Chemisches und elektrochemisches Verhalten von Schwefel und Sulfiden in elektrochemischen Zellen

The cumulative dissertation is about different possibilities to use sulfur as part of electrochemical storage devices and is based on four independent publications. One is dealing with the mobility and identity of elemental sulfur in a porous carbon matrix. The property changes of sulfur which is staying in physical contact with carbon were monitored by different analytical methods and are discussed. The relevance of the findings regarding metal/sulfur-batteries was experimentally verified. The second topic was about the (electro)-chemical stability of the Li3PS4 solid electrolyte against lithium electrodes and InLi-alloy electrodes of different stoichiometry. The article discusses the relationship between electrode potential, electrode phase composition, and electrode/electrolyte-interface stability. Further, it provides a guideline for using InLi electrodes correctly in combination with thiophosphate solid electrolytes. The last project describes the realization of a Na/polysulfide-cell with two liquid electrolyte chambers separated by a solid electrolyte. Poor cyclability characteristics were counteracted with two approaches: The use of P2S5 as additive and tetramethylurea as solvent. Moreover, Vis-spectroscopy was applied and the tetramethylurea electrolyte has been characterized. A review article presenting the different concepts of sulfur utilization in electrochemical cells is also included. Therein, advantages, disadvantages, and challenges of the concepts are discussed. Besides the publications, the dissertation contains additional material. Among them, a review on low-temperature Na/S-batteries is given, detailed descriptions of electrochemical cell assemblies are provided, and relevant parameters towards electrochemical characterization methods are explained

Polyimide@Ketjenblack Composite: A Porous Organic Cathode for Fast Rechargeable Potassium-Ion Batteries

Potassium‐ion batteries (PIBs) configurated by organic electrodes have been identified as a promising alternative to lithium‐ion batteries. Here, a porous organic Polyimide@Ketjenblack is demonstrated in PIBs as a cathode, which exhibits excellent performance with a large reversible capacity (143 mAh g^{-1} at 100 mA g^{-1}), high rate capability (125 and 105 mAh g^{-1} at 1000 and 5000 mA g^{-1}), and long cycling stability (76% capacity retention at 2000 mA g^{-1} over 1000 cycles). The domination of fast capacitive‐like reaction kinetics is verified, which benefits from the porous structure synthesized using in situ polymerization. Moreover, a renewable and low‐cost full cell is demonstrated with superior rate behavior (106 mAh g^{-1} at 3200 mA g^{-1}). This work proposes a strategy to design polymer electrodes for high‐performance organic PIBs

A rapid protocol for ribosome profiling of low input samples.

Ribosome profiling provides quantitative, comprehensive, and high-resolution snapshots of cellular translation by the high-throughput sequencing of short mRNA fragments that are protected by ribosomes from nucleolytic digestion. While the overall principle is simple, the workflow of ribosome profiling experiments is complex and challenging, and typically requires large amounts of sample, limiting its broad applicability. Here, we present a new protocol for ultra-rapid ribosome profiling from low-input samples. It features a robust strategy for sequencing library preparation within one day that employs solid phase purification of reaction intermediates, allowing to reduce the input to as little as 0.1 pmol of ∼30 nt RNA fragments. Hence, it is particularly suited for the analyses of small samples or targeted ribosome profiling. Its high sensitivity and its ease of implementation will foster the generation of higher quality data from small samples, which opens new opportunities in applying ribosome profiling

Refractive Index and Optical Dispersion of In2O3, InBO3 and Gahnite

Refractive indices of In₂O₃, In₂₋ₓSnₓO₃, InBO₃ and 2 different gahnite crystals (ZnAl₂O₄ and Zn.₉₅Fe.₀₅Al₂O₄) were measured at wavelengths of 435.8 to 643.8 nm and were used to calculate n at λ = 589.3 nm ( nD ) and at λ = ∞ (n∞) using the one-term Sellmeier equation 1/(n²-1) = -A/λ² + B. Total polarizabilities, αₜₒₜₐₗ, were calculated from n∞ and the Lorenz-Lorentz equation. Refractive indices, nD and dispersion values, A, were, respectively, 2.093 x 10-16 m² and 133 x 10⁻¹⁶ m² for In₂O₃; 2.0755 and 138 x 10⁻¹⁶ m² for In₂₋ₓSnₓO₃; 1.7940 and 57 x 10⁻¹⁶ m² for ZnAl₂O₄ and 1.7995 and 56 x 10⁻¹⁶ m² for Zn.₉₅Fe.₀₅Al₂O₄ and n₀ = 1.8782 and ne = 1.7756 and x 10⁻¹⁶ m² for InBO₃.Please note: Authors differ slightly in the published version

Investigating the Prevalence of RNA-Binding Metabolic Enzymes in E. coli

An open research field in cellular regulation is the assumed crosstalk between RNAs, metabolic enzymes, and metabolites, also known as the REM hypothesis. High-throughput assays have produced extensive interactome data with metabolic enzymes frequently found as hits, but only a few examples have been biochemically validated, with deficits especially in prokaryotes. Therefore, we rationally selected nineteen Escherichia coli enzymes from such datasets and examined their ability to bind RNAs using two complementary methods, iCLIP and SELEX. Found interactions were validated by EMSA and other methods. For most of the candidates, we observed no RNA binding (12/19) or a rather unspecific binding (5/19). Two of the candidates, namely glutamate-5-kinase (ProB) and quinone oxidoreductase (QorA), displayed specific and previously unknown binding to distinct RNAs. We concentrated on the interaction of QorA to the mRNA of yffO, a grounded prophage gene, which could be validated by EMSA and MST. Because the physiological function of both partners is not known, the biological relevance of this interaction remains elusive. Furthermore, we found novel RNA targets for the MS2 phage coat protein that served us as control. Our results indicate that RNA binding of metabolic enzymes in procaryotes is less frequent than suggested by the results of high-throughput studies, but does occur

Targeted escape of SARS-CoV-2 in vitro from monoclonal antibody S309, the precursor of sotrovimab

Class 1 and 2 monoclonal antibodies inhibit SARS-CoV-2 entry by blocking the interaction of the viral receptor-binding domain with angiotensin-converting enzyme 2 (ACE2), while class 3 antibodies target a highly conserved epitope outside the ACE2 binding site. We aimed to investigate the plasticity of the spike protein by propagating wild-type SARS-CoV-2 in the presence of class 3 antibody S309. After 12 weeks, we obtained a viral strain that was completely resistant to inhibition by S309, due to successively evolving amino acid exchanges R346S and P337L located in the paratope of S309. The antibody lost affinity to receptor-binding domains carrying P337L or both amino acid exchanges, while ACE2 binding was not affected. The resistant strain replicated efficiently in human CaCo-2 cells and was more susceptible to inhibition of fusion than the original strain. Overall, SARS-CoV-2 escaped inhibition by class 3 antibody S309 through a slow, but targeted evolution enabling immune escape and altering cell entry. This immune-driven enhancement of infectivity and pathogenicity could play an important role in the future evolution of SARSCoV-2, which is under increasing immunological pressure from vaccination and previous infections

Insights into the evolutionary conserved regulation of Rio ATPase activity

Department of Biochemistry III ‘House of the Ribosome’ and by the DFG Collaborative Research Center [SFB960-AP1] ‘Ribosome formation: principles of RNP biogenesis and control of their function’ (to S.F.-C.).; Work in the MacNeill laboratory was funded by Forskningsrådet for Natur og Univers (FNU) [sagsnr. 272-05-0446]; Scottish Universities Life Sciences Alliance (SULSA); Research in the Medenbach laboratory is supported by the Bavarian Research Network for Molecular Biosystems (BioSysNet); German Research Foundation (DFG) [ME4238/1-1]; DFG Collaborative Research Center [SFB960-B11] ‘Ribosome formation: principles of RNP biogenesis and control of their function’; German Federal Ministry of Education and Research (BMBF) within the framework of the e:Med research and funding concept [01ZX1401D]; Work in the Siebers laboratory was funded by a grant from the German Science Foundation (DFG) [SI642/10-1] from the Federal Ministry of Education and Research (BMBF) [0316188A]; Work in the LaRonde laboratory was funded by National Science Foundation [MCB0953493]; Publishing of this work was supported by the German Research Foundation (DFG) within the funding program Open Access Publishing. Funding for open access charge: DFG—Open Access program.Eukaryotic ribosome biogenesis is a complex dynamic process which requires the action of numerous ribosome assembly factors. Among them, the eukaryotic Rio protein family members (Rio1, Rio2 and Rio3) belong to an ancient conserved atypical protein kinase/ ATPase family required for the maturation of the small ribosomal subunit (SSU). Recent structure-function analyses suggested an ATPase-dependent role of the Rio proteins to regulate their dynamic association with the nascent pre-SSU. However, the evolutionary origin of this feature and the detailed molecular mechanism that allows controlled activation of the catalytic activity remained to be determined. In this work we provide functional evidence showing a conserved role of the archaeal Rio proteins for the synthesis of the SSU in archaea. Moreover, we unravel a conserved RNA-dependent regulation of the Rio ATPases, which in the case of Rio2 involves, at least, helix 30 of the SSU rRNA and the P-loop lysine within the shared RIO domain. Together, our study suggests a ribosomal RNA-mediated regulatory mechanism enabling the appropriate stimulation of Rio2 catalytic activity and subsequent release of Rio2 from the nascent pre- 40S particle. Based on our findings we propose a unified release mechanism for the Rio proteins.Publisher PDFPeer reviewe

Molecular insights into RNA recognition and gene regulation by the TRIM-NHL protein Mei-P26

The TRIM-NHL protein Meiotic P26 (Mei-P26) acts as a regulator of cell fate in Drosophila. Its activity is critical for ovarian germline stem cell maintenance, differentiation of oocytes, and spermatogenesis. Mei-P26 functions as a post-transcriptional regulator of gene expression; however, the molecular details of how its NHL domain selectively recognizes and regulates its mRNA targets have remained elusive. Here, we present the crystal structure of the Mei-P26 NHL domain at 1.6 Å resolution and identify key amino acids that confer substrate specificity and distinguish Mei-P26 from closely related TRIM-NHL proteins. Furthermore, we identify mRNA targets of Mei-P26 in cultured Drosophila cells and show that Mei-P26 can act as either a repressor or activator of gene expression on different RNA targets. Our work reveals the molecular basis of RNA recognition by Mei-P26 and the fundamental functional differences between otherwise very similar TRIM-NHL proteins

InBO3 and ScBO3 at high pressures: an ab initio study of elastic and thermodynamic properties

We have theoretically investigated the elastic properties of calcite-type orthoborates ABO(3) (A= Sc and In) at high pressure by means of ab initio total-energy calculations. From the elastic stiffness coefficients, we have obtained the elastic moduli (B, G and E), Poisson's ratio (nu), B/G ratio, universal elastic anisotropy index (A(U)), Vickers hardness, and sound wave velocities for both orthoborates. Our simulations show that both borates are more resistive to volume compression than to shear deformation (B > G). Both compounds are ductile and become more ductile, with an increasing elastic anisotropy, as pressure increases. We have also calculated some thermodynamic properties, like Debye temperature and minimum thermal conductivity. Finally, we have evaluated the theoretical mechanical stability of both borates at high hydrostatic pressures. It has been found that the calcite-type structure of InBO3 and ScBO3 becomes mechanically unstable at pressures beyond 56.2 and 57.7 GPa, respectively. (C) 2016 Elsevier Ltd. All rights reserved.This study is supported by the Spanish MICINN projects MAT2013-46649-C4-2-P/3-P and MAT2015-71070-REDC. H.M.O., A.M., and P.R-H. acknowledge computing time provided by Red Espanola de Supercomputacion (RES) and MALTA-Cluster. J.A.S. acknowledges Juan de la Cierva fellowship program for financial support.Gomis, O.; Ortiz, HM.; Sans Tresserras, JÁ.; Manjón Herrera, FJ.; Santamaría-Pérez, D.; Rodríguez-Hernández, P.; Muñoz, A. (2016). InBO3 and ScBO3 at high pressures: an ab initio study of elastic and thermodynamic properties. Journal of Physics and Chemistry of Solids. 98:198-208. https://doi.org/10.1016/j.jpcs.2016.07.002S1982089