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1.
J Biol Chem ; 299(10): 105218, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37660910

RESUMO

Human G protein-coupled receptor 35 is regulated by agonist-mediated phosphorylation of a set of five phospho-acceptor amino acids within its C-terminal tail. Alteration of both Ser300 and Ser303 to alanine in the GPR35a isoform greatly reduces the ability of receptor agonists to promote interactions with arrestin adapter proteins. Here, we have integrated the use of cell lines genome edited to lack expression of combinations of G protein receptor kinases (GRKs), selective small molecule inhibitors of subsets of these kinases, and antisera able to specifically identify either human GPR35a or mouse GPR35 only when Ser300 and Ser303 (orce; the equivalent residues in mouse GPR35) have become phosphorylated to demonstrate that GRK5 and GRK6 cause agonist-dependent phosphorylation of these residues. Extensions of these studies demonstrated the importance of the GRK5/6-mediated phosphorylation of these amino acids for agonist-induced internalization of the receptor. Homology and predictive modeling of the interaction of human GPR35 with GRKs showed that the N terminus of GRK5 is likely to dock in the same methionine pocket on the intracellular face of GPR35 as the C terminus of the α5 helix of Gα13 and, that while this is also the case for GRK6, GRK2 and GRK3 are unable to do so effectively. These studies provide unique and wide-ranging insights into modes of regulation of GPR35, a receptor that is currently attracting considerable interest as a novel therapeutic target in diseases including ulcerative colitis.

2.
J Biol Chem ; 298(10): 102421, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-36030052

RESUMO

Recent studies identified a missense mutation in the gene coding for G protein-coupled receptor kinase 6 (GRK6) that segregates with type 2 diabetes (T2D). To better understand how GRK6 might be involved in T2D, we used pharmacological inhibition and genetic knockdown in the mouse ß-cell line, MIN6, to determine whether GRK6 regulates insulin dynamics. We show inhibition of GRK5 and GRK6 increased insulin secretion but reduced insulin processing while GRK6 knockdown revealed these same processing defects with reduced levels of cellular insulin. GRK6 knockdown cells also had attenuated insulin secretion but enhanced proinsulin secretion consistent with decreased processing. In support of these findings, we demonstrate GRK6 rescue experiments in knockdown cells restored insulin secretion after glucose treatment. The altered insulin profile appears to be caused by changes in the proprotein convertases, the enzymes responsible for proinsulin to insulin conversion, as GRK6 knockdown resulted in significantly reduced convertase expression and activity. To identify how the GRK6-P384S mutation found in T2D patients might affect insulin processing, we performed biochemical and cell biological assays to study the properties of the mutant. We found that while GRK6-P384S was more active than WT GRK6, it displayed a cytosolic distribution in cells compared to the normal plasma membrane localization of GRK6. Additionally, GRK6 overexpression in MIN6 cells enhanced proinsulin processing, while GRK6-P384S expression had little effect. Taken together, our data show that GRK6 regulates insulin processing and secretion in a glucose-dependent manner and provide a foundation for understanding the contribution of GRK6 to T2D.


Assuntos
Diabetes Mellitus Tipo 2 , Quinases de Receptores Acoplados a Proteína G , Insulina , Proinsulina , Animais , Camundongos , Diabetes Mellitus Tipo 2/genética , Glucose/farmacologia , Insulina/metabolismo , Proinsulina/genética , Proinsulina/metabolismo , Quinases de Receptores Acoplados a Proteína G/genética , Quinases de Receptores Acoplados a Proteína G/metabolismo , Linhagem Celular
3.
Int J Mol Sci ; 24(11)2023 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-37298725

RESUMO

Achillea fragrantissima, a desert plant commonly known as yarrow, is traditionally used as an antimicrobial agent in folklore medicine in Saudi Arabia. The current study was undertaken to determine its antibiofilm activity against methicillin-resistant Staphylococcus aureus (MRSA) and multi-drug-resistant Pseudomonas aeruginosa (MDR-P. aeruginosa) using in vitro and in vivo studies. A biofilm model induced through an excision wound in diabetic mice was used to evaluate its effect in vivo. The skin irritation and cytotoxic effects of the extract were determined using mice and HaCaT cell lines, respectively. The Achillea fragrantissima methanolic extract was analyzed with LC-MS to detect different phytoconstituents, which revealed the presence of 47 different phytoconstituents. The extract inhibited the growth of both tested pathogens in vitro. It also increased the healing of biofilm-formed excision wounds, demonstrating its antibiofilm, antimicrobial, and wound-healing action in vivo. The effect of the extract was concentration-dependent, and its activity was stronger against MRSA than MDR-P. aeruginosa. The extract formulation was devoid of a skin irritation effect in vivo and cytotoxic effect on HaCaT cell lines in vitro.


Assuntos
Achillea , Anti-Infecciosos , Diabetes Mellitus Experimental , Staphylococcus aureus Resistente à Meticilina , Camundongos , Animais , Pseudomonas aeruginosa , Diabetes Mellitus Experimental/tratamento farmacológico , Anti-Infecciosos/farmacologia , Biofilmes , Extratos Vegetais/farmacologia , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Testes de Sensibilidade Microbiana
4.
Nat Chem Biol ; 16(5): 577-586, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32094923

RESUMO

Receptor tyrosine kinases (RTKs) are transmembrane receptors of great clinical interest due to their role in disease. Historically, therapeutics targeting RTKs have been identified using in vitro kinase assays. Due to frequent development of drug resistance, however, there is a need to identify more diverse compounds that inhibit mutated but not wild-type RTKs. Here, we describe MaMTH-DS (mammalian membrane two-hybrid drug screening), a live-cell platform for high-throughput identification of small molecules targeting functional protein-protein interactions of RTKs. We applied MaMTH-DS to an oncogenic epidermal growth factor receptor (EGFR) mutant resistant to the latest generation of clinically approved tyrosine kinase inhibitors (TKIs). We identified four mutant-specific compounds, including two that would not have been detected by conventional in vitro kinase assays. One of these targets mutant EGFR via a new mechanism of action, distinct from classical TKI inhibition. Our results demonstrate how MaMTH-DS is a powerful complement to traditional drug screening approaches.


Assuntos
Ensaios de Triagem em Larga Escala/métodos , Inibidores de Proteínas Quinases/farmacologia , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Carcinoma Pulmonar de Células não Pequenas/genética , Linhagem Celular , Linhagem Celular Tumoral , DNA Nucleotidiltransferases/genética , Descoberta de Drogas , Resistencia a Medicamentos Antineoplásicos/genética , Receptores ErbB/antagonistas & inibidores , Receptores ErbB/genética , Genes Reporter , Humanos , Luciferases/genética , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/genética , Mutação , Fosforilação/efeitos dos fármacos , Reprodutibilidade dos Testes , Bibliotecas de Moléculas Pequenas/farmacologia , Estaurosporina/análogos & derivados , Estaurosporina/farmacologia
5.
J Environ Manage ; 314: 115070, 2022 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-35452888

RESUMO

A technoeconomic analysis (TEA) and life cycle assessment (LCA) was conducted on the use of landfill gas (LFG) for electricity generation using an internal combustion engine. This study provides insights that can guide LFG waste to energy (WTE) operators on decisions concerning installation of contaminant removal from LFG for electricity generation. Four scenarios were analyzed; the first (Scenario 1) was a facility with a single siloxane removal unit (SREU) sized for 6 months of continuous use, the second (Scenario 2) was a facility with parallel SREUs sized for one month of use, the third (Scenario 3) was a facility with no SREU, and the fourth was a facility that flared all LFG captured. The TEA revealed that the chiller cost was over 50% the total purchase cost of the LFG pre-treatment system. When the complete LFG to electricity process was analyzed, the internal combustion engine had the highest percentage of total capital investment and the total annual cost. For the base case, it became economically beneficial to install a SREU at facilities with LFG flowrates greater than ∼2000 m3/h. Sensitivity analysis showed that at a base case of 1700 m3/h, LFG (50% CH4), and 50 mg/m3 D4, the net income of facilities in Scenarios 1 to 3 became positive at an electricity sales price greater than 5.5 cents/kWh. LCA revealed that Scenario 2 had the greatest CO2 emission reduction. Scenario 3 is observed to save less CO2 emissions as biogas flowrate increases due to frequent engine shutdowns. Although there are differences in the global warming potential (GWP 100) for Scenarios 1 to 3, with Scenario 2 being the best and Scenario 3 being the worst, the differences are very small. For this reason, economics alone are sufficient in decision making.


Assuntos
Eliminação de Resíduos , Siloxanas , Dióxido de Carbono , Eletricidade , Metano , Instalações de Eliminação de Resíduos
6.
Molecules ; 27(14)2022 Jul 13.
Artigo em Inglês | MEDLINE | ID: mdl-35889362

RESUMO

The present study investigated the wound healing activity of Moringa oleifera leaf extract on an infected excision wound model in rats. Infection was induced using methicillin-resistant Staphylococcus aureus (MRSA) or Pseudomonas aeruginosa. An investigation was also done to study the effect of Moringa extract on the vascular endothelial growth factor (VEGF) and transforming growth factor-beta 1 (TGF-ß1) gene expression in vitro using human keratinocytes (HaCaT). The methanol extract of M. oleifera leaves was analyzed for the presence of phytochemicals by LCMS. The antimicrobial activity of the extract was also determined. Wound contraction, days for epithelization, antioxidant enzyme activities, epidermal height, angiogenesis, and collagen deposition were studied. M. oleifera showed an antimicrobial effect and significantly improved wound contraction, reduced epithelization period, increased antioxidant enzymes activity, and reduced capillary density. Effect of the extract was less in wounds infected with P. aeruginosa when compared to MRSA. The VEGF and TGF-ß1 gene expression was increased by M. oleifera.


Assuntos
Anti-Infecciosos , Staphylococcus aureus Resistente à Meticilina , Moringa oleifera , Infecção dos Ferimentos , Animais , Antibacterianos/farmacologia , Anti-Infecciosos/farmacologia , Antioxidantes/farmacologia , Expressão Gênica , Humanos , Extratos Vegetais/farmacologia , Folhas de Planta , Pseudomonas aeruginosa , Ratos , Fator de Crescimento Transformador beta1 , Fator A de Crescimento do Endotélio Vascular/genética , Infecção dos Ferimentos/tratamento farmacológico
7.
Molecules ; 27(23)2022 Dec 05.
Artigo em Inglês | MEDLINE | ID: mdl-36500645

RESUMO

Methicillin-resistant Staphylococcus aureus (MRSA) is one of the leading causes of infection worldwide. Clove oil's ability to inhibit the growth of MRSA was studied through in vitro and in vivo studies. The phytochemical components of clove oil were determined through gas chromatography-mass spectrometry (GC-MS) analysis. The antibacterial effects of clove oil and its interaction with imipenem were determined by studying MIC, MBC, and FIC indices in vitro. The in vivo wound-healing effect of the clove oil and infection control were determined using excision wound model rats. The GC-MS analysis of clove oil revealed the presence of 16 volatile compounds. Clove oil showed a good antibacterial effect in vitro but no interaction was observed with imipenem. Clove bud oil alone or in combination with imipenem healed wounds faster and reduced the microbial load in wounds. The findings of this study confirmed the antibacterial activity of clove oil in vitro and in vivo and demonstrated its interaction with imipenem.


Assuntos
Staphylococcus aureus Resistente à Meticilina , Óleos Voláteis , Syzygium , Infecção dos Ferimentos , Ratos , Animais , Syzygium/química , Óleo de Cravo/farmacologia , Óleo de Cravo/química , Imipenem/farmacologia , Óleos Voláteis/farmacologia , Óleos Voláteis/química , Testes de Sensibilidade Microbiana , Antibacterianos/farmacologia , Antibacterianos/química
8.
Knee Surg Sports Traumatol Arthrosc ; 29(4): 1251-1257, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32712683

RESUMO

PURPOSE: To compare the clinical, radiological outcomes, economic and technical differences for ORIF by cancellous screw fixation versus ARIF by double-tunnel suture fixation for displaced tibial-side PCL avulsion fractures. METHODS: Forty patients with displaced tibial-sided PCL avulsions were operated upon after randomizing them into two groups (20 patients each in the open and arthroscopic group) and followed up prospectively. Assessment included duration of surgery, cost involved, pre- and post-operative functional scores, radiological assessment of union, and posterior laxity using stress radiography and complications. RESULTS: The mean follow-up period was 33 months (27-42) (open group) and 30 months (26-44) (arthroscopic group). The duration of surgery was significantly larger in the arthroscopic group (47.8 ± 17.9 min) as compared to the open group (33.4 ± 10.1 min). The costs involved were significantly higher in the arthroscopic group (p- 0.01). At final follow-up, knee function in the form of IKDC (International Knee Documentation Committee) evaluation (89.9 ± 4.8-open and 89.3 ± 5.9-arthroscopic) and Lysholm scores (94.2 ± 4.1-open and 94.6 ± 4.1-arthroscopic) had improved significantly with the difference (n.s.) between the two groups. The mean posterior tibial displacement was 5.7 ± 1.8 mm in the open group and 6.3 ± 3.1 mm in the arthroscopic group which was (n.s.). There were two non-unions and one popliteal artery injury in the arthroscopic group. CONCLUSION: Both ARIF and ORIF for PCL avulsion fractures yield good clinical and radiological outcomes. However, ORIF was better than ARIF in terms of cost, duration of surgery, and complications like non-union and iatrogenic vascular injury. LEVEL OF EVIDENCE: II.


Assuntos
Artroscopia/métodos , Fixação Interna de Fraturas/métodos , Fratura Avulsão/cirurgia , Redução Aberta/métodos , Fraturas da Tíbia/cirurgia , Adolescente , Adulto , Artroscopia/efeitos adversos , Parafusos Ósseos , Feminino , Seguimentos , Fixação Interna de Fraturas/efeitos adversos , Fratura Avulsão/diagnóstico por imagem , Humanos , Instabilidade Articular/etiologia , Masculino , Pessoa de Meia-Idade , Redução Aberta/efeitos adversos , Duração da Cirurgia , Complicações Pós-Operatórias , Estudos Prospectivos , Radiografia , Técnicas de Sutura , Fraturas da Tíbia/diagnóstico por imagem , Resultado do Tratamento , Adulto Jovem
9.
J Biol Chem ; 294(12): 4546-4571, 2019 03 22.
Artigo em Inglês | MEDLINE | ID: mdl-30696771

RESUMO

Na+-H+ exchanger regulatory factor-1 (NHERF1) is a PDZ protein that scaffolds membrane proteins, including sodium-phosphate co-transport protein 2A (NPT2A) at the plasma membrane. NHERF1 is a phosphoprotein with 40 Ser and Thr residues. Here, using tandem MS analysis, we characterized the sites of parathyroid hormone (PTH)-induced NHERF1 phosphorylation and identified 10 high-confidence phosphorylation sites. Ala replacement at Ser46, Ser162, Ser181, Ser269, Ser280, Ser291, Thr293, Ser299, and Ser302 did not affect phosphate uptake, but S290A substitution abolished PTH-dependent phosphate transport. Unexpectedly, Ser290 was rapidly dephosphorylated and rephosphorylated after PTH stimulation, and we found that protein phosphatase 1α (PP1α), which binds NHERF1 through a conserved VxF/W PP1 motif, dephosphorylates Ser290 Mutating 257VPF259 eliminated PP1 binding and blunted dephosphorylation. Tautomycetin blocked PP1 activity and abrogated PTH-sensitive phosphate transport. Using fluorescence lifetime imaging (FLIM), we observed that PTH paradoxically and transiently elevates intracellular phosphate. Added phosphate blocked PP1α-mediated Ser290 dephosphorylation of recombinant NHERF1. Hydrogen-deuterium exchange MS revealed that ß-sheets in NHERF1's PDZ2 domain display lower deuterium uptake than those in the structurally similar PDZ1, implying that PDZ1 is more cloistered. Dephosphorylated NHERF1 exhibited faster exchange at C-terminal residues suggesting that NHERF1 dephosphorylation precedes Ser290 rephosphorylation. Our results show that PP1α and NHERF1 form a holoenzyme and that a multiprotein kinase cascade involving G protein-coupled receptor kinase 6A controls the Ser290 phosphorylation status of NHERF1 and regulates PTH-sensitive, NPT2A-mediated phosphate uptake. These findings reveal how reversible phosphorylation modifies protein conformation and function and the biochemical mechanisms underlying PTH control of phosphate transport.


Assuntos
Hormônio Paratireóideo/fisiologia , Fosfatos/metabolismo , Fosfoproteínas/metabolismo , Trocadores de Sódio-Hidrogênio/metabolismo , Proteínas Cotransportadoras de Sódio-Fosfato Tipo IIa/fisiologia , Sequência de Aminoácidos , Cristalografia por Raios X , Furanos/farmacologia , Células HEK293 , Humanos , Transporte de Íons/fisiologia , Lipídeos/farmacologia , Fosfoproteínas/química , Fosforilação , Conformação Proteica , Receptores de Neuropeptídeo Y/antagonistas & inibidores , Receptores de Neuropeptídeo Y/metabolismo , Serina/metabolismo , Trocadores de Sódio-Hidrogênio/química
10.
Appl Microbiol Biotechnol ; 104(7): 2871-2882, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32037467

RESUMO

Advanced developments in the field of enzyme technology have increased the use of enzymes in industrial applications, especially in detergents. Enzymes as detergent additives have been extensively studied and the demand is considerably increasing due to its distinct properties and potential applications. Enzymes from microorganisms colonized at various geographical locations ranging from extreme hot to cold are explored for compatibility studies as detergent additives. Especially psychrophiles growing at cold conditions have cold-active enzymes with high catalytic activity and their stability under extreme conditions makes it as an appropriate eco-friendly and cost-effective additive in detergents. Adequate number of reports are available on cold-active enzymes such as proteases, lipases, amylases, and cellulases with high efficiency and exceptional features. These enzymes with increased thermostability and alkaline stability have become the premier choice as detergent additives. Modern approaches in genomics and proteomics paved the way to understand the compatibility of cold-active enzymes as detergent additives in broader dimensions. The molecular techniques such as gene coding, amino acid sequencing, and protein engineering studies helped to solve the mysteries related to alkaline stability of these enzymes and their chemical compatibility with oxidizing agents. The present review provides an overview of cold-active enzymes used as detergent additives and molecular approaches that resulted in development of these enzymes as commercial hit in detergent industries. The scope and challenges in using cold-active enzymes as eco-friendly and sustainable detergent additive are also discussed.


Assuntos
Proteínas de Bactérias/química , Temperatura Baixa , Detergentes/química , Enzimas/química , Bactérias/enzimologia , Bactérias/genética , Bactérias/metabolismo , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Estabilidade Enzimática , Enzimas/genética , Enzimas/metabolismo , Concentração de Íons de Hidrogênio , Oxidantes/química , Engenharia de Proteínas
11.
Phys Chem Chem Phys ; 20(23): 15926-15938, 2018 Jun 13.
Artigo em Inglês | MEDLINE | ID: mdl-29850683

RESUMO

Using density functional theory, we study the effect of injected electrons (simulating photoexcited electrons) on the energetics, structures, and binding sites available to CO2 molecules on subnanometer Pt clusters decorated onto anatase TiO2(101) surfaces, shedding light on the first and key step of CO2 photoreduction. Upon the addition of one, two, or three electrons, the O-C-O angles of adsorbed CO2 become progressively smaller in binding sites that directly contact Pt clusters, while no significant change is found in the intra bond length of the adsorbed CO2 and in the bonding distances between the adsorbed CO2 and supported clusters. The extra electrons lead to the stabilization of adsorption sites identified on neutral slabs, including previously metastable configurations, suggesting the enhancement of accessible CO2 binding sites. Furthermore, supported clusters are able to populate the electronic states of adsorbed CO2 species, facilitating the formation of the CO2- anion. To help interpret experimentally observed frequencies, conversion factors are proposed to gain insight into the charge state and O-C-O angle of the adsorbed CO2. Interestingly, upon electron addition, cluster reconstruction may exist due to the bonding inclination between CO2 and atoms in the Pt cluster, further stabilizing the intermediate complexes. Finally, the rate-limiting step (C-O bond cleavage) in the CO2 dissociation to CO is slightly reduced by the introduction of an extra electron. Our results show that subnanometer metal cluster based photocatalysts are good candidates for CO2 photoreduction.

12.
Waste Manag Res ; 36(12): 1177-1189, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30112976

RESUMO

Municipal solid waste (MSW) management is a major concern in Indian cities. This work rigorously assesses the relative costs and the environmental and health benefits of alternative MSW management methods. Management of MSW over the next 20 years for the city of Greater Mumbai was considered. A generic model was developed to determine the costs for (i) dumping on open ground, (ii) sanitary landfill without leachate treatment, (iii) landfilling with leachate treatment and (iv) regional composting and landfilling. LandGEM was used to quantify the gaseous emissions from landfill, while emissions from leachate and composting were taken from literature. The life cycle impact model of one tonne of MSW was developed using OpenLCA software and the International Reference Life Cycle Data System (ILCD) 2011 method was used for impact assessment. The cost of disposal of one tonne of waste was found to be INR344 (US$5.17), INR741 (US$11.13) and INR1367 (US$20.53), respectively, for the first three scenarios. As compared to open dumping, landfill gas flaring reduced the global warming potential by 32% and leachate treatment reduced freshwater ecotoxicity and total human toxicity marginally, by 20% and 60%, respectively. Composting-landfilling was the most preferred option, with a cost of INR531 tonne-1 (US$7.97), leading to a reduction in global warming potential by 79% and a slight decrease in freshwater ecotoxicity by 64%. Further, emissions due to accidental fires were also quantified. The study provides valuable insights for the selection of MSW management options for large metropolitan cities in developing countries.


Assuntos
Eliminação de Resíduos , Resíduos Sólidos , Cidades , Humanos , Índia , Instalações de Eliminação de Resíduos
13.
Phys Chem Chem Phys ; 17(38): 25379-92, 2015 Oct 14.
Artigo em Inglês | MEDLINE | ID: mdl-26360461

RESUMO

Using density functional theory calculations, we investigate the influence of size-dependent cluster morphology on the synergistic catalytic properties of anatase TiO2(101) surfaces decorated with subnanometer Pt clusters. Focusing on the formation of the key precursor in the CO2 photoreduction reaction (bent CO2(-)), we find that flatter (2D-like) Pt clusters that "wet" the TiO2 surface offer significantly less benefit than 3D-like Pt clusters. We attribute the differences to three factors. First, the 3D clusters provide a greater number of accessible Pt-TiO2 interfacial sites with geometries that can aid CO2 bond bending and charge transfer processes. Second, binding competition among each Pt-CO2 bonding interaction mitigates maximum orbital overlaps, leading to insufficient CO2 binding. Third and also most interestingly, the 3D clusters tend to possess higher structural fluxionality than the flatter clusters, which is shown to correlate positively with CO2 binding strength. The preferred morphology adopted by the clusters depends on several factors, including the cluster size and the presence of oxygen vacancies on the TiO2 surface; this suggests a strategy for optimizing the synergistic effect between Pt clusters and TiO2 surfaces for CO2 photocatalysis. Clusters of ∼6-8 atoms should provide the largest benefit, since they retain the desired 3D morphology, yet are small enough to exhibit high structural fluxionality. Electronic structure analysis provides additional insight into the electronic motivations for the enhanced binding of CO2 on TiO2-supported 3D Pt clusters, as well as suppressed binding on flattened, 2D-like clusters.


Assuntos
Dióxido de Carbono/química , Adsorção , Catálise , Oxirredução , Platina/química , Propriedades de Superfície , Titânio/química
14.
Microb Biotechnol ; 17(4): e14467, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38656876

RESUMO

Microorganisms known as psychrophiles/psychrotrophs, which survive in cold climates, constitute majority of the biosphere on Earth. Their capability to produce cold-active enzymes along with other distinguishing characteristics allows them to survive in the cold environments. Due to the relative ease of large-scale production compared to enzymes from plants and animals, commercial uses of microbial enzyme are alluring. The ocean depths, polar, and alpine regions, which make up over 85% of the planet, are inhabited to cold ecosystems. Microbes living in these regions are important for their metabolic contribution to the ecosphere as well as for their enzymes, which may have potential industrial applications. Cold-adapted microorganisms are a possible source of cold-active enzymes that have high catalytic efficacy at low and moderate temperatures at which homologous mesophilic enzymes are not active. Cold-active enzymes can be used in a variety of biotechnological processes, including food processing, additives in the detergent and food industries, textile industry, waste-water treatment, biopulping, environmental bioremediation in cold climates, biotransformation, and molecular biology applications with great potential for energy savings. Genetically manipulated strains that are suitable for producing a particular cold-active enzyme would be crucial in a variety of industrial and biotechnological applications. The potential advantage of cold-adapted enzymes will probably lead to a greater annual market than for thermo-stable enzymes in the near future. This review includes latest updates on various microbial source of cold-active enzymes and their biotechnological applications.


Assuntos
Bactérias , Biotecnologia , Temperatura Baixa , Enzimas , Biotecnologia/métodos , Bactérias/enzimologia , Bactérias/genética , Bactérias/metabolismo , Bactérias/classificação , Enzimas/metabolismo , Estabilidade Enzimática
15.
Nanotechnology ; 24(40): 405402, 2013 Oct 11.
Artigo em Inglês | MEDLINE | ID: mdl-24028861

RESUMO

Converting carbon dioxide (CO2) to hydrocarbons that can be used as fuels is beneficial from both environmental and economic points of view. In this study, nanoparticles are designed to enhance the photoreduction of CO2 on a titanium dioxide (TiO2) catalyst. An increase in catalytic activity is reported when silver (Ag), platinum (Pt) or bimetallic Ag-Pt and core-shell Ag@silica (SiO2) nanoparticles are used with the TiO2 semiconductor catalyst. Nanoparticles with different elemental composition or geometrical structure facilitate successive photo-excitation steps-generation, transport, storage and interfacial transfer of electrons and holes. Results show that while the addition of either type of nanoparticles augments product formation rates, bimetallic co-catalysts improve product selectivity. When both bimetallic co-catalysts and Ag@SiO2 nanoparticles are used in combination, product yields are enhanced more than seven fold in comparison to native TiO2 and high selectivity for methane (CH4) is observed. When the bimetallic Ag-Pt co-catalysts are tuned, a selectivity of CH4 of approximately 80%, as compared to 20% with only TiO2, can be achieved.

16.
Biotechnol Appl Biochem ; 60(5): 459-81, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23826937

RESUMO

Nitriles are organic compounds bearing a − C ≡ N group; they are frequently known to occur naturally in both fauna and flora and are also synthesized chemically. They have wide applicability in the fields of medicine, industry, and environmental monitoring. However, the majority of nitrile compounds are considered to be lethal, mutagenic, and carcinogenic in nature and are known to cause potential health problems such as nausea, bronchial irritation, respiratory distress, convulsions, coma, and skeletal deformities in humans. Nitrile-converting enzymes, which are extracted from microorganisms, are commonly termed nitrilases and have drawn the attention of researchers all over the world to combat the toxicity of nitrile compounds. The present review focuses on the utility of nitrile-converting enzymes, sources, classification, structure, properties, and applications, as well as the future perspective on nitrilases.


Assuntos
Aminoidrolases/metabolismo , Biocatálise , Biotecnologia , Nitrilas/metabolismo , Química Verde , Indústrias , Nitrilas/química , Nitrilas/toxicidade
17.
Microorganisms ; 11(3)2023 Mar 08.
Artigo em Inglês | MEDLINE | ID: mdl-36985266

RESUMO

The study developed a simple and inexpensive method to induce biofilm formation in-vivo for the evaluation of the antibiofilm activity of pharmacological agents using Swiss albino mice. Animals were made diabetic using streptozocin and nicotinamide. A cover slip containing preformed biofilm along with MRSA culture was introduced into the excision wound in these animals. The method was effective in developing biofilm on the coverslip after 24 h incubation in MRSA broth which was confirmed by microscopic examination and a crystal violet assay. Application of preformed biofilm along with microbial culture induced a profound infection with biofilm formation on excision wounds in 72 h. This was confirmed by macroscopic, histological, and bacterial load determination. Mupirocin, a known antibacterial agent effective against MRSA was used to demonstrate antibiofilm activity. Mupirocin was able to completely heal the excised wounds in 19 to 21 days while in the base-treated group, healing took place between 30 and 35 days. The method described is robust and can be reproduced easily without the use of transgenic animals and sophisticated methods such as confocal microscopy.

18.
ACS Med Chem Lett ; 14(2): 199-210, 2023 Feb 09.
Artigo em Inglês | MEDLINE | ID: mdl-36793435

RESUMO

B cell lymphoma 6 (BCL6), a highly regulated transcriptional repressor, is deregulated in several forms of non-Hodgkin lymphoma (NHL), most notably in diffuse large B-cell lymphoma (DLBCL). The activities of BCL6 are dependent on protein-protein interactions with transcriptional co-repressors. To find new therapeutic interventions addressing the needs of patients with DLBCL, we initiated a program to identify BCL6 inhibitors that interfere with co-repressor binding. A virtual screen hit with binding activity in the high micromolar range was optimized by structure-guided methods, resulting in a novel and highly potent inhibitor series. Further optimization resulted in the lead candidate 58 (OICR12694/JNJ-65234637), a BCL6 inhibitor with low nanomolar DLBCL cell growth inhibition and an excellent oral pharmacokinetic profile. Based on its overall favorable preclinical profile, OICR12694 is a highly potent, orally bioavailable candidate for testing BCL6 inhibition in DLBCL and other neoplasms, particularly in combination with other therapies.

19.
Pharmaceuticals (Basel) ; 15(5)2022 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-35631354

RESUMO

Moringa oleifera is known to possess wound healing activity. The present study evaluated the healing properties of methanolic extract of M. oleifera leaves in excision wounds infected with methicillin-resistant Staphylococcus aureus (MRSA) or P. aeruginosa in diabetic rats. An in vitro study was also carried out to determine the gene expression of VEGF and TGF-ß1. Preliminary phytochemical and GC-MS analyses were carried out to determine different chemical constituents present in the extract. M. oleifera was applied locally as an ointment at two different concentrations. Wound contraction, period of epithelization, antioxidant enzyme activities and histological changes were determined. For the gene expression study, HaCaT cell lines were used. The formulation of M. oleifera extract improved wound contraction and decreased the period of epithelization, which was associated with an increase in antioxidant enzyme activities, epithelization, capillary density and collagen formation in MRSA-infected diabetic rats. However, this effect was reduced in diabetic animals infected with P. aeruginosa. An increase in the expression of VEGF and TGF-ß1 was observed in HaCaT cell lines. M. oleifera extract promotes the healing of infected wounds in MRSA-infected diabetic rats but is less effective in the healing of wounds infected with P. aeruginosa in diabetic rats.

20.
Antibiotics (Basel) ; 11(11)2022 Nov 10.
Artigo em Inglês | MEDLINE | ID: mdl-36358246

RESUMO

Frankincense (Boswellia sacra oleo gum resin) is reported to possess antimicrobial activity against several pathogens in-vitro. The antimicrobial effects of frankincense oil and its interaction with imipenem and gentamicin against methicillin-resistant Staphylococcus aureus (MRSA) and multidrug-resistant P. aeruginosa were determined through in-vitro methods and an in-vivo study using a rat pneumonia model. Frankincense oil was subjected to GC-MS analysis to determine the different volatile components. Antibacterial effects against MRSA and MDR-P. aeruginosa was evaluated and its MIC and MBC were determined. For the rat pneumonia model (in-vivo), oil was administered at a dose of 500 mg/kg and 1000 mg/kg followed by determination of CFU in lung tissue and histological studies. Frankincense oil did not show a very potent inhibitory effect against MRSA or MDR-P. aeruginosa; the oil did not affect the zone of inhibition or FIC when combined with imipenem or gentamicin indicating a lack of interaction between the oil and the antibiotics. Furthermore, there was no interaction between the antibiotics and the frankincense oil in the in-vivo model. The result of the study revealed that frankincense oil has a weak inhibitory effect against MRSA and MDR-P. aeruginosa, and it did not show any interaction with imipenem or gentamicin.

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