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1.
Clin Otolaryngol ; 43(2): 525-532, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-29054113

RESUMO

BACKGROUND: Recently, topical steroid therapy delivery using high-volume sinonasal irrigations has been used more frequently, following endoscopic sinus surgery (ESS), to improve drug delivery into the paranasal sinuses. OBJECTIVE: The goal of this study was to perform a systematic review with meta-analysis of the efficacy of steroid nasal irrigation on post-operative management of Chronic rhinosinusitis (CRS) following ESS. METHODS: Five databases (PubMed, SCOPUS, Embase, Web of Science, and the Cochrane database) from inception to March 2017 were independently reviewed by two researchers. Studies that scored CRS endoscopic findings and CRS-related quality of life (QOL) post-operatively before and after steroid nasal irrigation and that compared the effects of steroid nasal irrigation (treatment groups) with saline alone irrigation (control group) were included in the analysis. RESULTS: Twelve studies (n = 360) met inclusion criteria. Steroid nasal irrigation significantly reduced the endoscopic score compared with pre-treatment values and also improved QOL. Adverse effects following steroid nasal irrigation such as increased intraocular pressure (IOP) and hypothalamus-pituitary-adrenal (HPA) axis disturbance were not significant. However, compared with saline alone irrigation, the additional effects of steroid irrigation were not significant in the view of the endoscopic score and disease-specific QOL. CONCLUSION: Although steroid nasal irrigation would not induce adverse effects related to systemic steroid absorption, the beneficial effects of additional steroids in saline irrigation were ambiguous in regard to endoscopic score and CRS-related QOL improvement compared with saline alone irrigation. However, further clinical trials with robust research methodologies should be conducted to confirm the results of this study.


Assuntos
Corticosteroides/administração & dosagem , Endoscopia , Cuidados Pós-Operatórios , Rinite/terapia , Sinusite/terapia , Doença Crônica , Humanos , Irrigação Terapêutica , Resultado do Tratamento
2.
Int J Tuberc Lung Dis ; 21(9): 996-1001, 2017 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-28826448

RESUMO

SETTING: Many drugs with potential QT prolongation effects (QT drugs) have already been used for decades in patients with multidrug-resistant TB (MDR-TB) or non-tuberculous mycobacterial (NTM) disease, but without a common consensus. OBJECTIVE: To investigate the effects of QT drugs on cardiac events in patients with MDR-TB or NTM disease. METHODS: We retrospectively reviewed 373 patients (mean age: 56.4 years) with MDR-TB or NTM disease treated for >1 month with clofazimine (CFZ), moxifloxacin (MFX), bedaquiline (BDQ), delamanid (DLM) or macrolides (clarithromycin or azithromycin). Adverse cardiac events, death and QTcF changes were evaluated. RESULTS: Forty-four per cent had MDR-TB; 165 (44%), 315 (85%), 10 (3%), 229 (61%) and 1 patient received CFZ, MFX, BDQ, macrolides and DLM, respectively. Except for three patients (0.8%) lost to follow-up with unknown cause of death, 3 (0.8%, 95%CI 0.2-2.4) adverse cardiac events were documented: atrial fibrillation, cardiac tamponade due to TB pericarditis and cardiac arrest, which was determined to not have been caused by QT drugs. Clinically significant QTcF changes (QTcF > 500 msec or an increase > 60 msec) were observed in 10/60 patients (17%, 95%CI 8.0-30.7) without clinical events. CONCLUSION: The use of QT drugs, alone or in combination, in the treatment of MDR-TB or NTM disease is relatively safe.


Assuntos
Infecções por Mycobacterium não Tuberculosas/tratamento farmacológico , Tuberculose Resistente a Múltiplos Medicamentos/tratamento farmacológico , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Antituberculosos/uso terapêutico , Azitromicina/uso terapêutico , Criança , Claritromicina/uso terapêutico , Clofazimina/uso terapêutico , Diarilquinolinas/uso terapêutico , Feminino , Fluoroquinolonas/uso terapêutico , Seguimentos , Humanos , Perda de Seguimento , Macrolídeos/uso terapêutico , Masculino , Pessoa de Meia-Idade , Moxifloxacina , Mycobacterium tuberculosis/efeitos dos fármacos , Nitroimidazóis/uso terapêutico , Micobactérias não Tuberculosas/efeitos dos fármacos , Oxazóis/uso terapêutico , Estudos Retrospectivos , Adulto Jovem
3.
Drug Alcohol Depend ; 153: 250-7, 2015 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-26036603

RESUMO

INTRODUCTION: Alcohol use disorder symptoms frequently occur in adolescents and younger adults who seldom acknowledge a need for help. We identified sociodemographic, clinical, and familial predictors of alcohol problem recognition and help seeking in an offspring of twin sample. METHOD: We analyzed longitudinal data from the Children of Alcoholics and Twins as Parents studies, which are combinable longitudinal data sources due to their equivalent design. We analyzed respondents (n=1073, 56.0% of the total sample) with alcohol use disorder symptoms at the baseline interview. Familial characteristics included perceptions of alcohol problems and help seeking for alcohol problems within the immediate family and a categorical variable indicating genetic and environmental risk. We used logistic regression to examine predictors of alcohol problem recognition and help seeking. RESULTS: Approximately 25.9% recognized their alcohol problems and 26.7% sought help for drinking. In covariate-adjusted analyses, help seeking among family members predicted problem recognition, several clinical characteristics predicted both problem recognition and help seeking, and familial risk predicted help seeking. Alcohol problem recognition mediated the association between alcohol use disorder symptoms and incident help seeking. CONCLUSIONS: Facilitating the self-recognition of alcohol use disorder symptoms, and perhaps the awareness of family members' help seeking for alcohol problems, may be potentially promising methods to facilitate help seeking.


Assuntos
Transtornos Relacionados ao Uso de Álcool/diagnóstico , Transtornos Relacionados ao Uso de Álcool/psicologia , Autoavaliação Diagnóstica , Família/psicologia , Aceitação pelo Paciente de Cuidados de Saúde/psicologia , Gêmeos/psicologia , Adolescente , Adulto , Feminino , Interação Gene-Ambiente , Humanos , Modelos Logísticos , Estudos Longitudinais , Masculino , Fatores de Risco , Adulto Jovem
4.
Prostate Cancer Prostatic Dis ; 15(4): 369-73, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-22890388

RESUMO

BACKGROUND: Runt-related transcription factor 2 (RUNX2) is a transcription factor that is closely related to bone formation, and prostate cancer (CaP) is the most common cancer to metastasize to bone. The present study investigated the expression levels of RUNX2 in human prostate tissue, and the correlation between RUNX2 levels and the clinicopathological characteristics of CaP. METHODS: A case-control study was conducted including 114 cases of newly diagnosed CaP and 114 age-matched BPH patients as controls. RUNX2 expression was estimated using real-time PCR and immunohistochemical staining. RESULTS: The mRNA expression of RUNX2 did not differ between CaP tissues and non-cancer BPH controls (P=0.825). However, RUNX2 expression was significantly decreased in patients with elevated PSA levels (≥20 ng ml(-1)), a Gleason score ≥8 and metastatic disease compared to those with low PSA, low Gleason score and non-metastatic disease (P=0.023, 0.005 and 0.014, respectively). Immunohistochemical analysis showed that 65.2% of the patients with positive RUNX2 nuclear staining had metastatic disease, which was present in only 25.9% of those with negative staining (P=0.010). CONCLUSIONS: RUNX2 mRNA expression was negatively correlated with CaP aggressiveness. Moreover, the nuclear location of RUNX2 may be a prognostic marker of metastasis in CaP.


Assuntos
Neoplasias Ósseas , Subunidade alfa 1 de Fator de Ligação ao Core , Neoplasias da Próstata , Transcrição Gênica , Idoso , Idoso de 80 Anos ou mais , Neoplasias Ósseas/genética , Neoplasias Ósseas/patologia , Neoplasias Ósseas/secundário , Nucléolo Celular/metabolismo , Nucléolo Celular/ultraestrutura , Subunidade alfa 1 de Fator de Ligação ao Core/genética , Subunidade alfa 1 de Fator de Ligação ao Core/metabolismo , Regulação Neoplásica da Expressão Gênica , Humanos , Masculino , Pessoa de Meia-Idade , Gradação de Tumores , Estadiamento de Neoplasias , Prognóstico , Neoplasias da Próstata/genética , Neoplasias da Próstata/metabolismo , Neoplasias da Próstata/patologia
5.
Placenta ; 32(10): 732-6, 2011 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-21839511

RESUMO

OBJECTIVE: To compare the relative predictive values of amniotic fluid (AF) matrix metalloproteinase-9 (MMP-9), interleukin-6 (IL-6), and serum C-reactive protein (CRP) for histologic chorioamnionitis and intra-amniotic infection in women with preterm labor or preterm premature rupture of membranes (PROM). STUDY DESIGN: This retrospective cohort study included 99 consecutive women with preterm labor or preterm PROM (21-35 weeks' gestation) who delivered within 72 h of transabdominal amniocentesis. The AF was cultured for aerobic and anaerobic bacteria and for genital mycoplasmas and was assayed for MMP-9 and IL-6 levels. Maternal serum CRP was measured immediately after amniocentesis. The placentas were examined histologically. MAIN OUTCOME MEASURES: histologic chorioamnionitis and intra-amniotic infection. RESULTS: The prevalence of histologic chorioamnionitis and a positive AF culture was 44% (44/99) and 28% (28/99), respectively. In predicting intra-amniotic infection, AF MMP-9 had a significantly higher area under the curve (AUC: 0.94 [95% CI, 0.87-0.98]) than AF IL-6 (0.87 [95% CI, 0.78-0.84]; P < 0.05) and serum CRP (0.76 [95% CI, 0.66-0.84]; P < 0.001) and a higher sensitivity and specificity than serum CRP (P < 0.01, respectively). However, in predicting histologic chorioamnionitis, there were no significant differences in AUCs among the three tests (AF MMP-9: 0.78 [95% CI, 0.68-0.85]; AF IL-6: 0.76 [95% CI, 0.66-0.84]; serum CRP: 0.76 [95% CI, 0.66-0.84]). In a sub-analysis of 71 women without intra-amniotic infection, histologic chorioamnionitis was associated with an elevated serum CRP level (P < 0.05), but not with the level of AF IL-6 or MMP-9 (P = 0.232 and P = 0.402, respectively). CONCLUSIONS: The AF MMP-9 has a better overall diagnostic performance than the AF IL-6 and maternal serum CRP in predicting intra-amniotic infection. However, the serum CRP level obtained up to 72 h before delivery appears to be an important marker for early identification of histologic chorioamnionitis in women without intra-amniotic infection.


Assuntos
Líquido Amniótico/metabolismo , Corioamnionite/metabolismo , Mediadores da Inflamação/metabolismo , Trabalho de Parto Prematuro/metabolismo , Placenta/metabolismo , Adulto , Biomarcadores/sangue , Biomarcadores/metabolismo , Proteína C-Reativa/metabolismo , Corioamnionite/sangue , Corioamnionite/diagnóstico , Estudos de Coortes , Feminino , Humanos , Mediadores da Inflamação/sangue , Interleucina-6/metabolismo , Metaloproteinase 9 da Matriz/metabolismo , Trabalho de Parto Prematuro/sangue , Valor Preditivo dos Testes , Gravidez , Estudos Retrospectivos , Sensibilidade e Especificidade
6.
Aust Vet J ; 87(10): 417-20, 2009 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-19796164

RESUMO

A 3-year-old, neutered male Persian cat with chronic ulcerative facial dermatitis was diagnosed with feline idiopathic facial dermatitis based on signalment, clinical history and diagnostic test results, including dermatohistopathological evaluation. Initial treatment started with 4 weeks of oral antifungal/antibiotic medication for severe secondary infectious dermatitis of Malassezia and bacteria. As the lesions gradually improved, the oral medication was withdrawn, leaving only 0.1% topical FK506 (tacrolimus) ointment for the remaining lesions. Topical treatment was administered just in case any new lesions developed. The patient has been managed effectively with topical tacrolimus and no side-effects were observed during treatment. Feline idiopathic facial dermatitis is known as a difficult dermatosis to manage successfully, but our experience suggests that it may respond to topical tacrolimus.


Assuntos
Doenças do Gato/tratamento farmacológico , Dermatomicoses/veterinária , Imunossupressores/uso terapêutico , Malassezia/crescimento & desenvolvimento , Tacrolimo/uso terapêutico , Administração Tópica , Animais , Antifúngicos/uso terapêutico , Doenças do Gato/microbiologia , Doenças do Gato/patologia , Gatos , Dermatomicoses/tratamento farmacológico , Dermatomicoses/microbiologia , Dermatomicoses/patologia , Masculino
7.
Tissue Antigens ; 69 Suppl 1: 114-7, 2007 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-17445182

RESUMO

Interactions between killer cell immunoglobulin-like receptors (KIRs) and human leukocyte antigen class I ligands influence the development of the natural killer cell repertoire and the responses to infection, cancer, and allogeneic tissue. In this study, the association of KIR genes with acute graft-vs-host disease (GVHD) was investigated in 44 pairs of leukemia patients and their unrelated donors for hematopoietic stem cell transplantation (HSCT). Donors with more than 12 KIR genes showed significantly decreased frequencies of severe acute GVHD compared with donors with less than 11 KIR genes (P < 0.05). The distribution of KIR genotypes was not different between severe and mild acute GVHD in patients and donors, respectively. These results suggest that the number of KIR genes in donors could influence the occurrence of acute GVHD after unrelated HSCT.


Assuntos
Doença Enxerto-Hospedeiro/etiologia , Efeito Enxerto vs Leucemia , Transplante de Células-Tronco Hematopoéticas , Células Matadoras Naturais/imunologia , Leucemia/terapia , Receptores Imunológicos/genética , Doença Aguda , Antígenos HLA-C/fisiologia , Teste de Histocompatibilidade , Humanos , Coreia (Geográfico) , Leucemia/complicações , Leucemia/imunologia , Receptores Imunológicos/imunologia , Receptores KIR , Doadores de Tecidos
9.
Adv Exp Med Biol ; 506(Pt A): 687-95, 2002.
Artigo em Inglês | MEDLINE | ID: mdl-12613978

RESUMO

For the first time, the current series of studies provide a possible pathophysiologic mechanism of NO-induced ocular surface disease. NO is present in tear and aqueous humor and is suspected of having an important physiological role in maintaining normal homeostasis of the ocular surface. NO concentrations are higher in aqueous humor compared to tears, though some variability exists between different species. When inflammation was induced by PTK wounding or LPS, three forms of NOS expression were seen in corneal cells. Each isoform of NOS was expressed uniquely according to the specific location of inflammation. When concentrations of NO peaked, the levels of iNOS were markedly increased in fibroblasts and inflammatory cells. The correlation between NO and inflammation was confirmed by treatment with NOS inhibitor, which abrogated the amount of both NO and inflammation. The tissue damage by NO was measured by nitrotyrosine formation. Damage was detected mainly in inflammatory cells, especially those localized in and around the limbal vessel. It is likely that expression of iNOS in limbal fibroblasts has other roles related to survival of limbal stem cells and fibroblasts as well. Because the main source of NO are fibroblasts, we were able to determine the effect of various concentrations of NO on cell viability using a fibroblast culture system. Cell viability increased in dose dependent manner from 10 microM to 500 microM of the NO generator SNAP, but decreased at concentrations above 1000 microM, suggesting that the in vivo mechanism of cell death was indirect, through specific biologic pathways. Therefore, the pathophysiological mechanism of NO action is bimodal with a toxicological component in ocular surface diseases. Furthermore, its concentration and interaction with other oxygen mediators appear to vary depending on the degree of inflammation.


Assuntos
Doenças da Córnea/fisiopatologia , Óxido Nítrico/metabolismo , Animais , Apoptose/fisiologia , Humor Aquoso/metabolismo , Córnea/efeitos dos fármacos , Córnea/metabolismo , Córnea/patologia , Córnea/fisiopatologia , Doenças da Córnea/patologia , Meios de Cultura Livres de Soro/farmacologia , Fibroblastos/efeitos dos fármacos , Fibroblastos/fisiologia , Humanos , Necrose , Concentração Osmolar , Ácido Peroxinitroso/biossíntese , Coelhos , Ratos , Ratos Sprague-Dawley , Lágrimas/metabolismo
10.
Biochimie ; 83(9): 907-13, 2001 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-11698113

RESUMO

Incubation of glutamate dehydrogenase isoproteins (GDH I and GDH II) from bovine brains with perphenazine resulted in a time-dependent loss of enzyme activity. 2-Oxoglutarate and NADH, separately or together, gave partial but not complete protection against the inhibition. Although there were no detectable differences between GDH I and GDH II in inhibition by perphenazine in the absence of ADP, the sensitivities to the inhibition by the drug were significantly distinct for the two isoproteins in the presence of ADP. Low concentrations of ADP (0.05-0.20 mM) did not interfere with the inhibition of GDH I and GDH II by perphenazine. However, in the presence of high concentrations of ADP (0.5-1.0 mM), inhibitory effects of perphenazine on GDH isoproteins were significantly diminished as determined by enzyme kinetics and quantitative affinity chromatography on perphenazine-Sepharose. GDH I was more sensitively reacted with ADP than GDH II on the inhibition by perphenazine. Since physiological ADP levels can vary from 0.05 to > 1.0 mM depending on the rate of oxidative phosphorylation, our results suggest a possibility that two types of GDHs are differently regulated by the antipsychotic actions of perphenazine depending on the physiological concentrations of ADP. GTP and L-leucine, other well-known allosteric regulators, did not affect the inhibitory actions of perphenazine on bovine brain GDH isoproteins.


Assuntos
Difosfato de Adenosina/farmacologia , Encéfalo/metabolismo , Glutamato Desidrogenase/metabolismo , Isoenzimas/metabolismo , Perfenazina/farmacologia , Animais , Antipsicóticos/farmacologia , Encéfalo/enzimologia , Bovinos , Relação Dose-Resposta a Droga , Inibidores Enzimáticos/farmacologia , Glutamato Desidrogenase/química , Glutamato Desidrogenase/genética , Glutamato Desidrogenase/isolamento & purificação , Guanosina Trifosfato/farmacologia , Concentração de Íons de Hidrogênio , Isoenzimas/química , Isoenzimas/genética , Isoenzimas/isolamento & purificação , Ácidos Cetoglutáricos/farmacologia , Cinética , NAD/farmacologia , Sensibilidade e Especificidade , Temperatura , Fatores de Tempo
11.
J Biol Chem ; 276(51): 47930-6, 2001 Dec 21.
Artigo em Inglês | MEDLINE | ID: mdl-11600502

RESUMO

It has been reported that the hyperinsulinism-hyperammonemia syndrome is caused by mutations in glutamate dehydrogenase (GDH) gene that affects enzyme sensitivity to GTP-induced inhibition. To identify the GTP binding site(s) within human GDH, mutant GDHs at Tyr-266 or Lys-450 position were constructed by cassette mutagenesis. More than 90% of the initial activities were remained at the concentration of GTP up to 300 microm for the Lys-450 mutant GDHs regardless of their size, hydrophobicity, and ionization of the side chains, whereas the wild type GDH and the Tyr-266 mutant GDHs were completely inhibited by 30 microm GTP. The binding of GTP to the wild type GDH or the mutant GDHs was further examined by photoaffinity labeling with 8-[gamma-(32)P]azidoguanosine 5'-triphosphate (8-N(3)-GTP). Saturation of photoinsertion with 8-N(3)-GTP occurred apparent K(d) values near 20 microm for the wild type GDH or the Tyr-266 mutant GDH, and the photoinsertion of 8-N(3)-[gamma-(32)P]GTP was significantly decreased in the presence of 300 microm GTP. Unlike the wild type GDH or the Tyr-266 mutant GDH, less than 10% of photoinsertion was detected in the Lys-450 mutant GDH, and the photoinsertion was not affected by the presence of 300 microm GTP. The results with cassette mutagenesis and photoaffinity labeling demonstrate selectivity of the photoprobe for the GTP binding site and suggest that Lys-450, but not Tyr-266, is required for efficient binding of GTP to GDH. Interestingly, studies of the steady-state velocity showed that both the wild type GDH and the Tyr-266 mutant GDHs were inhibited by ATP at concentrations between 10 and 100 microm, whereas less than 10% of the initial activities of the Lys-450 mutant GDHs were diminished by ATP. These results indicate that Lys-450, but not Tyr-266, may be also responsible for the ATP inhibition; therefore, ATP bound to the GTP site.


Assuntos
Glutamato Desidrogenase/metabolismo , Guanosina Trifosfato/metabolismo , Marcadores de Fotoafinidade , Sequência de Aminoácidos , Sítios de Ligação , Escherichia coli/genética , Glutamato Desidrogenase/antagonistas & inibidores , Glutamato Desidrogenase/química , Glutamato Desidrogenase/genética , Humanos , Dados de Sequência Molecular , Mutagênese Insercional , Mutagênese Sítio-Dirigida , Mapeamento de Peptídeos , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Homologia de Sequência de Aminoácidos
12.
Eur J Biochem ; 268(11): 3205-13, 2001 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-11389722

RESUMO

It has been suggested that reactive lysine residue(s) may play an important role in the catalytic activities of glutamate dehydrogenase (GDH). There are, however, conflicting views as to whether the lysine residues are involved in Schiff's base formation with catalytic intermediates, stabilization of negatively charged groups or the carbonyl group of 2-oxoglutarate during catalysis, or some other function. We have expanded on these speculations by constructing a series of cassette mutations at Lys130, a residue that has been speculated to be responsible for the activity of GDH and the inactivation of GDH by pyridoxal 5'-phosphate (PLP). For these studies, a 1557-bp gene that encodes human GDH has been synthesized and inserted into Escherichia coli expression vectors. The mutant enzymes containing Glu, Gly, Met, Ser, or Tyr at position 130, as well as the wild-type human GDH encoded by the synthetic gene, were efficiently expressed as a soluble protein and are indistinguishable from that isolated from human and bovine tissues. Despite an approximately 400-fold decrease in the respective apparent Vmax of the Lys130 mutant enzymes, apparent Km values for NADH and 2-oxoglutarate were almost unchanged, suggesting the direct involvement of Lys130 in catalysis rather than in the binding of coenzyme or substrate. Unlike the wild-type GDH, the mutant enzymes were unable to interact with PLP, indicating that Lys130 plays an important role in PLP binding. The results with analogs of PLP suggest that the aldehyde moiety of PLP, but not the phosphate moiety, is required for efficient binding to GDH.


Assuntos
Genes Bacterianos , Glutamato Desidrogenase/química , Lisina/química , Sequência de Aminoácidos , Sequência de Bases , Catálise , Eletroforese em Gel de Poliacrilamida , Escherichia coli/genética , Escherichia coli/metabolismo , Regulação Enzimológica da Expressão Gênica , Glutamato Desidrogenase/genética , Glutamato Desidrogenase/isolamento & purificação , Humanos , Cinética , Dados de Sequência Molecular , Mutagênese Insercional , Fosfato de Piridoxal/farmacologia , Espectrometria de Fluorescência , Espectrofotometria Ultravioleta
13.
Mol Cells ; 10(2): 213-9, 2000 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-10850664

RESUMO

Tobacco vein mottling virus (TVMV) belongs to the potyviridae that consists of about 200 plant viruses. Potyviruses have RNA genomes of approximately 10,000 bases from which a single polyprotein is expressed from each virus upon infection. The NIa proteinase is known to process the polyprotein at seven distinct junctions between proteins. Kinetic constants were determined for the reactions of the recombinant TVMV NIa protease (27 kDa) with synthetic oligopeptides containing the sequences for the cleavage sites. For optimum activity, the substrate needs to have six amino acids (P6-P1) in the amino region and four (P1'-P4') in the carboxy region, including four conserved amino acids (V-R-F-Q) in P4-P1 positions. Mutation of any of four conserved amino acids to Gly made the substrate inert to the enzyme. Among the substrates, the oligopeptides containing the sequences for junctions, P3-6K1, NIa (VPg-Pro), and NIa-NIb were not processed by the NIa protease. Those junctions have Glu at P3, Glu at P1, and Thr at P2. The implications of high substrate specificity and size dependence in polyprotein processing and viral replication are discussed.


Assuntos
Endopeptidases/metabolismo , Oligopeptídeos/metabolismo , Potyviridae/enzimologia , Processamento de Proteína Pós-Traducional , Proteínas Virais/metabolismo , Motivos de Aminoácidos , Sítios de Ligação , Endopeptidases/genética , Endopeptidases/isolamento & purificação , Cinética , Oligopeptídeos/química , Plantas Tóxicas , Potyviridae/genética , Proteínas Recombinantes de Fusão/metabolismo , Especificidade por Substrato , Nicotiana/virologia , Proteínas Virais/genética , Proteínas Virais/isolamento & purificação
14.
Anal Biochem ; 277(2): 228-31, 2000 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-10625510

RESUMO

Turnip mosaic virus (TuMV) NIa protease cleaves the viral polyprotein at seven distinct junctions out of nine. The amino acid sequences of the seven cleavage sites have three conserved amino acids, V, H, Q in positions P4, P2, P1, respectively. Small molecules as well as conjugated peptides were tested for proteolytic activity of the enzyme. None of small molecules tested, such as methylumbelliferyl-p-guanidinobenzoate, p-nitrophenyl-p'-guanidinobenzoate, p-nitrophenyl acetate, and methylumbelliferyl-N-acetylglutamate, were hydrolyzed. Ac-V-Y-H-Q-Mca was also not hydrolyzed. Intramolecularly quenched fluorogenic substrates Dns-P-V-Y-H-Q-A-W-NH(2) and Dns-P-V-Y-H-Q-W-NH(2) emitted fluorescence after addition of TuMV NIa protease. The proteolysis rate of Dns-P-V-Y-H-Q-A-W-NH(2) was comparable to that of the tetradecapeptide with an optimum sequence, but Dns-P-V-Y-H-Q-W-NH(2) was hydrolyzed at a slower rate, which was confirmed independently by HPLC analysis. These results suggest that intramolecularly quenched fluorogenic substrates can be used for the continuous assay of TuMV NIa protease.


Assuntos
Proteínas Virais/análise , Proteínas Virais/química , Brassica/virologia , Endopeptidases , Fluorometria/métodos , Vírus do Mosaico/química , Vírus do Mosaico/enzimologia
15.
J Biol Chem ; 274(20): 13948-53, 1999 May 14.
Artigo em Inglês | MEDLINE | ID: mdl-10318805

RESUMO

The ADP binding site within two types of bovine brain glutamate dehydrogenase isoproteins (GDH I and GDH II) was identified using photoaffinity labeling with [alpha-32P]8-azidoadenosine 5'-diphosphate (8N3ADP). 8N3ADP, without photolysis, mimicked the activatory properties of ADP on GDH I and GDH II activities, although maximal activity with 8N3ADP was about 75% of maximal ADP-stimulated activity. Saturation of photoinsertion with [alpha-32P]8N3ADP occurred at around 40 approximately 50 microM photoprobe with apparent Kd values near 25 and 40 microM for GDH I and GDH II, respectively. Photoinsertion of [alpha-32P]8N3ADP was decreased best by ADP in comparison with other nucleotides. With the combination of immobilized aluminum affinity chromatography and reversed-phase high performance liquid chromatography, photolabel-containing peptides generated by tryptic digestion were isolated. This identified a portion of the adenine ring binding domain of GDH isoproteins as in the region containing the sequence, EMSWIADTYASTIGHYDIN. Photolabeling of the peptide was prevented over 90% by the presence of 1 mM ADP during photolysis, while other nucleotides could not reduce the amount of photoinsertion as effectively as ADP. These results demonstrate selectivity of the photoprobe for the ADP binding site and suggest that the photolabeled peptide with the residues Glu179-Asn197 is within the ADP binding domain of the brain GDH isoproteins.


Assuntos
Adenosina/análogos & derivados , Azidas/metabolismo , Encéfalo/enzimologia , Glutamato Desidrogenase/metabolismo , Isoenzimas/metabolismo , Marcadores de Fotoafinidade/metabolismo , Adenosina/metabolismo , Difosfato de Adenosina/metabolismo , Sequência de Aminoácidos , Animais , Domínio Catalítico , Bovinos , Ativação Enzimática , Humanos , Camundongos , Dados de Sequência Molecular , Ratos , Tripsina/metabolismo
16.
J Biol Chem ; 273(47): 31125-30, 1998 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-9813015

RESUMO

Photoaffinity labeling with [32P]nicotinamide 2-azidoadenosine dinucleotide (2N3NAD+) was used to identify the NAD+ binding site within two types of glutamate dehydrogenase isoproteins (GDH I and GDH II) isolated from bovine brain. In the absence of photolysis, 2N3NAD+ is a substrate for the GDH isoproteins. When the enzymes were covalently modified by photolysis in the presence of saturating amounts of photoprobe, about 50% inhibition of the GDH activities was observed. Photoinsertion of probe was increased by GTP or glutarate and decreased by NAD+ or ADP. With the combination of immobilized boronate affinity chromatography and reversed-phase HPLC, photolabel-containing peptides generated with trypsin were isolated. This identified a portion of the adenine ring binding domain of GDH isoproteins as the region containing the sequence, CIAVGXSDGSIWNPDGIDPK for both GDH isoproteins, corresponding to Cys270 through Lys289 of the amino acid sequence of well known bovine liver GDH. The X indicates a position for which no phenylthiohydantoin-derivative could be assigned. The missing residue, however, can be designated as a photolabeled glutamate since the sequences including the glutamate residue in question have a complete identity with those of the other GDH species known. Photolabeling of these peptides was prevented by the presence of NAD+ during photolysis. These results demonstrate selectivity of the photoprobe for the NAD+ binding site and suggest that the peptide identified using the photoprobe is located in the NAD+ binding domain of the brain GDH isoproteins. Both amino acid sequencing and compositional analysis identified Glu275 as the site of photoinsertion.


Assuntos
Encéfalo/enzimologia , Glutamato Desidrogenase/metabolismo , NAD/metabolismo , Sequência de Aminoácidos , Animais , Sítios de Ligação , Bovinos , Glutamato Desidrogenase/química , Isoenzimas/química , Isoenzimas/metabolismo , Dados de Sequência Molecular , Mapeamento de Peptídeos , Marcadores de Fotoafinidade , Homologia de Sequência de Aminoácidos
17.
Dev Biol ; 169(1): 261-72, 1995 May.
Artigo em Inglês | MEDLINE | ID: mdl-7538477

RESUMO

The antigen recognized by U1 alpha, a monoclonal antibody to the alpha chain of a chicken integrin fibronectin receptor, was identified as alpha 5. It identifies the same polypeptide as antisera raised to a sequence from the alpha 5 cytoplasmic domain. The U1 alpha antibody has the unusual functional property for alpha chain antibodies of enhancing the binding of alpha 5 beta 1 for its ligand fibronectin. U1 alpha was used to examine the function of alpha 5 beta 1 during myogenic differentiation. As myogenic cells differentiated from replicating myoblasts to bipolar myocytes there was a decrease in their adhesion to the substrate caused by inactivation of alpha 5 beta 1, which could be reversed by treatment of the cells with U1 alpha. The U1 alpha induced increased adhesion to fibronectin but did not inhibit the differentiation process as measured by formation of myotubes. However, U1 alpha did interfere with both cell migration and morphogenesis of myotubes. The resulting myotubes were smaller, more branched, and showed less regular alignment of nuclei. The results suggest that the ability of the cell to regulate alpha 5 beta 1 affinity is critical to myogenic morphogenesis.


Assuntos
Anticorpos Monoclonais/farmacologia , Fibronectinas/metabolismo , Integrinas/metabolismo , Desenvolvimento Muscular , Receptores de Fibronectina/metabolismo , Animais , Especificidade de Anticorpos , Adesão Celular/fisiologia , Diferenciação Celular/efeitos dos fármacos , Movimento Celular/efeitos dos fármacos , Separação Celular , Células Cultivadas , Embrião de Galinha , Cromatografia de Afinidade , Integrinas/imunologia , Músculos/citologia , Músculos/imunologia , Ligação Proteica/efeitos dos fármacos , Receptores de Fibronectina/imunologia
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