المؤلفون: Roske, Yvette, Lindemann, Florian, Diehl, Anne, Cremer, Nils, Higman, Victoria A., Schlegel, Brigitte, Leidert, Martina, Driller, Kristina, Turgay, Kürşad, Schmieder, Peter, Heinemann, Udo, Oschkinat, Hartmut

المصدر: Proceedings of the National Academy of Sciences of the United States of America (PNAS) 120 (2023), Nr. 17 ; Proceedings of the National Academy of Sciences of the United States of America (PNAS)

مصطلحات موضوعية: Bacillus subtilis, Bacterial Proteins, Biofilms, Magnetic Resonance Spectroscopy, Molecular Chaperones, ddc:000, ddc:500

الوصف: Studying mechanisms of bacterial biofilm generation is of vital importance to understanding bacterial cell–cell communication, multicellular cohabitation principles, and the higher resilience of microorganisms in a biofilm against antibiotics. Biofilms of the nonpathogenic, gram-positive soil bacterium Bacillus subtilis serve as a model system with biotechnological potential toward plant protection. Its major extracellular matrix protein components are TasA and TapA. The nature of TasA filaments has been of debate, and several forms, amyloidic and non-Thioflavin T-stainable have been observed. Here, we present the three-dimensional structure of TapA and uncover the mechanism of TapA-supported growth of nonamyloidic TasA filaments. By analytical ultracentrifugation and NMR, we demonstrate TapA-dependent acceleration of filament formation from solutions of folded TasA. Solid-state NMR revealed intercalation of the N-terminal TasA peptide segment into subsequent protomers to form a filament composed of β-sandwich subunits. The secondary structure around the intercalated N-terminal strand β0 is conserved between filamentous TasA and the Fim and Pap proteins, which form bacterial type I pili, demonstrating such construction principles in a gram-positive organism. Analogous to the chaperones of the chaperone-usher pathway, the role of TapA is in donating its N terminus to serve for TasA folding into an Ig domain-similar filament structure by donor-strand complementation. According to NMR and since the V-set Ig fold of TapA is already complete, its participation within a filament beyond initiation is unlikely. Intriguingly, the most conserved residues in TasA-like proteins (camelysines) of Bacillaceae are located within the protomer interface.

العلاقة: ESSN:1091-6490; http://dx.doi.org/10.15488/14851Test; https://www.repo.uni-hannover.de/handle/123456789/14970Test

الإتاحة: https://doi.org/10.15488/14851Test
https://doi.org/10.1073/pnas.2217070120Test
https://www.repo.uni-hannover.de/handle/123456789/14970Test

المؤلفون: Berzins, Andris, Grube, Hugo, Lazda, Reinis, Hannig, Marc A., Smits, Janis, Fescenko, Ilja

المصدر: Ultramicroscopy 242 (2022) ; Ultramicroscopy

مصطلحات موضوعية: Magnetic field imaging microscopy, Nitrogen–Vacancy centers, Optically detected magnetic resonance, Tunable magnetic field source, ddc:570

الوصف: In this work, we present a novel, compact, power efficient and variable magnetic field source design for magnetic field imaging microscopy. The device is based on a pair of diametrically magnetized permanent magnet cylinders with electro-mechanical rotation control and ferrite flux homogenizers. A Hall probe and NV centers in diamond are used to demonstrate a proof of concept of a proposed magnetic field setup and to characterize the homogeneity of the produced magnetic field on a micrometer scale. Numerical simulation results are compared with experimental results showing good agreement of the distribution of the magnetic field in the setup. As a result, a magnetic field source with a tunable field amplitude in the range from 1 mT to 222 mT is demonstrated, achieving a magnetic field homogeneity of 2 ppm/μm or 0.5 μT/μm at 222 mT in a 25 × 25 μm field of view.

العلاقة: ESSN:1879-2723; http://dx.doi.org/10.15488/13983Test; https://www.repo.uni-hannover.de/handle/123456789/14097Test

الإتاحة: https://doi.org/10.15488/13983Test
https://doi.org/10.1016/j.ultramic.2022.113624Test
https://www.repo.uni-hannover.de/handle/123456789/14097Test

المؤلفون: Bigall, Nadja C., Rodio, Marina, Avugadda, Sahitya, Leal, Manuel Pernia, Di Corato, Riccardo, Conteh, John S., Intartaglia, Romuald, Pellegrino, Teresa

المصدر: Journal of Physical Chemistry A: Molecules, Clusters, and Aerosols 126 (2022), Nr. 51 ; Journal of Physical Chemistry A: Molecules, Clusters, and Aerosols

مصطلحات موضوعية: Ferric Compounds, Magnetic Resonance Imaging, Nanoparticles, Polymers, Crosslinking, ddc:530

الوصف: The growing interest in multifunctional nano-objects based on polymers and magnetic nanoparticles for biomedical applications motivated us to develop a scale-up protocol to increase the yield of polymeric magnetic nanobeads while aiming at keeping the structural features at optimal conditions. The protocol was applied to two different types of magnetic ferrite nanoparticles: the Mn-ferrite selected for their properties as contrast agents in magnetic resonance imaging and iron oxide nanostar shaped nanoparticles chosen for their heat performance in magnetic hyperthermia. At the same time, some experiments on surface functionalization of nanobeads with amino modified polyethyelene glycol (PEG) molecules have provided further insight into the formation mechanism of magnetic nanobeads and the need to cross-link the polymer shell to improve the stability of the beads, making them more suitable for further manipulation and use. The present work summarizes the most important parameters required to be controlled for the upscaling of nanobead synthesis in a bench protocol and proposes an alternative cross-linking strategy based on prefunctionalization of the polymer prior to the nanobead formation as a key parameter to improve the nanobead structural stability in solutions at different pHs and during surface functionalization.

العلاقة: ESSN:1520-5215; http://dx.doi.org/10.15488/13918Test; https://www.repo.uni-hannover.de/handle/123456789/14032Test

الإتاحة: https://doi.org/10.15488/13918Test
https://doi.org/10.1021/acs.jpca.2c05902Test
https://www.repo.uni-hannover.de/handle/123456789/14032Test

المؤلفون: Aguion, Philipp Innig, Kirkpatrick, John, Carlomagno, Teresa, Marchanka, Alexander

المصدر: Angewandte Chemie - International Edition 60 (2021), Nr. 44 ; Angewandte Chemie - International Edition

مصطلحات موضوعية: 1H detection, base-pair pattern, RNA structure, RNA-protein complex, solid-state NMR spectroscopy, Light polarization, Nuclear magnetic resonance spectroscopy, Proteins, Base pairs, Cellular process, High molecular weight, Nucleobases, RNA structures, RNA-protein complexes, Solid state NMR, RNA, base pairing, nuclear magnetic resonance, proton nuclear magnetic resonance, Biomolecular, Proton Magnetic Resonance Spectroscopy, ddc:540

الوصف: Knowledge of RNA structure, either in isolation or in complex, is fundamental to understand the mechanism of cellular processes. Solid-state NMR (ssNMR) is applicable to high molecular-weight complexes and does not require crystallization; thus, it is well-suited to study RNA as part of large multicomponent assemblies. Recently, we solved the first structures of both RNA and an RNA-protein complex by ssNMR using conventional 13C- and 15N-detection. This approach is limited by the severe overlap of the RNA peaks together with the low sensitivity of multidimensional experiments. Here, we overcome the limitations in sensitivity and resolution by using 1H-detection at fast MAS rates. We develop experiments that allow the identification of complete nucleobase spin-systems together with their site-specific base pair pattern using sub-milligram quantities of one uniformly labelled RNA sample. These experiments provide rapid access to RNA secondary structure by ssNMR in protein-RNA complexes of any size. © 2021 The Authors. Angewandte Chemie International Edition published by Wiley-VCH GmbH

العلاقة: ESSN:1521-3773; http://dx.doi.org/10.15488/12454Test; https://www.repo.uni-hannover.de/handle/123456789/12553Test

الإتاحة: https://doi.org/10.15488/12454Test
https://doi.org/10.1002/anie.202107263Test
https://www.repo.uni-hannover.de/handle/123456789/12553Test

المؤلفون: Huang, Yu-Chieh, Rao, Ashit, Huang, Shing-Jong, Chang, Chun-Yu, Drechsler, Markus, Knaus, Jennifer, Chan, Jerry Chun Chung, Raiteri, Paolo, Gale, Julian D., Gebaue, Denis

المصدر: Angewandte Chemie - International Edition 60 (2021), Nr. 30 ; Angewandte Chemie - International Edition

مصطلحات موضوعية: amorphous materials, bicarbonate, calcium carbonate, mineral nucleation, NMR spectroscopy, Calcite, Carbonate minerals, Crystallization, Geology, Mineralogy, Molecular dynamics, Nuclear magnetic resonance spectroscopy, Nucleation, Quantum theory, Amorphous minerals, Calcium carbonate formation, Geological environment, Mechanistic pathways, Molecular dynamics simulations, Quantum-mechanical calculation, Solid state nuclear magnetic resonance spectroscopy, Structural component, Ions, ddc:540

الوصف: Mechanistic pathways relevant to mineralization are not well-understood fundamentally, let alone in the context of their biological and geological environments. Through quantitative analysis of ion association at near-neutral pH, we identify the involvement of HCO3− ions in CaCO3 nucleation. Incorporation of HCO3− ions into the structure of amorphous intermediates is corroborated by solid-state nuclear magnetic resonance spectroscopy, complemented by quantum mechanical calculations and molecular dynamics simulations. We identify the roles of HCO3− ions as being through (i) competition for ion association during the formation of ion pairs and ion clusters prior to nucleation and (ii) incorporation as a significant structural component of amorphous mineral particles. The roles of HCO3− ions as active soluble species and structural constituents in CaCO3 formation are of fundamental importance and provide a basis for a better understanding of physiological and geological mineralization. © 2021 The Authors. Angewandte Chemie International Edition published by Wiley-VCH GmbH

العلاقة: ESSN:1521-3773; http://dx.doi.org/10.15488/12394Test; https://www.repo.uni-hannover.de/handle/123456789/12493Test

الإتاحة: https://doi.org/10.15488/12394Test
https://doi.org/10.1002/anie.202104002Test
https://www.repo.uni-hannover.de/handle/123456789/12493Test

المؤلفون: Rolletschek, Hardy, Schwender, Jörg, König, Christina, Chapman, Kent D., Romsdahl, Trevor, Lorenz, Christin, Braun, Hans-Peter, Denolf, Peter, van Audenhove, Katrien, Munz, Eberhard, Heinzel, Nicolas, Ortleb, Stefan, Rutten, Twan, McCorkle, Sean, Borysyuk, Taras, Guendel, André, Shi, Hai, Auwermeulen, Michiel Vander, Bourot, Stephane, Borisjuk, Ljudmilla

المصدر: Plant Cell 32 (2020), Nr. 7 ; Plant Cell

مصطلحات موضوعية: amino acid, carbon, cruciferin protein, Brassica napus, membrane lipid, napin, napin protein, nitrogen, oleosin protein, plant antigen, plant protein, seed storage protein, cytology, gene expression regulation, genetics, metabolism, nuclear magnetic resonance spectroscopy, plant cell, plant seed, rapeseed, RNA interference, transgenic plant, 2S Albumins, Plant, Amino Acids, Antigens, Magnetic Resonance Spectroscopy, Membrane Lipids, Plant Cells, Plant Proteins

الوصف: The tradeoff between protein and oil storage in oilseed crops has been tested here in oilseed rape (Brassica napus) by analyzing the effect of suppressing key genes encoding protein storage products (napin and cruciferin). The phenotypic outcomes were assessed using NMR and mass spectrometry imaging, microscopy, transcriptomics, proteomics, metabolomics, lipidomics, immunological assays, and flux balance analysis. Surprisingly, the profile of storage products was only moderately changed in RNA interference transgenics. However, embryonic cells had undergone remarkable architectural rearrangements. The suppression of storage proteins led to the elaboration of membrane stacks enriched with oleosin (sixfold higher protein abundance) and novel endoplasmic reticulum morphology. Protein rebalancing and amino acid metabolism were focal points of the metabolic adjustments to maintain embryonic carbon/nitrogen homeostasis. Flux balance analysis indicated a rather minor additional demand for cofactors (ATP and NADPH). Thus, cellular plasticity in seeds protects against perturbations to its storage capabilities and, hence, contributes materially to homeostasis. This study provides mechanistic insights into the intriguing link between lipid and protein storage, which have implications for biotechnological strategies directed at improving oilseed crops.

العلاقة: ESSN:1532-298X; http://dx.doi.org/10.15488/11677Test; https://www.repo.uni-hannover.de/handle/123456789/11770Test

الإتاحة: https://doi.org/10.15488/11677Test
https://doi.org/10.1105/tpc.19.00879Test
https://www.repo.uni-hannover.de/handle/123456789/11770Test

المؤلفون: Lu, Hao, Huang, Yu-Chieh, Hunger, Johannes, Gebauer, Denis, Cölfen, Helmut, Bonn, Mischa

المصدر: Journal of the American Chemical Society : JACS 143 (2021), Nr. 4 ; Journal of the American Chemical Society : JACS

مصطلحات موضوعية: Animals, Calcium Carbonate, Circular Dichroism, Magnetic Resonance Spectroscopy, Minerals, ddc:540

الوصف: Biomineralization occurs in aqueous environments. Despite the ubiquity and relevance of CaCO3 biomineralization, the role of water in the biomineralization process has remained elusive. Here, we demonstrate that water reorganization accompanies CaCO3 biomineralization for sea urchin spine generation in a model system. Using surface-specific vibrational spectroscopy, we probe the water at the interface of the spine-associated protein during CaCO3 mineralization. Our results show that, while the protein structure remains unchanged, the structure of interfacial water is perturbed differently in the presence of both Ca2+ and CO32- compared to the addition of only Ca2+. This difference is attributed to the condensation of prenucleation mineral species. Our findings are consistent with a nonclassical mineralization pathway for sea urchin spine generation and highlight the importance of protein hydration in biomineralization.

العلاقة: ESSN:1520-5126; http://dx.doi.org/10.15488/14282Test; https://www.repo.uni-hannover.de/handle/123456789/14396Test

الإتاحة: https://doi.org/10.15488/14282Test
https://doi.org/10.1021/jacs.0c11976Test
https://www.repo.uni-hannover.de/handle/123456789/14396Test

المؤلفون: Wang, Ying, Kirkpatrick, John, Lage, Susanne zur, Korn, Sophie M., Neißner, Konstantin, Schwalbe, Harald, Schlundt, Andreas, Carlomagno, Teresa

المصدر: Biomolecular NMR Assignments 15 (2021), Nr. 2 ; Biomolecular NMR Assignments

مصطلحات موضوعية: 5′ untranslated region, New drug targets, NMR spectroscopy, Non-structural proteins, Nsp1, viral protein, chemistry, molecular model, nuclear magnetic resonance, protein domain, Models, Molecular, Biomolecular, Protein Domains, SARS-CoV-2, Viral Nonstructural Proteins, ddc:570

الوصف: The current COVID-19 pandemic caused by the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) has become a worldwide health crisis, necessitating coordinated scientific research and urgent identification of new drug targets for treatment of COVID-19 lung disease. The covid19-nmr consortium seeks to support drug development by providing publicly accessible NMR data on the viral RNA elements and proteins. The SARS-CoV-2 genome comprises a single RNA of about 30 kb in length, in which 14 open reading frames (ORFs) have been annotated, and encodes approximately 30 proteins. The first two-thirds of the SARS-CoV-2 genome is made up of two large overlapping open-reading-frames (ORF1a and ORF1b) encoding a replicase polyprotein, which is subsequently cleaved to yield 16 so-called non-structural proteins. The non-structural protein 1 (Nsp1), which is considered to be a major virulence factor, suppresses host immune functions by associating with host ribosomal complexes at the very end of its C-terminus. Furthermore, Nsp1 facilitates initiation of viral RNA translation via an interaction of its N-terminal domain with the 5′ untranslated region (UTR) of the viral RNA. Here, we report the near-complete backbone chemical-shift assignments of full-length SARS-CoV-2 Nsp1 (19.8 kDa), which reveal the domain organization, secondary structure and backbone dynamics of Nsp1, and which will be of value to further NMR-based investigations of both the biochemical and physiological functions of Nsp1. © 2021, The Author(s).

العلاقة: ESSN:1874-270X; http://dx.doi.org/10.15488/12342Test; https://www.repo.uni-hannover.de/handle/123456789/12441Test

الإتاحة: https://doi.org/10.15488/12342Test
https://doi.org/10.1007/s12104-021-10019-6Test
https://www.repo.uni-hannover.de/handle/123456789/12441Test

المؤلفون: Micheli, Leticia, Stallen, Mirre, Sanfey, Alan G.

المصدر: Brain Sciences 11 (2021), Nr. 3 ; Brain Sciences

مصطلحات موضوعية: Cooperation, Public goods game, Social and financial incentives, fMRI, adult, controlled study, economic incentive, female, functional magnetic resonance imaging, human, human experiment, lateral orbitofrontal cortex, male, medial orbitofrontal cortex, neuroimaging, precuneus, social incentive, ddc:570

الوصف: Incentives are frequently used by governments and employers to encourage cooperation. Here, we investigated the effect of centralized incentives on cooperation, firstly in a behavioral study and then replicated in a subsequent neuroimaging (fMRI) study. In both studies, participants completed a novel version of the Public Goods Game, including experimental conditions in which the administration of centralized incentives was probabilistic and incentives were either of a financial or social nature. Behavioral results showed that the prospect of potentially receiving financial and social incentives significantly increased cooperation, with financial incentives yielding the strongest effect. Neuroimaging results showed that activation in the bilateral lateral orbitofrontal cortex and precuneus increased when participants were informed that incentives would be absent versus when they were present. Furthermore, activation in the medial orbitofrontal cortex increased when participants would potentially receive a social versus a financial incentive. These results speak to the efficacy of different types of centralized incentives in increasing cooperative behavior, and they show that incentives directly impact the neural mechanisms underlying cooperation. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.

العلاقة: ESSN:2076-3425; http://dx.doi.org/10.15488/12290Test; https://www.repo.uni-hannover.de/handle/123456789/12388Test

الإتاحة: https://doi.org/10.15488/12290Test
https://doi.org/10.3390/brainsci11030317Test
https://www.repo.uni-hannover.de/handle/123456789/12388Test

المؤلفون: Klinkenberg, Nele, Kraft, Sophia, Polarz, Sebastian

المصدر: Advanced Materials 33 (2021), Nr. 8 ; Advanced Materials

مصطلحات موضوعية: carbon capture, carbon dioxide activation, organic–inorganic hybrids, porous materials, surface design, Adsorption, Binding energy, Nuclear magnetic resonance spectroscopy, Silica, Adsorption capacities, Binding properties, Click chemistry, Conventional approach, Direct interactions, Heat of adsorption, Molecular environment, Solid state NMR, Carbon dioxide, ddc:540, ddc:660

الوصف: Improved carbon capture materials are crucial for managing the CO2 level in the atmosphere. The past focus was on increasing adsorption capacities. It is widely known that controlling the heat of adsorption (ΔHads) is equally important. If it is too low, CO2 uptake takes place at unfavorable conditions and with insufficient selectivity. If it is too high, chemisorption occurs, and the materials can hardly be regenerated. The conventional approach for influencing ΔHads is the modification of the adsorbing center. This paper proposes an alternative strategy. The hypothesis is that fine-tuning of the molecular environment around the adsorbing center is a powerful tool for the adjustment of CO2-binding properties. Via click chemistry, any desired neighboring group (NG) can be incorporated on the surfaces of the nanoporous organosilica model materials. Passive NGs induce a change in the polarity of the surface, whereas active NGs are capable of direct interaction with the active center/CO2 pair. The effects on ΔHads and on the selectivity are studied. A situation can be realized which resembles frustrated Lewis acid–base pairs, and the investigation of the binding-species by solid-state NMR indicates that the push–pull effects could play an essential role not only in CO2 adsorption but also in its activation. © 2021 The Authors. Advanced Materials published by Wiley-VCH GmbH

العلاقة: ESSN:1521-4095; http://dx.doi.org/10.15488/12302Test; https://www.repo.uni-hannover.de/handle/123456789/12400Test

الإتاحة: https://doi.org/10.15488/12302Test
https://doi.org/10.1002/adma.202007734Test
https://www.repo.uni-hannover.de/handle/123456789/12400Test