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2.
Emerg Infect Dis ; 27(7): 1821-1830, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34152951

RESUMO

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) emerged in late 2019, and the outbreak rapidly evolved into the current coronavirus disease pandemic. SARS-CoV-2 is a respiratory virus that causes symptoms similar to those caused by influenza A and B viruses. On July 2, 2020, the US Food and Drug Administration granted emergency use authorization for in vitro diagnostic use of the Influenza SARS-CoV-2 Multiplex Assay. This assay detects influenza A virus at 102.0, influenza B virus at 102.2, and SARS-CoV-2 at 100.3 50% tissue culture or egg infectious dose, or as few as 5 RNA copies/reaction. The simultaneous detection and differentiation of these 3 major pathogens increases overall testing capacity, conserves resources, identifies co-infections, and enables efficient surveillance of influenza viruses and SARS-CoV-2.


Assuntos
COVID-19 , Vírus da Influenza A , Humanos , Vírus da Influenza A/genética , Vírus da Influenza B/genética , Reação em Cadeia da Polimerase Multiplex , Transcrição Reversa , SARS-CoV-2
3.
Cell Death Dis ; 12(2): 138, 2021 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-33542227

RESUMO

The interaction between LncRNA and RNA-binding protein (RBPs) plays an essential role in the regulation over the malignant progression of tumors. Previous studies on the mechanism of SNHG1, an emerging lncRNA, have primarily focused on the competing endogenous RNA (ceRNA) mechanism. Nevertheless, the underlying mechanism between SNHG1 and RBPs in tumors remains to be explored, especially in prostate cancer (PCa). SNHG1 expression profiles in PCa were determined through the analysis of TCGA data and tissue microarray at the RNA level. Gain- and loss-of-function experiments were performed to investigate the biological role of SNHG1 in PCa initiation and progression. RNA-seq, immunoblotting, RNA pull-down and RNA immunoprecipitation analyses were utilized to clarify potential pathways with which SNHG1 might be involved. Finally, rescue experiments were carried out to further confirm this mechanism. We found that SNHG1 was dominantly expressed in the nuclei of PCa cells and significantly upregulated in PCa patients. The higher expression level of SNHG1 was dramatically correlated with tumor metastasis and patient survival. Functionally, overexpression of SNHG1 in PCa cells induced epithelial-mesenchymal transition (EMT), accompanied by down-regulation of the epithelial marker, E-cadherin, and up-regulation of the mesenchymal marker, vimentin. Increased proliferation and migration, as well as accelerated xenograft tumor growth, were observed in SNHG1-overexpressing PCa cells, while opposite effects were achieved in SNHG1-silenced cells. Mechanistically, SNHG1 competitively interacted with hnRNPL to impair the translation of protein E-cadherin, thus activating the effect of SNHG1 on the EMT pathway, eventually promoting the metastasis of PCa. Our findings demonstrate that SNHG1 is a positive regulator of EMT activation through the SNHG1-hnRNPL-CDH1 axis. SNHG1 may serve as a novel potential therapeutic target for PCa.


Assuntos
Antígenos CD/metabolismo , Caderinas/metabolismo , Regulação Neoplásica da Expressão Gênica/genética , Neoplasias da Próstata/genética , RNA Longo não Codificante/metabolismo , Humanos , Masculino , Metástase Neoplásica , Neoplasias da Próstata/patologia
4.
PLoS One ; 15(10): e0240309, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33075098

RESUMO

INTRODUCTION: Etiology studies of severe acute respiratory infections (SARI) in adults are limited. We studied potential etiologies of SARI among adults in six countries using multi-pathogen diagnostics. METHODS: We enrolled both adults with SARI (acute respiratory illness onset with fever and cough requiring hospitalization) and asymptomatic adults (adults hospitalized with non-infectious illnesses, non-household members accompanying SARI patients, adults enrolled from outpatient departments, and community members) in each country. Demographics, clinical data, and nasopharyngeal and oropharyngeal specimens were collected from both SARI patients and asymptomatic adults. Specimens were tested for presence of 29 pathogens utilizing the Taqman® Array Card platform. We applied a non-parametric Bayesian regression extension of a partially latent class model approach to estimate proportions of SARI caused by specific pathogens. RESULTS: We enrolled 2,388 SARI patients and 1,135 asymptomatic adults from October 2013 through October 2015. We detected ≥1 pathogen in 76% of SARI patients and 67% of asymptomatic adults. Haemophilus influenzae and Streptococcus pneumoniae were most commonly detected (≥23% of SARI patients and asymptomatic adults). Through modeling, etiology was attributed to a pathogen in most SARI patients (range among countries: 57.3-93.2%); pathogens commonly attributed to SARI etiology included influenza A (14.4-54.4%), influenza B (1.9-19.1%), rhino/enterovirus (1.8-42.6%), and RSV (3.6-14.6%). CONCLUSIONS: Use of multi-pathogen diagnostics and modeling enabled attribution of etiology in most adult SARI patients, despite frequent detection of multiple pathogens in the upper respiratory tract. Seasonal flu vaccination and development of RSV vaccine would likely reduce the burden of SARI in these populations.


Assuntos
Bactérias/classificação , Infecções Respiratórias/epidemiologia , Infecções Respiratórias/microbiologia , Vírus/classificação , Adulto , Idoso , Doenças Assintomáticas/epidemiologia , Bactérias/genética , Bactérias/isolamento & purificação , Bangladesh , Teorema de Bayes , Feminino , Guatemala , Humanos , Masculino , Pessoa de Meia-Idade , Modelos Teóricos , Epidemiologia Molecular , Nasofaringe/microbiologia , Orofaringe/microbiologia , Reação em Cadeia da Polimerase , Vírus/genética , Vírus/isolamento & purificação , Adulto Jovem
5.
Zhongguo Zhen Jiu ; 40(5): 513-8, 2020 May 12.
Artigo em Chinês | MEDLINE | ID: mdl-32394659

RESUMO

OBJECTIVE: To observe the effect of electroacupuncture (EA) on the expression of insulin phosphatidylinositol-3 kinase/glycogen synthetase kinase-3α (PI3K/GSK3α) signal pathway related proteins in the hippocampus in mice with Alzheimer's disease (AD), and to explore the regulatory mechanism of EA on improving the pathological characteristics of AD. METHODS: Twelve male APP/PS1 double transgenic mice were randomly divided a model group and a treatment group, 6 mice in each group; another 6 wild-type male mice were taken as the control group. The mice in the treatment group were treated with EA (continuous wave, 2 Hz of frequency) at "Baihui" (GV 20) and bilateral "Shenshu" (BL 23), once a day; 7-day treatment was taken as a course of treatment, and 2 courses of treatment were given. The immunohistochemistry method and Western blot method were used to detect the distribution and expression level of hippocampal PI3K/GSK3α signal pathway related proteins P85α, P110α, GSK3α and pS21GSK3α, and the number of hippocampal senile plaques (SP) was observed. RESULTS: The proteins of P85α, P110α, GSK3α and pS21GSK3α were mainly distributed in the cytoplasm of hippocampal neurons, and the GSK3α was also distributed in the axons of neurons in the model group and the treatment group. The immunohistochemistry results showed that the distribution level of GSK3α in the hippocampus in the model group was significantly higher than that in the control group (P<0.001), and the distribution level of pS21GSK3α, P85α and P110α was significantly decreased (P<0.01, P<0.001); compared with the model group, the distribution level of GSK3α in the hippocampus in the treatment group was significantly decreased (P<0.001), and the distribution level of pS21GSK3α, P85α and P110α in hippocampus was significantly increased (P<0.05, P<0.001). The Western blot results showed compared with the control group, the expression of pS21GSK3α, P85α and P110α as well as the ratio of pS21GSK3α/GSK3α in the hippocampus in the model group were significantly decreased (P<0.001), and the expression of GSK3α was increased (P<0.05); compared with the model group, the expression of pS21GSK3α, P85α, P110α and the ratio of pS21GSK3α/GSK3α in the hippocampus in the treatment group were significantly increased (P<0.01, P<0.001), and the expression of GSK3α was decreased (P<0.05). Compared with the control group, the number of hippocampal SP in the model group was significantly increased (P<0.001); compared with the model group, the number of hippocampal SP in the treatment group was significantly decreased (P<0.01). CONCLUSION: EA could effectively regulate the expression of PI3K/GSK3α signal pathway related proteins in the hippocampus in mice with AD, so as to reduce the formation and deposition of SP.


Assuntos
Doença de Alzheimer/terapia , Eletroacupuntura , Hipocampo/fisiologia , Insulina/fisiologia , Transdução de Sinais , Animais , Masculino , Camundongos , Camundongos Transgênicos , Distribuição Aleatória
6.
Zhen Ci Yan Jiu ; 43(4): 215-20, 2018 Apr 25.
Artigo em Chinês | MEDLINE | ID: mdl-29888573

RESUMO

OBJECTIVE: To observe the effect of electroacupuncture (EA) intervention on learning-memory ability and the expression of senile plaques (SP), amyloid precursor protein (APP), ß-secretase 1(BACE 1) and insulin degrading enzyme (IDE) in the hippocampus in APP/presenilin 1 (PS 1) double transgenic Alzheimer's disease (AD) mice, so as to reveal its mechanisms underlying improvement of AD. METHODS: A total of 18 male APP/PS 1 double transgenic AD mice were randomly divided into model, EA-2-week and EA-3-week groups (n=6 in each). The control group was consisted of 6 male wild mice. EA (2 Hz, 2 mA) was applied to "Baihui" (GV 20) and bilateral "Shenshu" (BL 23) for 15 min, once a day, with 7 days being a therapeutic course, 2 or 3 courses altogether and with an one day's interval between every two courses. The spatial learning-memory ability was assessed using Morris water maze test during 5 days' training. The immunoactivity of SP in the hippocampus tissue was detected by immunohistochemistry, and the expression levels of APP, BACE 1 and IDE in the hippocampus were analyzed by Western blot. RESULTS: Following modeling, the escape latency and path length of hidden platform tests were significantly increased (P<0.01, P<0.05), and the platform crossing time of spatial probing test significantly decreased (P<0.01) in the model group compared with the control group. After EA intervention, the escape latency on the 5th day of training, and the path length on the 4th and 5th day of training in both EA-2-week and EA-3-week groups were significantly shorter relevant to the model group (P<0.01), and those of the EA-3-week group were considerably shorter than those of the EA-2-week group in the escape latency and path length (P<0.05, P<0.01). The platform crossing times of spatial probing test were significanthy increased in both EA-2-week and EA-3-week groups in comparison with the model group (P<0.01), and that of the EA-3-week group was considerably increased compared with the EA-2-week group (P<0.05). Immunohistochemical staining showed that the number of SP in the hippocampus was markedly increased in the model group compared with the control group (P<0.01), and was markedly reduced in both EA-2-week and EA-3-week groups (P<0.01), and that of the EA-3-week group was significantly decreased compared with the EA-2-week group (P<0.01). The expression levels of hippocampal APP and BACE 1 proteins were significantly higher in the model group than in the control group (P<0.01), and that of hippocampal IDE was markedly lower in the model group than in the control group (P<0.01). After EA, the increased expression levels of APP and BACE 1 proteins and the decreased expression level of IDE in the EA-2-week and EA-3-week groups were significantly inhibited (P<0.01). The effects of EA-3-week were significantly stronger than those of EA-2-week in down-regulating the expression of APP and BACE 1 proteins and up-regulating the expression of IDE (P<0.01, P<0.05). CONCLUSION: EA stimulation of GV 20 and BL 23 can improve the learning-memory ability in APP/PS 1 double transgenic AD mice, which may be related to its effects in down-regulating the expression of SP, APP and BACE 1 proteins and up-regulating the expression of IDE protein in the hippocampus.


Assuntos
Doença de Alzheimer , Eletroacupuntura , Doença de Alzheimer/terapia , Animais , Modelos Animais de Doenças , Hipocampo , Masculino , Camundongos , Camundongos Transgênicos , Placa Amiloide , Presenilina-1 , Ratos Sprague-Dawley
7.
Nan Fang Yi Ke Da Xue Xue Bao ; 37(3): 388-392, 2017 Mar 20.
Artigo em Chinês | MEDLINE | ID: mdl-28377358

RESUMO

OBJECTIVE: To investigate the effect of androgen receptor (AR) on IgG protein expression and the proliferation and migration of prostate cancer cells. METHODS: Western blotting was used to detect the expression of AR protein and IgG in androgen-dependent prostate cancer LNCap cells and castration-resistant prostate cancer PC-3 cells. In AR-overexpressing cells (PC-3-AR cells) established by transfecting PC-3 with AR gene (pCDNA3.1) and LNCap cells with small interfering RNA-mediated AR silencing (LNCap-siAR cells) were analyzed for expressions of AR protein and IgG with Western blotting; the expression of IgG mRNA was detected by Q-PCR, and the cell proliferation and migration were assessed with MTT assay and wound healing assay, respectively. RESULTS: Compared with PC-3 cells, LNCap cells expressed a higher level of AR protein and a lower level of IgG (P<0.05). PC-3-AR cells showed attenuated proliferation and migration with a lowered expression of IgG (P<0.01), while LNCap-siAR cells showed enhanced proliferation and migration with increased expression of IgG (P<0.01). CONCLUSION: The expression of AR is inversely correlated with IgG and is associated with the proliferation and migration of prostate cancer cells in vitro.


Assuntos
Proliferação de Células , Imunoglobulina G/metabolismo , Neoplasias da Próstata/patologia , Receptores Androgênicos/metabolismo , Linhagem Celular Tumoral , Movimento Celular , Humanos , Masculino
8.
PLoS One ; 7(4): e35382, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22539970

RESUMO

CvaB is the central membrane transporter of the colicin V secretion system that belongs to an ATP-binding cassette superfamily. Previous data showed that the N-terminal and C-terminal domains of CvaB are essential for the function of CvaB. N-terminal domain of CvaB possesses Ca(2+)-dependent cysteine proteolytic activity, and two critical residues, Cys32 and His105, have been identified. In this study, we also identify Asp121 as being the third residue of the putative catalytic triad within the active site of the enzyme. The Asp121 mutants lose both their colicin V secretion activity and N-terminal proteolytic activity. The adjacent residue Pro122 also appears to play a critical role in the colicin V secretion. However, the reversal of the two residues D121P - P122D results in loss of activity. Based on molecular modeling and protein sequence alignment, several residues adjacent to the critical residues, Cys32 and His105, were also examined and characterized. Site-directed mutagenesis of Trp101, Asp102, Val108, Leu76, Gly77, and Gln26 indicate that the neighboring residues around the catalytic triad affect colicin V secretion. Several mutated CvaB proteins with defective secretion were also tested, including Asp121 and Pro122, and were found to be structurally stable. These results indicate that the residues surrounding the identified catalytic triad are functionally involved in the secretion of biologically active colicin V.


Assuntos
Transportadores de Cassetes de Ligação de ATP/genética , Colicinas/metabolismo , Proteínas de Escherichia coli/metabolismo , Transportadores de Cassetes de Ligação de ATP/química , Transportadores de Cassetes de Ligação de ATP/metabolismo , Sequência de Aminoácidos , Domínio Catalítico , Escherichia coli/metabolismo , Proteínas de Escherichia coli/química , Proteínas de Escherichia coli/genética , Dados de Sequência Molecular , Mutagênese Sítio-Dirigida , Estrutura Terciária de Proteína , Alinhamento de Sequência
9.
J Clin Microbiol ; 49(7): 2614-9, 2011 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-21593260

RESUMO

Swine influenza viruses (SIV) have been shown to sporadically infect humans and are infrequently identified by the Influenza Division of the Centers for Disease Control and Prevention (CDC) after being received as unsubtypeable influenza A virus samples. Real-time reverse transcriptase PCR (rRT-PCR) procedures for detection and characterization of North American lineage (N. Am) SIV were developed and implemented at CDC for rapid identification of specimens from cases of suspected infections with SIV. These procedures were utilized in April 2009 for detection of human cases of 2009 A (H1N1) pandemic (pdm) influenza virus infection. Based on genetic sequence data derived from the first two viruses investigated, the previously developed rRT-PCR procedures were optimized to create the CDC rRT-PCR Swine Flu Panel for detection of the 2009 A (H1N1) pdm influenza virus. The analytical sensitivity of the CDC rRT-PCR Swine Flu Panel was shown to be 5 copies of RNA per reaction and 10(-1.3 - -0.7) 50% infectious doses (ID(50)) per reaction for cultured viruses. Cross-reactivity was not observed when testing human clinical specimens or cultured viruses that were positive for human seasonal A (H1N1, H3N2) and B influenza viruses. The CDC rRT-PCR Swine Flu Panel was distributed to public health laboratories in the United States and internationally from April 2009 until June 2010. The CDC rRT-PCR Swine Flu Panel served as an effective tool for timely and specific detection of 2009 A (H1N1) pdm influenza viruses and facilitated subsequent public health response implementation.


Assuntos
Técnicas de Laboratório Clínico/métodos , Vírus da Influenza A Subtipo H1N1/isolamento & purificação , Influenza Humana/diagnóstico , Influenza Humana/virologia , Reação em Cadeia da Polimerase Via Transcriptase Reversa/métodos , Virologia/métodos , Centers for Disease Control and Prevention, U.S. , Reações Cruzadas , Humanos , Vírus da Influenza A Subtipo H1N1/genética , Sensibilidade e Especificidade , Estados Unidos
10.
J Mol Diagn ; 13(2): 123-8, 2011 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-21354045

RESUMO

The recent influenza pandemic, caused by a novel H1N1 influenza A virus, as well as the seasonal influenza outbreaks caused by varieties of influenza A and B viruses, are responsible for hundreds of thousands of deaths worldwide. Few studies have evaluated the utility of real-time reverse transcription-PCR to detect influenza virus RNA from formalin-fixed, paraffin-embedded tissues obtained at autopsy. In this work, respiratory autopsy tissues from 442 suspect influenza cases were tested by real-time reverse transcription-PCR for seasonal influenza A and B and 2009 pandemic influenza A (H1N1) viruses and the results were compared to those obtained by immunohistochemistry. In total, 222 cases were positive by real-time reverse transcription-PCR, and of 218 real-time, reverse transcription-PCR-positive cases also tested by immunohistochemistry, only 107 were positive. Although formalin-fixed, paraffin-embedded tissues can be used for diagnosis, frozen tissues offer the best chance to make a postmortem diagnosis of influenza because these tissues possess nucleic acids that are less degraded and, as a consequence, provide longer sequence information than that obtained from fixed tissues. We also determined that testing of all available respiratory tissues is critical for optimal detection of influenza virus in postmortem tissues.


Assuntos
Autopsia , Vírus da Influenza A/genética , Vírus da Influenza B/genética , Influenza Humana/diagnóstico , RNA Viral/análise , Humanos , Imuno-Histoquímica , Influenza Humana/virologia , Sistema Respiratório/anatomia & histologia , Sistema Respiratório/virologia , Reação em Cadeia da Polimerase Via Transcriptase Reversa/métodos
11.
Clin Infect Dis ; 47(3): 328-38, 2008 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-18558873

RESUMO

BACKGROUND: Each year, Bordetella pertussis infection causes an estimated 294,000 deaths worldwide, primarily among young, nonvaccinated children. Approximately 90% of all deaths due to pertussis in the Unites States occur in young infants. These children often develop intractable pulmonary hypertension; however, the pathophysiologic mechanism responsible for this complication has not been well characterized, and there have been no detailed descriptions of the pathology of this disease since the 1940s. METHODS: Respiratory tissue samples obtained at autopsy from 15 infants aged

Assuntos
Bordetella pertussis/isolamento & purificação , Broncopneumonia/microbiologia , Broncopneumonia/patologia , Coqueluche/microbiologia , Coqueluche/patologia , Estudos de Coortes , Constrição Patológica , Feminino , Humanos , Hipertensão Pulmonar/etiologia , Hipóxia/etiologia , Imuno-Histoquímica , Lactente , Recém-Nascido , Leucocitose/microbiologia , Pulmão/microbiologia , Pulmão/patologia , Masculino , Artéria Pulmonar/patologia , Coqueluche/complicações
12.
Diagn Microbiol Infect Dis ; 61(3): 264-72, 2008 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-18440175

RESUMO

Novel, highly specific, and sensitive real-time polymerase chain reaction (PCR) assays using 2 targets, insertion sequence (IS481) and pertussis toxin subunit 1 (ptxS1), were developed to detect Bordetella pertussis and to differentiate between relevant Bordetella spp. Sixty-four non-Bordetella isolates were negative by both assays, demonstrating the specificity of the assays. B. pertussis, Bordetella parapertussis, and Bordetella holmesii isolates were specifically identified using the assays. The lower limit of detection was less than 10 genomic equivalents per reaction for the IS481 and ptxS1 assays. These assays were evaluated using 145 human clinical specimens obtained during cough-illness outbreak investigations, and PCR results were compared with Bordetella spp. culture results. Twenty-seven (18.6%) specimens had late positive cycle threshold (Ct) values (35

Assuntos
Infecções por Bordetella/diagnóstico , Bordetella/classificação , Bordetella/isolamento & purificação , Reação em Cadeia da Polimerase/métodos , Bordetella/genética , Infecções por Bordetella/epidemiologia , Infecções por Bordetella/microbiologia , Bordetella parapertussis , Bordetella pertussis , Elementos de DNA Transponíveis , DNA Bacteriano/genética , Surtos de Doenças , Humanos , Toxina Pertussis/genética , Sensibilidade e Especificidade
13.
J Med Microbiol ; 57(Pt 3): 388-391, 2008 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-18287306

RESUMO

We report co-infection with two phenotypically and genotypically distinct strains of Bordetella pertussis in an infant male hospitalized with a 2-week history of cough, paroxysms and vomiting. Colonies from the two B. pertussis phenotypes were isolated and evaluated by PFGE profile analysis, gene sequence typing and PCR-RFLP of a portion of the 23S rRNA gene. These results demonstrated simultaneous infection with two different strains of B. pertussis.


Assuntos
Antibacterianos/farmacologia , Bordetella pertussis/classificação , Bordetella pertussis/efeitos dos fármacos , Farmacorresistência Bacteriana/genética , Eritromicina/farmacologia , Coqueluche/microbiologia , Sequência de Bases , Bordetella pertussis/genética , Bordetella pertussis/isolamento & purificação , Eletroforese em Gel de Campo Pulsado , Genes de RNAr/genética , Genótipo , Humanos , Lactente , Masculino , Dados de Sequência Molecular , Fenótipo , Reação em Cadeia da Polimerase , Polimorfismo de Fragmento de Restrição , RNA Ribossômico 23S/genética , Análise de Sequência de DNA
14.
J Clin Microbiol ; 44(3): 1074-6, 2006 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-16517896

RESUMO

Formalin-fixed lung or trachea tissue specimens from four infants and one adolescent who died of respiratory illness were tested for Bordetella pertussis by conventional and real-time PCR assays. B. pertussis was confirmed in all cases. PCR can be an invaluable retrospective diagnostic tool for evaluating archival tissues from patients with suspected fatal pertussis.


Assuntos
Bordetella pertussis/genética , Bordetella pertussis/isolamento & purificação , Coqueluche/diagnóstico , Coqueluche/microbiologia , Adolescente , Sequência de Bases , DNA Bacteriano/genética , Fixadores , Formaldeído , Humanos , Lactente , Pulmão/microbiologia , Reação em Cadeia da Polimerase , Estudos Retrospectivos , Fixação de Tecidos
15.
J Biol Chem ; 279(2): 901-9, 2004 Jan 09.
Artigo em Inglês | MEDLINE | ID: mdl-14570918

RESUMO

CvaB, a member of the ATP-binding cassette transporter superfamily, is the central membrane transporter of the colicin V secretion system in Escherichia coli. Cys32 and His105 in the N-terminal domain of CvaB were identified as critical residues for both colicin V secretion and cysteine proteolytic activity. By inhibiting degradation with N-ethylmaleimide and a mixture of protease inhibitors, a stable wild-type N-terminal domain (which showed cysteine protease activity when activated) was purified. Such protease activity was Ca2+- and concentration-dependent and could be inhibited by antipain, N-ethylmaleimide, EDTA, and EGTA. At low concentrations, the Ca2+ analogs Tb3+ and La3+ (but not Fe3+) significantly enhanced proteolytic activity, suggesting that the size of the cations is important for activity. Together with comparisons of the sequences of members of the cysteine protease family, these results indicate that Cys32 and His105 are the critical residues in the CvaB N-terminal domain for the calcium-dependent cysteine protease activity and secretion of colicin V.


Assuntos
Transportadores de Cassetes de Ligação de ATP/química , Cisteína/química , Proteínas de Escherichia coli/química , Histidina/química , Transportadores de Cassetes de Ligação de ATP/metabolismo , Sequência de Aminoácidos , Animais , Western Blotting , Cálcio/metabolismo , Calpaína/química , Divisão Celular , Colicinas/metabolismo , Meios de Cultura/farmacologia , Cisteína Endopeptidases/química , Relação Dose-Resposta a Droga , Ácido Edético/química , Ácido Egtázico/química , Proteínas de Escherichia coli/metabolismo , Etilmaleimida/química , Humanos , Concentração de Íons de Hidrogênio , Dados de Sequência Molecular , Mutagênese Sítio-Dirigida , Mutação , Peptídeos/química , Plasmídeos/metabolismo , Inibidores de Proteases/química , Ligação Proteica , Estrutura Terciária de Proteína , Ratos , Homologia de Sequência de Aminoácidos , Fatores de Tempo
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