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1.
Cell ; 185(4): 630-640.e10, 2022 02 17.
Artigo em Inglês | MEDLINE | ID: mdl-35093192

RESUMO

The coronavirus disease 2019 (COVID-19) pandemic continues worldwide with many variants arising, some of which are variants of concern (VOCs). A recent VOC, omicron (B.1.1.529), which obtains a large number of mutations in the receptor-binding domain (RBD) of the spike protein, has risen to intense scientific and public attention. Here, we studied the binding properties between the human receptor ACE2 (hACE2) and the VOC RBDs and resolved the crystal and cryoelectron microscopy structures of the omicron RBD-hACE2 complex as well as the crystal structure of the delta RBD-hACE2 complex. We found that, unlike alpha, beta, and gamma, omicron RBD binds to hACE2 at a similar affinity to that of the prototype RBD, which might be due to compensation of multiple mutations for both immune escape and transmissibility. The complex structures of omicron RBD-hACE2 and delta RBD-hACE2 reveal the structural basis of how RBD-specific mutations bind to hACE2.


Assuntos
Enzima de Conversão de Angiotensina 2/química , Receptores Virais/química , SARS-CoV-2/química , Sequência de Aminoácidos , Microscopia Crioeletrônica , Humanos , Modelos Moleculares , Mutação/genética , Filogenia , Ligação Proteica , Domínios Proteicos , Glicoproteína da Espícula de Coronavírus/química , Glicoproteína da Espícula de Coronavírus/genética , Glicoproteína da Espícula de Coronavírus/ultraestrutura , Eletricidade Estática , Homologia Estrutural de Proteína
2.
Cell ; 181(4): 894-904.e9, 2020 05 14.
Artigo em Inglês | MEDLINE | ID: mdl-32275855

RESUMO

The recent emergence of a novel coronavirus (SARS-CoV-2) in China has caused significant public health concerns. Recently, ACE2 was reported as an entry receptor for SARS-CoV-2. In this study, we present the crystal structure of the C-terminal domain of SARS-CoV-2 (SARS-CoV-2-CTD) spike (S) protein in complex with human ACE2 (hACE2), which reveals a hACE2-binding mode similar overall to that observed for SARS-CoV. However, atomic details at the binding interface demonstrate that key residue substitutions in SARS-CoV-2-CTD slightly strengthen the interaction and lead to higher affinity for receptor binding than SARS-RBD. Additionally, a panel of murine monoclonal antibodies (mAbs) and polyclonal antibodies (pAbs) against SARS-CoV-S1/receptor-binding domain (RBD) were unable to interact with the SARS-CoV-2 S protein, indicating notable differences in antigenicity between SARS-CoV and SARS-CoV-2. These findings shed light on the viral pathogenesis and provide important structural information regarding development of therapeutic countermeasures against the emerging virus.


Assuntos
Betacoronavirus/química , Peptidil Dipeptidase A/química , Glicoproteína da Espícula de Coronavírus/química , Internalização do Vírus , Sequência de Aminoácidos , Enzima de Conversão de Angiotensina 2 , Betacoronavirus/fisiologia , Epitopos , Humanos , Modelos Moleculares , Peptidil Dipeptidase A/metabolismo , Filogenia , Domínios Proteicos , Coronavírus Relacionado à Síndrome Respiratória Aguda Grave/química , Coronavírus Relacionado à Síndrome Respiratória Aguda Grave/fisiologia , SARS-CoV-2 , Alinhamento de Sequência , Glicoproteína da Espícula de Coronavírus/metabolismo
3.
Cell ; 183(4): 1013-1023.e13, 2020 11 12.
Artigo em Inglês | MEDLINE | ID: mdl-32970990

RESUMO

Understanding how potent neutralizing antibodies (NAbs) inhibit SARS-CoV-2 is critical for effective therapeutic development. We previously described BD-368-2, a SARS-CoV-2 NAb with high potency; however, its neutralization mechanism is largely unknown. Here, we report the 3.5-Å cryo-EM structure of BD-368-2/trimeric-spike complex, revealing that BD-368-2 fully blocks ACE2 recognition by occupying all three receptor-binding domains (RBDs) simultaneously, regardless of their "up" or "down" conformations. Also, BD-368-2 treats infected adult hamsters at low dosages and at various administering windows, in contrast to placebo hamsters that manifested severe interstitial pneumonia. Moreover, BD-368-2's epitope completely avoids the common binding site of VH3-53/VH3-66 recurrent NAbs, evidenced by tripartite co-crystal structures with RBDs. Pairing BD-368-2 with a potent recurrent NAb neutralizes SARS-CoV-2 pseudovirus at pM level and rescues mutation-induced neutralization escapes. Together, our results rationalized a new RBD epitope that leads to high neutralization potency and demonstrated BD-368-2's therapeutic potential in treating COVID-19.


Assuntos
Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/imunologia , Betacoronavirus/imunologia , Infecções por Coronavirus/patologia , Pneumonia Viral/patologia , Animais , Anticorpos Neutralizantes/química , Anticorpos Neutralizantes/uso terapêutico , Anticorpos Antivirais/química , Anticorpos Antivirais/uso terapêutico , Reações Antígeno-Anticorpo , Sítios de Ligação , COVID-19 , Infecções por Coronavirus/tratamento farmacológico , Infecções por Coronavirus/virologia , Cricetinae , Microscopia Crioeletrônica , Modelos Animais de Doenças , Epitopos/química , Epitopos/imunologia , Feminino , Pulmão/patologia , Masculino , Simulação de Dinâmica Molecular , Pandemias , Pneumonia Viral/tratamento farmacológico , Pneumonia Viral/virologia , Estrutura Quaternária de Proteína , SARS-CoV-2 , Glicoproteína da Espícula de Coronavírus/química , Glicoproteína da Espícula de Coronavírus/imunologia
4.
Nature ; 624(7992): 557-563, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37913815

RESUMO

Perovskite solar cells with the formula FA1-xCsxPbI3, where FA is formamidinium, provide an attractive option for integrating high efficiency, durable stability and compatibility with scaled-up fabrication. Despite the incorporation of Cs cations, which could potentially enable a perfect perovskite lattice1,2, the compositional inhomogeneity caused by A-site cation segregation is likely to be detrimental to the photovoltaic performance of the solar cells3,4. Here we visualized the out-of-plane compositional inhomogeneity along the vertical direction across perovskite films and identified the underlying reasons for the inhomogeneity and its potential impact for devices. We devised a strategy using 1-(phenylsulfonyl)pyrrole to homogenize the distribution of cation composition in perovskite films. The resultant p-i-n devices yielded a certified steady-state photon-to-electron conversion efficiency of 25.2% and durable stability.

5.
Nature ; 581(7807): 215-220, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32225176

RESUMO

A new and highly pathogenic coronavirus (severe acute respiratory syndrome coronavirus-2, SARS-CoV-2) caused an outbreak in Wuhan city, Hubei province, China, starting from December 2019 that quickly spread nationwide and to other countries around the world1-3. Here, to better understand the initial step of infection at an atomic level, we determined the crystal structure of the receptor-binding domain (RBD) of the spike protein of SARS-CoV-2 bound to the cell receptor ACE2. The overall ACE2-binding mode of the SARS-CoV-2 RBD is nearly identical to that of the SARS-CoV RBD, which also uses ACE2 as the cell receptor4. Structural analysis identified residues in the SARS-CoV-2 RBD that are essential for ACE2 binding, the majority of which either are highly conserved or share similar side chain properties with those in the SARS-CoV RBD. Such similarity in structure and sequence strongly indicate convergent evolution between the SARS-CoV-2 and SARS-CoV RBDs for improved binding to ACE2, although SARS-CoV-2 does not cluster within SARS and SARS-related coronaviruses1-3,5. The epitopes of two SARS-CoV antibodies that target the RBD are also analysed for binding to the SARS-CoV-2 RBD, providing insights into the future identification of cross-reactive antibodies.


Assuntos
Betacoronavirus/química , Peptidil Dipeptidase A/química , Peptidil Dipeptidase A/metabolismo , Receptores Virais/química , Receptores Virais/metabolismo , Glicoproteína da Espícula de Coronavírus/química , Glicoproteína da Espícula de Coronavírus/metabolismo , Sequência de Aminoácidos , Enzima de Conversão de Angiotensina 2 , Anticorpos Neutralizantes/imunologia , Betacoronavirus/metabolismo , Sítios de Ligação , Sequência Conservada , Cristalografia por Raios X , Epitopos/química , Epitopos/imunologia , Evolução Molecular , Humanos , Ligação de Hidrogênio , Modelos Moleculares , Ligação Proteica , Domínios Proteicos , Coronavírus Relacionado à Síndrome Respiratória Aguda Grave/química , SARS-CoV-2 , Sais/química , Alinhamento de Sequência , Água/análise , Água/química
6.
J Biol Chem ; 300(6): 107379, 2024 May 16.
Artigo em Inglês | MEDLINE | ID: mdl-38762184

RESUMO

Bacterial RecJ exhibits 5'→3' exonuclease activity that is specific to ssDNA; however, archaeal RecJs show 5' or 3' exonuclease activity. The hyperthermophilic archaea Methanocaldococcus jannaschii encodes the 5'-exonuclease MjRecJ1 and the 3'-exonuclease MjRecJ2. In addition to nuclease activity, archaeal RecJ interacts with GINS, a structural subcomplex of the replicative DNA helicase complex. However, MjRecJ1 and MjRecJ2 do not interact with MjGINS. Here, we report the structural basis for the inability of the MjRecJ2 homologous dimer to interact with MjGINS and its efficient 3' hydrolysis polarity for short dinucleotides. Based on the crystal structure of MjRecJ2, we propose that the interaction surface of the MjRecJ2 dimer overlaps the potential interaction surface for MjGINS and blocks the formation of the MjRecJ2-GINS complex. Exposing the interaction surface of the MjRecJ2 dimer restores its interaction with MjGINS. The cocrystal structures of MjRecJ2 with substrate dideoxynucleotides or product dCMP/CMP show that MjRecJ2 has a short substrate binding patch, which is perpendicular to the longer patch of bacterial RecJ. Our results provide new insights into the function and diversification of archaeal RecJ/Cdc45 proteins.

7.
Biochem Biophys Res Commun ; 724: 150230, 2024 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-38865813

RESUMO

The SARS-CoV-2 coronavirus is characterized by high mutation rates and significant infectivity, posing ongoing challenges for therapeutic intervention. To address potential challenges in the future, the continued development of effective drugs targeting SARS-CoV-2 remains an important task for the scientific as well as the pharmaceutical community. The main protease (Mpro) of SARS-CoV-2 is an ideal therapeutic target for COVID-19 drug development, leading to the introduction of various inhibitors, both covalent and non-covalent, each characterized by unique mechanisms of action and possessing inherent strengths and limitations. Natural products, being compounds naturally present in the environment, offer advantages such as low toxicity and diverse activities, presenting a viable source for antiviral drug development. Here, we identified a natural compound, rosmarinic acid, which exhibits significant inhibitory effects on the Mpro of the SARS-CoV-2. Through detailed structural biology analysis, we elucidated the precise crystal structure of the complex formed between rosmarinic acid and SARS-CoV-2 Mpro, revealing the molecular basis of its inhibitory mechanism. These findings not only enhance our understanding of the antiviral action of rosmarinic acid, but also provide valuable structural information and mechanistic insights for the further development of therapeutic strategies against SARS-CoV-2.


Assuntos
Antivirais , Cinamatos , Proteases 3C de Coronavírus , Depsídeos , Ácido Rosmarínico , SARS-CoV-2 , Depsídeos/química , Depsídeos/farmacologia , Cinamatos/química , Cinamatos/farmacologia , SARS-CoV-2/efeitos dos fármacos , SARS-CoV-2/enzimologia , Proteases 3C de Coronavírus/antagonistas & inibidores , Proteases 3C de Coronavírus/química , Proteases 3C de Coronavírus/metabolismo , Humanos , Antivirais/farmacologia , Antivirais/química , Inibidores de Proteases/química , Inibidores de Proteases/farmacologia , Modelos Moleculares , Cristalografia por Raios X , Tratamento Farmacológico da COVID-19 , COVID-19/virologia , Sítios de Ligação , Ligação Proteica
8.
Small ; : e2309945, 2024 Feb 24.
Artigo em Inglês | MEDLINE | ID: mdl-38400705

RESUMO

In-sensor computing has attracted considerable interest as a solution for overcoming the energy efficiency and response time limitations of the traditional von Neumann architecture. Recently, emerging memristors based on transition-metal oxides (TMOs) have attracted attention as promising candidates for in-memory computing owing to their tunable conductance, high speed, and low operational energy. However, the poor photoresponse of TMOs presents challenges for integrating sensing and processing units into a single device. This integration is crucial for eliminating the need for a sensor/processor interface and achieving energy-efficient in-sensor computing systems. In this study, a Si/CuO heterojunction-based photomemristor is proposed that combines the reversible resistive switching behavior of CuO with the appropriate optical absorption bandgap of the Si substrate. The proposed photomemristor demonstrates a simultaneous reconfigurable, non-volatile, and self-powered photoresponse, producing a microampere-level photocurrent at zero bias. The controlled migration of oxygen vacancies in CuO result in distinct energy-band bending at the interface, enabling multiple levels of photoresponsivity. Additionally, the device exhibits high stability and ultrafast response speed to the built-in electric field. Furthermore, the prototype photomemristor can be trained to emulate the attention-driven nature of the human visual system, indicating the tremendous potential of TMO-based photomemristors as hardware foundations for in-sensor computing.

9.
J Synchrotron Radiat ; 31(Pt 2): 378-384, 2024 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-38241124

RESUMO

An integrated computer software system for macromolecular crystallography (MX) data collection at the BL02U1 and BL10U2 beamlines of the Shanghai Synchrotron Radiation Facility is described. The system, Finback, implements a set of features designed for the automated MX beamlines, and is marked with a user-friendly web-based graphical user interface (GUI) for interactive data collection. The Finback client GUI can run on modern browsers and has been developed using several modern web technologies including WebSocket, WebGL, WebWorker and WebAssembly. Finback supports multiple concurrent sessions, so on-site and remote users can access the beamline simultaneously. Finback also cooperates with the deployed experimental data and information management system, the relevant experimental parameters and results are automatically deposited to a database.

10.
PLoS Biol ; 19(5): e3001209, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33961621

RESUMO

The ongoing Coronavirus Disease 2019 (COVID-19) pandemic caused by Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) threatens global public health and economy unprecedentedly, requiring accelerating development of prophylactic and therapeutic interventions. Molecular understanding of neutralizing antibodies (NAbs) would greatly help advance the development of monoclonal antibody (mAb) therapy, as well as the design of next generation recombinant vaccines. Here, we applied H2L2 transgenic mice encoding the human immunoglobulin variable regions, together with a state-of-the-art antibody discovery platform to immunize and isolate NAbs. From a large panel of isolated antibodies, 25 antibodies showed potent neutralizing activities at sub-nanomolar levels by engaging the spike receptor-binding domain (RBD). Importantly, one human NAb, termed PR1077, from the H2L2 platform and 2 humanized NAb, including PR953 and PR961, were further characterized and subjected for subsequent structural analysis. High-resolution X-ray crystallography structures unveiled novel epitopes on the receptor-binding motif (RBM) for PR1077 and PR953, which directly compete with human angiotensin-converting enzyme 2 (hACE2) for binding, and a novel non-blocking epitope on the neighboring site near RBM for PR961. Moreover, we further tested the antiviral efficiency of PR1077 in the Ad5-hACE2 transduction mouse model of COVID-19. A single injection provided potent protection against SARS-CoV-2 infection in either prophylactic or treatment groups. Taken together, these results shed light on the development of mAb-related therapeutic interventions for COVID-19.


Assuntos
Anticorpos Neutralizantes/imunologia , COVID-19/virologia , SARS-CoV-2/imunologia , Animais , Anticorpos Monoclonais/imunologia , Anticorpos Monoclonais/metabolismo , Anticorpos Neutralizantes/metabolismo , Anticorpos Neutralizantes/ultraestrutura , Anticorpos Antivirais/imunologia , COVID-19/epidemiologia , COVID-19/imunologia , COVID-19/metabolismo , Epitopos/imunologia , Humanos , Camundongos , Camundongos Transgênicos , Testes de Neutralização , Pandemias , Ligação Proteica , Domínios Proteicos , Receptores Virais/imunologia , Glicoproteína da Espícula de Coronavírus/imunologia
11.
Biochem Biophys Res Commun ; 657: 16-23, 2023 05 21.
Artigo em Inglês | MEDLINE | ID: mdl-36965419

RESUMO

PF-07321332 and PF-07304814, inhibitors against SARS-CoV-2 developed by Pfizer, exhibit broad-spectrum inhibitory activity against the main protease (Mpro) from various coronaviruses. Structures of PF-07321332 or PF-07304814 in complex with Mpros of various coronaviruses reveal their inhibitory mechanisms against different Mpros. However, the structural information on the lower pathogenic coronavirus Mpro with PF-07321332 or PF-07304814 is currently scarce, which hinders our comprehensive understanding of the inhibitory mechanisms of these two inhibitors. Meanwhile, given that some immunocompromised individuals are still affected by low pathogenic coronaviruses, we determined the structures of lower pathogenic coronavirus HCoV-229E Mpro with PF-07321332 and PF-07304814, respectively, and analyzed and defined in detail the structural basis for the inhibition of HCoV-229E Mpro by both inhibitors. Further, we compared the crystal structures of multiple coronavirus Mpro complexes with PF-07321332 or PF-07304814 to illustrate the differences in the interaction of Mpros, and found that the inhibition mechanism of lower pathogenic coronavirus Mpro was more similar to that of moderately pathogenic coronaviruses. Our structural studies provide new insights into drug development for low pathogenic coronavirus Mpro, and provide theoretical basis for further optimization of both inhibitors to contain potential future coronaviruses.


Assuntos
COVID-19 , Coronavirus Humano 229E , Humanos , Coronavirus Humano 229E/fisiologia , SARS-CoV-2/metabolismo , Peptídeo Hidrolases/metabolismo
12.
J Virol ; 96(1): e0125321, 2022 01 12.
Artigo em Inglês | MEDLINE | ID: mdl-34586857

RESUMO

Over the past 20 years, the severe acute respiratory syndrome coronavirus (SARS-CoV), Middle East respiratory syndrome CoV (MERS-CoV), and SARS-CoV-2 emerged, causing severe human respiratory diseases throughout the globe. Developing broad-spectrum drugs would be invaluable in responding to new, emerging coronaviruses and to address unmet urgent clinical needs. Main protease (Mpro; also known as 3CLpro) has a major role in the coronavirus life cycle and is one of the most important targets for anti-coronavirus agents. We show that a natural product, noncovalent inhibitor, shikonin, is a pan-main protease inhibitor of SARS-CoV-2, SARS-CoV, MERS-CoV, human coronavirus (HCoV)-HKU1, HCoV-NL63, and HCoV-229E with micromolar half maximal inhibitory concentration (IC50) values. Structures of the main protease of different coronavirus genus, SARS-CoV from the betacoronavirus genus and HCoV-NL63 from the alphacoronavirus genus, were determined by X-ray crystallography and revealed that the inhibitor interacts with key active site residues in a unique mode. The structure of the main protease inhibitor complex presents an opportunity to discover a novel series of broad-spectrum inhibitors. These data provide substantial evidence that shikonin and its derivatives may be effective against most coronaviruses as well as emerging coronaviruses of the future. Given the importance of the main protease for coronavirus therapeutic indication, insights from these studies should accelerate the development and design of safer and more effective antiviral agents. IMPORTANCE The current pandemic has created an urgent need for broad-spectrum inhibitors of SARS-CoV-2. The main protease is relatively conservative compared to the spike protein and, thus, is one of the most promising targets in developing anti-coronavirus agents. We solved the crystal structures of the main protease of SARS-CoV and HCoV-NL63 that bound to shikonin. The structures provide important insights, have broad implications for understanding the structural basis underlying enzyme activity, and can facilitate rational design of broad-spectrum anti-coronavirus ligands as new therapeutic agents.


Assuntos
Antivirais/química , Proteases 3C de Coronavírus/antagonistas & inibidores , Inibidores de Proteases/química , Domínio Catalítico , Coronavirus/classificação , Coronavirus/enzimologia , Proteases 3C de Coronavírus/química , Cristalografia por Raios X , Simulação de Acoplamento Molecular , Naftoquinonas/química , Ligação Proteica
13.
BMC Infect Dis ; 23(1): 163, 2023 Mar 16.
Artigo em Inglês | MEDLINE | ID: mdl-36927441

RESUMO

BACKGROUND: Ureaplasma urealyticum is the most prevalent genital mycoplasma isolated from the urogenital tract of females, but there is no unified treatment plan. This study aimed to evaluate the efficacy of azithromycin in treating Ureaplasma urealyticum. METHODS: From the earliest to June 2022, published randomized controlled trials (RCTs) on azithromycin treatment of Ureaplasma urealyticum were retrieved by searching PubMed, Embase, Cochrane Library, and Web of Science. Two reviewers independently extracted the data. We utilized the Cochrane risk-of-bias assessment technique to assess the quality of included RCTs. The data were analyzed using the R language (version 4.0.4) software. RESULTS: Seven RCTs were finally included, involving 512 participants (240 in the experimental group, 272 in the control group). The experimental group was treated with azithromycin monotherapy, while the control group was treated with doxycycline or a placebo. Meta-analysis results suggested that azithromycin has a comparable therapeutic effect on Ureaplasma urealyticum in comparison to that of controls (risk ratio [RR] = 1.03, 95% confidence interval [CI] 0.94-1.12). Subgroup analysis showed that the dose and duration of azithromycin may don't affect its efficacy. CONCLUSION: Regarding the meta-analysis that we performed based on existing clinical studies, azithromycin is quite effective in treating Ureaplasma urealyticum.


Assuntos
Azitromicina , Infecções por Ureaplasma , Feminino , Humanos , Azitromicina/uso terapêutico , Azitromicina/farmacologia , Ureaplasma urealyticum , Doxiciclina/uso terapêutico , Infecções por Ureaplasma/tratamento farmacológico , Antibacterianos/uso terapêutico , Antibacterianos/farmacologia , Ureaplasma
14.
Acta Biochim Biophys Sin (Shanghai) ; 55(8): 1257-1264, 2023 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-37357528

RESUMO

Main protease (M pro) serves as an indispensable factor in the life cycle of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) as well as its constantly emerging variants and is therefore considered an attractive target for antiviral drug development. Benzothiazole-based inhibitors targeting M pro have recently been investigated by several groups and proven to be promising leads for coronaviral drug development. In the present study, we determine the crystal structures of a benzothiazole-based inhibitor, YH-53, bound to M pro mutants from SARS-CoV-2 variants of concern (VOCs) or variants of interest (VOIs), including K90R (Beta, B.1.351), G15S (Lambda, C.37), Y54C (Delta, AY.4), M49I (Omicron, BA.5) and P132H (Omicron, B.1.1.529). The structures show that the benzothiazole group in YH-53 forms a C-S covalent bond with the sulfur atom of catalytic residue Cys145 in SARS-CoV-2 M pro mutants. Structural analysis reveals the key molecular determinants necessary for interaction and illustrates the binding mode of YH-53 to these mutant M pros. In conclusion, structural insights from this study offer more information to develop benzothiazole-based drugs that are broader spectrum, more effective and safer.


Assuntos
COVID-19 , SARS-CoV-2 , Humanos , SARS-CoV-2/genética , SARS-CoV-2/metabolismo , Inibidores de Proteases/química , Cisteína Endopeptidases/genética , Cisteína Endopeptidases/metabolismo , Antivirais/farmacologia , Benzotiazóis , Simulação de Acoplamento Molecular
15.
J Biol Chem ; 296: 100479, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33640454

RESUMO

Nucleoside homeostasis, which is mediated by transporters and channels, is essential for all life on Earth. In Escherichia coli, NupG mediates the transport of nucleosides and was deemed to be the prototype of the nucleoside proton symporter (NHS) family and the major facilitator superfamily. To date, the substrate recognition and transport mechanisms of NHS transporters are still elusive. Here, we report two crystal structures of NupG (WT and D323A NupG) resolved at 3.0 Å. Both structures reveal an identical inward-open conformation. Together with molecular docking and molecular dynamics simulations and in vitro uridine-binding assays, we found that the uridine binding site, which locates in the central cavity between N and C domains of NupG, is constituted by R136, T140, F143, Q225, N228, Q261, E264, Y318, and F322. Moreover, we found that D323 is very important for substrate binding via in vitro uridine-binding assays using D323 mutations, although it does not have a direct contact with uridine. Our structural and biochemical data therefore provide an important framework for the mechanistic understanding of nucleoside transporters of the NHS family.


Assuntos
Proteínas de Escherichia coli/metabolismo , Proteínas de Membrana Transportadoras/metabolismo , Sequência de Aminoácidos , Sítios de Ligação , Transporte Biológico , Escherichia coli/genética , Proteínas de Escherichia coli/genética , Proteínas de Membrana Transportadoras/genética , Modelos Moleculares , Simulação de Acoplamento Molecular , Proteínas de Transporte de Nucleosídeos/genética , Proteínas de Transporte de Nucleosídeos/metabolismo , Nucleosídeos/metabolismo , Simportadores/metabolismo
16.
Acta Biochim Biophys Sin (Shanghai) ; 54(5): 637-646, 2022 May 25.
Artigo em Inglês | MEDLINE | ID: mdl-35920197

RESUMO

Apurinic/apyrimidic (AP) sites are severe DNA damages and strongly block DNA extension by major DNA polymerases. Y-family DNA polymerases possess a strong ability to bypass AP sites and continue the DNA synthesis reaction, which is called translesion synthesis (TLS) activity. To investigate the effect of the molecular structure of the AP site on the TLS efficiency of Dbh, a Y-family DNA polymerase from Sulfolobus acidocaldarius, a series of different AP site analogues (various spacers) are used to characterize the bypass efficiency. We find that not only the molecular structure and atomic composition but also the number and position of AP site analogues determine the TLS efficiency of Dbh. Increasing the spacer length decreases TLS activity. The TLS efficiency also decreases when more than one spacer exists on the DNA template. The position of the AP site analogues is also an important factor for TLS. When the spacer is opposite to the first incorporated dNTPs, the TLS efficiency is the lowest, suggesting that AP sites are largely harmful for the formation of hydrogen bonds. These results deepen our understanding of the TLS activity of Y-family DNA polymerases and provide a biochemical basis for elucidating the TLS mechanism in Sulfolobus acidocaldarius cells.


Assuntos
Sulfolobus acidocaldarius , DNA/química , Dano ao DNA , Reparo do DNA , Replicação do DNA , DNA Polimerase Dirigida por DNA/genética , Sulfolobus acidocaldarius/genética , Sulfolobus acidocaldarius/metabolismo
17.
Sensors (Basel) ; 22(18)2022 Sep 18.
Artigo em Inglês | MEDLINE | ID: mdl-36146404

RESUMO

Synthetic aperture radar (SAR) is an important remote sensing sensor whose application is becoming more and more extensive. Compared with traditional optical sensors, it is not easy to be disturbed by the external environment and has a strong penetration. Limited by its working principles, SAR images are not easily interpreted, and fusing SAR images with optical multispectral images is a good solution to improve the interpretability of SAR images. This paper presents a novel image fusion method based on non-subsampled shearlet transform and activity measure to fuse SAR images with multispectral images, whose aim is to improve the interpretation ability of SAR images easily obtained at any time, rather than producing a fused image containing more information, which is the pursuit of previous fusion methods. Three different sensors, together with different working frequencies, polarization modes and spatial resolution SAR datasets, are used to evaluate the proposed method. Both visual evaluation and statistical analysis are performed, the results show that satisfactory fusion results are achieved through the proposed method and the interpretation ability of SAR images is effectively improved compared with the previous methods.

18.
BMC Nurs ; 21(1): 256, 2022 Sep 19.
Artigo em Inglês | MEDLINE | ID: mdl-36123689

RESUMO

BACKGROUND: Due to the high nursing pressure of patients with cerebral hemorrhage and the general shortage of clinical nurses, nursing support workers often participate in clinical nursing work, but the influence of nursing support workers' participation on the negative emotion, quality of life and life satisfaction of patients with intracerebral hemorrhage is unknown. METHODS: This quasi-experimental study was conducted with a pretest-posttest design. A total of 181 ICH patients admitted to our hospital from January 2022 to April 2022 were enrolled, including 81 patients receiving conventional care (CG control group) and 80 patients receiving nursing support worker participation (RG research group). All patients were recorded with self-perceived Burden Scale (SPBS), Hamilton Depression Scale (HAMD), Quality of Life Scale (SF-36), Somatic Self rating Scale (SSS), Patient self-care ability assessment scale (Barthel) and Satisfaction with life scale (SWLS) scores. RESULTS: Patients with high negative emotion were more willing to participate in clinical nursing work (p < 0.05). Nursing support workers involved in cerebral hemorrhage patients can alleviate negative emotions, improve life quality, improve life satisfaction (p < 0.05). CONCLUSION: The participation of nursing support workers can alleviate the negative emotions of ICH patients, enhance their self-management ability, and improve their life quality.

19.
J Struct Biol ; 213(2): 107710, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33610655

RESUMO

KW-2478 is a promising anti-cancer lead compound targeting to the molecular chaperone heat shock protein 90 N (Hsp90N). Absence of complex crystal structure of Hsp90N-KW-2478, however, hampered further structure optimization of KW-2478 and understanding on the molecular interaction mechanism. Herein, a high-resolution complex crystal structure of Hsp90N-KW-2478 was determined by X-ray diffraction (XRD, resolution limit: 1.59 Å; PDB ID: 6LT8) and their molecular interaction was analyzed in detail, which suggested that KW-2478 perfectly bound in the N-terminal ATP-binding pocket of Hsp90 to disable its molecular chaperone function, therefore suppressed or killed cancer cells. The results from thermal shift assay (TSA, ΔTm, 18.82 ± 0.51 °C) and isothermal titration calorimetry (ITC, Kd, 7.30 ± 2.20 nM) suggested that there is an intense binding force and favorable thermodynamic changes during the process of KW-2478 binding with Hsp90N. Additionally, KW-2478 exhibited favorable anti-NSCLC activity in vitro, as it inhibited cell proliferation (IC50, 8.16 µM for A549; 14.29 µM for H1975) and migration, induced cell cycle arrest and promoted apoptosis. Thirty-six novel KW-2478 derivatives were designed, based on the complex crystal structure and molecular interaction analysis of Hsp90N-KW-2478 complex. Among them, twenty-two derivatives exhibited increased binding force with Hsp90N evaluated by molecular docking assay. The results would provide new guidance for anti-NSCLC new drug development based on the lead compound KW-2478.


Assuntos
Antineoplásicos/farmacologia , Proteínas de Choque Térmico HSP90/antagonistas & inibidores , Proteínas de Choque Térmico HSP90/química , Morfolinas/química , Morfolinas/farmacologia , Antineoplásicos/química , Antineoplásicos/metabolismo , Apoptose/efeitos dos fármacos , Calorimetria , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Carcinoma Pulmonar de Células não Pequenas/patologia , Pontos de Checagem do Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Cristalografia por Raios X , Proteínas de Choque Térmico HSP90/metabolismo , Humanos , Ligação de Hidrogênio , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/patologia , Simulação de Acoplamento Molecular , Morfolinas/metabolismo , Estabilidade Proteica , Relação Estrutura-Atividade
20.
Cell Mol Neurobiol ; 41(5): 961-975, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32323150

RESUMO

Compound 511 (511) is specially developed for opioid addiction treatment based on the Ancient Chinese drug rehabilitation literature, and its composition has profound effects in the treatment of drug addiction in various clinical trials and animal experiments. The effect of 511 on the rewarding properties of morphine and craving responses and its potential mechanisms remain unclear. Here, we have applied a conditioned place preference (CPP) paradigm in mice to measure morphine-induced rewarding effects under the treatment of 511. Then we used the RNA sequencing strategy to screen its potential mechanisms. In our research, firstly, we found 511 could decrease CPP score, locomotor activity, self-administration, jumping behavior, weight loss, wet-dog shakes, and stereotyped behavior. Then the brain VTA region tissues were performed mRNA sequencing to detect potential mechanisms. We found the brain-derived neurotrophic factor (BDNF) and tropomyosin-related kinase B (TrkB) were downregulated in morphine-induced CPP, whereas the decreased BDNF and TrkB were reversed after 511 treatment. We retested the levels of BDNF and TrkB using qRT-PCR and Western blot and found the similar results to mRNA sequencing. It has been widely reported that BDNF-TrkB signaling in the VTA is involved in multiple facets of addiction, including reward and motivation, so we focused on the BDNF-TrkB signaling to investigate the anti-addiction mechanisms of 511 in morphine addiction mice. We studied the downstream pathway of BDNF-TrkB and the soma size of dopaminergic neurons. The results showed 511 could increase the phosphorylation levels of PI3K and AKT, which were decreased in morphine-induced CPP. Simultaneously, 511 could decrease the level of PLCγ1 and the phosphorylation levels of ERK and S6K, which were increased in morphine-induced CPP. In addition, 511 also enlarged the soma size of VTA dopaminergic neurons, which was reduced in morphine-induced CPP. Hence, our research indicated 511 maybe mediate the BDNF-TrkB signaling in VTA to improve morphine addiction behavior.


Assuntos
Fator Neurotrófico Derivado do Encéfalo/metabolismo , Condicionamento Clássico/fisiologia , Medicamentos de Ervas Chinesas/farmacologia , Glicoproteínas de Membrana/metabolismo , Morfina/administração & dosagem , Proteínas Tirosina Quinases/metabolismo , Área Tegmentar Ventral/metabolismo , Animais , Fator Neurotrófico Derivado do Encéfalo/antagonistas & inibidores , Condicionamento Clássico/efeitos dos fármacos , Medicamentos de Ervas Chinesas/química , Masculino , Glicoproteínas de Membrana/antagonistas & inibidores , Camundongos , Camundongos Endogâmicos C57BL , Antagonistas de Entorpecentes/química , Antagonistas de Entorpecentes/farmacologia , Proteínas Tirosina Quinases/antagonistas & inibidores , Recompensa , Autoadministração , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/fisiologia , Área Tegmentar Ventral/efeitos dos fármacos
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