliation(s)
- Anirban Das
- Department of Chemical Sciences, Tata Institute of Fundamental Research, Colaba, Mumbai, India
| | - Vicky Vishvakarma
- Department of Chemical Sciences, Tata Institute of Fundamental Research, Colaba, Mumbai, India
| | - Arpan Dey
- Department of Chemical Sciences, Tata Institute of Fundamental Research, Colaba, Mumbai, India
| | - Simli Dey
- Department of Chemical Sciences, Tata Institute of Fundamental Research, Colaba, Mumbai, India
| | - Ankur Gupta
- Department of Chemical Sciences, Tata Institute of Fundamental Research, Colaba, Mumbai, India
| | - Mitradip Das
- Department of Chemical Sciences, Tata Institute of Fundamental Research, Colaba, Mumbai, India
| | | | - Debsankar Saha Roy
- Department of Chemical Sciences, Tata Institute of Fundamental Research, Colaba, Mumbai, India
| | - Swati Yadav
- National Centre for Biological Sciences, Tata Institute of Fundamental Research, Bangalore, Karnataka, India
| | - Shubham Kesarwani
- Centre for Cardiovascular Biology and Disease, Institute of Stem Cell Science and Regenerative Medicine (inStem), Gandhi Krishi Vigyan Kendra Campus, Bangalore, Karnataka, India
| | - Ravindra Venkatramani
- Department of Chemical Sciences, Tata Institute of Fundamental Research, Colaba, Mumbai, India
| | - Sudipta Maiti
- Department of Chemical Sciences, Tata Institute of Fundamental Research, Colaba, Mumbai, India.
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12
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Crown ether modified peptides: Length and crown ring size impact on membrane interactions. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2020; 1862:183261. [DOI: 10.1016/j.bbamem.2020.183261] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/16/2020] [Revised: 02/28/2020] [Accepted: 03/04/2020] [Indexed: 11/24/2022]
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13
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Chaubey B, Dey A, Banerjee A, Chandrakumar N, Pal S. Assessment of the Role of 2,2,2-Trifluoroethanol Solvent Dynamics in Inducing Conformational Transitions in Melittin: An Approach with Solvent 19F Low-Field NMR Relaxation and Overhauser Dynamic Nuclear Polarization Studies. J Phys Chem B 2020; 124:5993-6003. [DOI: 10.1021/acs.jpcb.0c03544] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Bhawna Chaubey
- Department of Chemistry, Indian Institute of Technology Jodhpur, Jodhpur, Rajasthan 342037, India
| | - Arnab Dey
- MRI-MRS Centre, Indian Institute of Technology Madras, Madras, Tamil Nadu 600036, India
| | - Abhishek Banerjee
- MRI-MRS Centre, Indian Institute of Technology Madras, Madras, Tamil Nadu 600036, India
| | - N. Chandrakumar
- MRI-MRS Centre, Indian Institute of Technology Madras, Madras, Tamil Nadu 600036, India
| | - Samanwita Pal
- Department of Chemistry, Indian Institute of Technology Jodhpur, Jodhpur, Rajasthan 342037, India
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14
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Folding and structural polymorphism of p53 C-terminal domain: One peptide with many conformations. Arch Biochem Biophys 2020; 684:108342. [DOI: 10.1016/j.abb.2020.108342] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2020] [Revised: 02/20/2020] [Accepted: 03/11/2020] [Indexed: 11/19/2022]
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15
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Lima PG, Souza PF, Freitas CD, Oliveira JT, Dias LP, Neto JX, Vasconcelos IM, Lopes JL, Sousa DO. Anticandidal activity of synthetic peptides: Mechanism of action revealed by scanning electron and fluorescence microscopies and synergism effect with nystatin. J Pept Sci 2020; 26:e3249. [DOI: 10.1002/psc.3249] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2020] [Revised: 02/28/2020] [Accepted: 03/04/2020] [Indexed: 12/28/2022]
Affiliation(s)
- Patrícia G. Lima
- Department of Biochemistry and Molecular BiologyFederal University of Ceará Fortaleza Brazil
| | - Pedro F.N. Souza
- Department of Biochemistry and Molecular BiologyFederal University of Ceará Fortaleza Brazil
| | - Cleverson D.T. Freitas
- Department of Biochemistry and Molecular BiologyFederal University of Ceará Fortaleza Brazil
| | - Jose T.A. Oliveira
- Department of Biochemistry and Molecular BiologyFederal University of Ceará Fortaleza Brazil
| | - Lucas P. Dias
- Department of Biochemistry and Molecular BiologyFederal University of Ceará Fortaleza Brazil
| | - João X.S. Neto
- Department of Biochemistry and Molecular BiologyFederal University of Ceará Fortaleza Brazil
| | - Ilka M. Vasconcelos
- Department of Biochemistry and Molecular BiologyFederal University of Ceará Fortaleza Brazil
| | - José L.S. Lopes
- Department of Applied PhysicsUniversity of Sao Paulo Sao Paulo Brazil
| | - Daniele O.B. Sousa
- Department of Biochemistry and Molecular BiologyFederal University of Ceará Fortaleza Brazil
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16
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Kumagai PS, Sousa VK, Donato M, Itri R, Beltramini LM, Araujo APU, Buerck J, Wallace BA, Lopes JLS. Unveiling the binding and orientation of the antimicrobial peptide Plantaricin 149 in zwitterionic and negatively charged membranes. EUROPEAN BIOPHYSICS JOURNAL: EBJ 2019; 48:621-633. [PMID: 31324942 DOI: 10.1007/s00249-019-01387-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/25/2019] [Revised: 06/05/2019] [Accepted: 07/01/2019] [Indexed: 12/24/2022]
Abstract
Antimicrobial peptides are a large group of natural compounds which present promising properties for the pharmaceutical and food industries, such as broad-spectrum activity, potential for use as natural preservatives, and reduced propensity for development of bacterial resistance. Plantaricin 149 (Pln149), isolated from Lactobacillus plantarum NRIC 149, is an intrinsically disordered peptide with the ability to inhibit bacteria from the Listeria and Staphylococcus genera, and which is capable of promoting inhibition and disruption of yeast cells. In this study, the interactions of Pln149 with model membranes composed of zwitterionic and/or anionic phospholipids were investigated using a range of biophysical techniques, including isothermal titration calorimetry, surface tension measurements, synchrotron radiation circular dichroism spectroscopy, oriented circular dichroism spectroscopy, and optical microscopy, to elucidate these peptides' mode of interactions and provide insight into their functional roles. In anionic model membranes, the binding of Pln149 to lipid bilayers is an endothermic process and induces a helical secondary structure in the peptide. The helices bind parallel to the surfaces of lipid bilayers and can promote vesicle disruption, depending on peptide concentration. Although Pln149 has relatively low affinity for zwitterionic liposomes, it is able to adsorb at their lipid interfaces, disturbing the lipid packing, assuming a similar parallel helix structure with a surface-bound orientation, and promoting an increase in the membrane surface area. Such findings can explain the intriguing inhibitory action of Pln149 in yeast cells whose cell membranes have a significant zwitterionic lipid composition.
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Affiliation(s)
- Patricia S Kumagai
- Instituto de Física de São Carlos, Universidade de São Paulo, São Carlos, SP, 13563-120, Brazil
| | - Victor K Sousa
- Departamento Física Aplicada, Instituto de Física, Universidade de São Paulo, Rua do Matão 1371, São Paulo, SP, 05508-090, Brazil
| | - Maressa Donato
- Departamento Física Aplicada, Instituto de Física, Universidade de São Paulo, Rua do Matão 1371, São Paulo, SP, 05508-090, Brazil
| | - Rosangela Itri
- Departamento Física Aplicada, Instituto de Física, Universidade de São Paulo, Rua do Matão 1371, São Paulo, SP, 05508-090, Brazil
| | - Leila M Beltramini
- Instituto de Física de São Carlos, Universidade de São Paulo, São Carlos, SP, 13563-120, Brazil
| | - Ana P U Araujo
- Instituto de Física de São Carlos, Universidade de São Paulo, São Carlos, SP, 13563-120, Brazil
| | - Jochen Buerck
- Institute of Biological Interfaces (IBG-2), Karlsruhe Institute of Technology (KIT), POB 3640, 76021, Karlsruhe, Germany
| | - B A Wallace
- Institute of Structural and Molecular Biology, Birkbeck College, University of London, London, WC1E 7HX, UK
| | - Jose L S Lopes
- Departamento Física Aplicada, Instituto de Física, Universidade de São Paulo, Rua do Matão 1371, São Paulo, SP, 05508-090, Brazil.
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17
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Jansens KJA, Lambrecht MA, Rombouts I, Monge Morera M, Brijs K, Rousseau F, Schymkowitz J, Delcour JA. Conditions Governing Food Protein Amyloid Fibril Formation-Part I: Egg and Cereal Proteins. Compr Rev Food Sci Food Saf 2019; 18:1256-1276. [PMID: 33336994 DOI: 10.1111/1541-4337.12462] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2019] [Revised: 04/26/2019] [Accepted: 05/13/2019] [Indexed: 12/18/2022]
Abstract
Conditions including heating mode, time, temperature, pH, moisture and protein concentration, shear, and the presence of alcohols, chaotropic/reducing agents, enzymes, and/or salt influence amyloid fibril (AF) formation as they can affect the accessibility of amino acid sequences prone to aggregate. As some conditions applied on model protein resemble conditions in food processing unit operations, we here hypothesize that food processing can lead to formation of protein AFs with a compact cross β-sheet structure. This paper reviews conditions and food constituents that affect amyloid fibrillation of egg and cereal proteins. While egg and cereal proteins often coexist in food products, their impact on each other's fibrillation remains unknown. Hen egg ovalbumin and lysozyme form AFs when subjected to moderate heating at acidic pH separately. AFs can also be formed at higher pH, especially in the presence of alcohols or chaotropic/reducing agents. Tryptic wheat gluten digests can form fibrillar structures at neutral pH and maize and rice proteins do so in aqueous ethanol or at acidic pH, respectively.
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Affiliation(s)
- Koen J A Jansens
- KU Leuven, Laboratory of Food Chemistry and Biochemistry and Leuven Food Science and Nutrition Research Centre (LFoRCe), Kasteelpark Arenberg 20, B-3001, Leuven, Belgium.,Nutrex NV, Achterstenhoek 5, B-2275, Lille, Belgium
| | - Marlies A Lambrecht
- KU Leuven, Laboratory of Food Chemistry and Biochemistry and Leuven Food Science and Nutrition Research Centre (LFoRCe), Kasteelpark Arenberg 20, B-3001, Leuven, Belgium
| | - Ine Rombouts
- KU Leuven, Laboratory of Food Chemistry and Biochemistry and Leuven Food Science and Nutrition Research Centre (LFoRCe), Kasteelpark Arenberg 20, B-3001, Leuven, Belgium.,KU Leuven, ECOVO, Kasteelpark Arenberg 21, B-3001, Leuven, Belgium
| | - Margarita Monge Morera
- KU Leuven, Laboratory of Food Chemistry and Biochemistry and Leuven Food Science and Nutrition Research Centre (LFoRCe), Kasteelpark Arenberg 20, B-3001, Leuven, Belgium
| | - Kristof Brijs
- KU Leuven, Laboratory of Food Chemistry and Biochemistry and Leuven Food Science and Nutrition Research Centre (LFoRCe), Kasteelpark Arenberg 20, B-3001, Leuven, Belgium
| | - Frederic Rousseau
- Switch Laboratory, VIB, and Dept. of Cellular and Molecular Medicine, KU Leuven, B-3000, Leuven, Belgium
| | - Joost Schymkowitz
- Switch Laboratory, VIB, and Dept. of Cellular and Molecular Medicine, KU Leuven, B-3000, Leuven, Belgium
| | - Jan A Delcour
- KU Leuven, Laboratory of Food Chemistry and Biochemistry and Leuven Food Science and Nutrition Research Centre (LFoRCe), Kasteelpark Arenberg 20, B-3001, Leuven, Belgium
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18
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Bakail M, Rodriguez‐Marin S, Hegedüs Z, Perrin ME, Ochsenbein F, Wilson AJ. Recognition of ASF1 by Using Hydrocarbon-Constrained Peptides. Chembiochem 2019; 20:891-895. [PMID: 30512234 PMCID: PMC6468270 DOI: 10.1002/cbic.201800633] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2018] [Indexed: 12/20/2022]
Abstract
Inhibiting the histone H3-ASF1 (anti-silencing function 1) protein-protein interaction (PPI) represents a potential approach for treating numerous cancers. As an α-helix-mediated PPI, constraining the key histone H3 helix (residues 118-135) is a strategy through which chemical probes might be elaborated to test this hypothesis. In this work, variant H3118-135 peptides bearing pentenylglycine residues at the i and i+4 positions were constrained by olefin metathesis. Biophysical analyses revealed that promotion of a bioactive helical conformation depends on the position at which the constraint is introduced, but that the potency of binding towards ASF1 is unaffected by the constraint and instead that enthalpy-entropy compensation occurs.
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Affiliation(s)
- May Bakail
- Institute for Integrative Biology of the Cell (I2BC)IBITECSCEACNRSUniversité Paris–SudUniversité Paris–Saclay91198Gif-sur-Yvette CedexFrance
- Present address: Inserm, U1016Institut CochinCNRSUMR8104Université Paris Descartes27, rue du Faubourg Saint-Jacques75014ParisFrance
| | - Silvia Rodriguez‐Marin
- School of ChemistryUniversity of LeedsWoodhouse LaneLeedsLS2 9JTUK
- Astbury Centre for Structural Molecular BiologyUniversity of LeedsWoodhouse LaneLeedsLS2 9JTUK
| | - Zsófia Hegedüs
- School of ChemistryUniversity of LeedsWoodhouse LaneLeedsLS2 9JTUK
- Astbury Centre for Structural Molecular BiologyUniversity of LeedsWoodhouse LaneLeedsLS2 9JTUK
| | - Marie E. Perrin
- Institute for Integrative Biology of the Cell (I2BC)IBITECSCEACNRSUniversité Paris–SudUniversité Paris–Saclay91198Gif-sur-Yvette CedexFrance
| | - Françoise Ochsenbein
- Institute for Integrative Biology of the Cell (I2BC)IBITECSCEACNRSUniversité Paris–SudUniversité Paris–Saclay91198Gif-sur-Yvette CedexFrance
| | - Andrew J. Wilson
- School of ChemistryUniversity of LeedsWoodhouse LaneLeedsLS2 9JTUK
- Astbury Centre for Structural Molecular BiologyUniversity of LeedsWoodhouse LaneLeedsLS2 9JTUK
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19
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Firpo V, Le JM, Pavone V, Lombardi A, Bren KL. Hydrogen evolution from water catalyzed by cobalt-mimochrome VI*a, a synthetic mini-protein. Chem Sci 2018; 9:8582-8589. [PMID: 30568783 PMCID: PMC6253682 DOI: 10.1039/c8sc01948g] [Citation(s) in RCA: 52] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2018] [Accepted: 09/14/2018] [Indexed: 12/14/2022] Open
Abstract
The folding of a synthetic mini-hydrogenase is shown to enhance catalyst efficiency and longevity.
A synthetic enzyme is reported that electrocatalytically reduces protons to hydrogen (H2) in water near neutral pH under aerobic conditions. Cobalt mimochrome VI*a (CoMC6*a) is a mini-protein with a cobalt deuteroporphyrin active site within a scaffold of two synthetic peptides covalently bound to the porphyrin. Comparison of the activity of CoMC6*a to that of cobalt microperoxidase-11 (CoMP11-Ac), a cobalt porphyrin catalyst with a single “proximal” peptide and no organized secondary structure, reveals that CoMC6*a has significantly enhanced longevity, yielding a turnover number exceeding 230 000, in comparison to 25 000 for CoMP11-Ac. Furthermore, comparison of cyclic voltammograms of CoMC6*a and CoMP11-Ac indicates that the trifluoroethanol-induced folding of CoMC6*a lowers the overpotential for catalytic H2 evolution by up to 100 mV. These results demonstrate that even a minimal polypeptide matrix can enhance longevity and efficiency of a H2-evolution catalyst.
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Affiliation(s)
- Vincenzo Firpo
- Department of Chemical Sciences , University of Naples Federico II , Complesso Universitario Monte S. Angelo , via Cintia 45 , 80126 Naples , Italy .
| | - Jennifer M Le
- Department of Chemistry , University of Rochester , Rochester , NY 14627 , USA .
| | - Vincenzo Pavone
- Department of Chemical Sciences , University of Naples Federico II , Complesso Universitario Monte S. Angelo , via Cintia 45 , 80126 Naples , Italy .
| | - Angela Lombardi
- Department of Chemical Sciences , University of Naples Federico II , Complesso Universitario Monte S. Angelo , via Cintia 45 , 80126 Naples , Italy .
| | - Kara L Bren
- Department of Chemistry , University of Rochester , Rochester , NY 14627 , USA .
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20
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Choi TS, Han JY, Heo CE, Lee SW, Kim HI. Electrostatic and hydrophobic interactions of lipid-associated α-synuclein: The role of a water-limited interfaces in amyloid fibrillation. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2018; 1860:1854-1862. [DOI: 10.1016/j.bbamem.2018.02.007] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/28/2017] [Revised: 02/05/2018] [Accepted: 02/05/2018] [Indexed: 12/22/2022]
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21
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Visentin C, Navarro S, Grasso G, Regonesi ME, Deriu MA, Tortora P, Ventura S. Protein Environment: A Crucial Triggering Factor in Josephin Domain Aggregation: The Role of 2,2,2-Trifluoroethanol. Int J Mol Sci 2018; 19:ijms19082151. [PMID: 30042316 PMCID: PMC6121581 DOI: 10.3390/ijms19082151] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2018] [Revised: 07/18/2018] [Accepted: 07/20/2018] [Indexed: 11/28/2022] Open
Abstract
The protein ataxin-3 contains a polyglutamine stretch that triggers amyloid aggregation when it is expanded beyond a critical threshold. This results in the onset of the spinocerebellar ataxia type 3. The protein consists of the globular N-terminal Josephin domain and a disordered C-terminal tail where the polyglutamine stretch is located. Expanded ataxin-3 aggregates via a two-stage mechanism: first, Josephin domain self-association, then polyQ fibrillation. This highlights the intrinsic amyloidogenic potential of Josephin domain. Therefore, much effort has been put into investigating its aggregation mechanism(s). A key issue regards the conformational requirements for triggering amyloid aggregation, as it is believed that, generally, misfolding should precede aggregation. Here, we have assayed the effect of 2,2,2-trifluoroethanol, a co-solvent capable of stabilizing secondary structures, especially α-helices. By combining biophysical methods and molecular dynamics, we demonstrated that both secondary and tertiary JD structures are virtually unchanged in the presence of up to 5% 2,2,2-trifluoroethanol. Despite the preservation of JD structure, 1% of 2,2,2-trifluoroethanol suffices to exacerbate the intrinsic aggregation propensity of this domain, by slightly decreasing its conformational stability. These results indicate that in the case of JD, conformational fluctuations might suffice to promote a transition towards an aggregated state without the need for extensive unfolding, and highlights the important role played by the environment on the aggregation of this globular domain.
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Affiliation(s)
- Cristina Visentin
- Institut de Biotecnologia i de Biomedicina and Departament de Bioquímica i Biologia Molecular, Universitat Autònoma de Barcelona, Bellaterra, 08193 Barcelona, Spain.
| | - Susanna Navarro
- Institut de Biotecnologia i de Biomedicina and Departament de Bioquímica i Biologia Molecular, Universitat Autònoma de Barcelona, Bellaterra, 08193 Barcelona, Spain.
| | - Gianvito Grasso
- Istituto Dalle Molle di Studi sull'Intelligenza Artificiale (IDSIA), Scuola Universitaria Professionale della Svizzera italiana (SUPSI), Università della Svizzera italiana (USI), CH-6928 Manno, Switzerland.
| | - Maria Elena Regonesi
- Dipartimento di Biotecnologie e Bioscienze, Università di Milano-Bicocca, 20126 Milano, Italy.
- Centro di Neuroscienze di Milano (Neuro-MI), 20126 Milano, Italy.
| | - Marco Agostino Deriu
- Istituto Dalle Molle di Studi sull'Intelligenza Artificiale (IDSIA), Scuola Universitaria Professionale della Svizzera italiana (SUPSI), Università della Svizzera italiana (USI), CH-6928 Manno, Switzerland.
| | - Paolo Tortora
- Dipartimento di Biotecnologie e Bioscienze, Università di Milano-Bicocca, 20126 Milano, Italy.
- Centro di Neuroscienze di Milano (Neuro-MI), 20126 Milano, Italy.
| | - Salvador Ventura
- Institut de Biotecnologia i de Biomedicina and Departament de Bioquímica i Biologia Molecular, Universitat Autònoma de Barcelona, Bellaterra, 08193 Barcelona, Spain.
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22
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Affiliation(s)
- Ferenc Zsila
- Biomolecular Self-Assembly Group; Institute of Materials and Environmental Chemistry; Research Centre for Natural Sciences; Hungarian Academy of Sciences; 1117 Budapest Hungary
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23
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Brancaccio D, Diana D, Di Maro S, Di Leva FS, Tomassi S, Fattorusso R, Russo L, Scala S, Trotta AM, Portella L, Novellino E, Marinelli L, Carotenuto A. Ligand-Based NMR Study of C-X-C Chemokine Receptor Type 4 (CXCR4)–Ligand Interactions on Living Cancer Cells. J Med Chem 2018. [DOI: 10.1021/acs.jmedchem.7b01830] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Affiliation(s)
- Diego Brancaccio
- Dipartimento di Farmacia, Università di Napoli Federico II, 80131 Naples, Italy
| | - Donatella Diana
- Istituto di Biostrutture e Bioimmagini, C.N.R., 80134 Naples, Italy
| | - Salvatore Di Maro
- Dipartimento di Scienze e Tecnologie Ambientali, Biologiche e Farmaceutiche, Università degli Studi della Campania “Luigi Vanvitelli”, 81100 Caserta, Italy
| | | | - Stefano Tomassi
- Dipartimento di Scienze e Tecnologie Ambientali, Biologiche e Farmaceutiche, Università degli Studi della Campania “Luigi Vanvitelli”, 81100 Caserta, Italy
| | - Roberto Fattorusso
- Dipartimento di Scienze e Tecnologie Ambientali, Biologiche e Farmaceutiche, Università degli Studi della Campania “Luigi Vanvitelli”, 81100 Caserta, Italy
| | - Luigi Russo
- Dipartimento di Scienze e Tecnologie Ambientali, Biologiche e Farmaceutiche, Università degli Studi della Campania “Luigi Vanvitelli”, 81100 Caserta, Italy
| | - Stefania Scala
- Molecular Immunology and Immunoregulation, Istituto Nazionale Tumori “Fondazione G. Pascale”, IRCCS-Napoli, 80131 Naples, Italy
| | - Anna Maria Trotta
- Molecular Immunology and Immunoregulation, Istituto Nazionale Tumori “Fondazione G. Pascale”, IRCCS-Napoli, 80131 Naples, Italy
| | - Luigi Portella
- Molecular Immunology and Immunoregulation, Istituto Nazionale Tumori “Fondazione G. Pascale”, IRCCS-Napoli, 80131 Naples, Italy
| | - Ettore Novellino
- Dipartimento di Farmacia, Università di Napoli Federico II, 80131 Naples, Italy
| | - Luciana Marinelli
- Dipartimento di Farmacia, Università di Napoli Federico II, 80131 Naples, Italy
| | - Alfonso Carotenuto
- Dipartimento di Farmacia, Università di Napoli Federico II, 80131 Naples, Italy
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24
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Advantages of synchrotron radiation circular dichroism spectroscopy to study intrinsically disordered proteins. EUROPEAN BIOPHYSICS JOURNAL: EBJ 2017; 46:599-606. [PMID: 28258312 DOI: 10.1007/s00249-017-1202-1] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/11/2016] [Revised: 02/16/2017] [Accepted: 02/17/2017] [Indexed: 10/20/2022]
Abstract
The unordered secondary structural content of an intrinsically disordered protein (IDP) is susceptible to conformational changes induced by many different external factors, such as the presence of organic solvents, removal of water, changes in temperature, binding to partner molecules, and interaction with lipids and/or other ligands. In order to characterize the high-flexibility nature of an IDP, circular dichroism (CD) spectroscopy is a particularly useful method due to its capability of monitoring both subtle and remarkable changes in different environments, relative ease in obtaining measurements, the small amount of sample required, and the capability for sample recovery (sample not damaged) and others. Using synchrotron radiation as the light source for CD spectroscopy represents the state-of-the-art version of this technique with feasibility of accessing the lower wavelength UV region, and therefore presenting a series of advantages over conventional circular dichroism (cCD) to monitor a protein conformational behavior, check protein stability, detect ligand binding, and many others. In this paper, we have performed a comparative study using cCD and SRCD methods for investigating the secondary structure and the conformational behavior of natively unfolded proteins: MEG-14 and soybean trypsin inhibitor. We show that the SRCD technique greatly improves the analysis and accuracy of the studies on the conformations of IDPs.
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25
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Abdul Ghani NS, Karjiban RA, Basri M, Faujan NH, Lim WZ. Unveiling Amyloid-β1–42 Interaction with Zinc in Water and Mixed Hexafluoroisopropanol Solution in Alzheimer’s Disease. Int J Pept Res Ther 2017. [DOI: 10.1007/s10989-016-9570-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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26
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Yarawsky AE, English LR, Whitten ST, Herr AB. The Proline/Glycine-Rich Region of the Biofilm Adhesion Protein Aap Forms an Extended Stalk that Resists Compaction. J Mol Biol 2017; 429:261-279. [PMID: 27890783 PMCID: PMC5363081 DOI: 10.1016/j.jmb.2016.11.017] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2016] [Revised: 11/22/2016] [Accepted: 11/22/2016] [Indexed: 12/11/2022]
Abstract
Staphylococcus epidermidis is one of the primary bacterial species responsible for healthcare-associated infections. The most significant virulence factor for S. epidermidis is its ability to form a biofilm, which renders the bacteria highly resistant to host immune responses and antibiotic action. Intercellular adhesion within the biofilm is mediated by the accumulation-associated protein (Aap), a cell wall-anchored protein that self-assembles in a zinc-dependent manner. The C-terminal portion of Aap contains a 135-aa-long, proline/glycine-rich region (PGR) that has not yet been characterized. The region contains a set of 18 nearly identical AEPGKP repeats. Analysis of the PGR using biophysical techniques demonstrated the region is a highly extended, intrinsically disordered polypeptide with unusually high polyproline type II helix propensity. In contrast to many intrinsically disordered polypeptides, there was a minimal temperature dependence of the global conformational state of PGR in solution as measured by analytical ultracentrifugation and dynamic light scattering. Furthermore, PGR was resistant to conformational collapse or α-helix formation upon the addition of the osmolyte trimethylamine N-oxide or the cosolvent 2,2,2-trifluoroethanol. Collectively, these results suggest PGR functions as a resilient, extended stalk that projects the rest of Aap outward from the bacterial cell wall, promoting intercellular adhesion between cells in the biofilm. This work sheds light on regions of low complexity often found near the attachment point of bacterial cell wall-anchored proteins.
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Affiliation(s)
- Alexander E Yarawsky
- Graduate Program in Molecular Genetics, Biochemistry & Microbiology, University of Cincinnati College of Medicine, Cincinnati, OH 45267, USA; Division of Immunobiology and Center for Systems Immunology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, USA
| | - Lance R English
- Department of Chemistry and Biochemistry, Texas State University, San Marcos, TX 78666, USA
| | - Steven T Whitten
- Department of Chemistry and Biochemistry, Texas State University, San Marcos, TX 78666, USA
| | - Andrew B Herr
- Division of Immunobiology and Center for Systems Immunology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, USA; Division of Infectious Diseases, Cincinnati Children's Hospital Medical Center, Cincinnati, OH 45229, USA.
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27
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Kocourková L, Novotná P, Čujová S, Čeřovský V, Urbanová M, Setnička V. Conformational study of melectin and antapin antimicrobial peptides in model membrane environments. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2017; 170:247-255. [PMID: 27450123 DOI: 10.1016/j.saa.2016.07.015] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2015] [Accepted: 07/07/2016] [Indexed: 06/06/2023]
Abstract
Antimicrobial peptides have long been considered as promising compounds against drug-resistant pathogens. In this work, we studied the secondary structure of antimicrobial peptides melectin and antapin using electronic (ECD) and vibrational circular dichroism (VCD) spectroscopies that are sensitive to peptide secondary structures. The results from quantitative ECD spectral evaluation by Dichroweb and CDNN program and from the qualitative evaluation of the VCD spectra were compared. The antimicrobial activity of the selected peptides depends on their ability to adopt an amphipathic α-helical conformation on the surface of the bacterial membrane. Hence, solutions of different zwitterionic and negatively charged liposomes and micelles were used to mimic the eukaryotic and bacterial biological membranes. The results show a significant content of α-helical conformation in the solutions of negatively charged liposomes mimicking the bacterial membrane, thus correlating with the antimicrobial activity of the studied peptides. On the other hand in the solutions of zwitterionic liposomes used as models of the eukaryotic membranes, the fraction of α-helical conformation was lower, which corresponds with their moderate hemolytic activity.
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Affiliation(s)
- Lucie Kocourková
- Department of Analytical Chemistry, University of Chemistry and Technology, Prague, Technická 5, 166 28 Prague 6, Czech Republic
| | - Pavlína Novotná
- Department of Analytical Chemistry, University of Chemistry and Technology, Prague, Technická 5, 166 28 Prague 6, Czech Republic
| | - Sabína Čujová
- Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, Flemingovo náměstí 2, 166 10 Prague 6, Czech Republic
| | - Václav Čeřovský
- Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, Flemingovo náměstí 2, 166 10 Prague 6, Czech Republic
| | - Marie Urbanová
- Department of Physics and Measurements, University of Chemistry and Technology, Prague, Technická 5, 166 28 Prague 6, Czech Republic
| | - Vladimír Setnička
- Department of Analytical Chemistry, University of Chemistry and Technology, Prague, Technická 5, 166 28 Prague 6, Czech Republic.
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28
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Halim AAA, Zaroog MS, Kadir HA, Tayyab S. Alcohol-induced structural transitions in the acid-denatured Bacillus licheniformis α-amylase. JOURNAL OF SAUDI CHEMICAL SOCIETY 2017. [DOI: 10.1016/j.jscs.2014.04.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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29
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Abstract
Substitution of a main chain i → i + 4 hydrogen bond with a covalent bond can nucleate and stabilize the α-helical conformation in peptides. Herein we describe the potential of different alkene isosteres to mimic intramolecular hydrogen bonds and stabilize α-helices in diverse peptide sequences.
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Affiliation(s)
- Stephen T Joy
- Department of Chemistry, New York University, New York, NY 10003, USA.
| | - Paramjit S Arora
- Department of Chemistry, New York University, New York, NY 10003, USA.
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30
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Owen MC, Strodel B, Csizmadia IG, Viskolcz B. Radical Formation Initiates Solvent-Dependent Unfolding and β-sheet Formation in a Model Helical Peptide. J Phys Chem B 2016; 120:4878-89. [PMID: 27169334 DOI: 10.1021/acs.jpcb.6b00174] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
We examined the effects of Cα-centered radical formation on the stability of a model helical peptide, N-Ac-KK(AL)10KK-NH2. Three, 100 ns molecular dynamics simulations using the OPLS-AA force field were carried out on each α-helical peptide in six distinct binary TIP4P water/2,2,2-trifluoroethanol (TFE) mixtures. The α-helicity was at a maximum in 20% TFE, which was inversely proportional to the number of H-bonds between water molecules and the peptide backbone. The radial distribution of TFE around the peptide backbone was highest in 20% TFE, which enhanced helix stability. The Cα-centered radical initiated the formation of a turn within 5 ns, which was a smaller kink at high TFE concentrations, and a loop at lower TFE concentrations. The highest helicity of the peptide radical was measured in 100% TFE. The formation of hydrogen bonds between the peptide backbone and water destabilized the helix, whereas the clustering of TFE molecules around the radical center stabilized the helix. Following radical termination, the once helical structure converted to a β-sheet rich state in 100% water only, and this transition did not occur in the nonradical control peptide. This study gives evidence on how the formation of peptide radicals can initiate α-helical to β-sheet transitions under oxidative stress conditions.
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Affiliation(s)
- Michael C Owen
- Institute of Complex Systems: Structural Biochemistry (ICS-6), Forschungszentrum Jülich , 52425 Jülich, Germany
| | - Birgit Strodel
- Institute of Complex Systems: Structural Biochemistry (ICS-6), Forschungszentrum Jülich , 52425 Jülich, Germany.,Institute of Theoretical and Computational Chemistry, Heinrich Heine University Düsseldorf , Universitätsstrasse 1, 40225 Düsseldorf, Germany
| | - Imre G Csizmadia
- Department of Chemistry, University of Toronto , Toronto, ON Canada M5S 3H6.,Institute of Chemistry, Faculty of Material Science, University of Miskolc , Egyetemváros 1, H-3529 Miskolc, Hungary.,Drug Discovery Research Center , 6720 Szeged, Hungary
| | - Béla Viskolcz
- Institute of Chemistry, Faculty of Material Science, University of Miskolc , Egyetemváros 1, H-3529 Miskolc, Hungary.,Drug Discovery Research Center , 6720 Szeged, Hungary
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31
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Bandyopadhyay D, Prakash S, Gupta K, Balaram P. Mass spectrometric analysis of dimer-disrupting mutations in Plasmodium triosephosphate isomerase. Anal Biochem 2016; 500:45-50. [PMID: 26919806 DOI: 10.1016/j.ab.2016.02.011] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2015] [Revised: 02/12/2016] [Accepted: 02/13/2016] [Indexed: 01/16/2023]
Abstract
Electrospray ionization mass spectrometry (ESI MS) under nanospray conditions has been used to examine the effects of mutation at two key dimer interface residues, Gln (Q) 64 and Thr (T) 75, in Plasmodium falciparum triosephosphate isomerase. Both residues participate in an intricate network of intra- and intersubunit hydrogen bonds. The gas phase distributions of dimeric and monomeric protein species have been examined for the wild type enzyme (TWT) and three mutants, Q64N, Q64E, and T75S, under a wide range of collision energies (40-160 eV). The results established the order of dimer stability as TWT > T75S > Q64E ∼ Q64N. The mutational effects on dimer stability are in good agreement with the previously reported estimates, based on the concentration dependence of enzyme activity. Additional experiments in solution, using inhibition of activity by a synthetic dimer interface peptide, further support the broad agreement between gas phase and solution studies.
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Affiliation(s)
| | - Sunita Prakash
- Molecular Biophysics Unit, Indian Institute of Science, Bangalore 560012, India
| | - Kallol Gupta
- Molecular Biophysics Unit, Indian Institute of Science, Bangalore 560012, India
| | - Padmanabhan Balaram
- Molecular Biophysics Unit, Indian Institute of Science, Bangalore 560012, India.
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32
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Vymětal J, Bednárová L, Vondrášek J. Effect of TFE on the Helical Content of AK17 and HAL-1 Peptides: Theoretical Insights into the Mechanism of Helix Stabilization. J Phys Chem B 2016; 120:1048-59. [DOI: 10.1021/acs.jpcb.5b11228] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Jiří Vymětal
- Institute of Organic Chemistry and Biochemistry, AS CR, Flemingovo náměsti 2, 166 10 Prague 6, Czech Republic
| | - Lucie Bednárová
- Institute of Organic Chemistry and Biochemistry, AS CR, Flemingovo náměsti 2, 166 10 Prague 6, Czech Republic
| | - Jiří Vondrášek
- Institute of Organic Chemistry and Biochemistry, AS CR, Flemingovo náměsti 2, 166 10 Prague 6, Czech Republic
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33
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Choi TS, Lee JW, Jin KS, Kim HI. Amyloid fibrillation of insulin under water-limited conditions. Biophys J 2015; 107:1939-1949. [PMID: 25418175 DOI: 10.1016/j.bpj.2014.09.008] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2014] [Revised: 08/01/2014] [Accepted: 09/10/2014] [Indexed: 02/08/2023] Open
Abstract
Amyloid fibrillation in water-organic mixtures has been widely studied to understand the effect of protein-solvent interactions on the fibrillation process. In this study, we monitored insulin fibrillation in formamide and its methyl derivatives (formamide, N-methyl formamide, N,N-dimethyl formamide) in the presence and absence of water. These model solvent systems mimic the cellular environment by providing denaturing conditions and a hydrophobic environment with limited water content. Thioflavin T (ThT) assay revealed that binary mixtures of water with formamide and its methyl derivatives enhanced fibrillation rates and ?-sheet abundance, whereas organic solvents suppressed insulin fibrillation. We utilized solution small-angle x-ray scattering (SAXS) and differential scanning calorimetry (DSC) to investigate the correlation between protein-solvent interactions and insulin fibrillation. SAXS experiments combined with simulated annealing of the protein indicated that the degree of denaturation of the hydrophobic core region at residues B11-B17 determines the fibrillation rate. In addition, DSC experiments suggested a crucial role of hydrophobic interactions in the fibrillation process. These results imply that an environment with limited water, which imitates a lipid membrane system, accelerates protein denaturation and the formation of intermolecular hydrophobic interactions during amyloid fibrillation.
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Affiliation(s)
- Tae Su Choi
- Department of Chemistry, Pohang University of Science and Technology (POSTECH), Pohang, Republic of Korea
| | - Jong Wha Lee
- Pohang Accelerator Laboratory, Pohang University of Science and Technology (POSTECH), Pohang, Republic of Korea
| | - Kyeong Sik Jin
- Division of Advanced Materials Science, Pohang University of Science and Technology (POSTECH), Pohang, Republic of Korea
| | - Hugh I Kim
- Department of Chemistry, Pohang University of Science and Technology (POSTECH), Pohang, Republic of Korea; Division of Advanced Materials Science, Pohang University of Science and Technology (POSTECH), Pohang, Republic of Korea.
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34
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Tan NY, Li R, Bräuer P, D'Agostino C, Gladden LF, Zeitler JA. Probing hydrogen-bonding in binary liquid mixtures with terahertz time-domain spectroscopy: a comparison of Debye and absorption analysis. Phys Chem Chem Phys 2015; 17:5999-6008. [DOI: 10.1039/c4cp04477k] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Terahertz time-domain spectroscopy is used to explore hydrogen bonding structure and dynamics in binary liquid mixtures, spanning a range of protic–protic, protic–aprotic and aprotic–aprotic systems.
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Affiliation(s)
- Nicholas Y. Tan
- Department of Chemical Engineering and Biotechnology
- University of Cambridge
- Cambridge CB2 3RA
- UK
| | - Ruoyu Li
- Department of Chemical Engineering and Biotechnology
- University of Cambridge
- Cambridge CB2 3RA
- UK
| | - Pierre Bräuer
- Department of Chemical Engineering and Biotechnology
- University of Cambridge
- Cambridge CB2 3RA
- UK
| | - Carmine D'Agostino
- Department of Chemical Engineering and Biotechnology
- University of Cambridge
- Cambridge CB2 3RA
- UK
| | - Lynn F. Gladden
- Department of Chemical Engineering and Biotechnology
- University of Cambridge
- Cambridge CB2 3RA
- UK
| | - J. Axel Zeitler
- Department of Chemical Engineering and Biotechnology
- University of Cambridge
- Cambridge CB2 3RA
- UK
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35
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Culik RM, Abaskharon RM, Pazos IM, Gai F. Experimental validation of the role of trifluoroethanol as a nanocrowder. J Phys Chem B 2014; 118:11455-61. [PMID: 25215518 PMCID: PMC4183368 DOI: 10.1021/jp508056w] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
![]()
Trifluoroethanol
(TFE) is commonly used to induce protein secondary
structure, especially α-helix formation. Due to its amphiphilic
nature, however, TFE can also self-associate to form micellelike,
nanometer-sized clusters. Herein, we hypothesize that such clusters
can act as nanocrowders to increase protein folding rates via the
excluded volume effect. To test this hypothesis, we measure the conformational
relaxation kinetics of an intrinsically disordered protein, the phosphorylated
kinase inducible domain (pKID), which forms a helix–turn–helix
in TFE solutions. We find that the conformational relaxation rate
of pKID displays a rather complex dependence on TFE percentage (v/v):
while it first decreases between 0 and 5%, between 5 and 15% the rate
increases and then remains relatively unchanged between 15 and 30%
and finally decreases again at higher percentages (i.e., 50%). This
trend coincides with the fact that TFE clustering is maximized in
the range of 15–30%, thus providing validation of our hypothesis.
Another line of supporting evidence comes from the observation that
the relaxation rate of a monomeric helical peptide, which due to its
predominantly local interactions in the folded state is less affected
by crowding, does not show a similar TFE dependence.
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Affiliation(s)
- Robert M Culik
- Department of Biochemistry & Biophysics and ‡Department of Chemistry, University of Pennsylvania , Philadelphia, Pennsylvania 19104, United States
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36
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Vymětal J, Vondrášek J. Parametrization of 2,2,2-trifluoroethanol based on the generalized AMBER force field provides realistic agreement between experimental and calculated properties of pure liquid as well as water-mixed solutions. J Phys Chem B 2014; 118:10390-404. [PMID: 25110944 DOI: 10.1021/jp505861b] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
We present a novel force field model of 2,2,2-trifluoroethanol (TFE) based on the generalized AMBER force field. The model was exhaustively parametrized to reproduce liquid-state properties of pure TFE, namely, density, enthalpy of vaporization, self-diffusion coefficient, and population of trans and gauche conformers. The model predicts excellently other liquid-state properties such as shear viscosity, thermal expansion coefficient, and isotropic compressibility. The resulting model describes unexpectedly well the state equation of the liquid region in the range of 100 K and 10 MPa. More importantly, the proposed TFE model was optimized for use in combination with the TIP4P/Ew and TIP4P/2005 water models. It does not manifest excessive aggregation, which is known for other models, and therefore, it is supposed to more realistically describe the behavior of TFE/water mixtures. This was demonstrated by means of the Kirkwood-Buff theory of solutions and reasonable agreement with experimental data. We explored a considerable part of the parameter space and systematically tested individual combinations of parameters for performance in combination with the TIP4P/Ew and TIP4P/2005 water models. We observed ambiguity in parameters describing pure liquid TFE; however, most of them failed for TFE/water mixtures. We clearly demonstrated the necessity for balanced TFE-TFE, TFE-water, and water-water interactions which can be acquired only by employing implicit polarization correction in the course of parametrization.
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Affiliation(s)
- Jiří Vymětal
- Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic (AS CR) , Flemingovo nám. 2, 166 10 Praha 6, Czech Republic
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37
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Raja M. Special Interaction of Anionic Phosphatidic Acid Promotes High Secondary Structure in Tetrameric Potassium Channel. J Membr Biol 2014; 247:747-52. [DOI: 10.1007/s00232-014-9704-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2014] [Accepted: 06/27/2014] [Indexed: 10/25/2022]
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38
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Acidic pH triggers conformational changes at the NH2-terminal propeptide of the precursor of pulmonary surfactant protein B to form a coiled coil structure. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2014; 1838:1738-51. [DOI: 10.1016/j.bbamem.2014.03.016] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/28/2014] [Revised: 03/19/2014] [Accepted: 03/24/2014] [Indexed: 11/21/2022]
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39
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Naidoo VB, Rautenbach M. Self-assembling organo-peptide bolaphiles with KLK tripeptide head groups display selective antibacterial activity. J Pept Sci 2014; 19:784-91. [PMID: 24243600 DOI: 10.1002/psc.2576] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2013] [Revised: 09/15/2013] [Accepted: 09/26/2013] [Indexed: 11/11/2022]
Abstract
In keeping with recent efforts to generate compounds for antibiotic and microbicide development, we focused on the creation of non-natural organo-peptide hybrids of antimicrobial peptide amides (KLK(L)n KLK-NH2 ) derived from sapecin B and a self-assembling oligoglycine organo-peptide bolaphile containing an ω-amino fatty acid residue. The hybrid organo-peptide bolaphiles with two cationic KLK tripeptide motifs linked with an ω-amino acid residue (penta-, octa- or undecamethylene chain) maintained the self-assembling properties of the root oligoglycine bolaphile. Electron microscopy clearly revealed complex supramolecular architectures for both sapecin B-derived peptides and the hybrid analogues. FT-IR spectroscopy indicated that the supramolecular structures were composed primarily of β-sheets. CD revealed that the hybrid bolaphiles did not share the same secondary structures as the sapecin B peptides in solution. However, although secondary structures of antimicrobial peptides are central in the activity, the organo-peptide bolaphiles also retained the potent antimicrobial activity of the leader sapecin B-derived peptide against both Gram-positive and Gram-negative bacteria. In general, the hybrids were more selective than the sapecin B peptides, as they displayed little or no appreciable haemolytic activity. The results obtained herald a new approach for the design of purpose-built hybrid organo-peptide bolaphiles.
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Affiliation(s)
- Venthan B Naidoo
- UNESCO Associated Centre for Macromolecules and Materials, Division of Polymer Science, Department of Chemistry, University of Stellenbosch, Private Bag X1, Matieland, 7600, South Africa; BIOPEP Peptide Group, Department of Biochemistry, University of Stellenbosch, Private Bag X1, Matieland, 7600, South Africa
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40
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Amani S, Naeem A. Deciphering aggregates, prefibrillar oligomers and protofibrils of cytochrome c. Amino Acids 2014; 46:1839-51. [DOI: 10.1007/s00726-014-1698-y] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2013] [Accepted: 02/14/2014] [Indexed: 11/28/2022]
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41
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Brister M, Pandey AK, Bielska AA, Zondlo NJ. OGlcNAcylation and phosphorylation have opposing structural effects in tau: phosphothreonine induces particular conformational order. J Am Chem Soc 2014; 136:3803-16. [PMID: 24559475 PMCID: PMC4004249 DOI: 10.1021/ja407156m] [Citation(s) in RCA: 65] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2013] [Indexed: 01/12/2023]
Abstract
Phosphorylation and OGlcNAcylation are dynamic intracellular protein post-translational modifications that frequently are alternatively observed on the same serine and threonine residues. Phosphorylation and OGlcNAcylation commonly occur in natively disordered regions of proteins, and often have opposing functional effects. In the microtubule-associated protein tau, hyperphosphorylation is associated with protein misfolding and aggregation as the neurofibrillary tangles of Alzheimer's disease, whereas OGlcNAcylation stabilizes the soluble form of tau. A series of peptides derived from the proline-rich domain (residues 174-251) of tau was synthesized, with free Ser/Thr hydroxyls, phosphorylated Ser/Thr (pSer/pThr), OGlcNAcylated Ser/Thr, and diethylphosphorylated Ser/Thr. Phosphorylation and OGlcNAcylation were found by CD and NMR to have opposing structural effects on polyproline helix (PPII) formation, with phosphorylation favoring PPII, OGlcNAcylation opposing PPII, and the free hydroxyls intermediate in structure, and with phosphorylation structural effects greater than OGlcNAcylation. For tau196-209, phosphorylation and OGlcNAcylation had similar structural effects, opposing a nascent α-helix. Phosphomimic Glu exhibited PPII-favoring structural effects. Structural changes due to Thr phosphorylation were greater than those of Ser phosphorylation or Glu, with particular conformational restriction as the dianion, with mean (3)JαN = 3.5 Hz (pThr) versus 5.4 Hz (pSer), compared to 7.2, 6.8, and 6.2 Hz for Thr, Ser, and Glu, respectively, values that correlate with the backbone torsion angle ϕ. Dianionic phosphothreonine induced strong phosphothreonine amide protection and downfield amide chemical shifts (δmean = 9.63 ppm), consistent with formation of a stable phosphate-amide hydrogen bond. These data suggest potentially greater structural importance of threonine phosphorylation than serine phosphorylation due to larger induced structural effects.
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Affiliation(s)
| | | | - Agata A. Bielska
- Department of Chemistry and
Biochemistry, University of Delaware, Newark, Delaware 19716, United States
| | - Neal J. Zondlo
- Department of Chemistry and
Biochemistry, University of Delaware, Newark, Delaware 19716, United States
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42
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Lopes JLS, Orcia D, Araujo APU, DeMarco R, Wallace BA. Folding factors and partners for the intrinsically disordered protein micro-exon gene 14 (MEG-14). Biophys J 2014; 104:2512-20. [PMID: 23746524 DOI: 10.1016/j.bpj.2013.03.063] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2012] [Revised: 02/27/2013] [Accepted: 03/12/2013] [Indexed: 01/09/2023] Open
Abstract
The micro-exon genes (MEG) of Schistosoma mansoni, a parasite responsible for the second most widely spread tropical disease, code for small secreted proteins with sequences unique to the Schistosoma genera. Bioinformatics analyses suggest the soluble domain of the MEG-14 protein will be largely disordered, and using synchrotron radiation circular dichroism spectroscopy, its secondary structure was shown to be essentially completely unfolded in aqueous solution. It does, however, show a strong propensity to fold into more ordered structures under a wide range of conditions. Partial folding was produced by increasing temperature (in a reversible process), contrary to the behavior of most soluble proteins. Furthermore, significant folding was observed in the presence of negatively charged lipids and detergents, but not in zwitterionic or neutral lipids or detergents. Absorption onto a surface followed by dehydration stimulated it to fold into a helical structure, as it did when the aqueous solution was replaced by nonaqueous solvents. Hydration of the dehydrated folded protein was accompanied by complete unfolding. These results support the identification of MEG-14 as a classic intrinsically disordered protein, and open the possibility of its interaction/folding with different partners and factors being related to multifunctional roles and states within the host.
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Affiliation(s)
- Jose Luiz S Lopes
- Institute of Structural and Molecular Biology, Birkbeck College, University of London, London, United Kingdom
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43
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Lee SJC, Lee JW, Choi TS, Jin KS, Lee S, Ban C, Kim HI. Probing Conformational Change of Intrinsically Disordered α-Synuclein to Helical Structures by Distinctive Regional Interactions with Lipid Membranes. Anal Chem 2014; 86:1909-16. [DOI: 10.1021/ac404132g] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Affiliation(s)
- Shin Jung C. Lee
- Department of Chemistry, ‡Pohang Accelerator
Laboratory, §Division of Advanced Materials Science, Pohang University of Science and Technology (POSTECH), Pohang, North Gyeongsang 790-784, South Korea
| | - Jong Wha Lee
- Department of Chemistry, ‡Pohang Accelerator
Laboratory, §Division of Advanced Materials Science, Pohang University of Science and Technology (POSTECH), Pohang, North Gyeongsang 790-784, South Korea
| | - Tae Su Choi
- Department of Chemistry, ‡Pohang Accelerator
Laboratory, §Division of Advanced Materials Science, Pohang University of Science and Technology (POSTECH), Pohang, North Gyeongsang 790-784, South Korea
| | - Kyeong Sik Jin
- Department of Chemistry, ‡Pohang Accelerator
Laboratory, §Division of Advanced Materials Science, Pohang University of Science and Technology (POSTECH), Pohang, North Gyeongsang 790-784, South Korea
| | - Seonghwan Lee
- Department of Chemistry, ‡Pohang Accelerator
Laboratory, §Division of Advanced Materials Science, Pohang University of Science and Technology (POSTECH), Pohang, North Gyeongsang 790-784, South Korea
| | - Changill Ban
- Department of Chemistry, ‡Pohang Accelerator
Laboratory, §Division of Advanced Materials Science, Pohang University of Science and Technology (POSTECH), Pohang, North Gyeongsang 790-784, South Korea
| | - Hugh I. Kim
- Department of Chemistry, ‡Pohang Accelerator
Laboratory, §Division of Advanced Materials Science, Pohang University of Science and Technology (POSTECH), Pohang, North Gyeongsang 790-784, South Korea
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44
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Ghosh R, Roy S, Bagchi B. Solvent Sensitivity of Protein Unfolding: Dynamical Study of Chicken Villin Headpiece Subdomain in Water–Ethanol Binary Mixture. J Phys Chem B 2013; 117:15625-38. [DOI: 10.1021/jp406255z] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Affiliation(s)
- Rikhia Ghosh
- Solid State and Structural
Chemistry Unit, Indian Institute of Science, C. V. Raman Avenue, Bangalore 560012, India
| | - Susmita Roy
- Solid State and Structural
Chemistry Unit, Indian Institute of Science, C. V. Raman Avenue, Bangalore 560012, India
| | - Biman Bagchi
- Solid State and Structural
Chemistry Unit, Indian Institute of Science, C. V. Raman Avenue, Bangalore 560012, India
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45
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Liu HL, Hsu CM. The Effects of Various Alcohols on the Stability of Melittin: A Molecular Dynamics Study. J CHIN CHEM SOC-TAIP 2013. [DOI: 10.1002/jccs.200300177] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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46
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Jaremko M, Jaremko L, Mazur A, Makowski M, Lisowski M. Enhanced β-turn conformational stability of tripeptides containing ΔPhe in cis over trans configuration. Amino Acids 2013; 45:865-75. [PMID: 23812673 DOI: 10.1007/s00726-013-1534-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2013] [Accepted: 06/07/2013] [Indexed: 11/28/2022]
Abstract
Conformations of three pairs of dehydropeptides with the opposite configuration of the ΔPhe residue, Boc-Gly-Δ(Z/E)Phe-Phe-p-NA (Z- p -NA and E- p -NA), Boc-Gly-Δ(Z/E)Phe-Phe-OMe (Z-OMe and E-OMe), and Boc-Gly-Δ(Z/E)Phe-Phe-OH (Z-OH and E-OH) were compared on the basis of CD and NMR studies in MeOH, TFE, and DMSO. The CD results were used as the additional input data for the NMR-based calculations of the detailed solution conformations of the peptides. It was found that Z- p -NA, E- p -NA, Z-OMe, and Z-OH adopt the β-turn conformations and E-OMe and E-OH are unordered. There are two overlapping type III β-turns in Z- p -NA, type II' β-turn in E- p -NA, and type II β-turn in Z-OMe and Z-OH. The results obtained indicate that in the case of methyl esters and peptides with a free carboxyl group, Δ(Z)Phe is a much stronger inducer of ordered conformations than Δ(E)Phe. It was also found that temperature coefficients of the amide protons are not reliable indicators of intramolecular hydrogen bonds donors in small peptides.
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Affiliation(s)
- Mariusz Jaremko
- Department of NMR-based Structural Biology, Max-Planck-Institute for Biophysical Chemistry, Am Fassberg 11, 37077, Göttingen, Germany,
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47
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Frankiewicz L, Betti C, Guillemyn K, Tourwé D, Jacquot Y, Ballet S. Stabilisation of a short α
-helical VIP fragment by side chain to side chain cyclisation: a comparison of common cyclisation motifs by circular dichroism. J Pept Sci 2013; 19:423-32. [DOI: 10.1002/psc.2515] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2013] [Revised: 03/15/2013] [Accepted: 04/08/2013] [Indexed: 12/11/2022]
Affiliation(s)
- Lukasz Frankiewicz
- Department of Organic Chemistry; Vrije Universiteit Brussel; Pleinlaan 2 B-1050 Brussels Belgium
| | - Cecilia Betti
- Department of Organic Chemistry; Vrije Universiteit Brussel; Pleinlaan 2 B-1050 Brussels Belgium
| | - Karel Guillemyn
- Department of Organic Chemistry; Vrije Universiteit Brussel; Pleinlaan 2 B-1050 Brussels Belgium
| | - Dirk Tourwé
- Department of Organic Chemistry; Vrije Universiteit Brussel; Pleinlaan 2 B-1050 Brussels Belgium
| | - Yves Jacquot
- Laboratory of the BioMolécules (LBM), Department of Chemistry, CNRS - UMR 7203; Ecole Normale Supérieure/Université Pierre et Marie Curie Paris 6; 24, rue Lhomond 75231 Paris Cedex 05 France
| | - Steven Ballet
- Department of Organic Chemistry; Vrije Universiteit Brussel; Pleinlaan 2 B-1050 Brussels Belgium
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Zaroog MS, Tayyab S. Halogenol- versus alkanol-induced structural transitions of acid-denatured glucoamylase: Characterization of alcohol-induced states. Process Biochem 2013. [DOI: 10.1016/j.procbio.2013.03.018] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Eichenberger AP, van Gunsteren WF, Smith LJ. Structure of hen egg-white lysozyme solvated in TFE/water: a molecular dynamics simulation study based on NMR data. JOURNAL OF BIOMOLECULAR NMR 2013; 55:339-353. [PMID: 23494634 DOI: 10.1007/s10858-013-9717-y] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/16/2013] [Accepted: 02/17/2013] [Indexed: 06/01/2023]
Abstract
Various experimental studies of hen egg white lysozyme (HEWL) in water and TFE/water clearly indicate structural differences between the native state and TFE state of HEWL, e.g. the helical content of the protein in the TFE state is much higher than in the native state. However, the available detailed NMR studies were not sufficient to determine fully a structure of HEWL in the TFE state. Different molecular dynamics (MD) simulations, i.e. at room temperature, at increased temperature and using proton-proton distance restraints derived from NMR NOE data, have been used to generate configurational ensembles corresponding to the TFE state of HEWL. The configurational ensemble obtained at room temperature using atom-atom distance restraints measured for HEWL in TFE/water solution satisfies the experimental data and has the lowest protein energy. In this ensemble residues 50-58, which are part of the β-sheet in native HEWL, adopt fluctuating α-helical secondary structure.
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Affiliation(s)
- Andreas P Eichenberger
- Laboratory of Physical Chemistry, Swiss Federal Institute of Technology, ETH, Zurich, Switzerland
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Jia X, Zhang JZ, Mei Y. Assessing the accuracy of the general AMBER force field for 2,2,2-trifluoroethanol as solvent. J Mol Model 2013; 19:2355-61. [DOI: 10.1007/s00894-013-1776-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2012] [Accepted: 01/17/2013] [Indexed: 10/27/2022]
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