Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 6 de 6
Filtrar
Mais filtros











Intervalo de ano de publicação
1.
Appl Biochem Biotechnol ; 191(3): 1258-1270, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32086706

RESUMO

Proteases are produced by the most diverse microorganisms and have a wide spectrum of applications. However, the use of wild microorganisms, mainly fungi, for enzyme production has some drawbacks. They are subject to physiological instability due to metabolic adaptations, causing complications and impairments in the production process. Thus, the objective of this work was to promote the heterologous expression of a collagenolytic aspartic protease (ProTiN31) from Thermomucor indicae seudaticae in Escherichia coli and Pichia pastoris. The pET_28a (+) and pPICZαA vectors were synthesized containing the gene of the enzyme and transformed into E. coli and P. pastoris, respectively. The recombinant enzymes produced by E. coli and P. pastoris showed maximum activity at pH 5.0 and 50 °C, and pH 5.0 and 60 °C, respectively. The enzyme produced by P. pastoris showed better thermostability when compared to that produced by E. coli. Both enzymes were stable at pH 6.0 and 6.5 for 24 h at 4 °C, and sensitive to pepstatin A, ß-mercaptoethanol, and Hg2+. Comparing the commercial collagen hydrolysate (Artrogen duo/Brazil) and gelatin degradation using protease from P. pastoris, they showed similar peptide profiles. There are its potential applications in a wide array of industrial sectors that use collagenolytic enzymes.


Assuntos
Ácido Aspártico Proteases/biossíntese , Colágeno/química , Escherichia coli/metabolismo , Mucorales/enzimologia , Saccharomycetales/metabolismo , Simulação por Computador , Fermentação , Tecnologia de Alimentos , Concentração de Íons de Hidrogênio , Microbiologia Industrial , Íons , Peptídeos/química , Proteínas Recombinantes/biossíntese , Temperatura
2.
Rev Soc Bras Med Trop ; 53: e20190214, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32049200

RESUMO

INTRODUCTION: The aim of this study was to evaluate some virulence factors in Candida albicans isolates from patients with onychomycosis and determine the correlation between these factors and the antifungal resistance profile. METHODS: Seventy species of C. albicans were confirmed using polymerase chain reaction amplification of the HWP1 gene. According to the Clinical & Laboratory Standards Institute guidelines, the susceptibility profile of four antifungal agents was investigated, and the production of aspartyl protease, phospholipase, haemolysin, and biofilm was determined. The correlation between these profiles was also investigated. RESULTS: The isolates indicated different levels of resistance and production of virulence factors. Significant correlations were observed between the minimum inhibitory concentration (MIC) of fluconazole/itraconazole and biofilm production, between phospholipase production and fluconazole/itraconazole MIC, and between fluconazole MIC and hemolytic activity in C. albicans isolates. The results also showed significant correlations between phospholipase activity and biofilm production. CONCLUSIONS: Our findings will contribute to a better understanding of the pathogenesis of C. albicans and characterize the relationship between virulence factors and antifungal resistance, which may suggest new therapeutic strategies considering the possible involvement of the virulence mechanism in the effectiveness of treatment.


Assuntos
Antifúngicos/farmacologia , Candida albicans/patogenicidade , Unhas/microbiologia , Onicomicose/microbiologia , Fatores de Virulência , Ácido Aspártico Proteases/biossíntese , Biofilmes/crescimento & desenvolvimento , Candida albicans/efeitos dos fármacos , Candida albicans/ultraestrutura , Farmacorresistência Fúngica , Hemólise , Humanos , Testes de Sensibilidade Microbiana , Microscopia Eletrônica de Varredura , Fosfolipases/biossíntese , Reação em Cadeia da Polimerase
3.
Protein Expr Purif ; 167: 105532, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-31711796

RESUMO

Schistosomes express a variety of aspartyl proteases (APs) with distinct roles in the helminth pathophysiology, among which degradation of host haemoglobin is key, since it is the main amino acid source for these parasites. A cathepsin D-like AP from Schistosoma mansoni (SmCD1) has been used as a model enzyme for vaccine and drug development studies in schistosomes and yet a reliable expression system for readily producing the recombinant enzyme in high yield has not been reported. To contribute to further advancing the knowledge about this valuable antischistosomal target, we developed a transient expression system in HEK 293T mammalian cells and performed a biochemical and biophysical characterization of the recombinant enzyme (rSmCD1). It was possible to express a recombinant C-terminal truncated form of SmCD1 (rSmCD1ΔCT) and purify it with high yield (16 mg/L) from the culture supernatant. When analysed by Size-Exclusion Chromatography and multi-angle laser light scattering, rSmCD1ΔCT behaved as a dimer at neutral pH, which is unusual for cathepsins D, turning into a monomer after acidification of the medium. Through analytical ultrancentrifugation, the dimer was confirmed for free rSmCD1ΔCT in solution as well as stabilization of the monomer during interaction with pepstatin. The mammalian cell expression system used here was able to produce rSmCD1ΔCT with high yields allowing for the first time the characterization of important kinetic parameters as well as initial description of its biophysical properties.


Assuntos
Catepsina D/isolamento & purificação , Schistosoma mansoni/enzimologia , Animais , Ácido Aspártico Proteases/biossíntese , Ácido Aspártico Proteases/química , Ácido Aspártico Proteases/isolamento & purificação , Ácido Aspártico Proteases/metabolismo , Catepsina D/biossíntese , Catepsina D/química , Catepsina D/metabolismo , Catepsinas/biossíntese , Catepsinas/química , Catepsinas/isolamento & purificação , Catepsinas/metabolismo , Cromatografia em Gel , Dimerização , Células HEK293 , Humanos , Cinética , Proteínas Recombinantes/biossíntese , Proteínas Recombinantes/química , Proteínas Recombinantes/isolamento & purificação , Proteínas Recombinantes/metabolismo , Ultracentrifugação/métodos
4.
Rev. Soc. Bras. Med. Trop ; Rev. Soc. Bras. Med. Trop;53: e20190214, 2020. tab, graf
Artigo em Inglês | LILACS | ID: biblio-1057290

RESUMO

Abstract INTRODUCTION: The aim of this study was to evaluate some virulence factors in Candida albicans isolates from patients with onychomycosis and determine the correlation between these factors and the antifungal resistance profile. METHODS: Seventy species of C. albicans were confirmed using polymerase chain reaction amplification of the HWP1 gene. According to the Clinical & Laboratory Standards Institute guidelines, the susceptibility profile of four antifungal agents was investigated, and the production of aspartyl protease, phospholipase, haemolysin, and biofilm was determined. The correlation between these profiles was also investigated. RESULTS: The isolates indicated different levels of resistance and production of virulence factors. Significant correlations were observed between the minimum inhibitory concentration (MIC) of fluconazole/itraconazole and biofilm production, between phospholipase production and fluconazole/itraconazole MIC, and between fluconazole MIC and hemolytic activity in C. albicans isolates. The results also showed significant correlations between phospholipase activity and biofilm production. CONCLUSIONS: Our findings will contribute to a better understanding of the pathogenesis of C. albicans and characterize the relationship between virulence factors and antifungal resistance, which may suggest new therapeutic strategies considering the possible involvement of the virulence mechanism in the effectiveness of treatment.


Assuntos
Humanos , Candida albicans/patogenicidade , Onicomicose/microbiologia , Fatores de Virulência , Antifúngicos/farmacologia , Unhas/microbiologia , Fosfolipases/biossíntese , Candida albicans/efeitos dos fármacos , Candida albicans/ultraestrutura , Microscopia Eletrônica de Varredura , Testes de Sensibilidade Microbiana , Reação em Cadeia da Polimerase , Biofilmes/crescimento & desenvolvimento , Farmacorresistência Fúngica , Ácido Aspártico Proteases/biossíntese , Hemólise
5.
Rev Inst Med Trop Sao Paulo ; 52(3): 139-43, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-20602023

RESUMO

Phospholipase and proteinase production and the ability of adhesion to buccal epithelial cells (BEC) of 112 Candida isolates originated from oral cavity of HIV infected patients and from blood and catheter of intensive care unit patients were investigated. The proteinase production was detected by inoculation into bovine serum albumin (BSA) agar and the phospholipase activity was performed using egg yolk emulsion. A yeast suspension of each test strain was incubated with buccal epithelial cells and the number of adherence yeast to epithelial cells was counted. A percentage of 88.1% and 55.9% of Candida albicans and 69.8% and 37.7% of non-albicans Candida isolates produced proteinase and phospholipase, respectively. Non-albicans Candida isolated from catheter were more proteolytic than C. albicans isolates. Blood isolates were more proteolytic than catheter and oral cavity isolates while oral cavity isolates produced more phospholipase than those from blood and catheter. C. albicans isolates from oral cavity and from catheter were more adherent to BEC than non-albicans Candida isolates, but the adhesion was not different among the three sources analyzed. The results indicated differences in the production of phospholipase and proteinase and in the ability of adhesion to BEC among Candida spp. isolates from different sources. This study suggests that the pathogenicity of Candida can be correlated with the infected site.


Assuntos
Ácido Aspártico Proteases/biossíntese , Aderência Bacteriana/fisiologia , Candida/enzimologia , Candida/fisiologia , Fosfolipases/biossíntese , Candida/isolamento & purificação , Cateteres de Demora/microbiologia , Células Epiteliais/microbiologia , Infecções por HIV/microbiologia , Humanos , Boca/microbiologia
6.
Rev. Inst. Med. Trop. Säo Paulo ; Rev. Inst. Med. Trop. Säo Paulo;52(3): 139-143, May-June 2010. tab
Artigo em Inglês | LILACS | ID: lil-550344

RESUMO

Phospholipase and proteinase production and the ability of adhesion to buccal epithelial cells (BEC) of 112 Candida isolates originated from oral cavity of HIV infected patients and from blood and catheter of intensive care unit patients were investigated. The proteinase production was detected by inoculation into bovine serum albumin (BSA) agar and the phospholipase activity was performed using egg yolk emulsion. A yeast suspension of each test strain was incubated with buccal epithelial cells and the number of adherence yeast to epithelial cells was counted. A percentage of 88.1 percent and 55.9 percent of Candida albicans and 69.8 percent and 37.7 percent of non-albicans Candida isolates produced proteinase and phospholipase, respectively. Non-albicans Candida isolated from catheter were more proteolytic than C. albicans isolates. Blood isolates were more proteolytic than catheter and oral cavity isolates while oral cavity isolates produced more phospholipase than those from blood and catheter. C. albicans isolates from oral cavity and from catheter were more adherent to BEC than non-albicans Candida isolates, but the adhesion was not different among the three sources analyzed. The results indicated differences in the production of phospholipase and proteinase and in the ability of adhesion to BEC among Candida spp. isolates from different sources. This study suggests that the pathogenicity of Candida can be correlated with the infected site.


A produção de proteinase e fosfolipase e habilidade de adesão à célula epitelial bucal de 112 isolados de Candida originadas da cavidade bucal de pacientes infectados pelo HIV e de sangue e cateter de pacientes hospitalizados foram investigados. A produção de proteinase foi detectada por inoculação em ágar soro albumina bovina e a atividade de fosfolipase foi realizada usando emulsão de gema de ovo. A suspensão de levedura de cada isolado foi incubada com célula epitelial e o número de leveduras aderidas a célula epitelial foi contada. Uma porcentagem de 88,1 e 55,9 por cento de C. albicans e 69,8 e 37,7 por cento de isolados de Candida não albicans produziram proteinase e fosfolipase, respectivamente. Candida não albicans obtidas do cateter foram mais proteolíticos que isolados de Candida albicans (p < 0,001). Isolados do sangue foram mais proteolíticos do que isolados do cateter e cavidade bucal, enquanto isolados da cavidade bucal produziram mais fosfolipase do que aqueles isolados do sangue e cateter. C. albicans isoladas da cavidade bucal e do cateter foram mais aderentes à célula epitelial bucal do que isolados de Candida não albicans, mas não houve diferença na adesão entre os três locais analisados. Os resultados indicaram diferenças na produção de fosfolipase e proteinase e na habilidade de adesão à célula epitelial bucal entre os isolados de Candida das diferentes fontes. Este estudo sugere que a patogenicidade de Candida spp pode estar correlacionada ao local infectado.


Assuntos
Humanos , Ácido Aspártico Proteases/biossíntese , Aderência Bacteriana/fisiologia , Candida/enzimologia , Candida/fisiologia , Fosfolipases/biossíntese , Candida/isolamento & purificação , Cateteres de Demora/microbiologia , Células Epiteliais/microbiologia , Infecções por HIV/microbiologia , Boca/microbiologia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA