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1.
Bull Environ Contam Toxicol ; 113(1): 3, 2024 Jul 04.
Artigo em Inglês | MEDLINE | ID: mdl-38965095

RESUMO

Sanitary leachate from urban landfills is known to be contaminated with multi-metals and residual antibiotics. Current research edges on exploring the multi-metal and antibiotic sensitivity profile of four indigenous strains, "Brevibacillus spp. Leclercia spp. Pseudescherichia spp., and Brucella spp." isolated from the leachate of a sanitary landfill in a tropical region. Indigenous isolates were observed to be antibiotic-resistant and have high tolerance against eight of the ten tested metals except Cu & Co. It was observed that interaction with multi-metals in laboratory conditions significantly altered the cell morphology of bacterial strains, as depicted by Scanning Electron Microscope. Metal adsorption onto the microbial surface was deciphered through Electron Dispersive Spectrometer analysis and elemental mapping. Application of isolated strains into real-time leachate matrix exhibits a complete reduction of Ag and Zn and for other tested metals. Their response to these toxicants may facilitate their application in bioremediation-based treatment technologies for urban landfill leachate.


Assuntos
Antibacterianos , Biodegradação Ambiental , Metais Pesados , Instalações de Eliminação de Resíduos , Poluentes Químicos da Água , Antibacterianos/farmacologia , Bactérias/efeitos dos fármacos
2.
Biochem Biophys Res Commun ; 670: 55-62, 2023 08 30.
Artigo em Inglês | MEDLINE | ID: mdl-37276791

RESUMO

The Poly (ADP-ribose) polymerase (PARP) inhibitor (PARPi) olaparib gives promising results against various types of cancers in clinical trials. The combination of drugs always increases therapeutic efficacy because of targeting multiple pathways of cancer progression. Our objective was to explore the potential synergistic anticancer activities of olaparib combined with p38 MAPK inhibitor (MAPKi) SB203580 on non-small cell lung carcinoma (NSCLC) A549 cells. The effects of the individual compound and their combination on cell survival, DNA damage as detected by γH2AX foci, expression of key proteins in Homologous Recombination (HR) and Non-Homologous End Joining (NHEJ) repair, caspase 3 activation, nuclear fragmentation and telomerase regulation were studied in A549 cells. The results showed that olaparib and SB203580 individually reduced cell viability in a dose-dependent manner but combined treatment synergistically reduced cell viability. Olaparib combined with SB203580 significantly reduced error-free HR repair via reducing MRE11-RAD50 and promoted error-prone NHEJ repair by increasing Ku70-Ku80 leading to increased DNA damage-induced apoptosis. Notably, the alteration of proteins in HR/NHEJ pathways, DNA damage and induction of apoptosis was significant by combined treatment but not by 1 µM olaparib treatment alone. In addition, combined treatment reduced telomerase activity more than single treatment via reducing telomerase subunits. These data implicated that the anticancer potential of olaparib was significantly increased by combining SB203580 through increasing DNA damage-induced apoptosis and inhibiting telomerase activity.


Assuntos
Antineoplásicos , Carcinoma Pulmonar de Células não Pequenas , Neoplasias Pulmonares , Telomerase , Humanos , Inibidores de Poli(ADP-Ribose) Polimerases/farmacologia , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Células A549 , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo , Telomerase/metabolismo , Linhagem Celular Tumoral , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Ftalazinas/farmacologia , Poli(ADP-Ribose) Polimerases/metabolismo , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/genética
3.
J Environ Manage ; 343: 118141, 2023 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-37245305

RESUMO

A simple scalable method has been developed to obtain protein hydrolysate from fleshing waste generated during leather processing. UV-Vis, FTIR and Solid State C13 NMR analyses identified that prepared protein hydrolysate is basically collagen hydrolysate. DLS and MALDI-TOF-MS spectra indicated that the prepared protein hydrolysate is mostly comprised of di- and tri-peptides and less poly-dispersed than the standard commercial product. A combination of 0.3% Yeast extract, 1% Protein Hydrolysate (PHz) and 2% Glucose is found to be the most efficient nutrient composition for the fermentative growth of three well-known chitosan producing zygomycetes group of fungi. Mucor sp. showed highest yield of biomass (2.74 g/L) as well as chitosan (335 mg/L). Biomass and chitosan yield for Rhizopus oryzae were found 1.53 g/L; 239 mg/L. Same for Absidia coerulea were 2.05 g/L and 212 mg/L, respectively. This work shows promising prospect of utilization of fleshing waste of leather processing for the low-cost production of industrially important biopolymer chitosan.


Assuntos
Quitosana , Quitosana/química , Quitosana/metabolismo , Hidrolisados de Proteína/metabolismo , Polímeros/metabolismo , Fungos/metabolismo , Fermentação
4.
World J Surg ; 46(9): 2174-2188, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-35831713

RESUMO

BACKGROUND: Soft tissue management (STM) training programs for surgeons are largely tradition based, and substantial differences exist among different surgical specialties. The lack of comprehensive and systematic clinical evidence on how surgical techniques and implants affect soft tissue healing makes it difficult to develop evidence-based curricula. As a curriculum development group (CDG), we set out to find common grounds in the form of a set of consensus statements to serve as the basis for surgical soft tissue education. METHODS: Following a backward planning process and Kern's six-step approach, the group selected 13 topics to build a cross-specialty STM curriculum. A set of statements based on the curriculum topics were generated by the CDG through discussions and a literature review of three topics. A modified Delphi process including one round of pilot voting through a face-to-face CDG meeting and two rounds of web-based survey involving 22 panelists were utilized for the generation of consensus statements. RESULTS: Seventy-one statements were evaluated, and 56 statements reached the 80% consensus for "can be taught as is." CONCLUSIONS: Using a modified Delphi method, a set of cross-specialty consensus statements on soft tissue management were generated. These consensus statements can be used as a foundation for multi-specialty surgical education. Similar methods that combine expert experience and clinical evidence can be used to develop specialty-specific consensus on soft tissue handling.


Assuntos
Especialidades Cirúrgicas , Consenso , Currículo , Técnica Delphi , Humanos , Especialidades Cirúrgicas/educação , Inquéritos e Questionários
5.
Environ Pollut ; 297: 118694, 2022 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-34952182

RESUMO

Rice is a staple crop, and food chain contamination of arsenic in rice grain possesses a serious health risk to billions of population. Arsenic stress negatively affects the rice growth, yield and quality of the grains. Nitric oxide (NO) is a major signaling molecule that may trigger various cellular responses in plants. The protective role of NO during arsenite (AsIII) stress and its relationship with plant physiological and metabolic responses is not explored in detail. Exogenous NO, supplemented through the roots in the form of sodium nitroprusside, has been shown to provide protection vis-à-vis AsIII toxicity. The NO-mediated variation in physiological traits such as stomatal density, size, chlorophyll content and photosynthetic rate maintained the growth of the rice plant during AsIII stress. Besides, NO exposure also enhanced the lignin content in the root, decreased total arsenic content and maintained the activities of antioxidant isoenzymes to reduce the ROS level essential for protecting from AsIII mediated oxidative damage in rice plants. Further, NO supplementation enhanced the GSH/GSSG ratio and PC/As molar ratio by modulating PC content to reduce arsenic toxicity. Further, NO-mediated modulation of the level of GA, IAA, SA, JA, amino acids and phenolic metabolites during AsIII stress appears to play a central role to cope up with AsIII toxicity. The study highlighted the role of NO in AsIII stress tolerance involving modulation of metalloid detoxification and physiological pathways in rice plants.


Assuntos
Arsênio , Metaloides , Oryza , Arsênio/toxicidade , Óxido Nítrico , Estresse Oxidativo , Raízes de Plantas , Estresse Fisiológico
6.
J Environ Manage ; 251: 109565, 2019 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-31557669

RESUMO

Low cost whey salt medium (WSM) and molasses salt medium (MSM) have been constructed utilizing food processing byproduct whey and molasses for the production of bio-polysaccharide chitosan from Rhizopus oryzae and subsequently comprehensive physico-chemical characterization of the fungal chitosan has been carried out using various analytical tools to apprehend its biochemical utility. Same has been repeated with chitosan from conventional potato dextrose broth (PDB) for comparison purpose. The yields of chitosan in three different media were 0.62 (WSM), 0.39 (MSM) and 0.63 (PDB) g/L respectively. Molecular weights of the chitosans were in the range of 100-300 kDa. WSM-chitosan and MSM-chitosan were less polydispersed, possessed more hydrated polymorph and loose crystal packing than PDB-chitosan. This indicate that WSM-chitosan and MSM-chitosan are highly exposed to the external reagent hence more reactive to the external reagents with compare to PDB-chitosan. Literature suggest isolated chitosans are useful for specific drug delivery applications.


Assuntos
Quitosana , Manipulação de Alimentos/métodos , Rhizopus/metabolismo , Melaço , Soro do Leite
7.
Carbohydr Polym ; 206: 778-791, 2019 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-30553384

RESUMO

Pectin (PC)-g-[methacrylic acid (MAA)-co-3-(N-isopropylacrylamido)-2-methylpropanoic acid (NIPAMPA)-co-N-isopropylacrylamide (NIPA)] (i.e., PC-g-TP), a novel interpenetrating terpolymer network hydrogel of excellent physicochemical properties and reusability, was synthesized via grafting of PC and in situ strategic protrusion of third monomer, i.e., NIPAMPA, during polymerization of MAA and NIPA, using response surface methodology optimized amounts of ingredients and temperature, for superadsorption of hazardous metal ions, such as Cd(II), Hg(II), and Pb(II). The in situ allocation of NIPAMPA via NH activation, grafting of PC into MAA-co-NIPAMPA-co-NIPA matrix, physicochemical properties, and superadsorption mechanism were rationalized via extensive microstructural analyses of unadsorbed and/or adsorbed PC-g-TP through 1H-/13C-NMR, XPS, FTIR,TGA, XRD, FESEM, DLS, %gel content, pHPZC, and %graft ratio. The spontaneous chemisorption data exhibited excellent fitting with Langmuir model. The adsorption capacities (ACs) were 1315.32, 1172.97, and 1269.09 mg g-1 for Cd(II), Hg(II), and Pb(II), respectively, at 293 K, 0.02 g of PC-g-TP, and within 500-1000 ppm.

8.
ACS Omega ; 3(9): 11486-11496, 2018 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-31459250

RESUMO

A novel porous polymer-inorganic hybrid biocomposite with various functional groups (hide substance/chitosan/hydroxyapatite) has been synthesized in simple, economic, and scalable process utilizing leather industry solid waste and seafood industry waste composed with hydroxyapatite. Physicochemical characterization of the material reveals formation of composites with homogenous distribution of the constituents in the material matrix. The composite is hard and porous (with 0.1632 cm3/g slit-shaped mesopores and micropores) having particle sizes 40-80 µm and a Brunauer-Emmett-Teller surface area of 55.54 m2/g. The material is polycrystalline in nature with a fair amount of amorphous substance and less hydrophilic in character than constituent polymers. The dye removal efficiency of the material has been tested with two model dyes, namely, methylene blue (MB) (cationic/basic dye) and sunset yellow (SY) (anionic/acid dye). Optimum adsorptions of 3.8 mg MB (pH 12, RT ≈ 27 °C) and 168 mg of SY (pH 3, RT ≈ 27 °C) have been found per gram of the composite material. Langmuir isotherm and pseudo second order rate models have been found to be the best-fit models to explain the equilibrium isotherm and kinetics of the adsorption process for both the dyes. However, higher and faster adsorption of SY in comparison with MB indicated higher binding efficiency of the material toward the acidic dye. Desorption of dyes from the dye-adsorbed material was studied using a suitable eluent of appropriate pH and recycling for five times showed without loss of efficiency. The prepared composite showed very high dye removal efficiency toward four different commercially used dyes (496 mg/g of Orange-NR, 477 mg/g of Red-VLN, 488 mg/g of Blue-113 dye, and 274 mg/g of Green-PbS dye) from their individual and cocktail solutions. It was also efficient to decolorize dye-bearing tannery exhaust bath. Hence, waste materials generated during industrial processes could be efficiently used for the decontamination of colored wastewater produced by various industries.

9.
Front Physiol ; 3: 275, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22934029

RESUMO

Arsenic (As) contamination of drinking water and groundwater used for irrigation can lead to contamination of the food chain and poses serious health risk to people worldwide. To reduce As intake through the consumption of contaminated food, identification of the mechanisms for As accumulation and detoxification in plant is a prerequisite to develop efficient phytoremediation methods and safer crops with reduced As levels. Transcriptome, proteome, and metabolome analysis of any organism reflects the total biological activities at any given time which are responsible for the adaptation of the organism to the surrounding environmental conditions. As these approaches are very important in analyzing plant As transport and accumulation, we termed "Arsenomics" as approach which deals transcriptome, proteome, and metabolome alterations during As exposure. Although, various studies have been performed to understand modulation in transcriptome in response to As, many important questions need to be addressed regarding the translated proteins of plants at proteomic and metabolomic level, resulting in various ecophysiological responses. In this review, the comprehensive knowledge generated in this area has been compiled and analyzed. There is a need to strengthen Arsenomics which will lead to build up tools to develop As-free plants for safe consumption.

10.
Phytochem Anal ; 22(6): 492-502, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21425379

RESUMO

INTRODUCTION: Withania somnifera (Ashwagandha) is a high-value Ayurvedic medicinal plant and an important constituent of several dietary supplements. In order to substantiate the health claims, the herb has drawn considerable scientific attention. OBJECTIVE: The objective of the study was to investigate the alterations in primary and secondary metabolites of W. somnifera fruits during its maturity using NMR spectroscopy. METHODOLOGY: Fruits at different stages of development from one week after fertilisation until maturity, classified in seven developmental stages, were analysed by a combined use of one- and two-dimensional NMR experiments. RESULTS: Seventeen metabolites were characterised and quantified from non-polar and polar extracts of different fruit development stages of W. somnifera. The principal component analysis of polar metabolites at different stages could be grossly classified into three metabolic phases, viz. initial phase, developmental phase and maturation phase. CONCLUSION: Qualitative and quantitative analysis of metabolites in W. somnifera fruits indicated specific stages when fruits can be harvested for obtaining substantial bioactive ingredients for desirable pharmacological activity. This study potentially provides a complementary tool for quality control of herbal medicinal products when W. somnifera fruits are used.


Assuntos
Frutas/metabolismo , Extratos Vegetais/química , Withania/metabolismo , Ácidos Cafeicos/química , Ácidos Cafeicos/metabolismo , Frutas/química , Frutas/crescimento & desenvolvimento , Lipídeos/química , Espectroscopia de Ressonância Magnética/métodos , Extratos Vegetais/análise , Análise de Componente Principal , Controle de Qualidade , Solubilidade , Sacarose/química , Sacarose/metabolismo , Withania/química , Withania/crescimento & desenvolvimento , Vitanolídeos/química , Vitanolídeos/metabolismo
11.
Appl Biochem Biotechnol ; 164(6): 767-79, 2011 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-21279697

RESUMO

A bacterial strain, Bacillus cereus M(1)(16) (MTCC 5521), isolated and identified in our laboratory produces a green pigment when grown in nutrient broth at stationary condition. Optimum fermentation parameters for maximum pigment production are pH 7.0, temperature 30°C, time of incubation 72 h and inoculum volume 1% from 20 h grown cell suspension. Magnesium ion enhances pigment production whereas calcium and zinc ions inhibit the process. The pigment is better extracted from the fermented broth with chloroform in comparison with diethyl ether, ethyl acetate, and butanol. The extracted crude pigment consists of three fractions as revealed from thin layer chromatogram on silica gel GF254 using ethyl acetate and hexane (1:1) solvent system. The major fraction C(3) shows antibacterial activity against different gram positive bacteria. The proposed structure of C(3) is 9-methyl-1,4,5,8-tetra-azaphenanthrene obtained by elemental analysis, GC-MS, and NMR spectra studies.


Assuntos
Antibacterianos/biossíntese , Bacillus cereus/metabolismo , Pigmentos Biológicos/biossíntese , Antibacterianos/análise , Antibacterianos/isolamento & purificação , Antibacterianos/farmacologia , Bacillus cereus/química , Fermentação , Bactérias Gram-Positivas/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Pigmentos Biológicos/análise , Pigmentos Biológicos/isolamento & purificação , Pigmentos Biológicos/farmacologia
12.
BMC Genomics ; 11: 648, 2010 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-21092124

RESUMO

BACKGROUND: Widespread use of chromium (Cr) contaminated fields due to careless and inappropriate management practices of effluent discharge, mostly from industries related to metallurgy, electroplating, production of paints and pigments, tanning, and wood preservation elevates its concentration in surface soil and eventually into rice plants and grains. In spite of many previous studies having been conducted on the effects of chromium stress, the precise molecular mechanisms related to both the effects of chromium phytotoxicity, the defense reactions of plants against chromium exposure as well as translocation and accumulation in rice remain poorly understood. RESULTS: Detailed analysis of genome-wide transcriptome profiling in rice root is reported here, following Cr-plant interaction. Such studies are important for the identification of genes responsible for tolerance, accumulation and defense response in plants with respect to Cr stress. Rice root metabolome analysis was also carried out to relate differential transcriptome data to biological processes affected by Cr (VI) stress in rice. To check whether the Cr-specific motifs were indeed significantly over represented in the promoter regions of Cr-responsive genes, occurrence of these motifs in whole genome sequence was carried out. In the background of whole genome, the lift value for these 14 and 13 motifs was significantly high in the test dataset. Though no functional role has been assigned to any of the motifs, but all of these are present as promoter motifs in the Database of orthologus promoters. CONCLUSION: These findings clearly suggest that a complex network of regulatory pathways modulates Cr-response of rice. The integrated matrix of both transcriptome and metabolome data after suitable normalization and initial calculations provided us a visual picture of the correlations between components. Predominance of different motifs in the subsets of genes suggests the involvement of motif-specific transcription modulating proteins in Cr stress response of rice.


Assuntos
Cromo/toxicidade , Perfilação da Expressão Gênica , Metabolômica , Oryza/genética , Oryza/metabolismo , Raízes de Plantas/genética , Estresse Fisiológico/efeitos dos fármacos , Biomassa , Análise por Conglomerados , Regulação para Baixo/efeitos dos fármacos , Regulação para Baixo/genética , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Genes de Plantas/genética , Malondialdeído/metabolismo , Redes e Vias Metabólicas/efeitos dos fármacos , Anotação de Sequência Molecular , Oryza/efeitos dos fármacos , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Raízes de Plantas/anatomia & histologia , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/metabolismo , Brotos de Planta/anatomia & histologia , Brotos de Planta/efeitos dos fármacos , Prolina/metabolismo , Regiões Promotoras Genéticas/genética , Plântula/efeitos dos fármacos , Plântula/fisiologia , Estresse Fisiológico/genética , Compostos de Sulfidrila/metabolismo , Regulação para Cima/efeitos dos fármacos , Regulação para Cima/genética
13.
Phytochemistry ; 71(10): 1085-94, 2010 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-20483437

RESUMO

Profiling of metabolites is a rapidly expanding area of research for resolving metabolic pathways. Metabolic fingerprinting in medicinally important plants is critical to establishing the quality of herbal medicines. In the present study, metabolic profiling of crude extracts of leaf and root of Withania somnifera (Ashwagandha), an important medicinal plant of Indian system of medicine (ISM) was carried out using NMR and chromatographic (HPLC and GC-MS) techniques. A total of 62 major and minor primary and secondary metabolites from leaves and 48 from roots were unambiguously identified. Twenty-nine of these were common to the two tissues. These included fatty acids, organic acids, amino acids, sugars and sterol based compounds. Eleven bioactive sterol-lactone molecules were also identified. Twenty-seven of the identified metabolites were quantified. Highly significant qualitative and quantitative differences were noticed between the leaf and root tissues, particularly with respect to the secondary metabolites.


Assuntos
Folhas de Planta/metabolismo , Raízes de Plantas/metabolismo , Withania/metabolismo , Cromatografia Líquida de Alta Pressão , Cromatografia Gasosa-Espectrometria de Massas
14.
PLoS One ; 4(4): e5197, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-19381295

RESUMO

BACKGROUND: Lipid metabolism in mammals is orchestrated by a family of transcription factors called sterol regulatory element-binding proteins (SREBPs) that control the expression of genes required for the uptake and synthesis of cholesterol, fatty acids, and triglycerides. SREBPs are thus essential for insulin-induced lipogenesis and for cellular membrane homeostasis and biogenesis. Although multiple players have been identified that control the expression and activation of SREBPs, gaps remain in our understanding of how SREBPs are coordinated with other physiological pathways. METHODOLOGY: To identify novel regulators of SREBPs, we performed a genome-wide cDNA over-expression screen to identify proteins that might modulate the transcription of a luciferase gene driven from an SREBP-specific promoter. The results were verified through secondary biological assays and expression data were analyzed by a novel application of the Gene Set Enrichment Analysis (GSEA) method. CONCLUSIONS/SIGNIFICANCE: We screened 10,000 different cDNAs and identified a number of genes and pathways that have previously not been implicated in SREBP control and cellular cholesterol homeostasis. These findings further our understanding of lipid biology and should lead to new insights into lipid associated disorders.


Assuntos
Proteínas de Ligação a Elemento Regulador de Esterol/fisiologia , Transcrição Gênica , Sequência de Bases , Linhagem Celular , Colesterol/metabolismo , DNA Complementar , Homeostase , Humanos , Regiões Promotoras Genéticas , Transdução de Sinais , Proteínas de Ligação a Elemento Regulador de Esterol/genética , Proteínas de Ligação a Elemento Regulador de Esterol/metabolismo
15.
Microbiol Res ; 164(3): 347-51, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-17825544

RESUMO

Supplementation of molasses-salt medium with plant growth hormones, viz., indoleacetic acid, indolebutyric acid, kinetin and gibberellic acid, increased chitosan production by Mucor rouxii as well as its growth at different optimum concentrations. The increase in yield of chitosan was found to range from 34% to 69% and mycelial growth from 12% to 17.4%. Gibberellic acid was the most potent in this respect. Sixty-nine percent more chitosan over the control could be obtained from 1l of the medium supplemented with 3mg gibberellic acid. Degree of acetylation of chitosan ( approximately 13%) was not changed due to addition of hormone in the medium but weight average molecular weight of chitosan increased by more than 50%. Thus, the plant growth hormones add a value to chitosan by increasing its molecular weight.


Assuntos
Quitosana/metabolismo , Mucor/efeitos dos fármacos , Mucor/crescimento & desenvolvimento , Reguladores de Crescimento de Plantas/farmacologia , Quitosana/química , Giberelinas/farmacologia , Ácidos Indolacéticos/farmacologia , Indóis/farmacologia , Cinetina/farmacologia , Peso Molecular , Mucor/metabolismo , Micélio/efeitos dos fármacos , Micélio/crescimento & desenvolvimento
16.
Int J Biol Macromol ; 42(2): 120-6, 2008 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-18023862

RESUMO

The effect of some plant growth hormones, viz., gibberellic acid, indole-3-acetic acid, indole-3-butyric acid, and kinetin on chitosan production by Rhizopus oryzae in deproteinized whey was studied. Hormones, at different concentrations, increase the mycelial growth by 19-32%. However, increase in chitosan content of the mycelia was relatively small (1.7-14.3%) over the control. Maximum enhancement was observed with gibberellic acid. Fifty percent more chitosan could be obtained from 1L of whey containing 0.1mg/L gibberellic acid. Hormones, at higher dose, instead of stimulation inhibited both growth and mycelial chitosan content. This study showed that hormones have no influence on degree of deacetylation of chitosan but increase the quality of the chitosan by increasing weight average molecular weight and decreasing polydispersity. All the hormones had been found to enhance chitin deacetylase activity of R. oryzae by 1.067-1.267-fold and may be one of the reasons for increased chitosan production.


Assuntos
Quitosana/metabolismo , Leite/química , Reguladores de Crescimento de Plantas/farmacologia , Rhizopus/efeitos dos fármacos , Rhizopus/crescimento & desenvolvimento , Animais , Soluções Tampão , Fenômenos Químicos , Físico-Química , Rhizopus/metabolismo
17.
Eur J Pharmacol ; 540(1-3): 10-7, 2006 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-16697367

RESUMO

The intramembrane-cleaving proteases (I-CLiPs) presenilin-1 and -2 (PS1 and PS2), signal peptide peptidase (SPP) and the Site-2 protease (S2P) catalyze critical steps in cell signaling and are implicated in diseases such as Alzheimer's disease, hepatitis C virus (HCV) infection and cholesterol homeostasis. Here we describe the development of a cellular assay based on cleavage of the transmembrane sequence of the HCV core protein precursor, releasing intra- and extra-cellular signals that represent sequential signal peptidase and SPP cleavage, respectively. We find that the SPP inhibitor (Z-LL)2-ketone (IC50 = 1.33 microM) and the gamma-secretase potent inhibitors NVP-AHW700-NX (IC50 = 51 nM) and LY411575 (IC50 = 61 nM) but not DAPT dose dependently inhibited SPP but not signal peptidase cleavage. Our data confirm that type II orientated substrates, like the HCV transmembrane sequence, are sequentially cleaved by signal peptidase then SPP. This dual assay provides a powerful tool to pharmacologically analyze sequential cleavage events of signal peptidase and SPP and their regulation.


Assuntos
Ácido Aspártico Endopeptidases/metabolismo , Proteínas Recombinantes de Fusão/metabolismo , Transdução de Sinais , Sequência de Aminoácidos , Animais , Ácido Aspártico Endopeptidases/antagonistas & inibidores , Ácido Aspártico Endopeptidases/genética , Sítios de Ligação/genética , Células CHO , Linhagem Celular , Cricetinae , Cricetulus , Dipeptídeos/farmacologia , Retículo Endoplasmático/metabolismo , Espaço Extracelular/efeitos dos fármacos , Espaço Extracelular/metabolismo , Hepacivirus/genética , Hepacivirus/metabolismo , Humanos , Espaço Intracelular/efeitos dos fármacos , Espaço Intracelular/metabolismo , Luciferases/genética , Luciferases/metabolismo , Dados de Sequência Molecular , Mutação/genética , Complexo de Endopeptidases do Proteassoma/metabolismo , Proteínas Recombinantes de Fusão/genética , Homologia de Sequência de Aminoácidos , Especificidade por Substrato , Transfecção , Proteínas Virais/genética , Proteínas Virais/metabolismo
18.
J Colloid Interface Sci ; 288(1): 30-5, 2005 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-15927558

RESUMO

The process of sorption is being increasingly used for ecofriendly and economic remediation of textile dye effluents. The present model study deals with the adsorption of a model anionic dye, eosin Y, from wastewater using conditioned chitosan hydrobeads. Conditioning reduced the pH sensitivity and maintained the maximum sorption capacity of the beads near pH 8. To understand the chemicophysical characteristics of the adsorption process we studied, the kinetics and isotherm behavior of the system. It was observed that temperature played a significant role in the process. The Langmuir model was found to be most appropriate for the description of the adsorption process. The kinetic results followed a second-order equation. It was observed that 1 g of chitosan adsorbed approximately 76 mg of eosin Y. The dye was desorbed from the beads by changing the pH of the solution, and the conditioned chitosan beads were reused five times without any loss of mechanical and chemical efficacy.


Assuntos
Quelantes/química , Quitosana/química , Corantes/química , Amarelo de Eosina-(YS)/química , Purificação da Água/métodos , Adsorção , Difusão , Concentração de Íons de Hidrogênio , Cinética , Modelos Biológicos , Temperatura , Indústria Têxtil
19.
Cell ; 109(1): 47-60, 2002 Apr 05.
Artigo em Inglês | MEDLINE | ID: mdl-11955446

RESUMO

Wnt/Wingless signaling controls many fundamental processes during animal development. Wnt transduction is mediated by the association of beta-catenin with nuclear TCF DNA binding factors. Here we report the identification of two segment polarity genes in Drosophila, legless (lgs), and pygopus (pygo), and we show that their products are required for Wnt signal transduction at the level of nuclear beta-catenin. Lgs encodes the homolog of human BCL9, and we provide genetic and molecular evidence that these proteins exert their function by physically linking Pygo to beta-catenin. Our results suggest that the recruitment of Pygo permits beta-catenin to transcriptionally activate Wnt target genes and raise the possibility that a deregulation of these events may play a causal role in the development of B cell malignancies.


Assuntos
Padronização Corporal/genética , Proteínas de Transporte/genética , Núcleo Celular/genética , Proteínas do Citoesqueleto/genética , Proteínas de Drosophila/genética , Drosophila melanogaster/crescimento & desenvolvimento , Proteínas de Grupo de Alta Mobilidade/genética , Peptídeos e Proteínas de Sinalização Intracelular , Proteínas de Neoplasias/genética , Proteínas Proto-Oncogênicas/genética , Proteínas Repressoras/genética , Transativadores , Fatores de Transcrição , Proteínas de Peixe-Zebra , Proteínas Adaptadoras de Transdução de Sinal , Animais , Proteínas do Domínio Armadillo , Proteínas de Transporte/isolamento & purificação , Núcleo Celular/metabolismo , Mapeamento Cromossômico , Clonagem Molecular , Proteínas de Drosophila/isolamento & purificação , Drosophila melanogaster/citologia , Drosophila melanogaster/metabolismo , Feminino , Testes Genéticos , Proteínas de Insetos/genética , Substâncias Macromoleculares , Masculino , Dados de Sequência Molecular , Estrutura Terciária de Proteína/genética , Homologia de Sequência de Aminoácidos , Homologia de Sequência do Ácido Nucleico , Transdução de Sinais/genética , Proteínas Wnt , Proteína Wnt1 , beta Catenina
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