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1.
Bol. latinoam. Caribe plantas med. aromát ; 23(2): 290-303, mar. 2024. graf
Artículo en Inglés | LILACS | ID: biblio-1552588

RESUMEN

We evaluated the effect of the total macerate (TM) and seed oil (SO) of mature Carica candamarcensis fruits, on the release of Matrix metalloproteinase 9 (MMP9) and the phosphorylation of MAPK in neutrophils. The antioxidant capacity of these extracts was evaluated by ABTS assay. Neutrophils stimulated with different dilutions of TM or SO were analyzed for cytotoxicity, MMP9 release, and MAPK phosphorylation, using trypan blue exclusion assays, zymography, and immunoblotting, respectively. Both extracts show antioxidant activity, being higher in TM; none presented cytotoxic effect. The 5% and 2.5% dilutions of TM significantly reduced MMP9 release, and all decreased MAPK phosphorylation. SO significantly increased the release o f MMP9 and MAPK phosphorylation, the effect being greater when they were prestimulated with lipopolysaccharide.TM may have anti - inflammatory potential, while SO could have a priming effect that needs to be confirmed


Evaluamos el efecto del macerado total (MT) y aceite de semillas (AV) de frutos maduros de Carica candamarcensis , en la liberación de Matriz metaloproteinasa 9 (MMP9) y la fosfor ilación de MAPK en neutrófilos. La capacidad antioxidante de estos extractos se evaluó por ensayo ABTS. En neutrófilos estimulados con diferentes diluciones de MT o AV se analizó la citotoxicidad, liberación de MMP9 y fosforilación de MAPK, mediante ensayo s de exclusión con azul de tripano, zimografía e inmunotransferencia, respectivamente. Ambos extractos muestran actividad antioxidante, siendo mayor en MT; ninguno presentó efecto citotóxico. Las diluciones 5% y 2,5% de MT redujeron significativamente la l iberación de MMP9, y todas disminuyeron la fosforilación de MAPK. El AV incrementó significativamente la liberación de MMP9 y la fosforilación de MAPK, el efecto fue mayor cuando se preestimularon con lipopolisacárido. El MT puede tener potencial antiinfla matorio, mientras que el AV podría tener un efecto "priming" que necesita ser corroborado.


Asunto(s)
Frutas/enzimología , Neutrófilos/efectos de los fármacos , Plantas Medicinales/química , Metaloproteinasa 9 de la Matriz/efectos de los fármacos , Látex/análisis
2.
J. venom. anim. toxins incl. trop. dis ; 30: e20230063, 2024. tab, graf
Artículo en Inglés | LILACS, VETINDEX | ID: biblio-1550522

RESUMEN

Background: In Colombia, several species of Buthidae scorpions belonging to the genera Centruroides and Tityus coexist, and their stings are considered life-threatening to humans because of their venom neurotoxins. Despite previous studies focusing on neurotoxins from these scorpion genera, little is known about the enzymes present in their venoms and their relationship with whole venom toxicity. Methods: Here, using proteomic and biochemical protocols the enzymatic activities of the venoms of three Colombian scorpion species, C. margaritatus, T. pachyurus, and T. n. sp. aff. metuendus, were compared to establish the presence and absence of enzymes such as phospholipases, hyaluronidases, and proteases that could be related to venom toxicity. Results: C. margaritatus was positive for hyaluronidases, T. n. sp. aff. metuendus for proteases, and T. pachyurus exhibited activity for all three mentioned enzymes. Conclusion: This information provides valuable insights into the specific enzyme diversity of each species' venom and their potential role in venom toxicity, which could contribute to the development of better treatments and prevention strategies for scorpion envenomation.


Asunto(s)
Venenos de Escorpión/enzimología , Venenos de Escorpión/toxicidad , Colombia
3.
Int. j. morphol ; 41(2): 466-470, abr. 2023. ilus, tab
Artículo en Inglés | LILACS | ID: biblio-1440328

RESUMEN

SUMMARY: The appearance of Pseudomonas aeruginosa strains with multi-resistance to antibiotics is a clinical problem of great relevance. The methods for detecting these resistances are laborious and slow, which is a complication when treating patients promptly. In this work, we developed a simple method for simultaneous detection of several carbapenem resistance genes using a multiplex PCR assay. The PCR assay developed, followed by electrophoretic separation of fragments, allows to simultaneously identify the presence of 6 antibiotic resistance genes: bla-VIM (261 bp), bla-IMP (587 bp), bla-SPM (648 bp), bla-GIM-1 (753 bp), bla-NDM-1 (813 bp) and bla-KPC (882 bp). We analyzed 7 clinical isolates of P. aeruginosa obtained in Chile, finding the resistance genes bla-VIM, bla-IMP, bla-SPM, bla-GIM, and bla-NDM in 5 of them. We found a perfect correlation between the detection of various resistance genes by PCR and the results obtained by antibiograms. Interestingly, 2 of the strains possessed 3 different resistance genes simultaneously. Finally, in this work, we found the presence of 3 genes never described before in clinical isolates of P. aeruginosa in Chile (bla-IMP, bla-SPM, and bla-GIM-1). We developed a rapid multiplex PCR test for the simultaneous detection of up to 6 antibiotic resistance genes of the metallo-β-lactamase family in P. aeruginosa.


La aparición de cepas de Pseudomonas aeruginosa con resistencias a diversos antibióticos es un problema clínico de gran relevancia. Los métodos de detección de dichas resistencias son laboriosos y lentos, lo que genera una complicación al momento de tratar a los pacientes oportunamente. En este trabajo desarrollamos un método simple de detección simultánea de varios genes de resistencia a carbapenem, mediante un sistema de PCR múltiple. El ensayo de PCR desarrollado, seguido de una separación electroforética de los amplicones, permite distinguir simultáneamente la presencia de 6 genes de resistencia a antibióticos: bla-VIM (261 pb), bla-IMP (587 pb), bla-SPM (648 pb), bla-GIM-1 (753 pb), bla-NDM-1 (813 pb) y bla-KPC (882 pb). Analizamos 7 aislados clínicos obtenidos en Chile, encontrando en 5 de ellos los genes de resistencia bla-VIM, bla-IMP, bla-SPM, bla-GIM y bla-NDM. Encontramos una perfecta correlación entre la detección de diversos genes de resistencia y los resultados obtenidos mediante antibiogramas. Interesantemente, 2 de las cepas mostraron poseer simultáneamente 3 genes de resistencia distintos. Por último, en este trabajo encontramos la presencia de 3 genes nunca antes descritos en aislados clínicos de P. aeruginosa en Chile (bla-IMP, bla-SPM y bla-GIM-1). Hemos desarrollado un test rápido de PCR múltiple, para la detección simultánea de hasta 6 genes de resistencia a antibióticos de la familia.a de las metallo-b-lactamases en P. aeruginosa.


Asunto(s)
Pseudomonas aeruginosa/enzimología , beta-Lactamasas/genética , Pseudomonas aeruginosa/genética , Farmacorresistencia Bacteriana , Reacción en Cadena de la Polimerasa Multiplex
4.
Int. j. morphol ; 41(2): 675-685, abr. 2023. ilus, tab
Artículo en Inglés | LILACS | ID: biblio-1440334

RESUMEN

SUMMARY: Pulmonary ventilation is a mechanical process in which the respiratory muscles act in coordination to maintain the oxygenation of the organism. Any alteration in the performance of these muscles may reduce the effectiveness of the process. The respiratory muscles differ from the other skeletal muscles in the vital support that they provide through rhythmiccontractions. The structure and energy system of the muscles are specially adapted to perform this function. The composition of the respiratory muscles is exceptional; they are small, and present an abundant capillary network, endowing them with a high aerobic level and resistance to fatigue. Coordinated regulation of the local renin-angiotensin system provides proper blood flow and energy supply in the myofibrils of the skeletal muscle tissue. Specifically, this performance will depend to a large extent on blood flow and glucose consumption, regulated by the renin-angiotensin system. The angiotensin converting enzyme is responsible for degrading kinins, which finally regulate muscle bioenergy and glucose between the blood vessel and the skeletal muscle. The objective of this review is to describe the structure of the respiratory muscles and their association with the angiotensin converting enzyme gene.


La ventilación pulmonar es un proceso mecánico en el que los músculos respiratorios actúan coordinadamente para mantener la oxigenación en el organismo. Así, cualquier alteración en el desempeño de estos músculos puede reducir la efectividad del proceso. Los músculos respiratorios se diferencian de otros músculos esqueléticos, debido al apoyo vital que brindan a través de sus contracciones rítmicas. La estructura y el sistema energético de estos músculos están especialmente adaptados para realizar esta función. La composición de los músculos respiratorios es especial; son pequeñas y presentan una abundante red capilar, lo que les otorga un alto nivel aeróbico y resistencia a la fatiga. La regulación coordinada del sistema renina-angiotensina local, proporciona un adecuado flujo sanguíneo y suministro de energía a las miofibrillas del músculo esquelético. En concreto, este rendimiento dependerá en gran medida del flujo sanguíneo y del consumo de glucosa, regulado por el sistema renina-angiotensina. Aquí, la enzima convertidora de angiotensina es responsable de degradar las kininas, que finalmente regulan la bioenergía muscular y la glucosa entre el vaso sanguíneo y el músculo esquelético. El objetivo de esta breve comunicación es describir la estructura de los músculos respiratorios y su asociación con el gen de la enzima convertidora de angiotensina.


Asunto(s)
Humanos , Músculos Respiratorios/anatomía & histología , Músculos Respiratorios/enzimología , Músculos Respiratorios/fisiología , Polimorfismo Genético , Sistema Renina-Angiotensina , Músculos Respiratorios/embriología , Peptidil-Dipeptidasa A/genética
5.
Braz. j. biol ; 83: 1-5, 2023. ilus
Artículo en Inglés | LILACS, VETINDEX | ID: biblio-1468930

RESUMEN

Diabetes mellitus (DM) is a non-communicable disease throughout the world in which there is persistently high blood glucose level from the normal range. The diabetes and insulin resistance are mainly responsible for the morbidities and mortalities of humans in the world. This disease is mainly regulated by various enzymes and hormones among which Glycogen synthase kinase-3 (GSK-3) is a principle enzyme and insulin is the key hormone regulating it. The GSK-3, that is the key enzyme is normally showing its actions by various mechanisms that include its phosphorylation, formation of protein complexes, and other cellular distribution and thus it control and directly affects cellular morphology, its growth, mobility and apoptosis of the cell. Disturbances in the action of GSK-3 enzyme may leads to various disease conditions that include insulin resistance leading to diabetes, neurological disease like Alzheimer’s disease and cancer. Fluoroquinolones are the most common class of drugs that shows dysglycemic effects via interacting with GSK-3 enzyme. Therefore, it is the need of the day to properly understand functions and mechanisms of GSK-3, especially its role in glucose homeostasis via effects on glycogen synthase.


O diabetes mellitus (DM) é uma doença não transmissível em todo o mundo, na qual existe nível glicêmico persistentemente alto em relação à normalidade. O diabetes e a resistência à insulina são os principais responsáveis pelas morbidades e mortalidades de humanos no mundo. Essa doença é regulada principalmente por várias enzimas e hormônios, entre os quais a glicogênio sintase quinase-3 (GSK-3) é uma enzima principal e a insulina é o principal hormônio que a regula. A GSK-3, que é a enzima-chave, normalmente mostra suas ações por vários mecanismos que incluem sua fosforilação, formação de complexos de proteínas e outras distribuições celulares e, portanto, controla e afeta diretamente a morfologia celular, seu crescimento, mobilidade e apoptose do célula. Perturbações na ação da enzima GSK-3 podem levar a várias condições de doença que incluem resistência à insulina que leva ao diabetes, doenças neurológicas como a doença de Alzheimer e câncer. As fluoroquinolonas são a classe mais comum de drogas que apresentam efeitos disglicêmicos por meio da interação com a enzima GSK-3. Portanto, é necessário hoje em dia compreender adequadamente as funções e mecanismos da GSK-3, principalmente seu papel na homeostase da glicose via efeitos na glicogênio sintase.


Asunto(s)
Humanos , Diabetes Mellitus/enzimología , Fluoroquinolonas/análisis , /análisis
6.
China Journal of Chinese Materia Medica ; (24): 2307-2315, 2023.
Artículo en Chino | WPRIM | ID: wpr-981306

RESUMEN

Cinnamomum camphora is an important economic tree species in China. According to the type and content of main components in the volatile oil of leaf, C. camphora were divided into five chemotypes, including borneol-type, camphor-type, linalool-type, cineole-type, and nerolidol-type. Terpene synthase(TPS) is the key enzyme for the formation of these compounds. Although several key enzyme genes have been identified, the biosynthetic pathway of(+)-borneol, which has the most economic value, has not been reported. In this study, nine terpenoid synthase genes CcTPS1-CcTPS9 were cloned through transcriptome analysis of four chemical-type leaves. After the recombinant protein was induced by Escherichia coli, geranyl pyrophosphate(GPP) and farnesyl pyrophosphate(FPP) were used as substrates for enzymatic reaction, respectively. Both CcTPS1 and CcTPS9 could catalyze GPP to produce bornyl pyrophosphate, which could be hydrolyzed by phosphohydrolase to obtain(+)-borneol, and the product of(+)-borneol accounted for 0.4% and 89.3%, respectively. Both CcTPS3 and CcTPS6 could catalyze GPP to generate a single product linalool, and CcTPS6 could also react with FPP to generate nerolidol. CcTPS8 reacted with GPP to produce 1,8-cineol(30.71%). Nine terpene synthases produced 9 monoterpene and 6 sesquiterpenes. The study has identified the key enzyme genes responsible for borneol biosynthesis in C. camphora for the first time, laying a foundation for further elucidating the molecular mechanism of chemical type formation and cultivating new varieties of borneol with high yield by using bioengineering technology.


Asunto(s)
Cinnamomum camphora/enzimología , Transferasas Alquil y Aril/química
7.
Protein & Cell ; (12): 17-27, 2023.
Artículo en Inglés | WPRIM | ID: wpr-971604

RESUMEN

The global COVID-19 coronavirus pandemic has infected over 109 million people, leading to over 2 million deaths up to date and still lacking of effective drugs for patient treatment. Here, we screened about 1.8 million small molecules against the main protease (Mpro) and papain like protease (PLpro), two major proteases in severe acute respiratory syndrome-coronavirus 2 genome, and identified 1851Mpro inhibitors and 205 PLpro inhibitors with low nmol/l activity of the best hits. Among these inhibitors, eight small molecules showed dual inhibition effects on both Mpro and PLpro, exhibiting potential as better candidates for COVID-19 treatment. The best inhibitors of each protease were tested in antiviral assay, with over 40% of Mpro inhibitors and over 20% of PLpro inhibitors showing high potency in viral inhibition with low cytotoxicity. The X-ray crystal structure of SARS-CoV-2 Mpro in complex with its potent inhibitor 4a was determined at 1.8 Å resolution. Together with docking assays, our results provide a comprehensive resource for future research on anti-SARS-CoV-2 drug development.


Asunto(s)
Humanos , Antivirales/química , COVID-19 , Tratamiento Farmacológico de COVID-19 , Ensayos Analíticos de Alto Rendimiento , Simulación del Acoplamiento Molecular , Inhibidores de Proteasas/química , SARS-CoV-2/enzimología , Proteínas no Estructurales Virales
8.
Chinese Journal of Industrial Hygiene and Occupational Diseases ; (12): 8-13, 2023.
Artículo en Chino | WPRIM | ID: wpr-970703

RESUMEN

Objective: To explore the value of paraquat (PQ) intake, urine protein and myocardial enzyme indexes in judging the prognosis of patients with acute PQ poisoning. Methods: From September to December 2021, all 201 patients with acute PQ poisoning admitted to Guangzhou Twelfth People's Hospital from January 2010 to December 2019 were selected as the research objects. Based on follow-up results 60 days after poisoning, the research objects were divided into survival group (n=78) and death group (n=123) . The differences in information about poisoning, treatment plan, PQ intake, urine protein, creatine kinase, creatine kinase isoenzyme, lactate dehydrogenase, and α-hydroxybutyrate dehydrogenase between the two groups of patients were compared and analyzed. Logistic regression and Cox regression were used to analyze the correlation between poisoning outcome and PQ intake, urine protein and myocardial enzymes. ROC curve and principal component analysis were used to explore high-efficiency indicators for predicting the outcome of acute PQ poisoning. Results: The PQ intake[50 (20, 100) ml], urine protein (total rank 15570.50) , creatine kinase[ (336.36±261.96) U/L], creatine kinase isoenzyme[ (43.91±43.74) U/L], lactate dehydrogenase [ (346.01±196.50) U/L], α-hydroxybutyrate dehydrogenase content[ (271.23±11.92) U/L] of patients in the death group were all higher than the survival group[15 (10, 20) ml, 4730.50, (187.78±178.06) U/L, (18.88±15.50) U/L, (190.92±60.50) U/L, (152.60±48.34) U/L, respectively] (P<0.05) . The outcome of acute PQ poisoning was positively correlated with PQ intake, urine protein, creatine kinase, creatine kinase isoenzyme, lactate dehydrogenase, and α-hydroxybutyrate dehydrogenase (P<0.05) . Multivariate logistic regression and multivariate Cox regression analysis showed that creatine kinase, creatine kinase isoenzyme, lactate dehydrogenase and α-hydroxybutyrate dehydrogenase was positively correlated with the prognosis of patients with acute PQ poisoning (P<0.05) . ROC curve analysis and principal component analysis showed that the combined indexes of PQ intake, urine protein and myocardial enzymes had the highest efficacy and weight in judging the prognosis of patients (AUC=0.91, weight coefficient=0.19, sensitivity=0.76, specificity=0.89) . When the combined score was ≥4, the probability of accurately predicting the death of patients was as high as 91% (positive predictive value=0.91) . Conclusion: PQ intake, urine protein combined with creatine kinase, creatine kinase isoenzyme, lactate dehydrogenase, and α-hydroxybutyrate dehydrogenase has high value in predicting the prognosis of patients with acute PQ poisoning.


Asunto(s)
Humanos , Creatina , Creatina Quinasa , Isoenzimas , Lactato Deshidrogenasas , Paraquat/envenenamiento , Pronóstico , Estudios Retrospectivos , Miocardio/enzimología , Orina/química
9.
Braz. j. biol ; 83: 1-5, 2023. tab, graf
Artículo en Inglés | LILACS, VETINDEX | ID: biblio-1468822

RESUMEN

The essential oil of citronella (Cymbopogon winterianus) has several biological activities, among them the insect repellent action. Some studies showed that cinnamic acid esters can be applied as natural pesticides, insecticides and fungicides. In this context, the objective of the present work was to evaluate the production of esters from citronella essential oil with cinnamic acid via enzymatic esterification. Besides, the essential oil toxicity before and after esterification against Artemia salina and larvicidal action on Aedes aegypti was investigated. Esters were produced using cinnamic acid as the acylating agent and citronella essential oil (3:1) in heptane and 15 wt% NS 88011 enzyme as biocatalysts, at 70 °C and 150 rpm. Conversion rates of citronellyl and geranyl cinnamates were 58.7 and 69.0% for NS 88011, respectively. For the toxicity to Artemia salina LC50 results of 5.29 μg mL-¹ were obtained for the essential oil and 4.36 μg mL-¹ for the esterified oils obtained with NS 88011. In the insecticidal activity against Aedes aegypti larvae, was obtained LC50 of 111.84 μg mL-¹ for the essential oil of citronella and 86.30 μg mL-¹ for the esterified oils obtained with the enzyme NS 88011, indicating high toxicity of the esters. The results demonstrated that the evaluated samples present potential of application as bioinsecticide.


O óleo essencial de citronela (Cymbopogon winterianus) possui diversas atividades biológicas, entre elas a ação repelente a insetos. Alguns estudos mostraram que os ésteres do ácido cinâmico podem ser aplicados como pesticidas naturais, inseticidas e fungicidas. Nesse contexto, o objetivo do presente trabalho foi avaliar a produção de ésteres a partir do óleo essencial de citronela com ácido cinâmico via esterificação enzimática. Além disso, foi investigada a toxicidade do óleo essencial antes e após a esterificação contra Artemia salina e a ação larvicida sobre Aedes aegypti. Os ésteres foram produzidos utilizando ácido cinâmico como agente acilante e óleo essencial de citronela (3: 1) em heptano e 15% em peso da enzima NS 88011 como biocatalisadores, a 70 ° C e 150 rpm. As taxas de conversão de cinamatos de citronelil e geranil foram 58,7 e 69,0% para NS 88011, respectivamente. Para a toxicidade sobre Artemia salina foram obtidos CL50 de 5,29 μg mL-¹ para o óleo essencial e 4,36 μg mL-¹ para os óleos esterificados com NS 88011. Na atividade inseticida contra larvas de Aedes aegypti, obteve-se CL50 de 111,84 μg mL-¹ para o óleo essencial de citronela e 86,30 μg mL-¹ para os óleos esterificados com a enzima NS 88011, indicando alta toxicidade dos ésteres. Os resultados demonstraram que as amostras avaliadas apresentam potencial de aplicação como bioinseticida.


Asunto(s)
Animales , Aedes , Artemia , Cymbopogon/enzimología , Cymbopogon/toxicidad , Ésteres/toxicidad
10.
Braz. j. biol ; 83: 1-12, 2023. tab
Artículo en Inglés | LILACS, VETINDEX | ID: biblio-1468876

RESUMEN

Organo-mineral fertilizers supplemented with biological additives are an alternative to chemical fertilizers. In this study, thermoresistant microorganisms from composting mass were isolated by two-step procedures. First, samples taken at different time points and temperatures (33 days at 52 ºC, 60 days at 63 ºC, and over 365 days at 26 ºC) were pre-incubated at 80 oC for 30 minutes. Second, the microbial selection by in vitro culture-based methods and heat shock at 60 oC and 100 oC for 2h and 4h. Forty-one isolates were able to grow at 60 °C for 4h; twenty-seven at 100 °C for 2h, and two at 100 °C for 4h. The molecular identification by partial sequencing of the 16S ribosomal gene using universal primers revealed that thirty-five isolates were from eight Bacillus species, one Brevibacillus borstelensis, three Streptomyces thermogriseus, and two fungi (Thermomyces lanuginosus and T. dupontii). Data from amylase, phytase, and cellulase activity assays and the enzymatic index (EI) showed that 38 of 41 thermo-resistant isolates produce at least one enzyme. For amylase activity, the highest EI value was observed in Bacillus licheniformis (isolate 21C2, EI= 4.11), followed by Brevibacillus borstelensis (isolate 6C2, EI= 3.66), Bacillus cereus (isolate 18C2, EI= 3.52), and Bacillus paralicheniformis (isolate 20C2, EI= 3.34). For phytase, the highest EI values were observed for Bacillus cereus (isolate 18C2, EI= 2.30) and Bacillus licheniformis (isolate 3C1, EI= 2.15). Concerning cellulose production, B. altitudinis (isolate 6C1) was the most efficient (EI= 6.40), followed by three Bacillus subtilis (isolates 9C1, 16C2, and 19C2) with EI values of 5.66, 5.84, and 5.88, respectively, and one B. pumilus (isolate 27C2, EI= 5.78). The selected microorganisms are potentially useful as a biological additive in organo-mineral fertilizers and other biotechnological processes.


Os fertilizantes organo-minerais suplementados com aditivos biológicos são uma alternativa aos adubos químicos. Neste estudo, microrganismos termoresistentes foram isolados de compostagem por procedimentos de duas etapas. Inicialmente, as amostras tomadas em diferentes períodos e temperaturas (33 dias a 52 ºC, 60 dias a 63 ºC e mais de 365 dias a 26 ºC) foram pré-incubadas a 80 oC por 30 minutos. Posteriormente, a seleção microbiana foi conduzida por métodos baseados em cultura in vitro e choque térmico a 60 oC e 100 oC por 2h e 4h. Quarenta e um isolados foram capazes de crescer a 60 °C por 4h; vinte e sete a 100 °C por 2h e dois a 100 °C por 4h. A identificação molecular por sequenciamento parcial do gene ribossomal 16S usando primers universais revelou que trinta e cinco isolados eram de oito espécies de Bacillus, um Brevibacillus borstelensis, três Streptomyces thermogriseus e dois fungos (Thermomyces lanuginosus e T. dupontii). Os dados dos ensaios de atividade de amilase, fitase e celulase e o índice enzimático (IE) mostraram que 38 dos 41 isolados termorresistentes produziram pelo menos uma enzima. Para a atividade da amilase, o maior valor de IE foi observado em Bacillus licheniformis (isolado 21C2, IE = 4,11), seguido por Brevibacillus borstelensis (isolado 6C2, IE = 3,66), Bacillus cereus (isolado 18C2, IE = 3,52) e Bacillus paralicheniformis (isolado 20C2, IE = 3,34). Para a fitase, os maiores valores de IE foram observados para B. cereus (isolado 18C2, IE = 2,30) e B. licheniformis (isolado 3C1, IE = 2,15). Em relação à produção de celulose, B. altitudinis (isolado 6C1) foi o mais eficiente (IE = 6,40), seguido por três Bacillus subtilis (isolados 9C1, 16C2 e 19C2) com valores de IE de 5,66, 5,84 e 5,88, respectivamente, e um B. pumilus (isolado 27C2, IE = 5,78). Pode-se inferir que os microrganismos selecionados são potencialmente úteis como aditivos biológicos em fertilizantes organo-minerais e outros processos biotecnológicos.


Asunto(s)
Bacillus , Brevibacillus/enzimología , Compuestos Orgánicos , Hongos/enzimología , Microbiota/genética , /ultraestructura , Streptomyces/enzimología
11.
Rev. Ciênc. Plur ; 8(3): 27644, out. 2022. ilus, tab
Artículo en Portugués | LILACS, BBO | ID: biblio-1399339

RESUMEN

Introdução:uma vez conhecidos os mecanismos de patogênese do SARS-CoV-2, vários métodos de tratamento para a COVID-19 foram desenvolvidos, dentre eles destaca-se o uso dos anticorpos monoclonais para o contexto de pacientes em estágios graves da doença. Objetivo: compreender se o uso dos anticorpos monoclonais para tratamento da COVID-19 grave interfere nos níveis séricos da angiotensina II. Metodologia:Para a realização dessa pesquisa foram selecionados através do DeCS e MeSH os descritores "COVID-19", "Angiotensin II" e "Antibodies, Monoclonal" e seus respectivos "entry terms" sugeridos pela base MeSH. Posteriormente,utilizando-se os operadores booleanos OR e AND, foi montada uma estratégia de busca, a qual foi utilizada nas bases de dados PUBMED, EMBASE, Web of Science, Cochrane Library e Scopus, sem restrição dedata de publicação ou idioma. Resultados:ao final do processo de seleção dos artigos, 29 foram selecionados para a leitura e análise completa. Nesta revisão, foram abordados diferentes tipos de anticorpos monoclonais, os quais foram oportunamente agrupados de acordo com o seu mecanismo de ação. Conclusão: foi possível concluir que das cinco classes de anticorpos monoclonais tratadas neste trabalho, três potencialmente podem causar alterações nos níveis séricos de angiotensina II (AU).


Introduction:once the mechanisms of pathogenesis of SARS-CoV-2 are known, several methods of treatment for COVID-19 have been developed, among them the use of monoclonal antibodies for the context of patients in severe stages of the disease. Purpose:to understand whether the use of monoclonal antibodies for the treatment of severe COVID-19 interferes with serum angiotensin II levels. Methodology:For this research were selected through DeCS and MeSH the descriptors "COVID-19", "Angiotensin II" and "Antibodies, Monoclonal" and their respective entry "Terms" suggested by the MeSH database. Subsequently, using the boolean operators OR and AND, a search strategy was set up, which was used in the databases PUBMED, EMBASE, Web of Science, Cochrane Library and Scopus, without restriction of publication date or language. Results:at the end of the article selection process, 29 were selected for reading and full analysis. In this review, different types of monoclonal antibodies were addressed, which were opportunely grouped according to their mechanism of action. Conclusion:it was possible to conclude that of the five classes of monoclonal antibodies treated in this study, three potentially can cause changes in serum levels of angiotensin II (AU).


Introducción:Una vez conocidos los mecanismos de patogénesis del SARSCoV-2, se desarrollaron variosmétodos de tratamiento para el COVID-19, entre ellos, el uso de anticuerpos monoclonales para el contexto de pacientes en fases graves de la enfermedad. Objetivo:Comprender si el uso de anticuerpos monoclonales para el tratamiento de la COVID-19 grave interfiere en los niveles séricos de angiotensina II. Metodología:Los descriptores "COVID-19", "Angiotensina II", "Anticuerpos, Monoclonales" y sus respectivos "entry terms" (términos de entrada) sugeridos por el MeSH fueron seleccionados a través de DeCS yMeSH. Posteriormente, utilizando los operadores booleanos OR y AND, se estableció una estrategia de búsqueda que se utilizó en las bases de datos PUBMED, EMBASE, Web of Science, Cochrane Library y Scopus, sin restricción de fecha de publicación ni de idioma. Resultados:Al final del proceso de selección de artículos, se seleccionaron 29 artículos para su lectura y análisis completos. En esta revisión se han abordado diferentes tipos de anticuerpos monoclonales, que se han agrupado oportunamente según su mecanismo de acción. Conclusión:Se pudo concluir que de las cinco clases de anticuerpos monoclonales tratados en este trabajo, tres pueden potencialmente causar alteraciones en los niveles séricos de angiotensina II (AU).


Asunto(s)
Angiotensina II , COVID-19/tratamiento farmacológico , Factores Inmunológicos/uso terapéutico , Anticuerpos Monoclonales/uso terapéutico , SARS-CoV-2/enzimología
12.
Rev. Hosp. Ital. B. Aires (2004) ; 42(3): 129-134, sept. 2022. graf, tab
Artículo en Español | LILACS, UNISALUD, BINACIS | ID: biblio-1396276

RESUMEN

Introducción: la hepatotoxicidad por paracetamol está relacionada con la formación del metabolito N-acetil-parabenzoquinoneimina (NAPQI) y su falta de detoxificación a través del glutatión, cuyas reservas se deplecionan en el contexto de una sobredosis. La administración de N-acetilcisteína (NAC) como sustancia dadora de grupos tioles (-SH) contribuye a la prevención del daño hepático que puede desarrollarse con dosis terapéuticas o tóxicas. Métodos: se comentan 5 casos de exposición a paracetamol en los cuales se administró NAC por alteración de la función hepática. La gravedad de los cuadros varió en función de las dosis y del tiempo de latencia hasta la consulta. Resultados: cuatro pacientes ingirieron una única dosis tóxica y una paciente recibió la dosis diaria máxima de paracetamol de 4000 mg/día durante 5 días. La paciente que consultó dentro de las 4 horas posteriores a la ingesta no presentó elevación de transaminasas. Todas las pacientes recibieron NAC y sus valores de enzimas hepáticas se normalizaron al momento del alta. Conclusión: la administración temprana de NAC puede ser útil para prevenir daño hepático tanto en ingestas de dosis tóxicas, como en casos de utilización de dosis terapéuticas máximas durante varios días. (AU)


Introduction: paracetamol hepatotoxicity is related to the formation of the metabolite N-acetyl-parabenzoquinoneimine (NAPQI) and its lack of detoxification through glutathione, whose reserves are depleted in paracetamol overdose. The administration of N-acetylcysteine (NAC) as a donor of sulfhydryl groups (-SH) can prevent liver damage that could even occur with therapeutic or toxic doses. Methods: 5 cases of exposure to paracetamol are discussed, in which NAC was administered due to impaired liver function. These manifestations presented different severity depending on the drug doses and the time until medical consultation. Results: four patients ingested single toxic doses and one patient received the maximum daily dose of paracetamol of 4000 mg/day for 5 days. The patient who consulted within 4 hours after ingestion did not present elevation of transaminases. All patients received NAC, with normal liver enzymes at discharge. Conclusion: the early administration of NAC may be useful to prevent liver damage both in toxic dose intakes and in cases of use of maximum therapeutic doses for several days. (AU)


Asunto(s)
Humanos , Femenino , Adolescente , Adulto , Persona de Mediana Edad , Adulto Joven , Acetilcisteína/administración & dosificación , Enfermedad Hepática Inducida por Sustancias y Drogas/prevención & control , Enfermedad Hepática Inducida por Sustancias y Drogas/tratamiento farmacológico , Acetaminofén/toxicidad , Tiempo de Reacción/efectos de los fármacos , Cromatografía Liquida , Enfermedad Hepática Inducida por Sustancias y Drogas/enzimología , Transaminasas/sangre , Acetaminofén/administración & dosificación
13.
Med. infant ; 29(1): 17-22, Marzo 2022. Tab, ilus
Artículo en Español | LILACS, UNISALUD, BINACIS | ID: biblio-1366851

RESUMEN

Objetivo: evaluar la efectividad de la técnica de conteo de grasas y ajuste de enzimas pancreáticas en un grupo de pacientes con insuficiencia pancreática secundaria a fibrosis quística (FQ). Materiales y métodos: En un grupo de pacientes con FQ, sin otra patología asociada, mayores de 1 año, con >10 000 UKD (unidades por kilo por día) de lipasa; se realizó educación y aplicación de técnica de conteo de grasas con ajuste enzimático, solicitando Van de Kamer y registro alimentario de 5 días durante la recolección de la muestra con un intervalo de 3 meses entre ambas determinaciones. Se evaluó la efectividad de la misma y las dosis de enzimas utilizadas mediante el porcentaje de excreción grasa (PEG), así como las variaciones en la cantidad de enzimas utilizadas y la ganancia de peso. Los datos se registraron en RED Cap (Research Electronic Data Capture) y se analizaron mediante Stata 12. Resultados: De un total de 21 pacientes, 16 completaron la intervención. El 50% presentó un índice de masa corporal (IMC) mayor del Plo 25 antes y después, un 87% alcanzó adecuación calórica mayor del 120% de la ingestas diarias recomendadas (RDA) al final, logrando un aumento promedio de z score de peso de 0,28 con una media inicial de 17 kg y final de 18,2 kg. En cuanto a la media del requerimiento enzimático fue de 14 800 UKD antes y 10 145 UKD después (z=0,002), asimismo el porcentaje de excreción grasa (PEG) tuvo una disminución del 38% (p=0,1705). Conclusiones: La implementación de la técnica de conteo de grasas y ajuste enzimático, podría ser una estrategia válida para aquellos pacientes con FQ que tienen dosis altas de enzimas e inadecuada ganancia de peso (AU)


Objective: To evaluate the effectiveness of the fat counting technique and pancreatic enzyme adjustment in a group of patients with pancreatic insufficiency secondary to cystic fibrosis (CF). Materials and methods: A group of patients with CF without other associated diseases, older than 1 year of age, lipase dose >10 000 UKD (units per kilo per day), received education on the fat counting technique with enzyme adjustment followed by its implementation of the intervention. Van de Kamer was requested and a 5-day food record was kept during the sample collection with an interval of 3 months between both measurements. The effectiveness of the technique and the enzyme doses used were evaluated based on the percentage of fat excretion (PFE), as well as the variations in the amount of enzymes used and weight gain. Data were recorded in RED Cap (Research Electronic Data Capture) and analyzed using Stata 12. Results: Of a total of 21 patients, 16 completed the intervention. Fifty percent had a body mass index (BMI) greater than Plo 25 before and after the intervention; 87% had achieved a caloric increase greater than 120% of the recommended daily intake (RDA) at the end of the study and an average increase in weight z score of 0.28 with an initial mean of 17 kg and a final mean of 18.2 kg. Mean enzyme requirement was 14 800 UKD before and 10 145 UKD after the intervention (z=0.002). PFE decreased by 38% (p=0.1705). Conclusions: The implementation of the technique of fat counting and enzyme adjustment may be a valid strategy for CF patients with high enzyme doses and inadequate weight gain. (AU)


Asunto(s)
Lactante , Preescolar , Niño , Adolescente , Páncreas/enzimología , Insuficiencia Pancreática Exocrina , Grasas de la Dieta/administración & dosificación , Fibrosis Quística/dietoterapia , Glándulas Exocrinas/anomalías , Terapia de Reemplazo Enzimático
14.
Neuroscience Bulletin ; (6): 135-148, 2022.
Artículo en Inglés | WPRIM | ID: wpr-922667

RESUMEN

The family of voltage-gated potassium Kv2 channels consists of the Kv2.1 and Kv2.2 subtypes. Kv2.1 is constitutively highly phosphorylated in neurons and its function relies on its phosphorylation state. Whether the function of Kv2.2 is also dependent on its phosphorylation state remains unknown. Here, we investigated whether Kv2.2 channels can be phosphorylated by protein kinase C (PKC) and examined the effects of PKC-induced phosphorylation on their activity and function. Activation of PKC inhibited Kv2.2 currents and altered their steady-state activation in HEK293 cells. Point mutations and specific antibodies against phosphorylated S481 or S488 demonstrated the importance of these residues for the PKC-dependent modulation of Kv2.2. In layer II pyramidal neurons in cortical slices, activation of PKC similarly regulated native Kv2.2 channels and simultaneously reduced the frequency of action potentials. In conclusion, this study provides the first evidence to our knowledge that PKC-induced phosphorylation of the Kv2.2 channel controls the excitability of cortical pyramidal neurons.


Asunto(s)
Humanos , Potenciales de Acción , Células HEK293 , Proteína Quinasa C/metabolismo , Células Piramidales/enzimología , Canales de Potasio Shab/genética
15.
Chinese Journal of Oncology ; (12): 540-549, 2022.
Artículo en Chino | WPRIM | ID: wpr-940920

RESUMEN

Objective: To observe the platinum drugs resistance effect of N-acetyltransferase 10 (NAT10) overexpression in breast cancer cell line and elucidate the underlining mechanisms. Methods: The experiment was divided into wild-type (MCF-7 wild-type cells without any treatment) group, NAT10 overexpression group (H-NAT10 plasmid transfected into MCF-7 cells) and NAT10 knockdown group (SH-NAT10 plasmid transfected into MCF-7 cells). The invasion was detected by Transwell array, the interaction between NAT10 and PARP1 was detected by co-immunoprecipitation. The impact of NAT10 overexpression or knockdown on the acetylation level of PARP1 and its half-life was also determined. Immunostaining and IP array were used to detect the recruitment of DNA damage repair protein by acetylated PARP1. Flow cytometry was used to detect the cell apoptosis. Results: Transwell invasion assay showed that the number of cell invasion was 483.00±46.90 in the NAT10 overexpression group, 469.00±40.50 in the NAT10 knockdown group, and 445.00±35.50 in the MCF-7 wild-type cells, and the differences were not statistically significant (P>0.05). In the presence of 10 μmol/L oxaliplatin, the number of cell invasion was 502.00±45.60 in the NAT10 overexpression group and 105.00±20.50 in the NAT10 knockdown group, both statistically significant (P<0.05) compared with 219.00±31.50 in wild-type cells. In the presence of 10 μmol/L oxaliplatin, NAT10 overexpression enhanced the binding of PARP1 to NAT10 compared with wild-type cells, whereas the use of the NAT10 inhibitor Remodelin inhibited the mutual binding of the two. Overexpression of NAT10 induced PARP1 acetylation followed by increased PARP1 binding to XRCC1, and knockdown of NAT10 expression reduced PARP1 binding to XRCC1. Overexpression of NAT10 enhanced PARP1 binding to LIG3, while knockdown of NAT10 expression decreased PARP1 binding to LIG3. In 10 μmol/L oxaliplatin-treated cells, the γH2AX expression level was 0.38±0.02 in NAT10 overexpressing cells and 1.36±0.15 in NAT10 knockdown cells, both statistically significant (P<0.05) compared with 1.00±0.00 in wild-type cells. In 10 μmol/L oxaliplatin treated cells, the apoptosis rate was (6.54±0.68)% in the NAT10 overexpression group and (12.98±2.54)% in the NAT10 knockdown group, both of which were statistically significant (P<0.05) compared with (9.67±0.37)% in wild-type cells. Conclusion: NAT10 overexpression enhances the binding of NAT10 to PARP1 and promotes the acetylation of PARP1, which in turn prolongs the half-life of PARP1, thus enhancing PARP1 recruitment of DNA damage repair related proteins to the damage sites, promoting DNA damage repair and ultimately the survival of breast cancer cells.


Asunto(s)
Femenino , Humanos , Neoplasias de la Mama/enzimología , Línea Celular Tumoral , Resistencia a Antineoplásicos , Células MCF-7 , Acetiltransferasas N-Terminal/metabolismo , Compuestos Organoplatinos/farmacología , Oxaliplatino/farmacología , Proteína 1 de Reparación por Escisión del Grupo de Complementación Cruzada de las Lesiones por Rayos X
16.
Protein & Cell ; (12): 6-25, 2022.
Artículo en Inglés | WPRIM | ID: wpr-929158

RESUMEN

The serine/threonine p21-activated kinases (PAKs), as main effectors of the Rho GTPases Cdc42 and Rac, represent a group of important molecular switches linking the complex cytoskeletal networks to broad neural activity. PAKs show wide expression in the brain, but they differ in specific cell types, brain regions, and developmental stages. PAKs play an essential and differential role in controlling neural cytoskeletal remodeling and are related to the development and fate of neurons as well as the structural and functional plasticity of dendritic spines. PAK-mediated actin signaling and interacting functional networks represent a common pathway frequently affected in multiple neurodevelopmental and neurodegenerative disorders. Considering specific small-molecule agonists and inhibitors for PAKs have been developed in cancer treatment, comprehensive knowledge about the role of PAKs in neural cytoskeletal remodeling will promote our understanding of the complex mechanisms underlying neurological diseases, which may also represent potential therapeutic targets of these diseases.


Asunto(s)
Animales , Humanos , Citoesqueleto/genética , Enfermedades del Sistema Nervioso/genética , Neuronas/enzimología , Transducción de Señal , Quinasas p21 Activadas/metabolismo
17.
Braz. j. biol ; 82: 1-7, 2022. tab, ilus, graf
Artículo en Inglés | LILACS, VETINDEX | ID: biblio-1468429

RESUMEN

This work aimed to obtain aspartic proteases of industrial and biotechnological interest from the stomach of the crevalle jack fish (Caranx hippos). In order to do so, a crude extract (CE) of the stomach was obtained and subjected to a partial purification by salting-out, which resulted in the enzyme extract (EE) obtainment. EE proteases were characterized physicochemically and by means of zymogram. In addition, the effect of chemical agents on their activity was also assessed. By means of salting-out it was possible to obtain a purification of 1.6 times with a yield of 49.4%. Two acid proteases present in the EE were observed in zymogram. The optimum temperature and thermal stability for EE acidic proteases were 55 ºC and 45 °C, respectively. The optimum pH and pH stability found for these enzymes were pH 1.5 and 7.0, respectively. Total inhibition of EE acid proteolytic activity was observed in the presence of pepstatin A. dithiothreitol (DTT) and Ca2+ did not promote a significant effect on enzyme activity. In the presence of heavy metals, such as Al3+, Cd2+ and Hg2+, EE acidic proteases showed more than 70% of their enzymatic activity. The results show that it is possible to obtain, from the stomach of C. hippos, aspartic proteases with high proteolytic activity and characteristics that demonstrate potential for industrial and biotechnological applications.


Este trabalho objetivou obter proteases aspárticas de interesse industrial e biotecnológico a partir do estômago do peixe xaréu (Caranx hippos). Para isso, foi obtido um extrato bruto do estômago, o qual foi submetido a uma purificação parcial por salting-out onde se obteve o extrato enzimático (EE). As proteases do EE foram caracterizadas físico-quimicamente e através de zimograma. Além disso, o efeito de agentes químicos sobre sua atividade também foi avaliado. Através de salting-out foi possível obter uma purificação de 1,6 vezes com rendimento de 49,4%. Foram observadas duas proteases ácidas presentes no EE através de zimograma. A temperatura ótima e a estabilidade térmica para as proteases ácidas do EE foram de 55 ºC e 45 °C, respectivamente. O pH ótimo e a estabilidade ao pH encontrados para estas enzimas foram o pH 1,5 e 7,0, respectivamente. Observou-se a inibição total da atividade proteolítica ácida do EE na presença de pepstatina A. O ditiotreitol (DTT) e o Ca2+ não promoveram efeito significativo na atividade enzimática. Na presença de metais pesados, como Al3+, Cd2+ e Hg2+, o EE manteve mais de 70% de atividade enzimática do EE. Os resultados mostram que é possível obter, a partir do estômago de C. hippos, proteases aspárticas com alta atividade proteolítica e características que demonstram potencial para aplicações industriais e biotecnológicas.


Asunto(s)
Animales , Estómago/enzimología , Estómago/química , Peces , Proteasas de Ácido Aspártico/análisis , Proteasas de Ácido Aspártico/economía
18.
Braz. j. biol ; 82: 1-7, 2022. ilus, graf
Artículo en Inglés | LILACS, VETINDEX | ID: biblio-1468446

RESUMEN

Shewanella xiamenensis G5-03 was observed to decolorize the azo dye Congo red in synthetic wastewater. The influence of some factors on the dye decolorization efficiency was evaluated. The optimal decolorization conditions were temperature 30-35 °C, pH 10.0, incubation time 10 h, and static condition. The kinetic of Congo red decolorization fitted to the Michaelis–Menten model (Vmax = 111.11 mg L-¹ h-¹ and Km = 448.3 mg L-¹). The bacterium was also able to degrade benzidine, a product of azo bond breakage of the Congo red, which contributed to reduce the phytotoxicity. The ability of S. xiamenensis G5-03 for simultaneous decolorization and degradation of Congo red shows its potential application for the biological treatment of wastewaters containing azo dyes.


Shewanella xiamenensis G5-03 foi capaz de descolorir o corante azo vermelho Congo em água residuária sintética. A influência de alguns fatores na eficiência da descoloração do corante foi avaliada. As condições ótimas de descoloração foram temperatura de 30-35 °C, pH 10,0 e condições estáticas. A cinética de descoloração do vermelho Congo se ajustou ao modelo de Michaelis–Menten (Vmax = 111,11 mg L-¹ h-¹ and Km = 448,3 mg L-¹). A bactéria também foi capaz de degradar a benzidina, um produto da quebra da ligação azo do vermelho Congo, o que contribuiu para a redução da fitotoxicidade. A habilidade da S. xiamenensis G5-03 em simultaneamente descolorir e degradar o vermelho Congo demostra seu potencial de aplicação no tratamento de águas residuárias contendo corantes azo.


Asunto(s)
Bencidinas/aislamiento & purificación , Shewanella/enzimología , Aguas Residuales/análisis , Aguas Residuales/toxicidad
19.
Braz. j. biol ; 82: 1-9, 2022. tab, graf
Artículo en Inglés | LILACS, VETINDEX | ID: biblio-1468458

RESUMEN

The cockle Cerastoderma edule was exposed to four concentrations (5, 10, 20 and 70 μg L-¹) of carbamazepine (CBZ). This anticonvulsant was found to alter the mussel behavior of by reducing its clearance rate (CR). Analysis of CBZ accumulation in tissues of C. edule was carried out using HPLC-UV after 48 or 96 hours of exposure. In addition, an overproduction of H2O2 by the bivalves was detected following exposure to CBZ but nitrite levels remained unchanged. Moreover, superoxide dismutase and catalase activities showed a significant increase in relation to their contact with CBZ. The activity of the biotransformation enzyme gluthatione-S-transferase did not change during exposure. Malondialdehyde (MDA) levels indicating cellular damage, increased when bivalves were exposed to 20 and 70 μg l-¹ of carbamazepine for 96 h CBZ. The results also indicate that acetylcholinesterase activity (AChE) was inhibited in all CBZ concentrations during the 48 h exposure period. However, during the 96 h exposure period, AChE was only inhibited at the highest concentration. Further studies are needed now for more exploration of the toxicity of CBZ since it could be bioaccumulable throughout the food web and may affect non-target organisms.


O berbigão Cerastoderma edule foi exposto a quatro concentrações (5, 10, 20 e 70 μg L-¹) de carbamazepina (CBZ). Este anticonvulsivante alterou o comportamento do mexilhão, reduzindo sua taxa de depuração (CR). A análise do acúmulo de CBZ nos tecidos de C. edule foi realizada por HPLC-UV após 48 ou 96 horas de exposição. Além disso, uma superprodução de H2O2 pelos bivalves foi detectada após a exposição à CBZ, mas os níveis de nitrito permaneceram inalterados. Além disso, as atividades de superóxido dismutase e catalase apresentaram aumento significativo em relação ao contato com CBZ. A atividade da enzima de biotransformação glutationa-S-transferase não se alterou durante a exposição. Os níveis de malondialdeído (MDA), indicando dano celular, aumentaram quando os bivalves foram expostos a 20 e 70 μg l-1 de carbamazepina por 96 h CBZ. Os resultados também indicam que a atividade da acetilcolinesterase (AChE) foi inibida em todas as concentrações de CBZ durante o período de exposição de 48 horas. No entanto, durante o período de exposição de 96 horas, a AChE foi inibida apenas na concentração mais alta. Mais estudos são necessários agora para uma maior exploração da toxicidade da CBZ, uma vez que pode ser bioacumulável em toda a cadeia alimentar e pode afetar organismos não alvo.


Asunto(s)
Animales , Carbamazepina/administración & dosificación , Carbamazepina/toxicidad , Cardiidae/efectos de los fármacos , Cardiidae/enzimología , Biomarcadores/análisis
20.
Braz. j. biol ; 82: 1-8, 2022. tab, graf, ilus
Artículo en Inglés | LILACS, VETINDEX | ID: biblio-1468474

RESUMEN

Glutamine synthetase (GS), encoded by glnA, catalyzes the conversion of L-glutamate and ammonium to L-glutamine. This ATP hydrolysis driven process is the main nitrogen assimilation pathway in the nitrogen-fixing bacterium Azospirillum brasilense. The A. brasilense strain HM053 has poor GS activity and leaks ammonium into the medium under nitrogen fixing conditions. In this work, the glnA genes of the wild type and HM053 strains were cloned into pET28a, sequenced and overexpressed in E. coli. The GS enzyme was purified by affinity chromatography and characterized. The GS of HM053 strain carries a P347L substitution, which results in low enzyme activity and rendered the enzyme insensitive to adenylylation by the adenilyltransferase GlnE.


A glutamina sintetase (GS), codificada por glnA, catalisa a conversão de L-glutamato e amônio em L-glutamina. Este processo dependente da hidrólise de ATP é a principal via de assimilação de nitrogênio na bactéria fixadora de nitrogênio Azospirillum brasilense. A estirpe HM053 de A. brasilense possui baixa atividade GS e excreta amônio no meio sob condições de fixação de nitrogênio. Neste trabalho, os genes glnA das estirpes do tipo selvagem e HM053 foram clonados em pET28a, sequenciados e superexpressos em E. coli. A enzima GS foi purificada por cromatografia de afinidade e caracterizada. A GS da estirpe HM053 possui uma substituição P347L que resulta em baixa atividade enzimática e torna a enzima insensível à adenililação pela adenililtransferase GlnE.


Asunto(s)
Azospirillum brasilense/enzimología , Azospirillum brasilense/genética , Escherichia coli , Fijación del Nitrógeno , Glutamato-Amoníaco Ligasa/biosíntesis
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