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Vogelaar TD, Agger AE, Reseland JE, Linke D, Jenssen H, Lund R. Crafting Stable Antibiotic Nanoparticles via Complex Coacervation of Colistin with Block Copolymers. Biomacromolecules 2024. [PMID: 38886154 DOI: 10.1021/acs.biomac.4c00337] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/20/2024]
Abstract
To combat the ever-growing increase of multidrug-resistant (MDR) bacteria, action must be taken in the development of antibiotic formulations. Colistin, an effective antibiotic, was found to be nephrotoxic and neurotoxic, consequently leading to a ban on its use in the 1980s. A decade later, colistin use was revived and nowadays used as a last-resort treatment against Gram-negative bacterial infections, although highly regulated. If cytotoxicity issues can be resolved, colistin could be an effective option to combat MDR bacteria. Herein, we investigate the complexation of colistin with poly(ethylene oxide)-b-poly(methacrylic acid) (PEO-b-PMAA) block copolymers to form complex coacervate core micelles (C3Ms) to ultimately improve colistin use in therapeutics while maintaining its effectiveness. We show that well-defined and stable micelles can be formed in which the cationic colistin and anionic PMAA form the core while PEO forms a protecting shell. The resulting C3Ms are in a kinetically arrested and stable state, yet they can be made reproducibly using an appropriate experimental protocol. By characterization through dynamic light scattering (DLS) and small-angle X-ray scattering (SAXS), we found that the best C3M formulation, based on long-term stability and complexation efficiency, is at charge-matching conditions. This nanoparticle formulation was compared to noncomplexed colistin on its antimicrobial properties, enzymatic degradation, serum protein binding, and cytotoxicity. The studies indicate that the antimicrobial properties and cytotoxicity of the colistin-C3Ms were maintained while protein binding was limited, and enzymatic degradation decreased after complexation. Since colistin-C3Ms were found to have an equal effectivity but with increased cargo protection, such nanoparticles are promising components for the antibiotic formulation toolbox.
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Affiliation(s)
- Thomas D Vogelaar
- Department of Chemistry, University of Oslo, P.O. Box 1033, Blindern, NO-0315 Oslo, Norway
| | - Anne E Agger
- Department of Biomaterials, Institute of Clinical Dentistry, University of Oslo, P.O. Box 1109, Blindern, NO-0317 Oslo, Norway
| | - Janne E Reseland
- Department of Biomaterials, Institute of Clinical Dentistry, University of Oslo, P.O. Box 1109, Blindern, NO-0317 Oslo, Norway
| | - Dirk Linke
- Department of Biosciences, University of Oslo, P.O. Box 1066, Blindern, NO-0316 Oslo, Norway
| | - Håvard Jenssen
- Department of Science and Environment, Roskilde University, 4000 Roskilde, Denmark
| | - Reidar Lund
- Department of Chemistry, University of Oslo, P.O. Box 1033, Blindern, NO-0315 Oslo, Norway
- Hylleraas Centre for Quantum Molecular Sciences, University of Oslo, NO-0315 Oslo, Norway
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2
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Martínez-Lumbreras S, Träger LK, Mulorz MM, Payr M, Dikaya V, Hipp C, König J, Sattler M. Intramolecular autoinhibition regulates the selectivity of PRPF40A tandem WW domains for proline-rich motifs. Nat Commun 2024; 15:3888. [PMID: 38719828 PMCID: PMC11079029 DOI: 10.1038/s41467-024-48004-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2023] [Accepted: 04/18/2024] [Indexed: 05/12/2024] Open
Abstract
PRPF40A plays an important role in the regulation of pre-mRNA splicing by mediating protein-protein interactions in the early steps of spliceosome assembly. By binding to proteins at the 5´ and 3´ splice sites, PRPF40A promotes spliceosome assembly by bridging the recognition of the splices. The PRPF40A WW domains are expected to recognize proline-rich sequences in SF1 and SF3A1 in the early spliceosome complexes E and A, respectively. Here, we combine NMR, SAXS and ITC to determine the structure of the PRPF40A tandem WW domains in solution and characterize the binding specificity and mechanism for proline-rich motifs recognition. Our structure of the PRPF40A WW tandem in complex with a high-affinity SF1 peptide reveals contributions of both WW domains, which also enables tryptophan sandwiching by two proline residues in the ligand. Unexpectedly, a proline-rich motif in the N-terminal region of PRPF40A mediates intramolecular interactions with the WW tandem. Using NMR, ITC, mutational analysis in vitro, and immunoprecipitation experiments in cells, we show that the intramolecular interaction acts as an autoinhibitory filter for proof-reading of high-affinity proline-rich motifs in bona fide PRPF40A binding partners. We propose that similar autoinhibitory mechanisms are present in most WW tandem-containing proteins to enhance binding selectivity and regulation of WW/proline-rich peptide interaction networks.
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Affiliation(s)
- Santiago Martínez-Lumbreras
- Institute of Structural Biology, Molecular Targets and Therapeutics Center, Helmholtz Munich, Ingolstädter Landstrasse 1, 85764, Neuherberg, Germany.
- TUM School of Natural Sciences, Department of Bioscience and Bavarian NMR Center, Technical University of Munich, Lichtenbergstrasse 4, 85748, Garching, Germany.
| | - Lena K Träger
- TUM School of Natural Sciences, Department of Bioscience and Bavarian NMR Center, Technical University of Munich, Lichtenbergstrasse 4, 85748, Garching, Germany
| | - Miriam M Mulorz
- Institute of Molecular Biology (IMB) gGmbH, Ackermannweg 4, 55128, Mainz, Germany
| | - Marco Payr
- TUM School of Natural Sciences, Department of Bioscience and Bavarian NMR Center, Technical University of Munich, Lichtenbergstrasse 4, 85748, Garching, Germany
| | - Varvara Dikaya
- TUM School of Natural Sciences, Department of Bioscience and Bavarian NMR Center, Technical University of Munich, Lichtenbergstrasse 4, 85748, Garching, Germany
| | - Clara Hipp
- Institute of Structural Biology, Molecular Targets and Therapeutics Center, Helmholtz Munich, Ingolstädter Landstrasse 1, 85764, Neuherberg, Germany
- TUM School of Natural Sciences, Department of Bioscience and Bavarian NMR Center, Technical University of Munich, Lichtenbergstrasse 4, 85748, Garching, Germany
| | - Julian König
- Institute of Molecular Biology (IMB) gGmbH, Ackermannweg 4, 55128, Mainz, Germany
| | - Michael Sattler
- Institute of Structural Biology, Molecular Targets and Therapeutics Center, Helmholtz Munich, Ingolstädter Landstrasse 1, 85764, Neuherberg, Germany.
- TUM School of Natural Sciences, Department of Bioscience and Bavarian NMR Center, Technical University of Munich, Lichtenbergstrasse 4, 85748, Garching, Germany.
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3
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Saade C, Pozza A, Bonneté F, Finet S, Lutz-Bueno V, Tully MD, Varela PF, Lacapère JJ, Combet S. Enhanced structure/function of mTSPO translocator in lipid:surfactant mixed micelles. Biochimie 2024:S0300-9084(24)00083-X. [PMID: 38663457 DOI: 10.1016/j.biochi.2024.04.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2024] [Revised: 04/06/2024] [Accepted: 04/19/2024] [Indexed: 05/06/2024]
Abstract
TSPO is a ubiquitous transmembrane protein used as a pharmacological marker in neuroimaging. The only known atomic structure of mammalian TSPOs comes from the solution NMR of mouse TSPO (mTSPO) bound to the PK11195 ligand and in a DPC surfactant environment. No structure is available in a biomimetic environment and without PK11195 which strongly stiffens the protein. We measured the effect of different amphiphilic environments on ligand-free mTSPO to study its structure/function and find optimal solubilization conditions. By replacing the SDS surfactant, where the recombinant protein is purified, with mixed lipid:surfactant (DMPC:DPC) micelles at different ratios (0:1, 1:2, and 2:1, w:w), the α-helix content and interactions and the intrinsic tryptophan (Trp) fluorescence of mTSPO are gradually increased. Small-angle X-ray scattering (SAXS) shows a more extended mTSPO/belt complex with the addition of lipids: Dmax ∼95 Å in DPC alone versus ∼142 Å in DMPC:DPC (1:2). SEC-MALLS shows that the molecular composition of the mTSPO belt is ∼98 molecules for DPC alone and ∼58 DMPC and ∼175 DPC for DMPC:DPC (1:2). Additionally, DMPC:DPC micelles stabilize mTSPO compared to DPC alone, where the protein has a greater propensity to aggregate. These structural changes are consistent with the increased affinity of mTSPO for the PK11195 ligand in presence of lipids (Kd ∼70 μM in DPC alone versus ∼0.91 μM in DMPC:DPC, 1:2), as measured by microscale thermophoresis (MST). In conclusion, mixed lipid:surfactant micelles open new possibilities for the stabilization of membrane proteins and for their study in solution in a more biomimetic amphiphilic environment.
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Affiliation(s)
- Christelle Saade
- Laboratoire Léon-Brillouin (LLB), UMR12 CEA-CNRS, Université Paris-Saclay, F-91191, Gif-sur-Yvette CEDEX, France
| | - Alexandre Pozza
- Université Paris Cité, CNRS UMR7099, Biochimie des Protéines Membranaires, F-75005, Paris, France
| | - Françoise Bonneté
- Université Paris Cité, CNRS UMR7099, Biochimie des Protéines Membranaires, F-75005, Paris, France
| | - Stéphanie Finet
- Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie (IMPMC), UMR 7590 CNRS-Sorbonne Université Université, MNHN, IRD, F-75005, Paris, France
| | - Viviane Lutz-Bueno
- Laboratoire Léon-Brillouin (LLB), UMR12 CEA-CNRS, Université Paris-Saclay, F-91191, Gif-sur-Yvette CEDEX, France; Paul Scherrer Institut (PSI), Forschungsstrasse 111, 5232, Villigen PSI, Switzerland
| | - Mark D Tully
- The European Synchrotron (ESRF), 71 Avenue des Martyrs, F-38043, Grenoble, France
| | - Paloma F Varela
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Université Paris-Saclay, F-91191, Gif-sur-Yvette CEDEX, France
| | - Jean-Jacques Lacapère
- Sorbonne Université, Ecole Normale Supérieure, PSL University, CNRS UMR 7203, Laboratoire des BioMolécules (LBM), 4 Place Jussieu, F-75005, Paris, France
| | - Sophie Combet
- Laboratoire Léon-Brillouin (LLB), UMR12 CEA-CNRS, Université Paris-Saclay, F-91191, Gif-sur-Yvette CEDEX, France.
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4
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Sülzen H, Volkov AN, Geens R, Zahedifard F, Stijlemans B, Zoltner M, Magez S, Sterckx YGJ, Zoll S. Beyond the VSG layer: Exploring the role of intrinsic disorder in the invariant surface glycoproteins of African trypanosomes. PLoS Pathog 2024; 20:e1012186. [PMID: 38648216 PMCID: PMC11065263 DOI: 10.1371/journal.ppat.1012186] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2023] [Revised: 05/02/2024] [Accepted: 04/10/2024] [Indexed: 04/25/2024] Open
Abstract
In the bloodstream of mammalian hosts, African trypanosomes face the challenge of protecting their invariant surface receptors from immune detection. This crucial role is fulfilled by a dense, glycosylated protein layer composed of variant surface glycoproteins (VSGs), which undergo antigenic variation and provide a physical barrier that shields the underlying invariant surface glycoproteins (ISGs). The protective shield's limited permeability comes at the cost of restricted access to the extracellular host environment, raising questions regarding the specific function of the ISG repertoire. In this study, we employ an integrative structural biology approach to show that intrinsically disordered membrane-proximal regions are a common feature of members of the ISG super-family, conferring the ability to switch between compact and elongated conformers. While the folded, membrane-distal ectodomain is buried within the VSG layer for compact conformers, their elongated counterparts would enable the extension beyond it. This dynamic behavior enables ISGs to maintain a low immunogenic footprint while still allowing them to engage with the host environment when necessary. Our findings add further evidence to a dynamic molecular organization of trypanosome surface antigens wherein intrinsic disorder underpins the characteristics of a highly flexible ISG proteome to circumvent the constraints imposed by the VSG coat.
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Affiliation(s)
- Hagen Sülzen
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Prague, Czech Republic
- Faculty of Science, Charles University, Prague, Czech Republic
| | - Alexander N. Volkov
- VIB-VUB Center for Structural Biology, Flemish Institute of Biotechnology (VIB), Brussels, Belgium
- Jean Jeener NMR Centre, Vrije Universiteit Brussel (VUB), Brussels, Belgium
| | - Rob Geens
- VIB-VUB Center for Structural Biology, Flemish Institute of Biotechnology (VIB), Brussels, Belgium
- Laboratory of Medical Biochemistry (LMB) and the Infla-Med Center of Excellence, Department of Pharmaceutical Sciences, Universiteit of Antwerp, Wilrijk, Belgium
| | - Farnaz Zahedifard
- Department of Parasitology, Faculty of Science, Charles University in Prague, Biocev, Vestec, Czech Republic
| | - Benoit Stijlemans
- Brussels Center for Immunology (BCIM), Department of Bioengineering Sciences, Vrije Universiteit Brussel, Brussels, Belgium
- Myeloid Cell Immunology Laboratory, VIB Center for Inflammation Research, Brussels, Belgium
| | - Martin Zoltner
- Department of Parasitology, Faculty of Science, Charles University in Prague, Biocev, Vestec, Czech Republic
| | - Stefan Magez
- Brussels Center for Immunology (BCIM), Department of Bioengineering Sciences, Vrije Universiteit Brussel, Brussels, Belgium
- Department of Biochemistry and Microbiology, Ghent University, Gent, Belgium
- Laboratory for Biomedical Research, Department of Molecular Biotechnology, Environment Technology and Food Technology, Ghent University Global Campus, Incheon, South Korea
| | - Yann G.-J. Sterckx
- Laboratory of Medical Biochemistry (LMB) and the Infla-Med Center of Excellence, Department of Pharmaceutical Sciences, Universiteit of Antwerp, Wilrijk, Belgium
| | - Sebastian Zoll
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Prague, Czech Republic
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5
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Dudas EF, Tully MD, Foldes T, Kelly G, Tartaglia GG, Pastore A. The structural properties of full-length annexin A11. Front Mol Biosci 2024; 11:1347741. [PMID: 38516187 PMCID: PMC10955470 DOI: 10.3389/fmolb.2024.1347741] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2023] [Accepted: 01/17/2024] [Indexed: 03/23/2024] Open
Abstract
Annexin A11 (ANXA11) is a calcium-dependent phospholipid-binding protein belonging to the annexin protein family and implicated in the neurodegenerative amyotrophic lateral sclerosis. Structurally, ANXA11 contains a conserved calcium-binding C-terminal domain common to all annexins and a putative intrinsically unfolded N-terminus specific for ANXA11. Little is known about the structure and functions of this region of the protein. By analogy with annexin A1, it was suggested that residues 38 to 59 within the ANXA11 N-terminus could form a helical region that would be involved in interactions. Interestingly, this region contains residues that, when mutated, may lead to clinical manifestations. In the present study, we have studied the structural features of the full-length protein with special attention to the N-terminal region using a combination of biophysical techniques which include nuclear magnetic resonance and small angle X-ray scattering. We show that the N-terminus is intrinsically disordered and that the overall features of the protein are not markedly affected by the presence of calcium. We also analyzed the 38-59 helix hypothesis using synthetic peptides spanning both the wild-type sequence and clinically relevant mutations. We show that the peptides have a remarkable character typical of a native helix and that mutations do not alter the behaviour suggesting that they are required for interactions rather than being structurally important. Our work paves the way to a more thorough understanding of the ANXA11 functions.
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Affiliation(s)
- Erika F. Dudas
- Dementia Research Institute at King’s College London, The Wohl Institute, London, United Kingdom
- European Synchrotron Radiation Facility, Grenoble, France
| | - Mark D. Tully
- European Synchrotron Radiation Facility, Grenoble, France
| | - Tamas Foldes
- University College London, Department of Physics and Astronomy, University College London, London, United Kingdom
- Institut de Biologie Structurale (IBS), Institut Laue-Langevin, University Grenoble Alpes, Grenoble, France
| | - Geoff Kelly
- MRC Biomedical NMR Centre, The Francis Crick Institute, London, United Kingdom
| | | | - Annalisa Pastore
- Dementia Research Institute at King’s College London, The Wohl Institute, London, United Kingdom
- European Synchrotron Radiation Facility, Grenoble, France
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6
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Ujfalusi-Pozsonyi K, Bódis E, Nyitrai M, Kengyel A, Telek E, Pécsi I, Fekete Z, Varnyuné Kis-Bicskei N, Mas C, Moussaoui D, Pernot P, Tully MD, Weik M, Schirò G, Kapetanaki SM, Lukács A. ATP-dependent conformational dynamics in a photoactivated adenylate cyclase revealed by fluorescence spectroscopy and small-angle X-ray scattering. Commun Biol 2024; 7:147. [PMID: 38307988 PMCID: PMC10837130 DOI: 10.1038/s42003-024-05842-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2023] [Accepted: 01/22/2024] [Indexed: 02/04/2024] Open
Abstract
Structural insights into the photoactivated adenylate cyclases can be used to develop new ways of controlling cellular cyclic adenosine monophosphate (cAMP) levels for optogenetic and other applications. In this work, we use an integrative approach that combines biophysical and structural biology methods to provide insight on the interaction of adenosine triphosphate (ATP) with the dark-adapted state of the photoactivated adenylate cyclase from the cyanobacterium Oscillatoria acuminata (OaPAC). A moderate affinity of the nucleotide for the enzyme was calculated and the thermodynamic parameters of the interaction have been obtained. Stopped-flow fluorescence spectroscopy and small-angle solution scattering have revealed significant conformational changes in the enzyme, presumably in the adenylate cyclase (AC) domain during the allosteric mechanism of ATP binding to OaPAC with small and large-scale movements observed to the best of our knowledge for the first time in the enzyme in solution upon ATP binding. These results are in line with previously reported drastic conformational changes taking place in several class III AC domains upon nucleotide binding.
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Affiliation(s)
- K Ujfalusi-Pozsonyi
- Department of Biophysics, Medical School, University of Pécs, 7624, Pécs, Hungary
| | - E Bódis
- Department of Biophysics, Medical School, University of Pécs, 7624, Pécs, Hungary
| | - M Nyitrai
- Department of Biophysics, Medical School, University of Pécs, 7624, Pécs, Hungary
| | - A Kengyel
- Department of Biophysics, Medical School, University of Pécs, 7624, Pécs, Hungary
| | - E Telek
- Department of Biophysics, Medical School, University of Pécs, 7624, Pécs, Hungary
| | - I Pécsi
- Department of Biophysics, Medical School, University of Pécs, 7624, Pécs, Hungary
| | - Z Fekete
- Department of Biophysics, Medical School, University of Pécs, 7624, Pécs, Hungary
| | | | - C Mas
- Univ. Grenoble Alpes, CNRS, CEA, EMBL, ISBG, F-38000, Grenoble, France
| | - D Moussaoui
- European Synchrotron Radiation Facility (ESRF), Grenoble, France
| | - P Pernot
- European Synchrotron Radiation Facility (ESRF), Grenoble, France
| | - M D Tully
- European Synchrotron Radiation Facility (ESRF), Grenoble, France
| | - M Weik
- Institut de Biologie Structurale (IBS), Université Grenoble Alpes, CEA, CNRS, Grenoble, France
| | - G Schirò
- Institut de Biologie Structurale (IBS), Université Grenoble Alpes, CEA, CNRS, Grenoble, France
| | - S M Kapetanaki
- Institut de Biologie Structurale (IBS), Université Grenoble Alpes, CEA, CNRS, Grenoble, France.
- Department of Biophysics, Medical School, University of Pécs, 7624, Pécs, Hungary.
| | - A Lukács
- Department of Biophysics, Medical School, University of Pécs, 7624, Pécs, Hungary.
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7
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Carpentier P, van der Linden P, Mueller-Dieckmann C. The High-Pressure Freezing Laboratory for Macromolecular Crystallography (HPMX), an ancillary tool for the macromolecular crystallography beamlines at the ESRF. Acta Crystallogr D Struct Biol 2024; 80:80-92. [PMID: 38265873 PMCID: PMC10836400 DOI: 10.1107/s2059798323010707] [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: 07/25/2023] [Accepted: 12/13/2023] [Indexed: 01/26/2024] Open
Abstract
This article describes the High-Pressure Freezing Laboratory for Macromolecular Crystallography (HPMX) at the ESRF, and highlights new and complementary research opportunities that can be explored using this facility. The laboratory is dedicated to investigating interactions between macromolecules and gases in crystallo, and finds applications in many fields of research, including fundamental biology, biochemistry, and environmental and medical science. At present, the HPMX laboratory offers the use of different high-pressure cells adapted for helium, argon, krypton, xenon, nitrogen, oxygen, carbon dioxide and methane. Important scientific applications of high pressure to macromolecules at the HPMX include noble-gas derivatization of crystals to detect and map the internal architecture of proteins (pockets, tunnels and channels) that allows the storage and diffusion of ligands or substrates/products, the investigation of the catalytic mechanisms of gas-employing enzymes (using oxygen, carbon dioxide or methane as substrates) to possibly decipher intermediates, and studies of the conformational fluctuations or structure modifications that are necessary for proteins to function. Additionally, cryo-cooling protein crystals under high pressure (helium or argon at 2000 bar) enables the addition of cryo-protectant to be avoided and noble gases can be employed to produce derivatives for structure resolution. The high-pressure systems are designed to process crystals along a well defined pathway in the phase diagram (pressure-temperature) of the gas to cryo-cool the samples according to the three-step `soak-and-freeze method'. Firstly, crystals are soaked in a pressurized pure gas atmosphere (at 294 K) to introduce the gas and facilitate its interactions within the macromolecules. Samples are then flash-cooled (at 100 K) while still under pressure to cryo-trap macromolecule-gas complexation states or pressure-induced protein modifications. Finally, the samples are recovered after depressurization at cryo-temperatures. The final section of this publication presents a selection of different typical high-pressure experiments carried out at the HPMX, showing that this technique has already answered a wide range of scientific questions. It is shown that the use of different gases and pressure conditions can be used to probe various effects, such as mapping the functional internal architectures of enzymes (tunnels in the haloalkane dehalogenase DhaA) and allosteric sites on membrane-protein surfaces, the interaction of non-inert gases with proteins (oxygen in the hydrogenase ReMBH) and pressure-induced structural changes of proteins (tetramer dissociation in urate oxidase). The technique is versatile and the provision of pressure cells and their application at the HPMX is gradually being extended to address new scientific questions.
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Affiliation(s)
- Philippe Carpentier
- Université Grenoble Alpes CEA CNRS, IRIG–LCBM UMR 5249, 17 Avenue des Martyrs, 38000 Grenoble, France
- ESRF, The European Synchrotron, 71 Avenue des Martyrs, 38000 Grenoble, France
| | - Peter van der Linden
- ESRF, PSCM (Partnership for Soft Condensed Matter), 71 Avenue des Martyrs, 38000 Grenoble, France
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8
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Hopkins JB. BioXTAS RAW 2: new developments for a free open-source program for small-angle scattering data reduction and analysis. J Appl Crystallogr 2024; 57:194-208. [PMID: 38322719 PMCID: PMC10840314 DOI: 10.1107/s1600576723011019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2023] [Accepted: 12/21/2023] [Indexed: 02/08/2024] Open
Abstract
BioXTAS RAW is a free open-source program for reduction, analysis and modelling of biological small-angle scattering data. Here, the new developments in RAW version 2 are described. These include improved data reduction using pyFAI; updated automated Guinier fitting and D max finding algorithms; automated series (e.g. size-exclusion chromatography coupled small-angle X-ray scattering or SEC-SAXS) buffer- and sample-region finding algorithms; linear and integral baseline correction for series; deconvolution of series data using regularized alternating least squares (REGALS); creation of electron-density reconstructions using electron density via solution scattering (DENSS); a comparison window showing residuals, ratios and statistical comparisons between profiles; and generation of PDF reports with summary plots and tables for all analysis. Furthermore, there is now a RAW API, which can be used without the graphical user interface (GUI), providing full access to all of the functionality found in the GUI. In addition to these new capabilities, RAW has undergone significant technical updates, such as adding Python 3 compatibility, and has entirely new documentation available both online and in the program.
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Affiliation(s)
- Jesse B. Hopkins
- The Biophysics Collaborative Access Team (BioCAT), Department of Physics, Illinois Institute of Technology, Chicago, IL 60616, USA
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9
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Castelletto V, de Mello L, da Silva ER, Seitsonen J, Hamley IW. Self-Assembly and Cytocompatibility of Amino Acid Conjugates Containing a Novel Water-Soluble Aromatic Protecting Group. Biomacromolecules 2023; 24:5403-5413. [PMID: 37914531 PMCID: PMC10646988 DOI: 10.1021/acs.biomac.3c00860] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2023] [Revised: 10/11/2023] [Accepted: 10/11/2023] [Indexed: 11/03/2023]
Abstract
There has been considerable interest in peptides in which the Fmoc (9-fluorenylmethoxycarbonyl) protecting group is retained at the N-terminus, since this bulky aromatic group can drive self-assembly, and Fmoc-peptides are biocompatible and have applications in cell culture biomaterials. Recently, analogues of new amino acids with 2,7-disulfo-9-fluorenylmethoxycarbonyl (Smoc) protecting groups have been developed for water-based peptide synthesis. Here, we report on the self-assembly and biocompatibility of Smoc-Ala, Smoc-Phe and Smoc-Arg as examples of Smoc conjugates to aliphatic, aromatic, and charged amino acids, respectively. Self-assembly occurs at concentrations above the critical aggregation concentration (CAC). Cryo-TEM imaging and SAXS reveal the presence of nanosheet, nanoribbon or nanotube structures, and spectroscopic methods (ThT fluorescence circular dichroism and FTIR) show the presence of β-sheet secondary structure, although Smoc-Ala solutions contain significant unaggregated monomer content. Smoc shows self-fluorescence, which was used to determine CAC values of the Smoc-amino acids from fluorescence assays. Smoc fluorescence was also exploited in confocal microscopy imaging with fibroblast cells, which revealed its uptake into the cytoplasm. The biocompatibility of these Smoc-amino acids was found to be excellent with zero cytotoxicity (in fact increased metabolism) to fibroblasts at low concentration.
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Affiliation(s)
- Valeria Castelletto
- School
of Chemistry, Food Biosciences and Pharmacy, University of Reading, Whiteknights, Reading RG6 6AD, United Kingdom
| | - Lucas de Mello
- School
of Chemistry, Food Biosciences and Pharmacy, University of Reading, Whiteknights, Reading RG6 6AD, United Kingdom
- Departamento
de Biofísica, Universidade Federal
de São Paulo, São
Paulo 04023-062, Brazil
| | | | - Jani Seitsonen
- Nanomicroscopy
Center, Aalto University, Puumiehenkuja 2, FIN-02150 Espoo, Finland
| | - Ian W Hamley
- School
of Chemistry, Food Biosciences and Pharmacy, University of Reading, Whiteknights, Reading RG6 6AD, United Kingdom
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10
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Castelletto V, Kowalczyk RM, Seitsonen J, Hamley IW. Tuning the Solution Self-Assembly of a Peptide-PEG (Polyethylene Glycol) Conjugate with α-Cyclodextrin. Chembiochem 2023; 24:e202300472. [PMID: 37529857 DOI: 10.1002/cbic.202300472] [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: 06/23/2023] [Revised: 07/28/2023] [Accepted: 08/01/2023] [Indexed: 08/03/2023]
Abstract
Cyclodextrins are saccharide ring molecules which act as host cavities that can encapsulate small guest molecules or thread polymer chains. We investigate the influence of alpha-cyclodextrin (αCD) on the aqueous solution self-assembly of a peptide-polymer conjugate YYKLVFF-PEG3K previously studied by our group [Castelletto et al., Polym. Chem., 2010, 1, 453-459]. This conjugate comprises a designed amyloid-forming peptide YYKLVFF that contains the KLVFF sequence from Amyloid β peptide, Aβ16-20, along with two aromatic tyrosine residues to enhance hydrophobicity, as well as polyethylene glycol PEG with molar mass 3 kg mol-1 . The conjugate self-assembles into β-sheet fibrils in aqueous solution. Here we show that complexation with αCD instead generates free-floating nanosheets in aqueous solution (with a β-sheet structure). The nanosheets comprise a bilayer with a hydrophobic peptide core and highly swollen PEG outer layers. The transition from fibrils to nanosheets is driven by an increase in the number of αCD molecules threaded on the PEG chains, as determined by 1 H NMR spectroscopy. These findings point to the use of cyclodextrin additives as a powerful means to tune the solution self-assembly in peptide-polymer conjugates and potentially other polymer/biomolecular hybrids.
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Affiliation(s)
- Valeria Castelletto
- School of Chemistry, Food Biosciences and Pharmacy, University of Reading, Whiteknights, Reading, RG6 6AD, UK
| | - Radoslaw M Kowalczyk
- School of Chemistry, Food Biosciences and Pharmacy, University of Reading, Whiteknights, Reading, RG6 6AD, UK
| | - Jani Seitsonen
- Nanomicroscopy Center, Aalto University, Puumiehenkuja 2, 02150, Espoo, Finland
| | - Ian W Hamley
- School of Chemistry, Food Biosciences and Pharmacy, University of Reading, Whiteknights, Reading, RG6 6AD, UK
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Tants JN, Schlundt A. Advances, Applications, and Perspectives in Small-Angle X-ray Scattering of RNA. Chembiochem 2023; 24:e202300110. [PMID: 37466350 DOI: 10.1002/cbic.202300110] [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: 02/10/2023] [Revised: 04/22/2023] [Indexed: 07/20/2023]
Abstract
RNAs exhibit a plethora of functions far beyond transmitting genetic information. Often, RNA functions are entailed in their structure, be it as a regulatory switch, protein binding site, or providing catalytic activity. Structural information is a prerequisite for a full understanding of RNA-regulatory mechanisms. Owing to the inherent dynamics, size, and instability of RNA, its structure determination remains challenging. Methods such as NMR spectroscopy, X-ray crystallography, and cryo-electron microscopy can provide high-resolution structures; however, their limitations make structure determination, even for small RNAs, cumbersome, if at all possible. Although at a low resolution, small-angle X-ray scattering (SAXS) has proven valuable in advancing structure determination of RNAs as a complementary method, which is also applicable to large-sized RNAs. Here, we review the technological and methodological advancements of RNA SAXS. We provide examples of the powerful inclusion of SAXS in structural biology and discuss possible future applications to large RNAs.
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Affiliation(s)
- Jan-Niklas Tants
- Goethe University Frankfurt, Institute for Molecular Biosciences and Biomagnetic Resonance Centre (BMRZ), Max-von-Laue-Str. 9, 60438, Frankfurt, Germany
| | - Andreas Schlundt
- Goethe University Frankfurt, Institute for Molecular Biosciences and Biomagnetic Resonance Centre (BMRZ), Max-von-Laue-Str. 9, 60438, Frankfurt, Germany
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12
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Laroussi H, Juarez‐Martinez AB, Le Roy A, Boeri Erba E, Gabel F, de Massy B, Kadlec J. Characterization of the REC114-MEI4-IHO1 complex regulating meiotic DNA double-strand break formation. EMBO J 2023; 42:e113866. [PMID: 37431931 PMCID: PMC10425845 DOI: 10.15252/embj.2023113866] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2023] [Revised: 06/16/2023] [Accepted: 06/23/2023] [Indexed: 07/12/2023] Open
Abstract
Meiotic recombination is initiated by the formation of DNA double-strand breaks (DSBs), essential for fertility and genetic diversity. In the mouse, DSBs are formed by the catalytic TOPOVIL complex consisting of SPO11 and TOPOVIBL. To preserve genome integrity, the activity of the TOPOVIL complex is finely controlled by several meiotic factors including REC114, MEI4, and IHO1, but the underlying mechanism is poorly understood. Here, we report that mouse REC114 forms homodimers, that it associates with MEI4 as a 2:1 heterotrimer that further dimerizes, and that IHO1 forms coiled-coil-based tetramers. Using AlphaFold2 modeling combined with biochemical characterization, we uncovered the molecular details of these assemblies. Finally, we show that IHO1 directly interacts with the PH domain of REC114 by recognizing the same surface as TOPOVIBL and another meiotic factor ANKRD31. These results provide strong evidence for the existence of a ternary IHO1-REC114-MEI4 complex and suggest that REC114 could act as a potential regulatory platform mediating mutually exclusive interactions with several partners.
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Affiliation(s)
| | | | - Aline Le Roy
- Université Grenoble Alpes, CNRS, CEA, IBSGrenobleFrance
| | | | - Frank Gabel
- Université Grenoble Alpes, CNRS, CEA, IBSGrenobleFrance
| | - Bernard de Massy
- Institut de Génétique Humaine (IGH), Centre National de la Recherche ScientifiqueUniversity of MontpellierMontpellierFrance
| | - Jan Kadlec
- Université Grenoble Alpes, CNRS, CEA, IBSGrenobleFrance
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Hutin S, Kumita JR, Strotmann VI, Dolata A, Ling WL, Louafi N, Popov A, Milhiet PE, Blackledge M, Nanao MH, Wigge PA, Stahl Y, Costa L, Tully MD, Zubieta C. Phase separation and molecular ordering of the prion-like domain of the Arabidopsis thermosensory protein EARLY FLOWERING 3. Proc Natl Acad Sci U S A 2023; 120:e2304714120. [PMID: 37399408 PMCID: PMC10334799 DOI: 10.1073/pnas.2304714120] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2023] [Accepted: 06/06/2023] [Indexed: 07/05/2023] Open
Abstract
Liquid-liquid phase separation (LLPS) is an important mechanism enabling the dynamic compartmentalization of macromolecules, including complex polymers such as proteins and nucleic acids, and occurs as a function of the physicochemical environment. In the model plant, Arabidopsis thaliana, LLPS by the protein EARLY FLOWERING3 (ELF3) occurs in a temperature-sensitive manner and controls thermoresponsive growth. ELF3 contains a largely unstructured prion-like domain (PrLD) that acts as a driver of LLPS in vivo and in vitro. The PrLD contains a poly-glutamine (polyQ) tract, whose length varies across natural Arabidopsis accessions. Here, we use a combination of biochemical, biophysical, and structural techniques to investigate the dilute and condensed phases of the ELF3 PrLD with varying polyQ lengths. We demonstrate that the dilute phase of the ELF3 PrLD forms a monodisperse higher-order oligomer that does not depend on the presence of the polyQ sequence. This species undergoes LLPS in a pH- and temperature-sensitive manner and the polyQ region of the protein tunes the initial stages of phase separation. The liquid phase rapidly undergoes aging and forms a hydrogel as shown by fluorescence and atomic force microscopies. Furthermore, we demonstrate that the hydrogel assumes a semiordered structure as determined by small-angle X-ray scattering, electron microscopy, and X-ray diffraction. These experiments demonstrate a rich structural landscape for a PrLD protein and provide a framework to describe the structural and biophysical properties of biomolecular condensates.
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Affiliation(s)
- Stephanie Hutin
- Laboratoire de Physiologie Cellulaire et Végétale, University Grenoble Alpes, Centre national de la recherche scientifique, Commissariat à l'énergie atomique et aux énergies alternatives, Institut national de recherche pour l’agriculture, l’alimentation et l’environnement, Institut de recherche interdisciplinaire de Grenoble, Grenoble38054, France
| | - Janet R. Kumita
- Department of Pharmacology, University of Cambridge, CambridgeCB2 1PD, United Kingdom
| | - Vivien I. Strotmann
- Institute for Developmental Genetics, Heinrich-Heine University, DüsseldorfD-40225, Germany
| | - Anika Dolata
- Institute for Developmental Genetics, Heinrich-Heine University, DüsseldorfD-40225, Germany
| | - Wai Li Ling
- University Grenoble Alpes, Commissariat à l'énergie atomique et aux énergies alternatives, Centre national de la recherche scientifique, Institut de Biologie Structurale, Institut de recherche interdisciplinaire de Grenoble, Grenoble38000, France
| | - Nessim Louafi
- Centre de Biologie Structurale, University Montpellier, Centre national de la recherche scientifique, Institut national de la santé et de la recherche médicale, Montpellier34090, France
| | - Anton Popov
- European Synchrotron Radiation Facility, Structural Biology Group, Grenoble38000, France
| | - Pierre-Emmanuel Milhiet
- Centre de Biologie Structurale, University Montpellier, Centre national de la recherche scientifique, Institut national de la santé et de la recherche médicale, Montpellier34090, France
| | - Martin Blackledge
- University Grenoble Alpes, Commissariat à l'énergie atomique et aux énergies alternatives, Centre national de la recherche scientifique, Institut de Biologie Structurale, Institut de recherche interdisciplinaire de Grenoble, Grenoble38000, France
| | - Max H. Nanao
- European Synchrotron Radiation Facility, Structural Biology Group, Grenoble38000, France
| | - Philip A. Wigge
- Leibniz-Institut für Gemüse- und Zierpflanzenbau, 14979Grossbeeren, Germany
- Institute of Biochemistry and Biology, University of Potsdam, 14476Potsdam, Germany
| | - Yvonne Stahl
- Institute for Developmental Genetics, Heinrich-Heine University, DüsseldorfD-40225, Germany
- Cluster of Excellence on Plant Sciences, Heinrich-Heine University, DüsseldorfD-40225, Germany
| | - Luca Costa
- Centre de Biologie Structurale, University Montpellier, Centre national de la recherche scientifique, Institut national de la santé et de la recherche médicale, Montpellier34090, France
| | - Mark D. Tully
- European Synchrotron Radiation Facility, Structural Biology Group, Grenoble38000, France
| | - Chloe Zubieta
- Laboratoire de Physiologie Cellulaire et Végétale, University Grenoble Alpes, Centre national de la recherche scientifique, Commissariat à l'énergie atomique et aux énergies alternatives, Institut national de recherche pour l’agriculture, l’alimentation et l’environnement, Institut de recherche interdisciplinaire de Grenoble, Grenoble38054, France
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