¹H, ¹³C and ¹⁵N and ³¹P chemical shift assignment for stem-loop 4 from the 5′-UTR of SARS-CoV-2

The SARS-CoV-2 virus is the cause of the respiratory disease COVID-19. As of today, therapeutic interventions in severe COVID-19 cases are still not available as no effective therapeutics have been developed so far. Despite the ongoing development of a number of effective vaccines, therapeutics to fight the disease once it has been contracted will still be required. Promising targets for the development of antiviral agents against SARS-CoV-2 can be found in the viral RNA genome. The 5′- and 3′-genomic ends of the 30 kb SCoV-2 genome are highly conserved among Betacoronaviruses and contain structured RNA elements involved in the translation and replication of the viral genome. The 40 nucleotides (nt) long highly conserved stem-loop 4 (5_SL4) is located within the 5′-untranslated region (5′-UTR) important for viral replication. 5_SL4 features an extended stem structure disrupted by several pyrimidine mismatches and is capped by a pentaloop. Here, we report extensive ¹H, ¹³C and ¹⁵N and ³¹P resonance assignments of 5_SL4 as the basis for in-depth structural and ligand screening studies by solution NMR spectroscopy

Comprehensive Fragment Screening of the SARS-CoV-2 Proteome Explores Novel Chemical Space for Drug Development

12 pags., 4 figs., 3 tabs.SARS-CoV-2 (SCoV2) and its variants of concern pose serious challenges to the public health. The variants increased challenges to vaccines, thus necessitating for development of new intervention strategies including anti-virals. Within the international Covid19-NMR consortium, we have identified binders targeting the RNA genome of SCoV2. We established protocols for the production and NMR characterization of more than 80 % of all SCoV2 proteins. Here, we performed an NMR screening using a fragment library for binding to 25 SCoV2 proteins and identified hits also against previously unexplored SCoV2 proteins. Computational mapping was used to predict binding sites and identify functional moieties (chemotypes) of the ligands occupying these pockets. Striking consensus was observed between NMR-detected binding sites of the main protease and the computational procedure. Our investigation provides novel structural and chemical space for structure-based drug design against the SCoV2 proteome.Work at BMRZ is supported by the state of Hesse. Work in Covid19-NMR was supported by the Goethe Corona Funds, by the IWBEFRE-program 20007375 of state of Hesse, the DFG through CRC902: “Molecular Principles of RNA-based regulation.” and through infrastructure funds (project numbers: 277478796, 277479031, 392682309, 452632086, 70653611) and by European Union’s Horizon 2020 research and innovation program iNEXT-discovery under grant agreement No 871037. BY-COVID receives funding from the European Union’s Horizon Europe Research and Innovation Programme under grant agreement number 101046203. “INSPIRED” (MIS 5002550) project, implemented under the Action “Reinforcement of the Research and Innovation Infrastructure,” funded by the Operational Program “Competitiveness, Entrepreneurship and Innovation” (NSRF 2014–2020) and co-financed by Greece and the EU (European Regional Development Fund) and the FP7 REGPOT CT-2011-285950—“SEE-DRUG” project (purchase of UPAT’s 700 MHz NMR equipment). The support of the CERM/CIRMMP center of Instruct-ERIC is gratefully acknowledged. This work has been funded in part by a grant of the Italian Ministry of University and Research (FISR2020IP_02112, ID-COVID) and by Fondazione CR Firenze. A.S. is supported by the Deutsche Forschungsgemeinschaft [SFB902/B16, SCHL2062/2-1] and the Johanna Quandt Young Academy at Goethe [2019/AS01]. M.H. and C.F. thank SFB902 and the Stiftung Polytechnische Gesellschaft for the Scholarship. L.L. work was supported by the French National Research Agency (ANR, NMR-SCoV2-ORF8), the Fondation de la Recherche Médicale (FRM, NMR-SCoV2-ORF8), FINOVI and the IR-RMN-THC Fr3050 CNRS. Work at UConn Health was supported by grants from the US National Institutes of Health (R01 GM135592 to B.H., P41 GM111135 and R01 GM123249 to J.C.H.) and the US National Science Foundation (DBI 2030601 to J.C.H.). Latvian Council of Science Grant No. VPP-COVID-2020/1-0014. National Science Foundation EAGER MCB-2031269. This work was supported by the grant Krebsliga KFS-4903-08-2019 and SNF-311030_192646 to J.O. P.G. (ITMP) The EOSC Future project is co-funded by the European Union Horizon Programme call INFRAEOSC-03-2020—Grant Agreement Number 101017536. Open Access funding enabled and organized by Projekt DEALPeer reviewe

Large-Scale Recombinant Production of the SARS-CoV-2 Proteome for High-Throughput and Structural Biology Applications

The highly infectious disease COVID-19 caused by the Betacoronavirus SARS-CoV-2 poses a severe threat to humanity and demands the redirection of scientific efforts and criteria to organized research projects. The international COVID19-NMR consortium seeks to provide such new approaches by gathering scientific expertise worldwide. In particular, making available viral proteins and RNAs will pave the way to understanding the SARS-CoV-2 molecular components in detail. The research in COVID19-NMR and the resources provided through the consortium are fully disclosed to accelerate access and exploitation. NMR investigations of the viral molecular components are designated to provide the essential basis for further work, including macromolecular interaction studies and high-throughput drug screening. Here, we present the extensive catalog of a holistic SARS-CoV-2 protein preparation approach based on the consortium’s collective efforts. We provide protocols for the large-scale production of more than 80% of all SARS-CoV-2 proteins or essential parts of them. Several of the proteins were produced in more than one laboratory, demonstrating the high interoperability between NMR groups worldwide. For the majority of proteins, we can produce isotope-labeled samples of HSQC-grade. Together with several NMR chemical shift assignments made publicly available on covid19-nmr.com, we here provide highly valuable resources for the production of SARS-CoV-2 proteins in isotope-labeled form

Two new species of the family Hydrobiidae (Mollusca: Caenogastropoda) from Austria

Volume: 43Start Page: 179End Page: 18

Flow-through carbonation of waste incinerator bottom ash in a rotating drum batch reactor: Role of specific CO2 supply, mixing tools and fill level

Bottom ashes (BA) constitute the dominant solid residue of municipal solid waste incineration. Ageing of BA over a period of several months is known to reduce the reactivity and leachability of critical trace metals via carbonation by atmospheric CO2. This process may be accelerated by contacting the material with CO2-rich exhaust gas in rotating drum reactors. In this study, we investigated carbonation of BA under dynamic conditions with continuous feed of the reactant gas. This is of particular interest for the integration of the process with the management of BA at incinerator sites. The effects of specific CO2 supply, mixing tools, and reactor loadings on process performance were assessed by the leaching behaviour of the treated BA. The experiments were performed in a rotating drum. Overall, carbonation improved the leachate quality of BA. Leachate values characterized the reactor output as a non-hazardous waste when the specific CO2 supply was above 100 g CO2 per kg BA. The reaction could be accelerated to around 100 min and was enhanced by the use of mixing tools. Of the configurations tested, a perforated mixing cage performed best even at fill levels of up to 50%. This set-up was also least prone to the formation of BA incrustations

Leaching of hexavalent chromium from young chromite ore processing residue

Chromite ore processing residue (COPR) is a waste derived from the chromate extraction from roasted ores and is deposited in some countries in landfills. The objective of this study was to investigate the leaching characteristics of hexavalent Cr [Cr(VI)] from two COPR samples obtained from unlined landfills in the Kanpur area of northern India. Column experiments were conducted under water‐saturated conditions to simulate Cr release from the wastes caused by tropical heavy‐rain events. Leached Cr(VI) decreased from 1,800 to 300 mg L−1 (Rania site) and 1,200 to 163 mg L−1 (Chhiwali site) during exchange of 12 pore volumes, which approximately corresponds to 2 yr of monsoon precipitation. Flow interruptions for 10, 100, and 1,000 h had little effect on Cr(VI) concentrations in the leachate, suggesting that Cr(VI) leaching was not limited by slow release kinetics. Calcium aluminum chromium oxide hydrates (CAC), and highly soluble phases such as Na2CrO4 may play a role in controlling Cr(VI) concentration in the leachates. The amount of Cr(VI) leached from the columns accounted for 16% of the total Cr(VI) present in both COPR samples. A decrease in the solid‐phase Cr(VI)/Crtotal ratio along the column was identified by X‐ray absorption near edge structure (XANES) spectroscopy. Consistently, the smallest Cr(VI)/Crtotal ratios were found in the lower column section closest to the inflow. Our results suggest that Cr(VI) leaching from the unlined COPR landfills will continue for centuries, highlighting the urgent need to remediate these dumpsites.ISSN:1537-2537ISSN:0047-242

Environmental status of groundwater affected by chromite ore processing residue (COPR) dumpsites during pre-monsoon and monsoon seasons

Chromite ore processing residue (COPR) is generated by the roasting of chromite ores for the extraction of chromium. Leaching of carcinogenic hexavalent chromium (Cr(VI)) from COPR dumpsites and contamination of groundwater is a key environmental risk. The objective of the study was to evaluate Cr(VI) contamination in groundwater in the vicinity of three COPR disposal sites in Uttar Pradesh, India, in the pre-monsoon and monsoon seasons. Groundwater samples (n = 57 pre-monsoon, n = 70 monsoon) were taken in 2014 and analyzed for Cr(VI) and relevant hydrochemical parameters. The site-specific ranges of Cr(VI) concentrations in groundwater were <0.005 to 34.8 mg L-1 (Rania), <0.005 to 115 mg L-1 (Chhiwali), and <0.005 to 2.0 mg L-1 (Godhrauli). Maximum levels of Cr(VI) were found close to the COPR dumpsites and significantly exceeded safe drinking water limits (0.05 mg L-1). No significant dependence of Cr(VI) concentration on monsoons was observed

Full-scale accelerated carbonation of waste incinerator bottom ash under continuous-feed conditions

Bottom ash (BA) is the dominant residue derived from the incineration of municipal solid waste or refusederived fuel (RDF). Costs for the disposal of the material chiefly depend on the leachability of salts and trace metals which may be cut by ageing the BA for several months to promote carbonation via uptake of carbon dioxide (CO2). Enhanced exposure to CO2 sources has been referred to as accelerated carbonation. Here we report on the successful implementation of the accelerated carbonation of BA in a continuously fed full-scale rotating drum reactor. The reactor was operated with the fine fraction (< 20 mm) of BA from an RDF incinerator and the exhaust of a combined heat and power unit was used as the reactant gas. The system was tested in 15 experiments and the process efficiency was addressed by maximizing the reactor loading and minimizing the BA residence time. Results confirmed that the reactor loading depended on the rotation-normalized mass flow rate of BA where the slope and intercept of the characteristic varied with the design of the reactor discharge and the use of mixing tools. According to leaching test results, BA residence times as low as 60 min were sufficient to render the carbonated BA a nonhazardous waste and convert it to a material suited for geotechnical applications. This outperforms previous laboratory findings and opens new perspectives for implementing the accelerated carbonation at incinerator sites. (C) 2021 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY license (http:// creativecommons.org/licenses/by/4.0/)

Accelerated carbonation of waste incinerator bottom ash in a rotating drum batch reactor

Accelerated carbonation is known to improve the leaching behaviour and geotechnical properties of waste incineration bottom ash (BA). Regarding process implementation on the industrial scale dynamic reactor configurations may be particularly suited since they enhance the mass exchange between gas and solid. Here we evaluated the influence of fundamental parameters on accelerated carbonation of BA in a rotating drum batch reactor equipped with an automated CO2 supply at close to atmospheric pressure conditions. Firstly, the effect of rotation speed and reactor fill level on the solids motion was studied. Secondly, the effects of CO2-concentration, fill level, and moisture on BA carbonation were investigated. Evaluation was based on the observed CO2 uptake, self-heating, and BA leachability. The bed behaviour of BA strongly differed from that of standard materials and was more affected by fill level than by rotation speed. The fill level was not a limiting factor for BA carbonation within the tested range (7-45 vol.-%). Both the CO2 uptake rate and the final level of carbonation increased as the CO2-concentration was raised from 15 to 75 vol.-%. A close relationship between CO2 uptake and reactor temperature was confirmed by benchmarking a heat balance model against the carbonation enthalpy. Carbonated BA exhibited a strongly decreased mobility of Pb and Zn as compared to fresh BA. The leaching behaviour of BA could be improved such as to comply with the German landfill ordinance for non-hazardous waste