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

Binding of antioxidant flavone isovitexin to human serum albumin investigated by experimental and computational assays

The flavonoids are a large class of polyphenolic compounds which occur naturally in plants where they are widely distributed. Isovitexin (ISO) is a glycosylated flavonoid that exhibits a potential antioxidant activity. Some recent studies have shown the pharmacokinetic activity of isovitexin in rat blood plasma, however, without detailing the molecular target that is linked and what physicochemical forces govern the interaction. In mammalians, the most abundant protein in blood plasma is the albumin and is not unlike with human, which human serum albumin (HSA) is the major extracellular protein and functions as a carrier of various drugs. The interaction between HSA and ISO was investigated using fluorescence, UV-vis absorbance, circular dichroism (CD), Fourier transform infrared spectroscopy (FT-IR) together with, computational methods like ab initio and molecular modeling calculation. Fluorescence quenching indicated that ISO location is within the hydrophobic pocket in subdomain IIA (site I) of HSA, close to the Trp214 residue. The Stern-Volmer quenching constants determined at 288, 298 and 308 K and its dependence on temperature indicated that the quenching mechanism was static. From the analysis of binding equilibrium were determined; the binding site number and binding constants, with the correspondent thermodynamic parameters, Delta H, Delta G and Delta S for HSA-ISO complex. Also, a second binding analysis, binding density function (BDF) method, which is independent of any binding model pre-established obtained similar results. The fluorescence resonance energy transfer estimated the distance between the donor (HSA Trp214) and acceptor (ISO), while FT-IR and CD spectroscopy measured possible changes of secondary structure at the formation of the HSA ISO complex. The optimized geometry of isovitexin calculation performed with its ground state by using DFT/B3LYP/6-311+G(d,p) method. The HSA ISO complex interactions determined by molecular modeling tool corroborated with the thermodynamic analysis from the experimental data. (C) 2014 Elsevier B.V. All rights reserved.Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

Effect of modified clays on the structure and functional properties of biofilms produced with zein

The purpose of this study was to evaluate changes in the structure and some functional properties of biofilms added with modified clays (Cloisite (R) 15A and Cloisite (R) 30B) prepared by the casting method. The analysis of the microstructure of the films, scanning electron microscopy (SEM), Optical microscopy (MO), and Infrared Spectroscopy (FTIR) indicated that the addition of clay in the films resulted in the formation of a heterogeneous microstructure, microcomposite or tactoid. Due to the formation of a microcomposite structure, functional properties of the films added with both clays such as opacity, solubility, and permeability to water vapor (PVA), were not better than those of the control film. Thus, it was concluded that although it is possible to produce a film added with modified clays using the casting method, it was not possible to obtain intercalation or exfoliation in a nanocomposite, which would result in improved functional properties.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

Crystal structure of mature 2S albumin from Moringa oleifera seeds

2S albumins, the seed storage proteins, are the primary sources of carbon and nitrogen and are involved in plant defense. The mature form of Moringa oleifera (M. oleifera), a chitin binding protein isoform 3-1 (mMo-CBP3-1) a thermostable antifungal, antibacterial, flocculating 2S albumin is widely used for the treatment of water and is potentially interesting for the development of both antifungal drugs and transgenic crops. The crystal structure of mMo-CBP3-1 determined at 1.7 Å resolution demonstrated that it is comprised of two proteolytically processed α-helical chains, stabilized by four disulfide bridges that is stable, resistant to pH changes and has a melting temperature (TM) of approximately 98 °C. The surface arginines and the polyglutamine motif are the key structural factors for the observed flocculating, antibacterial and antifungal activities. This represents the first crystal structure of a 2S albumin and the model of the pro-protein indicates the structural changes that occur upon formation of mMo-CBP3-1 and determines the structural motif and charge distribution patterns for the diverse observed activities.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científco e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES

Active site mapping of Loxosceles phospholipases D: Biochemical and biological features

Brown spider phospholipases D from Loxosceles venoms are among the most widely studied toxins since they induce dermonecrosis, triggering inflammatory responses, increase vascular permeability, cause hemolysis, and renal failure. The catalytic (H12 and H47) and metal-ion binding (E32 and D34) residues in Loxosceles intermedia phospholipase D (LiRecDT1) were mutated to understand their roles in the observed activities. All mutants were identified using whole venom serum antibodies and a specific antibody to wild-type LiRecDT1, they were also analyzed by circular dichroism (CD) and differential scanning calorimetry (DSC). The phospholipase D activities of H12A, H47A, H12A-H47A, E32, D34 and E32A-D34A, such as vascular permeability, dermonecrosis, and hemolytic effects were inhibited. The mutant Y228A was equally detrimental to biochemical and biological effects of phospholipase D, suggesting an essential role of this residue in substrate recognition and binding. On the other hand, the mutant C53A-C201A reduced the enzyme's ability to hydrolyze phospholipids and promote dermonecrosis, hemolytic, and vascular effects. These results provide the basis understanding the importance of specific residues in the observed activities and contribute to the design of synthetic and specific inhibitors for Brown spider venom phospholipases D. (C) 2016 Elsevier B.V. All rights reserved.CAPESCNPqFAPESPFA-PRSETI-PRFed Univ Parana UFPR, Dept Cell Biol, Curitiba, Parana, BrazilSao Paulo State Univ UNESP, Dept Phys, Multiuser Ctr Biomol Innovat, Sao Jose Do Rio Preto, SP, BrazilFed Univ Sao Paulo UNIFESP, Dept Biochem, Sao Paulo, SP, BrazilNatl Ctr Res Energy & Mat CNPEM, Brazilian Biosci Natl Lab LNBio, Campinas, SP, BrazilFed Univ Sao Paulo UNIFESP, Dept Biochem, Sao Paulo, SP, BrazilWeb of Scienc

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.This work was supported by Goethe University (Corona funds), the DFG-funded CRC: “Molecular Principles of RNA-Based Regulation,” DFG infrastructure funds (project numbers: 277478796, 277479031, 392682309, 452632086, 70653611), the state of Hesse (BMRZ), the Fondazione CR Firenze (CERM), and the IWB-EFRE-program 20007375. This project has received funding from the European Union’s Horizon 2020 research and innovation program under Grant Agreement No. 871037. AS is supported by DFG Grant SCHL 2062/2-1 and by the JQYA at Goethe through project number 2019/AS01. Work in the lab of KV was supported by a CoRE grant from the University of New Hampshire. The FLI is a member of the Leibniz Association (WGL) and financially supported by the Federal Government of Germany and the State of Thuringia. Work in the lab of RM was supported by NIH (2R01EY021514) and NSF (DMR-2002837). BN-B was supported by theNSF GRFP.MCwas supported byNIH (R25 GM055246 MBRS IMSD), and MS-P was supported by the HHMI Gilliam Fellowship. Work in the labs of KJ and KT was supported by Latvian Council of Science Grant No. VPP-COVID 2020/1-0014. Work in the UPAT’s lab was supported by the INSPIRED (MIS 5002550) project, which is implemented under the Action “Reinforcement of the Research and Innovation Infrastructure,” funded by the Operational Program “Competitiveness, Entrepreneurship and Innovation” (NSRF 2014–2020) and cofinanced by Greece and the EU (European Regional Development Fund) and the FP7 REGPOT CT-2011- 285950–“SEE-DRUG” project (purchase of UPAT’s 700MHz NMR equipment). Work in the CM-G lab was supported by the Helmholtz society. Work in the lab of ABö was supported by the CNRS, the French National Research Agency (ANR, NMRSCoV2- ORF8), the Fondation de la Recherche Médicale (FRM, NMR-SCoV2-ORF8), and the IR-RMN-THC Fr3050 CNRS. Work in the lab of BM was supported by the Swiss National Science Foundation (Grant number 200020_188711), the Günthard Stiftung für Physikalische Chemie, and the ETH Zurich. Work in the labs of ABö and BM was supported by a common grant from SNF (grant 31CA30_196256). This work was supported by the ETHZurich, the grant ETH40 18 1, and the grant Krebsliga KFS 4903 08 2019. Work in the lab of the IBS Grenoble was supported by the Agence Nationale de Recherche (France) RA-COVID SARS2NUCLEOPROTEIN and European Research Council Advanced Grant DynamicAssemblies. Work in the CA lab was supported by Patto per il Sud della Regione Siciliana–CheMISt grant (CUP G77B17000110001). Part of this work used the platforms of the Grenoble Instruct-ERIC center (ISBG; UMS 3518 CNRS-CEA-UGA-EMBL) within the Grenoble Partnership for Structural Biology (PSB), supported by FRISBI (ANR-10-INBS-05-02) and GRAL, financed within the University Grenoble Alpes graduate school (Ecoles Universitaires de Recherche) CBH-EUR-GS (ANR-17-EURE- 0003). Work at the UW-Madison was supported by grant numbers NSF MCB2031269 and NIH/NIAID AI123498. MM is a Ramón y Cajal Fellow of the Spanish AEI-Ministry of Science and Innovation (RYC2019-026574-I), and a “La Caixa” Foundation (ID 100010434) Junior Leader Fellow (LCR/BQ/PR19/11700003). Funded by project COV20/00764 fromthe Carlos III Institute of Health and the SpanishMinistry of Science and Innovation to MMand DVL. VDJ was supported by the Boehringer Ingelheim Fonds. Part of this work used the resources of the Italian Center of Instruct-ERIC at the CERM/ CIRMMP infrastructure, supported by the Italian Ministry for University and Research (FOE funding). CF was supported by the Stiftung Polytechnische Gesellschaft. Work in the lab of JH was supported by NSF (RAPID 2030601) and NIH (R01GM123249).Peer reviewe