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Ploeckl B, Köhnlein H, Engelhardt TMJ, Herrmann A, Lang PT. Advanced ASDEX Upgrade pellet guiding system design. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2020; 91:083502. [PMID: 32872905 DOI: 10.1063/5.0012145] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Accepted: 07/16/2020] [Indexed: 06/11/2023]
Abstract
Cryogenic pellet injection will be the prime candidate to fuel future fusion power plants. In order to harvest optimum fueling performance, it is essential to inject pellets from the magnetic high field side of the tokamak. The pellet launching system of the tokamak ASDEX Upgrade injects cryogenic hydrogen pellets with a speed of up to 1000 m/s from the magnetic high field side via curved guiding tubes. Pellets passing the guiding tube are sliding on a gas cushion, generated by the Leidenfrost effect. The actual track has a rectangular cross section and is composed of a series of ellipses in order to generate the required 270° looping type turn; the path length is 17 m. The last part of this track is marked by strong geometrical constraints from the vacuum vessel port. The previous design was composed of a sequence of three sections of ellipses too, tangentially constant but discontinuous with regard to the curvature. It had been in operation for almost 20 years. Its steps in the curvature are supposed to limit the system performance. A novel and advanced geometry concept, adopting a method well-known from civil engineering (e.g., for the railroad track design), has been applied to develop an improved design. It relies on clothoid shape sections keeping the track curvatures continuous and, thus, provides a smooth transition between all the elements. The new design presented improves the pellet launching system performance on ASDEX Upgrade and provides knowledge for an advanced design of pellet guiding tubes in future fusion devices.
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Bhatia S, Hilsch M, Cuellar‐Camacho JL, Ludwig K, Nie C, Parshad B, Wallert M, Block S, Lauster D, Böttcher C, Herrmann A, Haag R. Adaptive Flexible Sialylated Nanogels as Highly Potent Influenza A Virus Inhibitors. Angew Chem Int Ed Engl 2020; 59:12417-12422. [PMID: 32441859 PMCID: PMC7384064 DOI: 10.1002/anie.202006145] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Indexed: 11/13/2022]
Abstract
Flexible multivalent 3D nanosystems that can deform and adapt onto the virus surface via specific ligand-receptor multivalent interactions can efficiently block virus adhesion onto the cell. We here report on the synthesis of a 250 nm sized flexible sialylated nanogel that adapts onto the influenza A virus (IAV) surface via multivalent binding of its sialic acid (SA) residues with hemagglutinin spike proteins on the virus surface. We could demonstrate that the high flexibility of sialylated nanogel improves IAV inhibition by 400 times as compared to a rigid sialylated nanogel in the hemagglutination inhibition assay. The flexible sialylated nanogel efficiently inhibits the influenza A/X31 (H3N2) infection with IC50 values in low picomolar concentrations and also blocks the virus entry into MDCK-II cells.
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Schnichels S, Hurst J, de Vries JW, Ullah S, Gruszka A, Kwak M, Löscher M, Dammeier S, Bartz-Schmidt KU, Spitzer MS, Herrmann A. Self-assembled DNA nanoparticles loaded with travoprost for glaucoma-treatment. NANOMEDICINE-NANOTECHNOLOGY BIOLOGY AND MEDICINE 2020; 29:102260. [PMID: 32629041 DOI: 10.1016/j.nano.2020.102260] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 01/08/2020] [Revised: 06/15/2020] [Accepted: 06/20/2020] [Indexed: 11/29/2022]
Abstract
Lipid DNA nanoparticles (NPs) exhibit an intrinsic affinity to the ocular surface and can be loaded by hybridization with fluorophore-DNA conjugates or with the anti-glaucoma drug travoprost by hybridizing an aptamer that binds the medication. In the travoprost-loaded NPs (Trav-NPs), the drug is bound by specific, non-covalent interactions, not requiring any chemical modification of the active pharmaceutical ingredient. Fluorescently labeled Trav-NPs show a long-lasting adherence to the eye, up to sixty minutes after eye drop instillation. Biosafety of the Trav-NPs was proved and in vivo. Ex vivo and in vivo quantification of travoprost via LC-MS revealed that Trav-NPs deliver at least twice the amount of the drug at every time-point investigated compared to the pristine drug. The data successfully show the applicability of a DNA-based drug delivery system in the field of ophthalmology for the treatment of a major retinal eye disease, i.e. glaucoma.
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Ochoukov R, Dreval M, Bobkov V, Faugel H, Herrmann A, Kammerloher L, Leitenstern P. Publisher's Note: "Ion temperature measurement techniques using fast sweeping retarding field analyzer (RFA) in strongly intermittent ASDEX Upgrade tokamak plasmas" [Rev. Sci. Instrum. 91, 063506 (2020)]. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2020; 91:079902. [PMID: 32752790 DOI: 10.1063/5.0019839] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/25/2020] [Indexed: 06/11/2023]
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Ma C, Dong J, Viviani M, Tulini I, Pontillo N, Maity S, Zhou Y, Roos WH, Liu K, Herrmann A, Portale G. De novo rational design of a freestanding, supercharged polypeptide, proton-conducting membrane. SCIENCE ADVANCES 2020; 6:eabc0810. [PMID: 32832651 PMCID: PMC7439445 DOI: 10.1126/sciadv.abc0810] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/07/2020] [Accepted: 06/04/2020] [Indexed: 05/31/2023]
Abstract
Proton translocation enables important processes in nature and man-made technologies. However, controlling proton conduction and fabrication of devices exploiting biomaterials remains a challenge. Even more difficult is the design of protein-based bulk materials without any functional starting scaffold for further optimization. Here, we show the rational design of proton-conducting, protein materials exceeding reported proteinaceous systems. The carboxylic acid-rich structures were evolved step by step by exploring various sequences from intrinsically disordered coils over supercharged nanobarrels to hierarchically spider β sheet containing protein-supercharged polypeptide chimeras. The latter material is characterized by interconnected β sheet nanodomains decorated on their surface by carboxylic acid groups, forming self-supportive membranes and allowing for proton conduction in the hydrated state. The membranes showed an extraordinary proton conductivity of 18.5 ± 5 mS/cm at RH = 90%, one magnitude higher than other protein devices. This design paradigm offers great potential for bioprotonic device fabrication interfacing artificial and biological systems.
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Bhatia S, Hilsch M, Cuellar‐Camacho JL, Ludwig K, Nie C, Parshad B, Wallert M, Block S, Lauster D, Böttcher C, Herrmann A, Haag R. Adaptive Flexible Sialylated Nanogels as Highly Potent Influenza A Virus Inhibitors. Angew Chem Int Ed Engl 2020. [DOI: 10.1002/ange.202006145] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
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Cuellar-Camacho JL, Bhatia S, Reiter-Scherer V, Lauster D, Liese S, Rabe JP, Herrmann A, Haag R. Quantification of Multivalent Interactions between Sialic Acid and Influenza A Virus Spike Proteins by Single-Molecule Force Spectroscopy. J Am Chem Soc 2020; 142:12181-12192. [PMID: 32538085 DOI: 10.1021/jacs.0c02852] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Multivalency is a key principle in reinforcing reversible molecular interactions through the formation of multiple bonds. The influenza A virus deploys this strategy to bind strongly to cell surface receptors. We performed single-molecule force spectroscopy (SMFS) to investigate the rupture force required to break individual and multiple bonds formed between synthetic sialic acid (SA) receptors and the two principal spike proteins of the influenza A virus (H3N2): hemagglutinin (H3) and neuraminidase (N2). Kinetic parameters such as the rupture length (χβ) and dissociation rate (koff) are extracted using the model by Friddle, De Yoreo, and Noy. We found that a monovalent SA receptor binds to N2 with a significantly higher bond lifetime (270 ms) compared to that for H3 (36 ms). By extending the single-bond rupture analysis to a multibond system of n protein-receptor pairs, we provide an unprecedented quantification of the mechanistic features of multivalency between H3 and N2 with SA receptors and show that the stability of the multivalent connection increases with the number of bonds from tens to hundreds of milliseconds. Association rates (kon) are also provided, and an estimation of the dissociation constants (KD) between the SA receptors to both proteins indicate a 17-fold higher binding affinity for the SA-N2 bond with respect to that of SA-H3. An optimal designed multivalent SA receptor showed a higher binding stability to the H3 protein of the influenza A virus than to the monovalent SA receptor. Our study emphasizes the influence of the scaffold on the presentation of receptors during multivalent binding.
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Khmelinskaia A, Marquês JMT, Bastos AEP, Antunes CAC, Bento-Oliveira A, Scolari S, Lobo GMDS, Malhó R, Herrmann A, Marinho HS, de Almeida RFM. Liquid-Ordered Phase Formation by Mammalian and Yeast Sterols: A Common Feature With Organizational Differences. Front Cell Dev Biol 2020; 8:337. [PMID: 32596234 PMCID: PMC7304482 DOI: 10.3389/fcell.2020.00337] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Accepted: 04/17/2020] [Indexed: 11/13/2022] Open
Abstract
Here, biophysical properties of membranes enriched in three metabolically related sterols are analyzed both in vitro and in vivo. Unlike cholesterol and ergosterol, the common metabolic precursor zymosterol is unable to induce the formation of a liquid ordered (l o) phase in model lipid membranes and can easily accommodate in a gel phase. As a result, Zym has a marginal ability to modulate the passive membrane permeability of lipid vesicles with different compositions, contrary to cholesterol and ergosterol. Using fluorescence-lifetime imaging microscopy of an aminostyryl dye in living mammalian and yeast cells we established a close parallel between sterol-dependent membrane biophysical properties in vivo and in vitro. This approach unraveled fundamental differences in yeast and mammalian plasma membrane organization. It is often suggested that, in eukaryotes, areas that are sterol-enriched are also rich in sphingolipids, constituting highly ordered membrane regions. Our results support that while cholesterol is able to interact with saturated lipids, ergosterol seems to interact preferentially with monounsaturated phosphatidylcholines. Taken together, we show that different eukaryotic kingdoms developed unique solutions for the formation of a sterol-rich plasma membrane, a common evolutionary trait that accounts for sterol structural diversity.
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Bento-Oliveira A, Santos FC, Marquês JT, Paulo PMR, Korte T, Herrmann A, Marinho HS, de Almeida RFM. Yeast Sphingolipid-Enriched Domains and Membrane Compartments in the Absence of Mannosyldiinositolphosphorylceramide. Biomolecules 2020; 10:biom10060871. [PMID: 32517183 PMCID: PMC7356636 DOI: 10.3390/biom10060871] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2020] [Revised: 05/25/2020] [Accepted: 06/02/2020] [Indexed: 12/14/2022] Open
Abstract
The relevance of mannosyldiinositolphosphorylceramide [M(IP)2C] synthesis, the terminal complex sphingolipid class in the yeast Saccharomyces cerevisiae, for the lateral organization of the plasma membrane, and in particular for sphingolipid-enriched gel domains, was investigated by fluorescence spectroscopy and microscopy. We also addressed how changing the complex sphingolipid profile in the plasma membrane could influence the membrane compartments (MC) containing either the arginine/ H+ symporter Can1p (MCC) or the proton ATPase Pma1p (MCP). To achieve these goals, wild-type (wt) and ipt1Δ cells, which are unable to synthesize M(IP)2C accumulating mannosylinositolphosphorylceramide (MIPC), were compared. Living cells, isolated plasma membrane and giant unilamellar vesicles reconstituted from plasma membrane lipids were labelled with various fluorescent membrane probes that report the presence and organization of distinct lipid domains, global order, and dielectric properties. Can1p and Pma1p were tagged with GFP and mRFP, respectively, in both yeast strains, to evaluate their lateral organization using confocal fluorescence intensity and fluorescence lifetime imaging. The results show that IPT1 deletion strongly affects the rigidity of gel domains but not their relative abundance, whereas no significant alterations could be perceived in ergosterol-enriched domains. Moreover, in these cells lacking M(IP)2C, a clear alteration in Pma1p membrane distribution, but no significant changes in Can1p distribution, were observed. Thus, this work reinforces the notion that sphingolipid-enriched domains distinct from ergosterol-enriched regions are present in the S. cerevisiae plasma membrane and suggests that M(IP)2C is important for a proper hydrophobic chain packing of sphingolipids in the gel domains of wt cells. Furthermore, our results strongly support the involvement of sphingolipid domains in the formation and stability of the MCP, possibly being enriched in this compartment.
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Ochoukov R, Dreval M, Bobkov V, Faugel H, Herrmann A, Kammerloher L, Leitenstern P. Ion temperature measurement techniques using fast sweeping retarding field analyzer (RFA) in strongly intermittent ASDEX Upgrade tokamak plasmas. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2020; 91:063506. [PMID: 32611035 DOI: 10.1063/5.0010788] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Accepted: 05/28/2020] [Indexed: 06/11/2023]
Abstract
This manuscript presents a new method of interpreting the ion temperature (Ti) measurement with a retarding field analyzer (RFA) that accounts for the intermittent/turbulent nature of the scrape off layer (SOL) plasmas in tokamaks. Fast measurements and statistical methods are desirable for an adequate description of random fluctuations caused by such intermittent events as edge localized modes (ELMs) and blobs. We use a RFA that can sweep its current-voltage (I-V) characteristics with up to 10 kHz. The RFA uses an electronics compensation stage to subtract the capacitive pickup due to the finite connecting cable capacitance, which greatly improves the signal-to-noise ratio. In the 10 kHz case, a single I-V characteristic is obtained in time, which is an order of magnitude faster than the ELM cycle. The fast sweeping frequency allows us to reconstruct the Ti probability density function (PDF), which we use as the Ti representation. The boundary conditions that we place on the I-V characteristics when calculating the Ti values impact the resulting Ti PDF. If the boundaries are insensitive to the plasma fluctuations, then the most probable Ti value of the PDF (20 eV-25 eV) is similar to the Ti value obtained via the classical conditional averaging method (20 eV-27 eV). However, if the boundary conditions follow the fluctuations, then the PDF-based method gives a substantially higher most probable Ti value (35 eV-60 eV). Overall, we show that a fast sweeping RFA diagnostic should be used in intermittent SOL plasmas to reconstruct the PDF for accurate Ti measurements.
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Lauster D, Klenk S, Ludwig K, Nojoumi S, Behren S, Adam L, Stadtmüller M, Saenger S, Zimmler S, Hönzke K, Yao L, Hoffmann U, Bardua M, Hamann A, Witzenrath M, Sander LE, Wolff T, Hocke AC, Hippenstiel S, De Carlo S, Neudecker J, Osterrieder K, Budisa N, Netz RR, Böttcher C, Liese S, Herrmann A, Hackenberger CPR. Phage capsid nanoparticles with defined ligand arrangement block influenza virus entry. NATURE NANOTECHNOLOGY 2020; 15:373-379. [PMID: 32231271 DOI: 10.1038/s41565-020-0660-2] [Citation(s) in RCA: 78] [Impact Index Per Article: 19.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2018] [Accepted: 02/25/2020] [Indexed: 05/21/2023]
Abstract
Multivalent interactions at biological interfaces occur frequently in nature and mediate recognition and interactions in essential physiological processes such as cell-to-cell adhesion. Multivalency is also a key principle that allows tight binding between pathogens and host cells during the initial stages of infection. One promising approach to prevent infection is the design of synthetic or semisynthetic multivalent binders that interfere with pathogen adhesion1-4. Here, we present a multivalent binder that is based on a spatially defined arrangement of ligands for the viral spike protein haemagglutinin of the influenza A virus. Complementary experimental and theoretical approaches demonstrate that bacteriophage capsids, which carry host cell haemagglutinin ligands in an arrangement matching the geometry of binding sites of the spike protein, can bind to viruses in a defined multivalent mode. These capsids cover the entire virus envelope, thus preventing its binding to the host cell as visualized by cryo-electron tomography. As a consequence, virus infection can be inhibited in vitro, ex vivo and in vivo. Such highly functionalized capsids present an alternative to strategies that target virus entry by spike-inhibiting antibodies5 and peptides6 or that address late steps of the viral replication cycle7.
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Ma C, Malessa A, Boersma AJ, Liu K, Herrmann A. Supercharged Proteins and Polypeptides. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2020; 32:e1905309. [PMID: 31943419 DOI: 10.1002/adma.201905309] [Citation(s) in RCA: 50] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/16/2019] [Revised: 10/10/2019] [Indexed: 06/10/2023]
Abstract
Electrostatic interactions play a vital role in nature. Biomacromolecules such as proteins are orchestrated by electrostatics, among other intermolecular forces, to assemble and organize biochemistry. Natural proteins with a high net charge exist in a folded state or are unstructured and can be an inspiration for scientists to artificially supercharge other protein entities. Recent findings show that supercharging proteins allows for control of their properties such as temperature resistance and catalytic activity. One elegant method to transfer the favorable properties of supercharged proteins to other proteins is the fabrication of fusions. Genetically engineered, supercharged unstructured polypeptides (SUPs) are just one promising fusion tool. SUPs can also be complexed with artificial entities to yield thermotropic and lyotropic liquid crystals and liquids. These architectures represent novel bulk materials that are sensitive to external stimuli. Interestingly, SUPs undergo fluid-fluid phase separation to form coacervates. These coacervates can even be directly generated in living cells or can be combined with dissipative fiber assemblies that induce life-like features. Supercharged proteins and SUPs are developed into exciting classes of materials. Their synthesis, structures, and properties are summarized. Moreover, potential applications are highlighted and challenges are discussed.
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Li J, Li B, Sun J, Ma C, Wan S, Li Y, Göstl R, Herrmann A, Liu K, Zhang H. Engineered Near-Infrared Fluorescent Protein Assemblies for Robust Bioimaging and Therapeutic Applications. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2020; 32:e2000964. [PMID: 32162422 DOI: 10.1002/adma.202000964] [Citation(s) in RCA: 43] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/11/2020] [Revised: 02/23/2020] [Accepted: 02/26/2020] [Indexed: 05/21/2023]
Abstract
Fluorescent proteins are investigated extensively as markers for the imaging of cells and tissues that are treated by gene transfection. However, limited transfection efficiency and lack of targeting restrict the clinical application of this method rooted in the challenging development of robust fluorescent proteins for in vivo bioimaging. To address this, a new type of near-infrared (NIR) fluorescent protein assemblies manufactured by genetic engineering is presented. Due to the formation of well-defined nanoparticles and spectral operation within the phototherapeutic window, the NIR protein aggregates allow stable and specific tumor imaging via simple exogenous injection. Importantly, in vivo tumor metastases are tracked and this overcomes the limitations of in vivo imaging that can only be implemented relying on the gene transfection of fluorescent proteins. Concomitantly, the efficient loading of hydrophobic drugs into the protein nanoparticles is demonstrated facilitating the therapy of tumors in a mouse model. It is believed that these theranostic NIR fluorescent protein assemblies, hence, show great potential for the in vivo detection and therapy of cancer.
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Ma C, Su J, Li B, Herrmann A, Zhang H, Liu K. Solvent-Free Plasticity and Programmable Mechanical Behaviors of Engineered Proteins. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2020; 32:e1907697. [PMID: 31990428 DOI: 10.1002/adma.201907697] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/23/2019] [Revised: 12/16/2019] [Indexed: 06/10/2023]
Abstract
Biopolymeric networks with plasticity show great competences in diverse fields owing to the combined biocompatible and mechanical characteristics. However, to realize such plasticity external complicated treatments, e.g., UV or organic solvent have to be applied, which in turn impair the biological nature and even mechanical properties of those systems. To address this challenge, one new type of anhydrous protein liquid crystalline (LC) gels, which exhibit flexible morphological plasticity and mechanical programmability is demonstrated. Supramolecular interactions in the smectic biogels play an important role for their high plasticity. Remarkably, the samples exhibit outstanding mechanical behaviors. The tensile strength and Young's modulus at MPa levels are comparable or even higher than chemically cross-linked hydrogels and LC elastomers. More importantly, mechanical programmability of the LC gels is achieved by genetically tuning the charge density of protein backbones. Consequently, the mechanical performance is manipulated in the range of one order of magnitude. Thus, this type of anhydrous protein LC gels offers great opportunities for load-bearing high-tech applications.
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Herrmann A. Photochemistry of 2-Oxoacetates: from Mechanistic Insights to Profragrances and Bursting Capsules. Chimia (Aarau) 2020; 74:39-48. [PMID: 32200785 DOI: 10.2533/chimia.2020.39] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Photoirradiation of 2-oxoacetates (α-ketoesters) with UV-A light proceeds via an intramolecular hydrogen abstraction of the triplet state in a Norrish type II pathway to form carbonyl compounds, carbon monoxide and/or dioxide, and a series of other side products. This review gives a detailed overview of the mechanistic aspects of photooxidation by explaining the pathways that yield the major products formed in the presence or absence of oxygen. Furthermore, it demonstrates how the photoreaction can be used for the light-induced controlled release of fragrances from non-polymeric profragrances, polymer conjugates and core-shell microcapsules in applications of functional perfumery. In the case of microcapsules, the gas formation accompanying the Norrish type II fragmentation can generate an overpressure that expands or cleaves the capsule wall to release fragrances and thus provides access to multi-stimuli responsive delivery systems.
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142
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Gupta A, Korte T, Herrmann A, Wohland T. Plasma membrane asymmetry of lipid organization: fluorescence lifetime microscopy and correlation spectroscopy analysis. J Lipid Res 2020; 61:252-266. [PMID: 31857388 PMCID: PMC6997606 DOI: 10.1194/jlr.d119000364] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2019] [Revised: 12/03/2019] [Indexed: 02/06/2023] Open
Abstract
A fundamental feature of the eukaryotic cell membrane is the asymmetric arrangement of lipids in its two leaflets. A cell invests significant energy to maintain this asymmetry and uses it to regulate important biological processes, such as apoptosis and vesiculation. The dynamic coupling of the inner or cytoplasmic and outer or exofacial leaflets is a challenging open question in membrane biology. Here, we combined fluorescence lifetime imaging microscopy (FLIM) with imaging total internal reflection fluorescence correlation spectroscopy (ITIR-FCS) to differentiate the dynamics and organization of the two leaflets of live mammalian cells. We characterized the biophysical properties of fluorescent analogs of phosphatidylcholine, sphingomyelin, and phosphatidylserine in the plasma membrane of two mammalian cell lines (CHO-K1 and RBL-2H3). Because of their specific transverse membrane distribution, these probes allowed leaflet-specific investigation of the plasma membrane. We compared the results of the two methods having different temporal and spatial resolution. Fluorescence lifetimes of fluorescent lipid analogs were in ranges characteristic for the liquid ordered phase in the outer leaflet and for the liquid disordered phase in the inner leaflet. The observation of a more fluid inner leaflet was supported by free diffusion in the inner leaflet, with high average diffusion coefficients. The liquid ordered phase in the outer leaflet was accompanied by slower diffusion and diffusion with intermittent transient trapping. Our results show that the combination of FLIM and ITIR-FCS with specific fluorescent lipid analogs is a powerful tool for investigating lateral and transbilayer characteristics of plasma membrane in live cell lines.
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Sun J, Su J, Ma C, Göstl R, Herrmann A, Liu K, Zhang H. Fabrication and Mechanical Properties of Engineered Protein-Based Adhesives and Fibers. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2020; 32:e1906360. [PMID: 31805206 DOI: 10.1002/adma.201906360] [Citation(s) in RCA: 67] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/27/2019] [Revised: 10/12/2019] [Indexed: 06/10/2023]
Abstract
Protein-based structural biomaterials are of great interest for various applications because the sequence flexibility within the proteins may result in their improved mechanical and structural integrity and tunability. As the two representative examples, protein-based adhesives and fibers have attracted tremendous attention. The typical protein adhesives, which are secreted by mussels, sandcastle worms, barnacles, and caddisfly larvae, exhibit robust underwater adhesion performance. In order to mimic the adhesion performance of these marine organisms, two main biological adhesives are presented, including genetically engineered protein-based adhesives and biomimetic chemically synthetized adhesives. Moreover, various protein-based fibers inspired by spider and silkworm proteins, collagen, elastin, and resilin are studied extensively. The achievements in synthesis and fabrication of structural biomaterials by DNA recombinant technology and chemical regeneration certainly will accelerate the explorations and applications of protein-based adhesives and fibers in wound healing, tissue regeneration, drug delivery, biosensors, and other high-tech applications. However, the mechanical properties of the biological structural materials still do not match those of natural systems. More efforts need to be devoted to the study of the interplay of the protein structure, cohesion and adhesion effects, fiber processing, and mechanical performance.
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Zhang C, Yue C, Herrmann A, Song J, Egelston C, Wang T, Zhang Z, Li W, Lee H, Aftabizadeh M, Li YJ, Lee PP, Forman S, Somlo G, Chu P, Kruper L, Mortimer J, Hoon DSB, Huang W, Priceman S, Yu H. STAT3 Activation-Induced Fatty Acid Oxidation in CD8 + T Effector Cells Is Critical for Obesity-Promoted Breast Tumor Growth. Cell Metab 2020; 31:148-161.e5. [PMID: 31761565 PMCID: PMC6949402 DOI: 10.1016/j.cmet.2019.10.013] [Citation(s) in RCA: 186] [Impact Index Per Article: 46.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/27/2018] [Revised: 06/21/2019] [Accepted: 10/28/2019] [Indexed: 12/21/2022]
Abstract
Although obesity is known to be critical for cancer development, how obesity negatively impacts antitumor immune responses remains largely unknown. Here, we show that increased fatty acid oxidation (FAO) driven by activated STAT3 in CD8+ T effector cells is critical for obesity-associated breast tumor progression. Ablating T cell Stat3 or treatment with an FAO inhibitor in obese mice spontaneously developing breast tumor reduces FAO, increases glycolysis and CD8+ T effector cell functions, leading to inhibition of breast tumor development. Moreover, PD-1 ligation in CD8+ T cells activates STAT3 to increase FAO, inhibiting CD8+ T effector cell glycolysis and functions. Finally, leptin enriched in mammary adipocytes and fat tissues downregulates CD8+ T cell effector functions through activating STAT3-FAO and inhibiting glycolysis. We identify a critical role of increased oxidation of fatty acids driven by leptin and PD-1 through STAT3 in inhibiting CD8+ T effector cell glycolysis and in promoting obesity-associated breast tumorigenesis.
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Háva J, Herrmann A. New faunistic records and remarks on Dermestidae (Coleoptera) : Part 20. ACTA ACUST UNITED AC 2020. [DOI: 10.24394/natsom.2019.34.9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The three species Globicornis cypriensis Háva & Herrmann, 2014 stat. nov., Thorictus westwoodi Wollaston, 1854 stat. nov., Dermestes (Dermestes) cernyi Háva, 2009 stat. nov. are moved to new status. Two new synonyms are proposed: Dermestes (Dermestes) palmi Sjöberg, 1950 (= Dermestes hoeltzermanni Kozminykh, 1998 syn. nov.); Anthrenus (Anthrenus) bilyi Háva, 2000 (= Anthrenus montanus Zhantiev, 2009 syn. nov.). Fauvel. Corrections to Holloway´s paper (2019) on Spanish Dermestidae are provided. 41 taxa are new records for the local fauna all over the World.
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146
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Hoell A, Raghuwanshi VS, Bocker C, Herrmann A, Rüssel C, Höche T. Crystallization of BaF 2 from droplets of phase separated glass – evidence of a core–shell structure by ASAXS. CrystEngComm 2020. [DOI: 10.1039/c9ce02003a] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Glasses with the mol% compositions 1.88 Na2O·15.04 K2O·7.52 Al2O3·69.56 SiO2·6.00 BaF2 and 1.88 Na2O·15.03 K2O·7.52 Al2O3·69.52 SiO2·6.00 BaF2·0.05 SmF3 were studied using X-ray diffraction, transmission electron microscopy, and anomalous small-angle X-ray scattering.
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147
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Ma C, Su J, Sun Y, Feng Y, Shen N, Li B, Liang Y, Yang X, Wu H, Zhang H, Herrmann A, Tanzi RE, Liu K, Zhang C. Significant Upregulation of Alzheimer's β-Amyloid Levels in a Living System Induced by Extracellular Elastin Polypeptides. Angew Chem Int Ed Engl 2019; 58:18703-18709. [PMID: 31609093 PMCID: PMC7187254 DOI: 10.1002/anie.201912399] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2019] [Indexed: 01/25/2023]
Abstract
Alzheimer's disease (AD) is a neurodegenerative disorder and the primary cause of age-related dementia. The etiology of AD is complex and has not been completely elucidated. Herein, we report that treatment with elastin-like polypeptides (ELPs), a component of the brain extracellular matrix (ECM), significantly increased the levels of AD-related amyloid-β peptides (Aβ) both in vitro and in vivo. Regarding the molecular mechanism(s), the upregulation of Aβ levels was related to increased proteolytic processing of the amyloid precursor protein. Furthermore, nesting tests demonstrated that the ELP-treated animals showed significant neurobehavioral deficits with cognitive impairment. These results suggest that the elastin is associated with AD-related pathological and behavioral changes. This finding presents a new aspect for Alzheimer's amyloidosis event and provides a great promise in developing ELP-based model systems to better understand the pathogenesis of AD.
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148
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Ball C, Forrester A, Herrmann A, Lemiere S, Ganapathy K. Comparative protective immunity provided by live vaccines of Newcastle disease virus or avian metapneumovirus when co-administered alongside classical and variant strains of infectious bronchitis virus in day-old broiler chicks. Vaccine 2019; 37:7566-7575. [PMID: 31607602 PMCID: PMC7127460 DOI: 10.1016/j.vaccine.2019.09.081] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2019] [Revised: 09/23/2019] [Accepted: 09/25/2019] [Indexed: 01/07/2023]
Abstract
This study reports on the simultaneous administration of live NDV or aMPV subtype B vaccines alongside two live IBV (Massachusetts-H120 and 793B-CR88) vaccines in day-old maternal-antibody positive commercial broiler chicks. In the first experiment, chicks were divided into four groups; one unvaccinated and three groups vaccinated with live NDV VG/GA-Avinew, live H120 + CR88, or VG/GA-Avinew + H120 + CR88. In the second experiment, live aMPV subtype B vaccine was used in place of NDV. Clinical signs were monitored daily and oropharyngeal swabs were taken at regular intervals for vaccine virus detection. Blood was collected at 21 dpv for serology. 10 chicks from each group were challenged with virulent strains of M41 or QX or aMPV subtype B. For IBV, after 5 days post challenge (dpc), tracheal ciliary protection was assessed. For aMPV, clinical scores were recorded up to 10 dpc. For NDV, haemagglutination inhibition (HI) antibody titres were assayed as an indicator of protective immunity. In both experiments, ciliary protection for IBV vaccinated groups was maintained above 90%. The protection against virulent aMPV challenge was not compromised when aMPV, H120 and CR88 were co-administered. NDV HI mean titres in single and combined NDV-vaccinated groups remained above the protective titre (>3 log2). Both experiments demonstrated that simultaneous administration of live NDV VG/GA-Avinew or aMPV subtype B alongside H120 and CR88 vaccines does not interfere with protection conferred against NDV, IBV or aMPV.
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149
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Friedrich D, Friedel L, Finzel A, Herrmann A, Preibisch S, Loewer A. Stochastic transcription in the p53-mediated response to DNA damage is modulated by burst frequency. Mol Syst Biol 2019; 15:e9068. [PMID: 31885199 PMCID: PMC6886302 DOI: 10.15252/msb.20199068] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2019] [Revised: 11/04/2019] [Accepted: 11/07/2019] [Indexed: 12/15/2022] Open
Abstract
Discontinuous transcription has been described for different mammalian cell lines and numerous promoters. However, our knowledge of how the activity of individual promoters is adjusted by dynamic signaling inputs from transcription factors is limited. To address this question, we characterized the activity of selected target genes that are regulated by pulsatile accumulation of the tumor suppressor p53 in response to ionizing radiation. We performed time-resolved measurements of gene expression at the single-cell level by smFISH and used the resulting data to inform a mathematical model of promoter activity. We found that p53 target promoters are regulated by frequency modulation of stochastic bursting and can be grouped along three archetypes of gene expression. The occurrence of these archetypes cannot solely be explained by nuclear p53 abundance or promoter binding of total p53. Instead, we provide evidence that the time-varying acetylation state of p53's C-terminal lysine residues is critical for gene-specific regulation of stochastic bursting.
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150
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Chakraborty G, Balinin K, Portale G, Loznik M, Polushkin E, Weil T, Herrmann A. Electrostatically PEGylated DNA enables salt-free hybridization in water. Chem Sci 2019; 10:10097-10105. [PMID: 32055364 PMCID: PMC6991176 DOI: 10.1039/c9sc02598g] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2019] [Accepted: 09/11/2019] [Indexed: 12/18/2022] Open
Abstract
Chemically modified nucleic acids have long served as a very important class of bio-hybrid structures. In particular, the modification with PEG has advanced the scope and performance of oligonucleotides in materials science, catalysis and therapeutics. Most of the applications involving pristine or modified DNA rely on the potential of DNA to form a double-stranded structure. However, a substantial requirement for metal-cations to achieve hybridization has restricted the range of applications. To extend the applicability of DNA in salt-free or low ionic strength aqueous medium, we introduce noncovalent DNA-PEG constructs that allow canonical base-pairing between individually PEGylated complementary strands resulting in a double-stranded structure in salt-free aqueous medium. This method relies on grafting of amino-terminated PEG polymers electrostatically onto the backbone of DNA, which results in the formation of a PEG-envelope. The specific charge interaction of PEG molecules with DNA, absolute absence of metal ions within the PEGylated DNA molecules and formation of a double helix that is significantly more stable than the duplex in an ionic buffer have been unequivocally demonstrated using multiple independent characterization techniques.
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