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1.
Zhonghua Nan Ke Xue ; 27(3): 231-235, 2021 Mar.
Artigo em Chinês | MEDLINE | ID: mdl-34914305

RESUMO

Objective: To investigate the clinical characteristics, diagnosis, treatment and etiology of persistent Müllerian duct syndrome (PMDS). METHODS: A 3-year-old boy was diagnosed with PMDS according to the clinical manifestations and the results of ultrasonography, laboratory examinations and earlier surgical examination. We performed genetic tests for the patient and his family members, removed the infantile uterus by laparoscopic wedge hysterectomy, biopsied and descended the bilateral testes, and ligated the bilateral internal rings, followed by a retrospective analysis and review of relevant literature. RESULTS: The operation was successful. Gonad biopsy revealed testis tissue, and PMDS was confirmed by intraoperative findings and related examinations. Good bilateral testicular blood supply was found during the 6-month follow-up after surgery. Medical exome sequencing showed the AMHR2 gene c.1499G > A (p.Cys500Tyr) mutant homozygote (A/A) in the patient and his sister and mutant heterozygote (G/A) in his parents. CONCLUSIONS: Laparoscopy is definitely effective for the treatment of PMDS. In surgery, the infantile uterus should be removed in case of good blood supply to the testis, and so were the bilateral testes if they cannot be descended. The homozygous mutation in the AMHR2 gene c. 1499G > A (p. Cys500Tyr) can lead to male PMDS. Pedigree investigation may provide some evidence for possible fertility in PMDS patients.


Assuntos
Laparoscopia , Pré-Escolar , Transtorno 46,XY do Desenvolvimento Sexual , Humanos , Masculino , Linhagem , Estudos Retrospectivos
3.
Cell ; 184(7): 1895-1913.e19, 2021 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-33657410

RESUMO

A dysfunctional immune response in coronavirus disease 2019 (COVID-19) patients is a recurrent theme impacting symptoms and mortality, yet a detailed understanding of pertinent immune cells is not complete. We applied single-cell RNA sequencing to 284 samples from 196 COVID-19 patients and controls and created a comprehensive immune landscape with 1.46 million cells. The large dataset enabled us to identify that different peripheral immune subtype changes are associated with distinct clinical features, including age, sex, severity, and disease stages of COVID-19. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RNA was found in diverse epithelial and immune cell types, accompanied by dramatic transcriptomic changes within virus-positive cells. Systemic upregulation of S100A8/A9, mainly by megakaryocytes and monocytes in the peripheral blood, may contribute to the cytokine storms frequently observed in severe patients. Our data provide a rich resource for understanding the pathogenesis of and developing effective therapeutic strategies for COVID-19.


Assuntos
COVID-19/imunologia , Megacariócitos/imunologia , Monócitos/imunologia , RNA Viral , SARS-CoV-2/genética , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , China , Estudos de Coortes , Citocinas/metabolismo , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , RNA Viral/sangue , RNA Viral/isolamento & purificação , Análise de Célula Única , Transcriptoma/imunologia , Adulto Jovem
4.
Oncogene ; 39(44): 6871-6878, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32978518

RESUMO

5-10% of total prostate cancer (PCa) cases are hereditary. Particularly, immune checkpoint inhibitor-sensitive tandem duplicator phenotype (TDP) accounts for 6.9% of PCa cases, whereas genetic susceptibility genes remain completely unknown. We identified a Chinese family with two PCa patients, in which the PCa phenotype co-segregated with a rare germline variant EGFRR831H. Patient-derived conditionally reprogrammed cells (CRC) exhibited increased EGFR and AKT phosphorylation, and a sensitivity to EGFR antagonist Afatinib in migration assays, suggesting the EGFR allele was constitutively active. Both EGFRR831H-mutant tumours contained biallelic CDK12 inactivation, together with prominent tandem duplication across the genome. These somatic mutations could be detected in urine before surgery. Analysis of public databases showed a significant correlation between the mutation status of EGFR and CDK12. Taken together, our genetic and functional analyses identified a previously undescribed link between EGFR and PCa.


Assuntos
Quinases Ciclina-Dependentes/genética , Predisposição Genética para Doença , Neoplasias da Próstata/genética , Idoso , Alelos , Linhagem Celular Tumoral , Quimioterapia Adjuvante , Variações do Número de Cópias de DNA , Análise Mutacional de DNA , Receptores ErbB/genética , Feminino , Mutação em Linhagem Germinativa , Humanos , Masculino , Linhagem , Próstata/patologia , Próstata/cirurgia , Prostatectomia , Neoplasias da Próstata/diagnóstico , Neoplasias da Próstata/patologia , Neoplasias da Próstata/terapia , Sequências de Repetição em Tandem/genética
5.
Kidney Int ; 94(5): 974-982, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-30173899

RESUMO

Genome-wide associations and HLA genotyping have revealed associations between HLA alleles and susceptibility to primary membranous nephropathy. However, associations with clinical phenotypes and kidney outcome are poorly defined. We previously identified DRB1*1501 and DRB1*0301 as independent risk alleles for primary membranous nephropathy. Here, we investigated HLA associations with demographic characteristics, anti-phospholipase A2 receptor (PLA2R) antibody, treatment response and kidney outcome after a median follow-up of 52 months in 258 patients. DRB1*0301, but not DRB1*1501, was associated with a significantly higher level of PLA2R antibody (odds ratio 1.58, 95% confidence interval 1.13-2.22). Although DRB1*1502, which differs from DRB1*1501 by a single amino acid, was not a risk allele for primary membranous nephropathy (odds ratio 1.01), it was associated with significantly lower estimated glomerular filtration rates both at baseline (1.79, 1.18-2.72) and at last follow-up (1.72, 1.17-2.53), a significantly worse renal outcome by Kaplan-Meier analysis and a significantly higher risk of end-stage renal disease by Cox regression analysis (hazard ratio 4.52, 1.22-16.74). Nevertheless, the absence of remission remained the only independent risk factor for end-stage renal disease by multivariate analysis. DRB1*1502 was also associated with a significantly higher median PLA2R antibody level [161.4 vs. 36.3 U/mL] and showed interaction with DRB1*0301 for this variable. Thus, HLA genes control PLA2R antibody production and primary membranous nephropathy severity and outcome. Additionally, DRB1*1502 behaves like a modifier gene with a strong predictor value when associated with HLA risk alleles. Other modifier genes need further investigations in larger cohorts.


Assuntos
Autoanticorpos/biossíntese , Glomerulonefrite Membranosa/genética , Cadeias HLA-DRB1/genética , Receptores da Fosfolipase A2/imunologia , Adulto , Idoso , Alelos , Feminino , Glomerulonefrite Membranosa/imunologia , Cadeias HLA-DRB1/química , Humanos , Masculino , Pessoa de Meia-Idade , Simulação de Acoplamento Molecular , Fenótipo , Modelos de Riscos Proporcionais
6.
Nucleic Acids Res ; 46(W1): W374-W379, 2018 07 02.
Artigo em Inglês | MEDLINE | ID: mdl-29750256

RESUMO

CavityPlus is a web server that offers protein cavity detection and various functional analyses. Using protein three-dimensional structural information as the input, CavityPlus applies CAVITY to detect potential binding sites on the surface of a given protein structure and rank them based on ligandability and druggability scores. These potential binding sites can be further analysed using three submodules, CavPharmer, CorrSite, and CovCys. CavPharmer uses a receptor-based pharmacophore modelling program, Pocket, to automatically extract pharmacophore features within cavities. CorrSite identifies potential allosteric ligand-binding sites based on motion correlation analyses between cavities. CovCys automatically detects druggable cysteine residues, which is especially useful to identify novel binding sites for designing covalent allosteric ligands. Overall, CavityPlus provides an integrated platform for analysing comprehensive properties of protein binding cavities. Such analyses are useful for many aspects of drug design and discovery, including target selection and identification, virtual screening, de novo drug design, and allosteric and covalent-binding drug design. The CavityPlus web server is freely available at http://repharma.pku.edu.cn/cavityplus or http://www.pkumdl.cn/cavityplus.


Assuntos
Internet , Proteínas/química , Software , Sítio Alostérico , Sítios de Ligação/genética , Fenômenos Biofísicos , Ligantes , Ligação Proteica/genética , Conformação Proteica , Proteínas/genética
7.
Mol Immunol ; 88: 1-9, 2017 08.
Artigo em Inglês | MEDLINE | ID: mdl-28570922

RESUMO

BACKGROUND: Anti-GBM disease is caused by autoimmunity to Goodpasture antigen on α3(IV)NC1 and had strong associations with HLA-DRB1*1501. Previous studies identified α3127-148 (P14: TDIPPCPHGWISLWKGFSFIMF) as a T cell epitope. The present study was aimed to investigate the binding capacity of P14 to HLA-DRB1*1501 and the critical amino acids for this binding. METHODS: A line of EBV-transformed human B cells homozygous for HLA-DRB1*1501 was used to detect the binding capacity of peptides to HLA-DRB1*1501 using flow cytometry analysis. P14 was sequentially truncated into 8 peptides with 15 amino acids to identify the core binding motif. A set of alanine substituted peptides of P14-2 was then synthesized to identify its critical residues for binding to HLA-DRB1*1501. The structure of HLA-DR2b-Peptide-TCR complex was constructed by modeling to analyze the interaction of each amino acids of P14-2 with the HLA-DR2b molecule. RESULTS: P14 could bind to HLA-DRB1*1501 expressed on B cell surface. The N-terminus of P14 was the core binding motif and the truncated peptide P14-2 (DIPPCPHGWISLWKG) 128-142 had the strongest binding capacity. After sequential amino acid substitution, we found the binding capacity of P14-2 was completely lost by the substitution of cysteine (C) 132 and significantly decreased by the substitution of tryptophan (W) 136, lysine (K) 141, or glycine (G) 142, but still at a high level. The modeling showed that (C) 132 had a strong interaction with pocket 4 on the ß chain of DR2b. Thus, C132, W 136, K141, and G142 were defined as the critical amino acid residues for the binding capacity of P14 to HLA-DRB1*1501. CONCLUSION: We identified α3128-142 (DIPPCPHGWISLWKG) as the core binding motif of P14 to HLA-DRB1*1501 molecule. And the critical amino acid residues for this binding were further defined as C132, W 136, K 141, and G 142.


Assuntos
Doença Antimembrana Basal Glomerular/imunologia , Autoantígenos/imunologia , Sítios de Ligação de Anticorpos/genética , Colágeno Tipo IV/imunologia , Epitopos de Linfócito T/genética , Cadeias HLA-DRB1/imunologia , Substituição de Aminoácidos , Doença Antimembrana Basal Glomerular/genética , Autoimunidade/imunologia , Linfócitos B/imunologia , Sítios de Ligação de Anticorpos/imunologia , Linhagem Celular Transformada , Epitopos de Linfócito T/imunologia , Cadeias HLA-DRB1/metabolismo , Humanos , Estrutura Secundária de Proteína
8.
Immunology ; 151(4): 395-404, 2017 08.
Artigo em Inglês | MEDLINE | ID: mdl-28342268

RESUMO

Goodpasture's disease is closely associated with HLA, particularly DRB1*1501. Other susceptible or protective HLA alleles are not clearly elucidated. The presentation models of epitopes by susceptible HLA alleles are also unclear. We genotyped 140 Chinese patients and 599 controls for four-digit HLA II genes, and extracted the encoding sequences from the IMGT/HLA database. T-cell epitopes of α3(IV)NC1 were predicted and the structures of DR molecule-peptide-T-cell receptor were constructed. We confirmed DRB1*1501 (OR = 4·6, P = 5·7 × 10-28 ) to be a risk allele for Goodpasture's disease. Arginine at position 13 (ARG13) (OR = 4·0, P = 1·0 × 10-17 ) and proline at position 11 (PRO11) (OR = 4·0, P = 2·0 × 10-17 ) on DRß1, encoded by DRB1*1501, were associated with disease susceptibility. α134-148 (HGWISLWKGFSFIMF) was predicted as a T-cell epitope presented by DRB1*1501. Isoleucine137 , tryptophan140 , glycine142 , phenylalanine143 and phenylalanine145 , were presented in peptide-binding pockets 1, 4, 6, 7 and 9 of DR2b, respectively. ARG13 in pocket 4 interacts with tryptophan140 and forms a hydrogen bond. In conclusion, we propose a mechanism for DRB1*1501 susceptibility for Goodpasture's disease through encoding ARG13 and PRO11 on MHC-DRß1 chain and presenting T-cell epitope, α134-148 , with five critical residues.


Assuntos
Doença Antimembrana Basal Glomerular/imunologia , Autoantígenos/metabolismo , Colágeno Tipo IV/metabolismo , Epitopos de Linfócito T/metabolismo , Cadeias HLA-DRB1/metabolismo , Linfócitos T/imunologia , Alelos , Autoantígenos/genética , China , Colágeno Tipo IV/genética , Simulação por Computador , Mapeamento de Epitopos , Epitopos de Linfócito T/genética , Predisposição Genética para Doença , Genótipo , Cadeias HLA-DRB1/genética , Humanos , Polimorfismo Genético , Ligação Proteica , Conformação Proteica , Receptores de Antígenos de Linfócitos T/metabolismo , Risco
9.
J Am Soc Nephrol ; 28(5): 1651-1664, 2017 May.
Artigo em Inglês | MEDLINE | ID: mdl-27852637

RESUMO

Epitopes of phospholipase A2 receptor (PLA2R), the target antigen in idiopathic membranous nephropathy (iMN), must be presented by the HLA-encoded MHC class II molecules to stimulate autoantibody production. A genome-wide association study identified risk alleles at HLA and PLA2R loci, with the top variant rs2187668 within HLA-DQA1 showing a risk effect greater than that of the top variant rs4664308 within PLA2R1. How the HLA risk alleles affect epitope presentation by MHC class II molecules in iMN is unknown. Here, we genotyped 261 patients with iMN and 599 healthy controls at the HLA-DRB1, HLA-DQA1, HLA-DQB1, and HLA-DPB1 loci with four-digit resolution and extracted the encoded amino acid sequences from the IMGT/HLA database. We predicted T cell epitopes of PLA2R and constructed MHC-DR molecule-PLA2R peptide-T cell receptor structures using Modeler. We identified DRB1*1501 (odds ratio, 4.65; 95% confidence interval [95% CI], 3.39 to 6.41; P<0.001) and DRB1*0301 (odds ratio, 3.96; 95% CI, 2.61 to 6.05; P<0.001) as independent risk alleles for iMN and associated with circulating anti-PLA2R antibodies. Strong gene-gene interaction was noted between rs4664308(AA) and HLA-DRB1*1501/DRB1*0301. Amino acid positions 13 (P<0.001) and 71 (P<0.001) in the MHC-DRß1 chain independently associated with iMN. Structural models showed that arginine13 and alanine71, encoded by DRB1*1501, and lysine71, encoded by DRB1*0301, facilitate interactions with T cell epitopes of PLA2R. In conclusion, we identified two risk alleles of HLA class II genes and three amino acid residues on positions 13 and 71 of the MHC-DRß1 chain that may confer susceptibility to iMN by presenting T cell epitopes on PLA2R.


Assuntos
Alelos , Aminoácidos/fisiologia , Genes MHC da Classe II/fisiologia , Glomerulonefrite Membranosa/genética , Glomerulonefrite Membranosa/imunologia , Antígenos HLA-DR/fisiologia , Humanos , Receptores da Fosfolipase A2/fisiologia , Fatores de Risco
10.
Chem Biol Drug Des ; 89(5): 732-740, 2017 05.
Artigo em Inglês | MEDLINE | ID: mdl-27882722

RESUMO

Polo-like kinase 1 (Plk1), a member of polo-like kinase family, regulates multiple essential steps of the cell cycle progression. Plk1 is overexpressed in multiple cancer cell lines and considered to be a prime anticancer target. Plk1 accumulates in the nucleus during S and G2 phases by its bipartite nuclear localization signal (NLS) sequence, which is crucial for Plk1 regulation during normal cell cycle progression. Here, through combined computational and experimental studies, we identified compound D110, which inhibits Plk1 kinase activity with an IC50 of 85 nm and blocks the nuclear localization of Plk1 during S and G2 phases. D110-treated cancer cells were arrested at mitosis with monopolar spindle, indicating the inhibition of the Plk1 kinase activity in cell. As D110 interacts with both the ATP site and the NLS in Plk1, it demonstrates good selectivity toward Plk2 and Plk3. The strategy of simultaneously inhibiting kinase activity and its subcellular translocations offers a novel approach for selective kinase inhibitor design.


Assuntos
Proteínas de Ciclo Celular/antagonistas & inibidores , Inibidores de Proteínas Quinases/química , Proteínas Proto-Oncogênicas/antagonistas & inibidores , Bases de Schiff/química , Tiazolidinas/química , Apoptose/efeitos dos fármacos , Sítios de Ligação , Proteínas de Ciclo Celular/metabolismo , Núcleo Celular/metabolismo , Desenho de Fármacos , Pontos de Checagem da Fase G2 do Ciclo Celular/efeitos dos fármacos , Células HeLa , Humanos , Microscopia de Fluorescência , Mitose/efeitos dos fármacos , Simulação de Acoplamento Molecular , Domínios Proteicos , Inibidores de Proteínas Quinases/síntese química , Inibidores de Proteínas Quinases/farmacologia , Proteínas Proto-Oncogênicas/metabolismo , Bases de Schiff/metabolismo , Bases de Schiff/farmacologia , Transdução de Sinais/efeitos dos fármacos , Tiazolidinas/metabolismo , Tiazolidinas/farmacologia
11.
J Med Chem ; 59(15): 7089-96, 2016 Aug 11.
Artigo em Inglês | MEDLINE | ID: mdl-27425654

RESUMO

Polo-like kinase 1(Plk1) is vital for cell mitosis and has been identified as anticancer target. Its polo-box domain (PBD) mediates substrate binding, blocking of which may offer selective Plk1 inhibition compared to kinase domain inhibitors. Although several PBD inhibitors were reported, most of them suffer from low cell activity. Here, we report the discovery of novel inhibitors to induce mitotic arrest in HeLa cells by virtual screening with Plk1 PBD and cellular activity testing. Of the 81 compounds tested in the cell assay, 10 molecules with diverse chemical scaffolds are potent to induce mitotic arrest of HeLa at low micromolar concentrations. The best compound induces mitotic arrest of HeLa cells with an EC50 of 4.4 µM. The cellular active inhibitors showed binding to Plk1 PBD and compete with PBD substrate in microscale thermophoresis analysis.


Assuntos
Proteínas de Ciclo Celular/antagonistas & inibidores , Descoberta de Drogas , Mitose/efeitos dos fármacos , Inibidores de Proteínas Quinases/farmacologia , Proteínas Proto-Oncogênicas/antagonistas & inibidores , Ciclo Celular/efeitos dos fármacos , Proteínas de Ciclo Celular/metabolismo , Proliferação de Células/efeitos dos fármacos , Relação Dose-Resposta a Droga , Células HeLa , Humanos , Modelos Moleculares , Estrutura Molecular , Inibidores de Proteínas Quinases/síntese química , Inibidores de Proteínas Quinases/química , Proteínas Proto-Oncogênicas/metabolismo , Relação Estrutura-Atividade , Células Tumorais Cultivadas
12.
J Cell Physiol ; 231(1): 172-80, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26058566

RESUMO

SHC3 is exclusively expressed in postmitotic neurons, while SHC1 is found in neural stem cells and neural precursor cells but absent in mature neurons. In this study, we discovered that suppression of p52SHC1 expression by RNA interference resulted in proliferation defects in neural stem cells, along with significantly reduced protein levels of cyclin E and cyclin A. At the same time, p52SHC3 RNAi caused cell cycle re-entry (9.54% in S phase and 5.70% in G2-M phase) in primary neurons with significantly up-regulated expression of cyclin D1, cyclin E, cyclin A, CDK2, and phosphorylated CDK2. When p52SHC3 was overexpressed, the cell cycle of neural stem cells was arrested with reduced protein levels of cyclin D1, cyclin E, and cyclin A, while overexpression of p52SHC1 did not result in significant changes in postmitotic neurons. Our results indicate that p52SHC3 plays an important role in maintaining the mitotic quiescence of neurons, while p52SHC1 regulates the proliferation of neural stem cells.


Assuntos
Ciclo Celular/fisiologia , Quinase 2 Dependente de Ciclina/metabolismo , Células-Tronco Neurais/metabolismo , Neurônios/metabolismo , Proteínas Adaptadoras da Sinalização Shc/metabolismo , Animais , Divisão Celular/fisiologia , Proliferação de Células/efeitos dos fármacos , Ciclina A/metabolismo , Ratos Wistar , Proteína 1 de Transformação que Contém Domínio 2 de Homologia de Src , Proteína 3 de Transformação que Contém Domínio 2 de Homologia de Src
13.
J Chem Inf Model ; 55(10): 2085-93, 2015 Oct 26.
Artigo em Inglês | MEDLINE | ID: mdl-26437739

RESUMO

Drug-induced liver injury (DILI) has been the single most frequent cause of safety-related drug marketing withdrawals for the past 50 years. Recently, deep learning (DL) has been successfully applied in many fields due to its exceptional and automatic learning ability. In this study, DILI prediction models were developed using DL architectures, and the best model trained on 475 drugs predicted an external validation set of 198 drugs with an accuracy of 86.9%, sensitivity of 82.5%, specificity of 92.9%, and area under the curve of 0.955, which is better than the performance of previously described DILI prediction models. Furthermore, with deep analysis, we also identified important molecular features that are related to DILI. Such DL models could improve the prediction of DILI risk in humans. The DL DILI prediction models are freely available at http://www.repharma.cn/DILIserver/DILI_home.php.


Assuntos
Doença Hepática Induzida por Substâncias e Drogas , Modelos Biológicos , Retirada de Medicamento Baseada em Segurança , Software/normas , Algoritmos , Glicina/química , Humanos , Curva ROC , Fatores de Risco
14.
J Mol Model ; 21(8): 208, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-26216223

RESUMO

Alpha-cyclodextrin (α-CD) glycosyltransferase (α-CGTase) can convert starch into α-CD blended with various proportions of ß-cyclodextrin (ß-CD) and/or γ-cyclodextrin (γ-CD). In this study, we verified the catalytic characteristics of purified Y195I α-CGTase and elucidated the mechanism of action with molecular dynamic (MD) simulations. We found that purified Y195I α-CGTase produced less α-CD, slightly more ß-CD, and significantly more γ-CD than wild-type α-CGTase. Correspondingly, α-CD-based K m values increased, and ß-CD- and γ-CD-based K m values decreased. MD simulation studies revealed that the dynamic trajectories of the substrate oligosaccharide chain in the mutant CGTase binding site were significantly different from those in the wild-type enzyme, with reduced hydrophobic interaction, finally resulting in different product specificity and more γ-CD formation.


Assuntos
Glucosiltransferases/química , Glucosiltransferases/metabolismo , Simulação de Dinâmica Molecular , Mutação de Sentido Incorreto , alfa-Ciclodextrinas/metabolismo , gama-Ciclodextrinas/metabolismo , Proteínas de Bactérias/química , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Glucosiltransferases/genética , Especificidade por Substrato , Thermoanaerobacterium/enzimologia
15.
Chem Biol Drug Des ; 84(2): 216-22, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24612767

RESUMO

Human non-pancreatic secretory phospholipase A2 was reported to be associated with inflammatory diseases and considered as a potential drug target for inflammation and other related disease treatment. Although many human non-pancreatic secretory phospholipase A2 inhibitors were reported, few entered into the drug development stage due to various problems. In this study, we discovered seven novel human non-pancreatic secretory phospholipase A2 inhibitors using virtual screen. Of the 99 compounds tested by continuous fluorescence assay, seven are potent human non-pancreatic secretory phospholipase A2 inhibitors with micromolar IC50 values. Typical molecules include 9-fluorenylmethoxycarbonyl protected α-phenylalanine derivatives and azo compounds, which may serve as novel scaffold for developing potent human non-pancreatic secretory phospholipase A2 inhibitors. These compounds bind to human non-pancreatic secretory phospholipase A2 by interacting with the catalytic calcium ion and the hydrophobic regions in the substrate-binding pocket.


Assuntos
Desenho de Fármacos , Inibidores de Fosfolipase A2/química , Inibidores de Fosfolipase A2/farmacologia , Fosfolipases A2 Secretórias/antagonistas & inibidores , Compostos Azo/química , Compostos Azo/farmacologia , Fluorenos/química , Fluorenos/farmacologia , Humanos , Simulação de Acoplamento Molecular , Fenilalanina/química , Fenilalanina/farmacologia , Fosfolipases A2 Secretórias/metabolismo , Espectrometria de Fluorescência
16.
PLoS One ; 7(1): e29554, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22279540

RESUMO

The 14-3-3 proteins are a family of regulatory signaling molecules that interact with other proteins in a phosphorylation-dependent manner and function as adapter or scaffold proteins in signal transduction pathways. One family member, 14-3-3ζ, is believed to function in cell signaling, cycle control, and apoptotic death. A systematic proteomic analysis done in our laboratory has identified signal transducers and activators of transcription 3 (Stat3) as a novel 14-3-3ζ interacting protein. Following our initial finding, in this study, we provide evidence that 14-3-3ζ interacts physically with Stat3. We further demonstrate that phosphorylation of Stat3 at Ser727 is vital for 14-3-3ζ interaction and mutation of Ser727 to Alanine abolished 14-3-3ζ/Stat3 association. Inhibition of 14-3-3ζ protein expression in U266 cells inhibited Stat3 Ser727 phosphorylation and nuclear translocation, and decreased both Stat3 DNA binding and transcriptional activity. Moreover, 14-3-3ζ is involved in the regulation of protein kinase C (PKC) activity and 14-3-3ζ binding to Stat3 protects Ser727 dephosphorylation from protein phosphatase 2A (PP2A). Taken together, our findings support the model that multiple signaling events impinge on Stat3 and that 14-3-3ζ serves as an essential coordinator for different pathways to regulate Stat3 activation and function in MM cells.


Assuntos
Proteínas 14-3-3/metabolismo , Núcleo Celular/metabolismo , Fator de Transcrição STAT3/metabolismo , Serina/metabolismo , Proteínas 14-3-3/química , Proteínas 14-3-3/genética , Transporte Ativo do Núcleo Celular , Algoritmos , Sequência de Aminoácidos , Sítios de Ligação/genética , Western Blotting , Linhagem Celular Tumoral , Humanos , Imunoprecipitação , Modelos Moleculares , Simulação de Dinâmica Molecular , Mutação , Fosforilação , Ligação Proteica , Proteína Quinase C/metabolismo , Estrutura Terciária de Proteína , Fator de Transcrição STAT3/química , Fator de Transcrição STAT3/genética , Serina/genética , Transdução de Sinais , Termodinâmica , Ativação Transcricional
17.
Bioorg Med Chem ; 19(10): 3221-8, 2011 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-21524585

RESUMO

A series of new sulfamide derivatives have been synthesized, their structures were confirmed by (1)H NMR and ESI-MS. Some target compounds were assessed by the tool of Dock6, and inhibition effects of all the new compounds on carbonic anhydrase II have been investigated. In addition, some compounds have been investigated for their antihypoxic effects in mice. Results indicated that nine target compounds exhibit as effectively as acetazolamide and 10 compounds have more potent inhibition effects on carbonic anhydrase II than acetazolamide. Three of them (I-8, I-18 and I'-3) can prolong markedly the survival time of mice in hypoxia, which are worth carrying out further studies.


Assuntos
Anidrase Carbônica II/metabolismo , Inibidores da Anidrase Carbônica/química , Inibidores da Anidrase Carbônica/uso terapêutico , Hipóxia/tratamento farmacológico , Sulfonamidas/química , Sulfonamidas/uso terapêutico , Animais , Anidrase Carbônica II/antagonistas & inibidores , Inibidores da Anidrase Carbônica/síntese química , Inibidores da Anidrase Carbônica/farmacologia , Humanos , Camundongos , Modelos Moleculares , Sulfonamidas/síntese química , Sulfonamidas/farmacologia
18.
Sci China Life Sci ; 54(4): 336-41, 2011 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-21509657

RESUMO

As a pivotal signal pathway, the Ras/Raf/MEK/ERK cascade can be activated by multiple extracellular stimuli and can transmit signals to diverse substrates. It remains to be elucidated how so many different signals can be variously transferred by only two MEK molecules (MEK1 and MEK2). Because of technological limitations the complete structures of the MEKs are still unavailable. Here, we report the full-length structure of MEK2 obtained by homology modeling and molecular dynamics simulations. The simulations show that the N-terminal part of MEK2 is highly flexible and this flexibility may enable MEK2 to interact with ERKs and other ligands in diverse manners that correspond to various upstream signals and downstream consequences.


Assuntos
MAP Quinase Quinase 2/química , Modelos Moleculares , Estrutura Terciária de Proteína , Sequência de Aminoácidos , Humanos , Imageamento Tridimensional , MAP Quinase Quinase 1/química , MAP Quinase Quinase 2/genética , MAP Quinase Quinase 2/metabolismo , Sistema de Sinalização das MAP Quinases/fisiologia , Simulação de Dinâmica Molecular , Dados de Sequência Molecular , Alinhamento de Sequência
19.
Chem Commun (Camb) ; 47(19): 5440-2, 2011 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-21475751

RESUMO

With single-molecule fluorescence imaging and single-molecule force measurement, we have found that the natural compound Naringenin exerts an inhibition effect on TGF-ß ligand-receptor interaction, the initial step of TGF-ß signaling.


Assuntos
Flavanonas/farmacologia , Microscopia de Força Atômica , Imagem Molecular , Fator de Crescimento Transformador beta/metabolismo , Células HeLa , Humanos , Ligantes , Ligação Proteica/efeitos dos fármacos
20.
Proteins ; 79(3): 720-34, 2011 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-21287608

RESUMO

Elucidating kinetic processes of protein-protein interactions (PPI) helps to understand how basic building blocks affect overall behavior of living systems. In this study, we used structure-based properties to build predictive models for kinetic constants of PPI. A highly diverse PPI dataset, protein-protein kinetic interaction data and structures (PPKIDS), was built. PPKIDS contains 62 PPI with complex structures and kinetic constants measured experimentally. The influence of structural properties on kinetics of PPI was studied using 35 structure-based features, describing different aspects of complex structures. Linear models for the prediction of kinetic constants were built by fitting with selected subsets of structure-based features. The models gave correlation coefficients of 0.801, 0.732, and 0.770 for k(off), k(on), and K(d), respectively, in leave-one-out cross validations. The predictive models reported here use only protein complex structures as input and can be generally applied in PPI studies as well as systems biology modeling. Our study confirmed that different properties play different roles in the kinetic process of PPI. For example, k(on) was affected by overall structural features of complexes, such as the composition of secondary structures, the change of translational and rotational entropy, and the electrostatic interaction; while k(off) was determined by interfacial properties, such as number of contacted atom pairs per 100 Ų. This information provides useful hints for PPI design.


Assuntos
Proteínas/química , Cinética , Modelos Moleculares , Estrutura Secundária de Proteína , Eletricidade Estática
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