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Silicase, an enzyme that catalyzes the hydrolysis of silicon-oxygen bonds, is a crucial player in breaking down silicates into silicic acid, particularly in organisms like aquatic sponges with siliceous skeletons. Despite its significance, our understanding of silicase remains limited. This study comprehensively examines silicase from the demosponge Suberites domuncula, focusing on its kinetics toward CO2 as a substrate, as well as its silicase and esterase activity. It investigates inhibition and activation profiles with a range of inhibitors and activators belonging to various classes. By comparing its esterase activity to human carbonic anhydrase II, we gain insights into its enzymatic properties. Moreover, we investigate silicase's inhibition and activation profiles, providing valuable information for potential applications. We explore the evolutionary relationship of silicase with related enzymes, revealing potential functional roles in biological systems. Additionally, we propose a biochemical mechanism through three-dimensional modeling, shedding light on its catalytic mechanisms and structural features for both silicase activity and CO2 hydration. We highlight nature's utilization of enzymatic expertise in silica metabolism. This study enhances our understanding of silicase and contributes to broader insights into ecosystem functioning and Earth's geochemical cycles, emphasizing the intricate interplay between biology and the environment.
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Dióxido de Carbono , Dióxido de Silício , Dióxido de Carbono/metabolismo , Animais , Dióxido de Silício/química , Dióxido de Silício/metabolismo , Humanos , Suberites/enzimologia , Suberites/metabolismo , Cinética , Anidrase Carbônica II/metabolismo , Anidrase Carbônica II/química , Modelos MolecularesRESUMO
The Research Collaboratory for Structural Bioinformatics Protein Data Bank (RCSB PDB), the US data center for the global PDB archive and a founding member of the Worldwide Protein Data Bank partnership, serves tens of thousands of data depositors in the Americas and Oceania and makes 3D macromolecular structure data available at no charge and without restrictions to millions of RCSB.org users around the world, including >660 000 educators, students and members of the curious public using PDB101.RCSB.org. PDB data depositors include structural biologists using macromolecular crystallography, nuclear magnetic resonance spectroscopy, 3D electron microscopy and micro-electron diffraction. PDB data consumers accessing our web portals include researchers, educators and students studying fundamental biology, biomedicine, biotechnology, bioengineering and energy sciences. During the past 2 years, the research-focused RCSB PDB web portal (RCSB.org) has undergone a complete redesign, enabling improved searching with full Boolean operator logic and more facile access to PDB data integrated with >40 external biodata resources. New features and resources are described in detail using examples that showcase recently released structures of SARS-CoV-2 proteins and host cell proteins relevant to understanding and addressing the COVID-19 global pandemic.
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Biologia Computacional/métodos , Bases de Dados de Proteínas , Substâncias Macromoleculares/química , Conformação Proteica , Proteínas/química , Bioengenharia/métodos , Pesquisa Biomédica/métodos , Biotecnologia/métodos , COVID-19/epidemiologia , COVID-19/prevenção & controle , COVID-19/virologia , Humanos , Substâncias Macromoleculares/metabolismo , Pandemias , Proteínas/genética , Proteínas/metabolismo , SARS-CoV-2/genética , SARS-CoV-2/metabolismo , SARS-CoV-2/fisiologia , Software , Proteínas Virais/química , Proteínas Virais/genética , Proteínas Virais/metabolismoRESUMO
Advanced chromophoric tools, besides being biologically active, need to meet the expectations of the technological demands including stability, colour retention, and proper solubility for their target. Many coordination compounds of conjugated ligands are antibacterial dyes, able to combine a strong dyeing performance with a useful biological activity. Specifically, palladium (II) complexes of Schiff base ligands are known for their relevant activity against common bacteria. In this article, we report the synthesis and comprehensive experimental and theoretical characterization of two novel Pd(II) chromophore complexes obtained from a cyclopalladated Schiff base as two different chelating azo dyes. The antibacterial response of these two novel complexes was tested against the ubiquitous Escherichia coli bacterium in an aqueous medium and revealed a noteworthy antimicrobial activity, higher than when compared with their uncoordinated biologically active ligands.
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Complexos de Coordenação , Bases de Schiff , Antibacterianos/farmacologia , Compostos Azo , Bactérias , Corantes , Escherichia coli , Ligantes , Testes de Sensibilidade Microbiana , Paládio/farmacologia , Bases de Schiff/farmacologiaRESUMO
The growing demand of responsive tools for biological and biomedical applications pushes towards new low-cost probes easy to synthesize and versatile. Current optical probes are theranostic tools simultaneously responsive to biological parameters/analyte and therapeutically operating. Among the optical methods for pH monitoring, simple small organic molecules including multifunctional probes for simultaneous biological activity being highly desired by scientists and technicians. Here, we present a novel pH-responsive probe with a three-ring heteroaromatic pattern and a flexible cationic chain. The novel molecule shows real-time naked-eye colorimetric and fluorescence response in the slightly acidic pH range besides its excellent solubility both in the organic phase and in water. In addition, the small probe shows significant antibacterial activity, particularly against Escherichia coli. Single-crystal X-ray study and density functional theory (DFT) calculations rationalize the molecule spectroscopic response. Finally, molecular dynamics (MD) elucidate the interactions between the probe and a model cell membrane.
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Anti-Infecciosos , Colorimetria , Anti-Infecciosos/farmacologia , Colorimetria/métodos , Corantes Fluorescentes/química , Concentração de Íons de Hidrogênio , Oxidiazóis , Água/químicaRESUMO
Solid-state emitters exhibiting mechano-fluorochromic or thermo-fluorochromic responses represent the foundation of smart tools for novel technological applications. Among fluorochromic (FC) materials, solid-state emissive coordination complexes offer a variety of fluorescence responses related to the dynamic of noncovalent metal-ligand coordination bonds. Relevant FC behaviour can result from the targeted choice of metal cation and ligands. Herein, we report the synthesis and characterization of two different colour emitters consisting of zinc complexes obtained from N,O bidentate ligands with different electron-withdrawing substituents. The two complexes are blue and orange solid-state fluorophores, respectively, highly responsive to thermal and mechanical stress. These emitters show a very different photoluminescent (PL) pattern as recorded before and after the annealing treatment. Through X-ray structural analysis combined with thermal analysis, infrared (IR) spectroscopy, PL, and DFT simulation we provide a comprehensive analysis of the structural feature involved in the fluorochromic response. Notably, we were able to correlate the on-off thermo-fluorochromism of the complexes with the structural rearrangement at the zinc coordination core.
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Complexos de Coordenação , Zinco , Complexos de Coordenação/química , Cristalografia por Raios X , Elétrons , Ligantes , Zinco/químicaRESUMO
The Research Collaboratory for Structural Bioinformatics Protein Data Bank (RCSB PDB, rcsb.org), the US data center for the global PDB archive, serves thousands of Data Depositors in the Americas and Oceania and makes 3D macromolecular structure data available at no charge and without usage restrictions to more than 1 million rcsb.org Users worldwide and 600 000 pdb101.rcsb.org education-focused Users around the globe. PDB Data Depositors include structural biologists using macromolecular crystallography, nuclear magnetic resonance spectroscopy and 3D electron microscopy. PDB Data Consumers include researchers, educators and students studying Fundamental Biology, Biomedicine, Biotechnology and Energy. Recent reorganization of RCSB PDB activities into four integrated, interdependent services is described in detail, together with tools and resources added over the past 2 years to RCSB PDB web portals in support of a 'Structural View of Biology.'
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Bases de Dados de Proteínas , Conformação Proteica , Pesquisa Biomédica/educação , Biotecnologia/educação , Curadoria de Dados , SoftwareRESUMO
Many human activities and cellular functions depend upon precise pH values, and pH monitoring is considered a fundamental task. Colorimetric and fluorescence sensors for pH measurements are chemical and biochemical tools able to sense protons and produce a visible signal. These pH sensors are gaining widespread attention as non-destructive tools, visible to the human eye, that are capable of a real-time and in-situ response. Optical "visual" sensors are expanding researchers' interests in many chemical contexts and are routinely used for biological, environmental, and medical applications. In this review we provide an overview of trending colorimetric, fluorescent, or dual-mode responsive visual pH sensors. These sensors include molecular synthetic organic sensors, metal organic frameworks (MOF), engineered sensing nanomaterials, and bioengineered sensors. We review different typological chemical entities of visual pH sensors, three-dimensional structures, and signaling mechanisms for pH sensing and applications; developed in the past five years. The progression of this review from simple organic molecules to biological macromolecules seeks to benefit beginners and scientists embarking on a project of pH sensing development, who needs background information and a quick update on advances in the field. Lessons learned from these tools will aid pH determination projects and provide new ways of thinking for cell bioimaging or other cutting-edge in vivo applications.
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Técnicas Biossensoriais/métodos , Estruturas Metalorgânicas/química , Bioengenharia , Colorimetria , Fluorescência , Humanos , Concentração de Íons de Hidrogênio , NanoestruturasRESUMO
In the field of optical sensors, small molecules responsive to metal cations are of current interest. Probes displaying aggregation-induced emission (AIE) can solve the problems due to the aggregation-caused quenching (ACQ) molecules, scarcely emissive as aggregates in aqueous media and in tissues. The addition of a metal cation to an AIE ligand dissolved in solution can cause a "turn-on" of the fluorescence emission. Half-cruciform-shaped molecules can be a winning strategy to build specific AIE probes. Herein, we report the synthesis and characterization of a novel L-shaped fluorophore containing a benzofuran core condensed with 3-hydroxy-2-naphthaldehyde crossed with a nitrobenzene moiety. The novel AIE probe produces a fast colorimetric and fluorescence response toward zinc (II) in both in neutral and basic conditions. Acting as a tridentate ligand, it produces a complex with enhanced and red-shifted emission in the DR/NIR spectral range. The AIE nature of both compounds was examined on the basis of X-ray crystallography and DFT analysis.
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Since the discovery of fullerene, carbon-based nanomolecules sparked a wealth of research across biological, medical and material sciences. Understanding the interactions of these materials with biological samples at the atomic level is crucial for improving the applications of nanomolecules and address safety aspects concerning their use in medicine. Protein crystallography provides the interface view between proteins and carbon-based nanomolecules. We review forefront structural studies of nanomolecules interacting with proteins and the mechanism underlying these interactions. We provide a systematic analysis of approaches used to select proteins interacting with carbon-based nanomolecules explored from the worldwide Protein Data Bank (wwPDB) and scientific literature. The analysis of van der Waals interactions from available data provides important aspects of interactions between proteins and nanomolecules with implications on functional consequences. Carbon-based nanomolecules modulate protein surface electrostatic and, by forming ordered clusters, could modify protein quaternary structures. Lessons learned from structural studies are exemplary and will guide new projects for bioimaging tools, tuning of intrinsically disordered proteins, and design assembly of precise hybrid materials.
Assuntos
Carbono/farmacologia , Ligantes , Modelos Moleculares , Proteínas/química , Conformação Molecular , Simulação de Acoplamento Molecular , Simulação de Dinâmica Molecular , Ligação Proteica , Proteínas/metabolismoRESUMO
Extensive efforts invested in understanding the rules of protein folding are now being applied, with good effect, in de novo design of proteins/peptides. For proteins containing standard α-amino acids alone, knowledge derived from experimentally determined three-dimensional (3D) structures of proteins and biologically active peptides are available from the Protein Data Bank (PDB), and the Cambridge Structural Database (CSD). These help predict and design protein structures, with reasonable confidence. However, our knowledge of 3D structures of biomolecules containing backbone modified amino acids is still evolving. A major challenge in de novo protein/peptide design concerns the engineering of conformationally constrained molecules with specific structural elements and chemical groups appropriately positioned for biological activity. This review explores four classes of amino acid modifications that constrain protein/peptide backbone structure. Systematic analysis of peptidic molecule structures (eg, bioactive peptides, inhibitors, antibiotics, and designed molecules), containing these backbone-modified amino acids, found in the PDB and CSD are discussed. The review aims to provide structure-function insights that will guide future design of proteins/peptides.
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Aminoácidos/química , Bases de Dados de Proteínas , Peptídeos/química , Engenharia de Proteínas , Conformação ProteicaRESUMO
The M2 protein from influenza A virus is a pH-activated proton channel that mediates acidification of the interior of viral particles entrapped in endosomes. M2 is the target of the anti-influenza drugs amantadine and rimantadine; recently, resistance to these drugs in humans, birds and pigs has reached more than 90% (ref. 1). Here we describe the crystal structure of the transmembrane-spanning region of the homotetrameric protein in the presence and absence of the channel-blocking drug amantadine. pH-dependent structural changes occur near a set of conserved His and Trp residues that are involved in proton gating. The drug-binding site is lined by residues that are mutated in amantadine-resistant viruses. Binding of amantadine physically occludes the pore, and might also perturb the pK(a) of the critical His residue. The structure provides a starting point for solving the problem of resistance to M2-channel blockers.
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Vírus da Influenza A/química , Proteínas da Matriz Viral/antagonistas & inibidores , Proteínas da Matriz Viral/química , Amantadina/química , Amantadina/metabolismo , Amantadina/farmacologia , Cristalografia por Raios X , Farmacorresistência Viral/genética , Histidina/metabolismo , Concentração de Íons de Hidrogênio , Vírus da Influenza A/genética , Vírus da Influenza A/metabolismo , Ativação do Canal Iônico/efeitos dos fármacos , Modelos Moleculares , Estrutura Quaternária de Proteína , Prótons , Relação Estrutura-Atividade , Triptofano/metabolismo , Proteínas da Matriz Viral/genética , Proteínas da Matriz Viral/metabolismoRESUMO
Fusaric acid (FA), a picolinic acid derivative, is a natural substance produced by a wide variety of fungal plant pathogens belonging to the Fusarium genus. As a metabolite, fusaric acid exerts several biological activities including metal chelation, electrolyte leakage, repression of ATP synthesis, and direct toxicity on plants, animals and bacteria. Prior studies on the structure of fusaric acid revealed a co-crystal dimeric adduct between FA and 9,10-dehydrofusaric acid. During an ongoing search for signaling genes differentially regulating FA production in the fungal pathogen Fusarium oxysporum (Fo), we found that mutants lacking pheromone expression have an increased production of FA compared to the wild type strain. Noteworthy, crystallographic analysis of FA extracted from Fo culture supernatants showed that crystals are formed by a dimeric form of two FA molecules (1:1 molar stoichiometry). Overall, our results suggest that pheromone signaling in Fo is required to regulate the synthesis of fusaric acid.
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Among modern biomaterials, hybrid tools containing an organic component and a metal cation are recognized as added value, and, for many advanced biomedical applications, synthetic polymers are used as thin protective/functional coatings for medical or prosthetic devices and implants. These materials require specific non-degradability, biocompatibility, antimicrobial, and antiproliferative properties to address safety aspects concerning their use in medicine. Moreover, bioimaging monitoring of the biomedical device and/or implant through biological tissues is a desirable ability. This article reports a novel hybrid metallopolymer obtained by grafting zinc-coordinated fragments to an organic polymeric matrix. This hybrid polymer, owing to its relevant emission in the deep red to near-infrared (DR/NIR) region, is monitorable; therefore, it represents a potential material for biomedical coating. Furthermore, it shows good biocompatibility and adhesion properties and excellent stability in slightly acidic/basic water solutions. Finally, in contact with the superficial layers of human skin, it shows antimicrobial properties against Staphylococcus aureus bacterial strains.
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(1) Background: The purpose of study was to compare the safety profile of glatiramer with natalizumab, alemtuzumab and ocrelizumab in pregnant and lactating women affected by multiple sclerosis (MS). (2) Methods: Individual case safety reports (ICSRs) were retrieved from the European spontaneous reporting system database (EudraVigilance). The reporting odds ratios (RORs) were computed to compare the reporting probability of events between natalizumab, alemtuzumab and ocrelizumab vs. glatiramer. (3) Results: A total of 1236 ICSRs reporting at least one DMT as a suspected drug were selected. More adverse drug reactions (ADRs) unrelated to pregnancy and breastfeeding (n = 1171; 32.6%) were reported than ADRs specific to pregnancy and breastfeeding (n = 1093; 30.4%). The most frequently reported unrelated ADR was MS relapse. Alemtuzumab and natalizumab seem to have a lower reporting probability of MS relapse compared to glatiramer (ROR 0.17, 95% CI 0.07-0.45 and ROR 0.34, 95% CI 0.20-0.57). Among pregnancy- and breastfeeding-related ADRs, the first most reported event was spontaneous abortion (n = 321; 8.9%). Natalizumab and ocrelizumab were associated with a higher reporting probability of spontaneous abortion compared to glatiramer (ROR 2.22, 95% CI 1.58-3.12; ROR 2.18, 95% CI 1.34-3.54, respectively), while alemtuzumab had a lower reporting frequency (ROR 0.32, 95% CI 0.17-0.60). (4) Conclusions: This study did not suggest any strong or new insights for DMTs in this special subpopulation. However, further studies need to be performed.
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BACKGROUND: Cladribine belongs to the group of disease-modifying therapies (DMTs) used to treat multiple sclerosis (MS). According to the highlights of a meeting held by the Pharmacovigilance Risk Assessment Committee (PRAC) on 14 January 2022, cladribine may be associated with the occurrence of liver injury, and thus liver function monitoring is recommended. OBJECTIVES AND METHODS: Using data from the European spontaneous reporting database (EudraVigilance-EV), we aimed to describe the main characteristics of Individual Case Safety Reports (ICSRs) reporting cases of hepatobiliary disorders related to cladribine. The reporting odds ratio (ROR) was calculated to provide the probability of reporting hepatobiliary ICSRs among DMTs used to treat MS. RESULTS: Overall, 118 ICSRs described the occurrence of cladribine-induced hepatobiliary ADRs. The majority of the ICSRs reported ADRs that were classified as serious (93%), and the outcome was mostly reported as "unknown" (50.8%). The most reported hepatobiliary disorders were drug-induced liver injury, abnormal hepatic function, ALT increases, liver disorders, hepatic failure, jaundice, lymphocyte count decreases, hepatotoxicity and hypertransaminasemia. The majority of cladribine-induced hepatic ADRs occurred in female patients belonging to the age group of 18-65 years. CONCLUSION: Considering the seriousness of cladribine-induced hepatic ADRs, a close monitoring of patients receiving this drug is highly recommended. In this context, further pharmacovigilance studies evaluating the hepatic safety profile of cladribine are strongly needed.
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During pre-approval clinical trials, the safety of axi-cel, a second-generation CAR-T-cell therapy directed against CD19, which dramatically improved the prognosis of intractable B-cell lymphomas, has been investigated only in about 400 patients. Therefore, additional information on this issue is urgently needed. In the present paper, we evaluated the 2905 ICSRs with axi-cel as the suspected drug that had been uploaded in the EudraVigilance database from 1 January 2018 to 31 December 2022. About 80% of the reported adverse events were serious, and about 20% of them did not fully resolve or caused death. The adverse events most-frequently reported were Nervous system disorders (25.6%) and, among them, immune-effector-cell-associated neurotoxicity syndrome, followed by Immune system disorders (23.1%), General disorders and administration site conditions (12.0%), Blood and lymphatic system disorders (7.2%), and Infections and infestations (5.8%). Disproportionality analysis showed that the frequency of reported adverse events related to the nervous system was higher with axi-cel than with the other approved CAR-T-cells, except brexu-cel. In conclusion, real-world pharmacovigilance data showed that nervous system and immune system disorders are the adverse events most reported in axi-cel-related ICSRs and suggest that axi-cel could be more neurotoxic than other CAR-T-cells.
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Designing metal sites into de novo proteins has significantly improved, recently. However, identifying the minimal coordination spheres, able to encompass the necessary information for metal binding and activity, still represents a great challenge, today. Here, we test our understanding with a benchmark, nevertheless difficult, case. We assemble into a miniature 28-residue protein, the quintessential elements required to fold properly around a FeCys4 redox center, and to function efficiently in electron-transfer. This study addresses a challenge in de novo protein design, as it reports the crystal structure of a designed tetra-thiolate metal-binding protein in sub-Å agreement with the intended design. This allows us to well correlate structure to spectroscopic and electrochemical properties. Given its high reduction potential compared to natural and designed FeCys4-containing proteins, we exploit it as terminal electron acceptor of a fully artificial chain triggered by visible light.
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Multisystem inflammatory syndrome in children (MIS-c) is an uncommon, but serious, inflammatory response that occurs after SARS-CoV-2 infection. As time went by, MIS-c was also reported as a potential adverse event following COVID-19 vaccination. A descriptive analysis was performed of Individual Case Safety Reports (ICSRs) associated with anti COVID-19 vaccines and related to the pediatric population from 2020 to 2022. The present pharmacovigilance study aimed to describe cases of MIS-c following COVID-19 vaccination, stratified by sex, reported in the Vaccine Adverse Events Reporting System (VAERS) and meeting the Brighton Collaboration criteria for case definition. We assessed all suspected cases through the case definition and classification of the Brighton Collaboration Group, and only definitive, probable, and possible cases were included in the analysis. The Reporting Odds Ratio (ROR) with 95% Confidence Interval (CI) was computed to assess if males have a lower/higher probability of reporting ICSRs with MIS-c compared with females. Overall, we found 79 cases of potentially reported MIS-c following vaccination. This study demonstrated that MIS-c following vaccination was more commonly reported for male subjects with a median age of 10 years (IQR 10.0-11.4), especially after the first dose of anti COVID-19 vaccines with a median time to onset of 27 days. Even so, the rate of occurrence of MIS-c following anti COVID-19 vaccines is lower (0.12/100,000 vaccinated subjects; 95% CI, 0.12-0.13). Overall, all ICSRs were serious and caused or prolonged hospitalization. Finally, disproportionality analysis showed that males had a higher reporting probability of MIS-c compared with females following immunization with mRNA COVID-19 vaccines. Since only a few years of marketing are available, further data from real-life contexts are needed.
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The 3.15-Å-resolution crystal structure of the R enantiomer of the highly bioactive and antiproliferative half-sandwich ruthenium complex DW12 bound to the ATP binding site of glycogen synthase kinase 3ß (GSK-3ß) is reported and the binding is compared with the GSK-3ß binding of staurosporine and other organic inhibitors. The structure reveals a close packing of the organometallic inhibitor in the ATP binding site of GSK-3ß via an induced-fit mechanism. The molecular structure of (R)-DW12 with the CO ligand oriented perpendicular to the pyridocarbazole heterocycle allows the complex to stretch the whole distance sandwiched between the faces of the N- and C-terminal lobes and to interact tightly with the flexible glycine-rich loop, which is uncommon for the interaction of GSK-3ß with organic inhibitors.
Assuntos
Antineoplásicos/farmacologia , Inibidores Enzimáticos/farmacologia , Quinase 3 da Glicogênio Sintase/antagonistas & inibidores , Compostos Organometálicos/farmacologia , Rutênio/química , Antineoplásicos/síntese química , Antineoplásicos/química , Sítios de Ligação/efeitos dos fármacos , Cristalografia por Raios X , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Inibidores Enzimáticos/síntese química , Inibidores Enzimáticos/química , Quinase 3 da Glicogênio Sintase/química , Quinase 3 da Glicogênio Sintase/isolamento & purificação , Glicogênio Sintase Quinase 3 beta , Modelos Moleculares , Conformação Molecular , Estrutura Molecular , Compostos Organometálicos/síntese química , Compostos Organometálicos/química , Estereoisomerismo , Relação Estrutura-AtividadeRESUMO
With growing populations and pressing environmental problems, future economies will be increasingly plant-based. Now is the time to reimagine plant science as a critical component of fundamental science, agriculture, environmental stewardship, energy, technology and healthcare. This effort requires a conceptual and technological framework to identify and map all cell types, and to comprehensively annotate the localization and organization of molecules at cellular and tissue levels. This framework, called the Plant Cell Atlas (PCA), will be critical for understanding and engineering plant development, physiology and environmental responses. A workshop was convened to discuss the purpose and utility of such an initiative, resulting in a roadmap that acknowledges the current knowledge gaps and technical challenges, and underscores how the PCA initiative can help to overcome them.