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1.
Sci Rep ; 7(1): 1963, 2017 05 16.
Artigo em Inglês | MEDLINE | ID: mdl-28512317

RESUMO

The recent global challenges to prevent and treat fungal infections strongly demand for the development of new antifungal strategies. The structurally very similar cysteine-rich antifungal proteins from ascomycetes provide a feasible basis for designing new antifungal molecules. The main structural elements responsible for folding, stability and antifungal activity are not fully understood, although this is an essential prerequisite for rational protein design. In this study, we used the Neosartorya fischeri antifungal protein (NFAP) to investigate the role of the disulphide bridges, the hydrophobic core, and the N-terminal amino acids in the formation of a highly stable, folded, and antifungal active protein. NFAP and its mutants carrying cysteine deletion (NFAPΔC), hydrophobic core deletion (NFAPΔh), and N-terminal amino acids exchanges (NFAPΔN) were produced in Pichia pastoris. The recombinant NFAP showed the same features in structure, folding, stability and activity as the native protein. The data acquired with mass spectrometry, structural analyses and antifungal activity assays of NFAP and its mutants proved the importance of the disulphide bonding, the hydrophobic core and the correct N-terminus for folding, stability and full antifungal function. Our findings provide further support to the comprehensive understanding of the structure-function relationship in members of this protein group.


Assuntos
Antifúngicos/química , Antifúngicos/farmacologia , Proteínas Fúngicas/química , Proteínas Fúngicas/farmacologia , Fungos/efeitos dos fármacos , Neosartorya/química , Dobramento de Proteína , Sequência de Aminoácidos , Proteínas Fúngicas/genética , Concentração de Íons de Hidrogênio , Testes de Sensibilidade Microbiana , Modelos Moleculares , Peso Molecular , Mutação , Neosartorya/genética , Conformação Proteica , Estabilidade Proteica , Proteínas Recombinantes/química , Proteínas Recombinantes/farmacologia , Relação Estrutura-Atividade , Temperatura
2.
Appl Environ Microbiol ; 83(6)2017 03 15.
Artigo em Inglês | MEDLINE | ID: mdl-28039140

RESUMO

Glycoside hydrolase (GH) family 12 comprises enzymes with a wide range of activities critical for the degradation of lignocellulose. However, the important roles of the loop regions of GH12 enzymes in substrate specificity and catalytic efficiency remain poorly understood. This study examined how the loop 3 region affects the enzymatic properties of GH12 glucanases using NfEG12A from Neosartorya fischeri P1 and EG (PDB 1KS4) from Aspergillus niger Acidophilic and thermophilic NfEG12A had the highest catalytic efficiency (kcat/Km , 3,001 and 263 ml/mg/s toward lichenin and carboxymethyl cellulose sodium [CMC-Na], respectively) known so far. Based on the multiple-sequence alignment and homology modeling, two specific sequences (FN and STTQA) were identified in the loop 3 region of GH12 endoglucanases from fungi. To determine their functions, these sequences were introduced into NfEG12A, or the counterpart sequence STTQA was removed from EG. These modifications had no effects on the optimal pH and temperature or substrate specificity but changed the catalytic efficiency (kcat/Km ) of these enzymes (in descending order, NfEG12A [100%], NfEG12A-FN [140%], and NfEG12A-STTQA [190%]; EG [100%] and EGΔSTTQA [41%]). Molecular docking and dynamic simulation analyses revealed that the longer loop 3 in GH12 may strengthen the hydrogen-bond interactions between the substrate and protein, thereby increasing the turnover rate (kcat). This study provides a new insight to understand the vital roles of loop 3 for GH12 endoglucanases in catalysis.IMPORTANCE Loop structures play critical roles in the substrate specificity and catalytic hydrolysis of GH12 enzymes. Three typical loops exist in these enzymes. Loops 1 and 2 are recognized as the catalytic loops and are closely related to the substrate specificity and catalytic efficiency. Loop 3 locates in the -1 or +1 subsite and varies a lot in amino acid composition, which may play a role in catalysis. In this study, two GH12 glucanases, NfEG12A and EG, which were mutated by introducing or deleting partial loop 3 sequences FN and/or STTQA, were selected to identify the function of loop 3. It revealed that the longer loop 3 of GH12 glucanases may strengthen the hydrogen network interactions between the substrate and protein, consequently increasing the turnover rate (kcat). This study proposes a strategy to increase the catalytic efficiency of GH12 glucanases by improving the hydrogen network between substrates and catalytic loops.


Assuntos
Aspergillus niger/enzimologia , Celulase/metabolismo , Glicosídeo Hidrolases/metabolismo , Lignina/metabolismo , Neosartorya/enzimologia , Domínios Proteicos/genética , Aspergillus niger/genética , Aspergillus niger/metabolismo , Catálise , Celulase/genética , Glucanos/metabolismo , Glicosídeo Hidrolases/genética , Ligação de Hidrogênio , Simulação de Acoplamento Molecular , Simulação de Dinâmica Molecular , Neosartorya/genética , Neosartorya/metabolismo , Especificidade por Substrato , beta-Glucanas/metabolismo
3.
J Biosci Bioeng ; 122(5): 539-544, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-27503553

RESUMO

Thermophilic Neosartorya fischeri P1 is an excellent lipase producer and harbors seven lipase genes. All genes were found to be functional after heterologous expression in Escherichia coli. One of them, LIP09, showed high-level expression in Pichia pastoris with the yield of 2.0 g/L in a 3.7-L fermentor. Deduced amino acid sequence of LIP09 consists of a putative signal peptide (residues 1-19) and a mature polypeptide (residues 20-562). Compared with other fungal counterparts, purified recombinant LIP09 has some superior properties. It exhibited maximum activity at 60°C and pH 5.0, had broad pH adaptability (>60% activity at pH 3.5-8.0) and stability (retaining >90% activity after incubation at pH 3.0-7.0 for 1 h at 40°C), and was highly thermostable (retaining >96% activity after incubation at 50°C for 30 min). The r-LIP09 had a preference for the medium-chain length p-nitrophenyl esters (C12) rather than short and long-chain length substrates. The high-level expression and excellent properties make LIP09 a potential enzyme candidate in food and feed industries.


Assuntos
Proteínas de Bactérias/biossíntese , Lipase/biossíntese , Neosartorya/enzimologia , Neosartorya/genética , Adaptação Biológica/genética , Sequência de Aminoácidos , Proteínas de Bactérias/genética , Clonagem Molecular , Estabilidade Enzimática/genética , Escherichia coli , Concentração de Íons de Hidrogênio , Lipase/genética , Pichia/genética , Proteínas Recombinantes/biossíntese , Proteínas Recombinantes/genética , Especificidade por Substrato
4.
Microb Cell Fact ; 15(1): 122, 2016 Jul 11.
Artigo em Inglês | MEDLINE | ID: mdl-27400964

RESUMO

BACKGROUND: The filamentous fungus Trichoderma reesei has the capacity to secret large amounts of cellulase and is widely used in a variety of industries. However, the T. reesei cellulase is weak in ß-glucosidase activity, which results in accumulation of cellobiose inhibiting the endo- and exo-cellulases. By expressing an exogenous ß-glucosidase gene, the recombinant T. reesei cellulase is expected to degrade cellulose into glucose more efficiently. RESULTS: The thermophilic ß-glucosidase NfBgl3A from Neosartorya fischeri is chosen for overexpression in T. reesei due to its robust activity. In vitro, the Pichia pastoris-expressed NfBgl3A aided the T. reesei cellulase in releasing much more glucose with significantly lower amounts of cellobiose from crystalline cellulose. The NfBgl3A gene was hence fused to the cbh1 structural gene and assembled between the strong cbh1 promoter and cbh1 terminator to obtain pRS-NfBgl3A by using the DNA assembler method. pRS-NfBgl3A was transformed into the T. reesei uridine auxotroph strain TU-6. Six positive transformants showed ß-glucosidase activities of 2.3-69.7 U/mL (up to 175-fold higher than that of wild-type). The largely different ß-glucosidase activities in the transformants may be ascribed to the gene copy numbers of NfBgl3A or its integration loci. The T. reesei-expressed NfBgl3A showed highly similar biochemical properties to that expressed in P. pastoris. As expected, overexpression of NfBgl3A enhanced the overall cellulase activity of T. reesei. The CBHI activity in all transformants increased, possibly due to the extra copies of cbh1 gene introduced, while the endoglucanase activity in three transformants also largely increased, which was not observed in any other studies overexpressing a ß-glucosidase. NfBgl3A had significant transglycosylation activity, generating sophorose, a potent cellulase inducer, and other oligosaccharides from glucose and cellobiose. CONCLUSIONS: We report herein the successful overexpression of a thermophilic N. fischeri ß-glucosidase in T. reesei. In the same time, the fusion of NfBgl3A to the cbh1 gene introduced extra copies of the cellobiohydrolase 1 gene. As a result, we observed improved ß-glucosidase and cellobiohydrolase activity as well as the overall cellulase activity. In addition, the endoglucanase activity also increased in some of the transformants. Our results may shed light on design of more robust T. reesei cellulases.


Assuntos
Celulase/metabolismo , Proteínas Fúngicas/genética , Neosartorya/enzimologia , Proteínas Recombinantes de Fusão/genética , Trichoderma/genética , beta-Glucosidase/genética , Celobiose/metabolismo , Celulase/genética , Celulose/metabolismo , Proteínas Fúngicas/metabolismo , Regulação Fúngica da Expressão Gênica , Glucose/metabolismo , Neosartorya/genética , Regiões Promotoras Genéticas , Proteínas Recombinantes de Fusão/metabolismo , Trichoderma/metabolismo , beta-Glucosidase/metabolismo
5.
Curr Genet ; 62(4): 853-860, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26972831

RESUMO

Bioactive ergot alkaloids produced by several species of fungi are important molecules in agriculture and medicine. Much of the ergot alkaloid pathway has been elucidated, but a few steps, including the gene controlling hydroxylation of festuclavine to fumigaclavine B, remain unsolved. Festuclavine is a key intermediate in the fumigaclavine branch of the ergot alkaloid pathway of the opportunistic pathogen Neosartorya fumigata and also in the dihydrolysergic acid-based ergot alkaloid pathway of certain Claviceps species. Based on several lines of evidence, the N. fumigata gene easM is a logical candidate to encode the festuclavine-hydroxylating enzyme. To test this hypothesis we disrupted easM function by replacing part of its coding sequences with a hygromycin resistance gene and transforming N. fumigata with this construct. High-pressure liquid chromatography analysis demonstrated that easM deletion mutants were blocked in the ergot alkaloid pathway at festuclavine, and downstream products were eliminated. An additional alkaloid, proposed to be a prenylated form of festuclavine on the basis of mass spectral data, also accumulated to higher concentrations in the easM knockout. Complementation with the wild-type allele of easM gene restored the ability of the fungus to produce downstream compounds. These results indicate that easM encodes an enzyme required for fumigaclavine B synthesis likely by hydroxylating festuclavine. The festuclavine-accumulating strain of N. fumigata may facilitate future investigations of the biosynthesis of dihydrolysergic acid derivatives, which are derived from festuclavine and are the basis for several important drugs.


Assuntos
Ergolinas/metabolismo , Alcaloides de Claviceps/metabolismo , Genes Fúngicos , Redes e Vias Metabólicas , Neosartorya/genética , Neosartorya/metabolismo , Técnicas de Inativação de Genes , Teste de Complementação Genética , Hidroxilação , Família Multigênica
6.
Environ Microbiol Rep ; 8(1): 45-52, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26487515

RESUMO

Hydrophilins are proteins that occur in all domains of life and protect cells and organisms against drought and other stresses. They include most of the late embryogenesis abundant (LEA) proteins and the heat shock protein (HSP) Hsp12. Here, the role of a predicted LEA-like protein (LeamA) and two Hsp12 proteins (Hsp12A and Hsp12B) of Neosartorya fischeri was studied. This filamentous fungus forms ascospores that belong to the most stress-resistant eukaryotic cells described to date. Heterologous expression of LeamA, Hsp12A and Hsp12B resulted in increased tolerance against salt and osmotic stress in Escherichia coli. These proteins were also shown to protect lactate dehydrogenase against dry heat and freeze-thaw cycles in vitro. Deletion of leamA caused diminished viability of sexual ascospores after drought and heat. This is the first report on functionality of Hsp12 and putative LeamA proteins derived from filamentous fungi, and their possible role in N. fischeri ascospore resistance against desiccation, high temperature and osmotic stress is discussed.


Assuntos
Desidratação , Proteínas Fúngicas/metabolismo , Neosartorya/fisiologia , Estresse Fisiológico , Clonagem Molecular , Secas , Escherichia coli/genética , Escherichia coli/fisiologia , Proteínas Fúngicas/genética , Deleção de Genes , Expressão Gênica , Temperatura Alta , L-Lactato Desidrogenase/análise , Viabilidade Microbiana/efeitos dos fármacos , Neosartorya/efeitos dos fármacos , Neosartorya/genética , Neosartorya/efeitos da radiação , Pressão Osmótica
7.
Appl Microbiol Biotechnol ; 99(3): 1261-72, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25487894

RESUMO

Thermophilic Neosartorya fischeri P1 is an excellent carbohydrate-active enzyme (CAZyme) producer. Two α-galactosidases of GH (glycoside hydrolase ) family 27 with a very low sequence identity (28.7%), Gal27A and Gal27B, were identified in strain P1 and functionally expressed in Pichia pastoris. In comparison to other characterized GH27 fungal counterparts, rGal27B has a higher temperature optimum (75 °C) and better thermostability (>50% activity at 70 °C for 15 min), and rGal27A shows stability over the broadest pH range (pH 2.0-12.0). Moreover, great distinctions lie in the two enzymes. When using pNPG as the substrate, rGal27B had a higher turnover number (1621.4 vs. 368.3 s(-1)) but lower affinity (2.84 vs. 0.8 mM) and catalytic efficiency (460.8 vs. 580.3 s(-1) mM(-1)) than rGal27A. rGal27B acted on galacto-oligosaccharides, whereas rGal27A was active on polymeric substrates. Although both enzymes showed synergy in galactomannan degradation when combined with a ß-mannanase of the same strain, enzyme combinations including rGal27A released more reducing sugars (up to 11.67-fold). Homology modeling predicts different loops in N. fischeri α-galactosidases, highlighting the larger tunnel structure in Gal27A to accommodate/bind branched galactomannan with high galactose contents. Phylogenetic analysis reveals the far relationship of Gal27A and Gal27B that they may evolve in different action modes, and their coexistence widens the substrate spectrum for nutrient utilization. This study illustrates the substrate profiles and synergistic mechanism of GH27 α-galactosidases of different structures.


Assuntos
Proteínas Fúngicas/química , Neosartorya/enzimologia , alfa-Galactosidase/química , Sequência de Aminoácidos , Estabilidade Enzimática , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Galactose/análogos & derivados , Temperatura Alta , Concentração de Íons de Hidrogênio , Cinética , Mananas/metabolismo , Dados de Sequência Molecular , Neosartorya/química , Neosartorya/classificação , Neosartorya/genética , Filogenia , Alinhamento de Sequência , Especificidade por Substrato , alfa-Galactosidase/genética , alfa-Galactosidase/metabolismo , beta-Manosidase/química , beta-Manosidase/genética , beta-Manosidase/metabolismo
8.
Protein Expr Purif ; 94: 79-84, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24269762

RESUMO

Neosartorya fischeri NRRL 181 isolate secretes a defensin-like antifungal protein (NFAP) which has a remarkable antifungal effect against ascomycetous filamentous fungi. This protein is a promising antifungal agent of biotechnological value; however in spite of the available knowledge of the nature of its 5'-upstream transcriptional regulation elements, the bulk production of NFAP has not been resolved yet. In this study we carried out its heterologous expression in the yeast Pichia pastoris and investigated the growth inhibition effect exerted by the heterologous NFAP (hNFAP) on filamentous fungal isolates from human infections compared with what was caused by the native NFAP. P. pastoris KM71H transformant strain harboring the pPICZαA plasmid with the mature NFAP encoding gene produced the protein. The final yield of the hNFAP was sixfold compared to the NFAP produced by N. fischeri NRRL 181. Based on the signal dispersion of the amide region, it was proven that the hNFAP exists in folded state. The purified hNFAP effectively inhibited the growth of fungal isolates belonging to the Aspergillus and to the Fusarium genus, but all investigated zygomycetous strain proved to be insusceptible. There was no significant difference between the growth inhibition effect exerted by the native and the heterologous NFAP. These data indicated that P. pastoris KM71H can produce the NFAP in an antifungally active folded state. Our results provide a base for further research, e.g., investigation the connection between the protein structure and the antifungal activity using site directed mutagenesis.


Assuntos
Antifúngicos/farmacologia , Defensinas/biossíntese , Proteínas Fúngicas/biossíntese , Fungos/efeitos dos fármacos , Sequência de Aminoácidos , Defensinas/genética , Defensinas/isolamento & purificação , Defensinas/farmacologia , Dermatomicoses/microbiologia , Proteínas Fúngicas/genética , Proteínas Fúngicas/isolamento & purificação , Proteínas Fúngicas/farmacologia , Fungos/patogenicidade , Humanos , Neosartorya/química , Neosartorya/genética , Neosartorya/metabolismo , Pichia/genética
9.
Microbiology (Reading) ; 159(Pt 10): 2169-2179, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23845975

RESUMO

A putative prenyltransferase gene, NFIA_043650, was amplified from Neosartorya fischeri NRRL 181 and cloned into the expression vector pQE60. The deduced polypeptide consisting of 445 amino acids with a molecular mass of 51 kDa was overproduced in Escherichia coli and purified as His6-tagged protein to near homogeneity. The purified soluble protein was subsequently assayed with potential aromatic substrates in the presence of dimethylallyl diphosphate. HPLC analysis of the reaction mixtures revealed acceptance of all tested tryptophan-containing cyclic dipeptides. Isolation and structural elucidation of enzyme products of five selected substrates indicated a reverse C2-prenylation on the indole nucleus, proving the enzyme to be a cyclic dipeptide C2-prenyltransferase (CdpC2PT). Differing significantly from two known brevianamide F reverse C2-prenyltransferases NotF and BrePT which use cyclo-l-Trp-l-Pro as their preferred substrate, CdpC2PT showed a clear substrate preference for (S)-benzodiazepinedinone and cyclo-l-Trp-l-Trp with KM values of 84.1 and 165.2 µM and turnover numbers at 0.63 and 0.30 s(-1), respectively. A possible role of CdpC2PT in the biosynthesis of fellutanines is discussed.


Assuntos
Dimetilaliltranstransferase/isolamento & purificação , Dimetilaliltranstransferase/metabolismo , Neosartorya/enzimologia , Cromatografia Líquida de Alta Pressão , Clonagem Molecular , Dimetilaliltranstransferase/química , Dimetilaliltranstransferase/genética , Escherichia coli/genética , Expressão Gênica , Cinética , Dados de Sequência Molecular , Peso Molecular , Neosartorya/genética , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/isolamento & purificação , Proteínas Recombinantes de Fusão/metabolismo , Análise de Sequência de DNA , Especificidade por Substrato
10.
Org Lett ; 15(4): 780-3, 2013 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-23368997

RESUMO

Activation of the polycyclic polyketide prenyltransferase (pcPTase)-containing silent clusters in Aspergillus fumigatus and Neosartorya fischeri led to isolation of a new metabolite neosartoricin (3). The structure of 3 was solved by X-ray crystallography and NMR to be a prenylated anthracenone. 3 exhibits T-cell antiproliferative activity with an IC(50) of 3 µM, suggestive of a physiological role as an immunosuppressive agent.


Assuntos
Aspergillus fumigatus/genética , Genoma , Imunossupressores/isolamento & purificação , Neosartorya/genética , Policetídeos/isolamento & purificação , Animais , Aspergillus fumigatus/química , Aspergillus fumigatus/enzimologia , Cristalografia por Raios X , Dimetilaliltranstransferase/metabolismo , Fungos/genética , Fungos/metabolismo , Células HeLa , Humanos , Imunossupressores/química , Imunossupressores/farmacologia , Macrófagos/efeitos dos fármacos , Camundongos , Conformação Molecular , Neosartorya/metabolismo , Ressonância Magnética Nuclear Biomolecular , Policetídeos/química , Policetídeos/farmacologia , Prenilação
11.
J Clin Microbiol ; 51(4): 1316-9, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23345294
13.
Microbiology (Reading) ; 159(Pt 2): 411-419, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23197172

RESUMO

Neosartorya fischeri antifungal protein (NFAP) is a ß-defensin-like peptide produced by the N. fischeri NRRL 181 isolate. In this study, we investigated the manifestation of the antimicrobial effect of NFAP via heterologous expression of the nfap gene in an NFAP-sensitive fungus, Aspergillus nidulans. Heterologous expression of the nfap gene was carried out in A. nidulans CS2902 using a pAMA1-based autonomous replicative vector construct. The effect of the produced NFAP on the germination of A. nidulans conidia was investigated by scanning electron microscopy (SEM), and by DAPI and Calcofluor white (CFW) staining. 2',7'-Dichlorodihydrofluorescein diacetate staining and an Annexin V-FITC Apoptosis Detection kit were used to reveal the accumulation of reactive oxygen species (ROS) and the possible apoptotic, necrotic effect. The impact of mono- and divalent cations on the antimicrobial activity of NFAP was also examined. Transformants expressing the nfap gene showed reduced hyphal growth compared with the untransformed strain. This effect was absent in the presence of mono- and divalent cations (50 and 100 mM KCl, Mg(2)SO(4), Na(2)SO(4)). Delayed and abnormal germination was observed in the case of transformants. Conidia developed short branching germination tubes with swollen tips. The great majority of germinating conidia were destroyed after 8 h of cultivation, although a few survived and developed into abnormal hyphae. Damage in the organization of the cell wall, the destruction of chitin filaments and the accumulation of nuclei at the broken hyphal tips were detected by SEM, DAPI and CFW staining. The accumulation of ROS and more frequent apoptotic, necrotic events were also observed in the case of the NFAP-producing A. nidulans strain.


Assuntos
Antifúngicos/farmacologia , Aspergillus nidulans/efeitos dos fármacos , Aspergillus nidulans/crescimento & desenvolvimento , Proteínas Fúngicas/biossíntese , Neosartorya/genética , Apoptose , Aspergillus nidulans/genética , Aspergillus nidulans/ultraestrutura , Proteínas Fúngicas/genética , Hifas/efeitos dos fármacos , Hifas/genética , Hifas/crescimento & desenvolvimento , Hifas/ultraestrutura , Microscopia Eletrônica de Varredura , Espécies Reativas de Oxigênio/análise , Proteínas Recombinantes/biossíntese , Proteínas Recombinantes/genética
14.
Chembiochem ; 13(17): 2583-92, 2012 Nov 26.
Artigo em Inglês | MEDLINE | ID: mdl-23109474

RESUMO

Previous studies showed that verruculogen is the end product of a biosynthetic gene cluster for fumitremorgin-type alkaloids in Aspergillus fumigatus and Neosartorya fischeri. In this study, we isolated fumitremorgin A from N. fischeri. This led to the identification of the responsible gene, ftmPT3, for O-prenylation of an aliphatic hydroxy group in verruculogen. This gene was found at a different location in the genome of N. fischeri than the identified cluster. The coding sequence of ftmPT3 was amplified by fusion PCR and overexpressed in Escherichia coli. The enzyme product of the soluble His(8)-FtmPT3 with verruculogen and dimethylallyl diphosphate (DMAPP) was identified unequivocally as fumitremorgin A by NMR and MS analyses. K(M) values of FtmPT3 were determined for verruculogen and DMAPP at 5.7 and 61.5 µM, respectively. Average turnover number (k(cat)) was calculated from kinetic parameters of verruculogen and DMAPP to be 0.069 s(-1). FtmPT3 also accepted biosynthetic precursors of fumitremorgin A, for example, fumitremorgin B and 12,13-dihydroxyfumitremorgin C, as substrates and catalyses their prenylation.


Assuntos
Biologia Computacional , Dimetilaliltranstransferase/genética , Dimetilaliltranstransferase/metabolismo , Indóis/metabolismo , Neosartorya/enzimologia , Neosartorya/genética , Cromossomos Fúngicos/genética , Técnicas de Cultura , Dimetilaliltranstransferase/biossíntese , Dimetilaliltranstransferase/química , Indenos/metabolismo , Cinética , Família Multigênica/genética , Neosartorya/metabolismo , Prenilação , Análise de Sequência , Especificidade por Substrato
15.
BMC Microbiol ; 12: 154, 2012 Jul 28.
Artigo em Inglês | MEDLINE | ID: mdl-22838495

RESUMO

BACKGROUND: Microsatellites (or short tandem repeats, STRs) are the genetic markers of choice for studying Aspergillus fumigatus molecular epidemiology due to its reproducibility and high discrimination power. However, the specificity of these markers must be investigated in a group of isolates from closely related species. The aim of this work was to test a microsatellite-based PCR multiplex previously designed for A. fumigatus in a set of species belonging to section Fumigati, namely Aspergillus fumigatiaffinis, Aspergillus lentulus, Aspergillus novofumigatus, Aspergillus unilateralis, Aspergillus viridinutans, Neosartorya fischeri, Neosartorya hiratsukae, Neosartorya pseudofischeri and Neosartorya udagawae. RESULTS: The reference A. fumigatus strain ATCC 46645 was easily genotyped in standard conditions showing a final electrophoretic profile of 8 expected peaks corresponding to each microsatellite locus. Inversely, no peaks were observed for all other species from section Fumigati, with an exception for marker MC6b in A. unilateralis. By screening the genome sequence of Neosartorya fischeri NRRL 181, the results showed that MC3, MC6a and MC7 might be employed for N. fischeri genotyping since these markers present several repeats of each motif. The accumulation of insertions and deletions was frequently observed in the genomic regions surrounding the microsatellites, including those where the A. fumigatus primers are located. The amplification of microsatellite markers in less stringent amplification conditions resulted in a distinct electrophoretic profile for species within section Fumigati. CONCLUSIONS: Therefore, the microsatellite-based PCR multiplex allow simple identification of A. fumigatus and, with a slight modification of temperature conditions, it also allows discriminating other pathogenic species within section Fumigati, particularly A. fumigatiaffinis, N. fischeri and N. udagawae.


Assuntos
Aspergillus/classificação , Variação Genética , Repetições de Microssatélites , Tipagem Molecular/métodos , Técnicas de Tipagem Micológica/métodos , Neosartorya/classificação , Aspergillus/genética , Aspergillus/patogenicidade , Humanos , Epidemiologia Molecular/métodos , Neosartorya/genética , Neosartorya/patogenicidade , Reação em Cadeia da Polimerase/métodos
16.
Appl Microbiol Biotechnol ; 94(2): 413-23, 2012 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-22042231

RESUMO

An isolated gene from Neosartorya fischeri NRRL181 encoding a ß-glucosidase (BGL) was cloned, and its nucleotide sequence was determined. DNA sequence analysis revealed an open reading frame of 1,467 bp, capable of encoding a polypeptide of 488 amino acid residues. The gene was over-expressed in Escherichia coli, and the protein was purified using nickel-nitrilotriacetic acid chromatography. The purified recombinant BGL showed a high level of catalytic activity, with V (max) of 886 µmol min(-1) mg-protein(-1) and a K (m) of 68 mM for p-nitrophenyl-ß-D: -glucopyranoside (pNPG). The optimal temperature for enzyme activity was about 40°C, and the optimal pH was about 6.0. A homology model of N. fischeri BGL1 was constructed based on the X-ray crystal structure of Phanerochaete chrysosporium BGLA. Molecular dynamics simulation studies of the enzyme with the pNPG and cellobiose shed light on the unique substrate specificity of N. fischeri BGL1 only towards pNPG.


Assuntos
Neosartorya/enzimologia , Neosartorya/genética , beta-Glucosidase/genética , beta-Glucosidase/metabolismo , Sequência de Aminoácidos , Cromatografia de Afinidade , Clonagem Molecular , DNA Fúngico/química , DNA Fúngico/genética , Estabilidade Enzimática , Escherichia coli/genética , Expressão Gênica , Concentração de Íons de Hidrogênio , Cinética , Modelos Moleculares , Dados de Sequência Molecular , Fases de Leitura Aberta , Conformação Proteica , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/isolamento & purificação , Proteínas Recombinantes/metabolismo , Análise de Sequência de DNA , Homologia de Sequência de Aminoácidos , Temperatura , beta-Glucosidase/química
17.
Artigo em Inglês | MEDLINE | ID: mdl-22175880

RESUMO

A new petroleum hydrocarbon-degrading fungus, isolated from an oil contaminant soil, was identified as Neosartorya (teleomorph of Aspergillus) sp. This isolate was able to degrade total petroleum hydrocarbons (TPHs) without a lag phase, but degradation rates decreased with increasing initial TPH concentrations (5,000-20,000 mg L(-1)). The TPH degradation by the isolate showed a substrate inhibition behavior with an inhibition constant (K(i)) of 1,860 mg L(-1). Dual lag phase of TPH degradation indicated the ability to adapt its metabolic activity to utilize different types of hydrocarbons as an electron donor. Initially n-alkanes were rapidly removed without lag phase in the whole range of substrate and heavy molecular weight alkanes (HMWAs; C23-C24) and low molecular weight alkanes (LMWAs C9-C15) out of n-alkane hydrocarbons were degraded rapidly, whereas the removal of mid molecular weight alkanes (MMWAs; C16-C22) was relatively slower. Relatively slow degradation of MMWAs is probably caused by biotransformation of HMWAs or non-alkane hydrocarbons to MMWAs.


Assuntos
Hidrocarbonetos/metabolismo , Neosartorya/metabolismo , Petróleo , Poluentes do Solo/metabolismo , Poluentes Químicos da Água/metabolismo , Biodegradação Ambiental , DNA Fúngico/genética , Concentração de Íons de Hidrogênio , Dados de Sequência Molecular , Peso Molecular , Neosartorya/genética , Neosartorya/isolamento & purificação , Análise de Sequência de DNA , Temperatura
18.
Microb Biotechnol ; 4(5): 663-72, 2011 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-21624102

RESUMO

A fungal strain isolated from a microbial consortium growing in a natural asphalt lake is able to grow in purified asphaltenes as the only source of carbon and energy. The asphaltenes were rigorously purified in order to avoid contamination from other petroleum fractions. In addition, most of petroporphyrins were removed. The 18S rRNA and ß-tubulin genomic sequences, as well as some morphologic characteristics, indicate that the isolate is Neosartorya fischeri. After 11 weeks of growth, the fungus is able to metabolize 15.5% of the asphaltenic carbon, including 13.2% transformed to CO(2) . In a medium containing asphaltenes as the sole source of carbon and energy, the fungal isolate produces extracellular laccase activity, which is not detected when the fungus grow in a rich medium. The results obtained in this work clearly demonstrate that there are microorganisms able to metabolize and mineralize asphaltenes, which is considered the most recalcitrant petroleum fraction.


Assuntos
Hidrocarbonetos/metabolismo , Neosartorya/isolamento & purificação , Neosartorya/metabolismo , Petróleo/metabolismo , Biodegradação Ambiental , Lagos/microbiologia , Neosartorya/classificação , Neosartorya/genética
19.
J Microbiol ; 49(2): 257-64, 2011 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-21538247

RESUMO

A phytase gene was cloned from Neosartorya spinosa BCC 41923. The gene was 1,455 bp in size, and the mature protein contained a polypeptide of 439 amino acids. The deduced amino acid sequence contains the consensus motif (RHGXRXP) which is conserved among phytases and acid phosphatases. Five possible disulfide bonds and seven potential N-glycosylation sites have been predicted. The gene was expressed in Pichia pastoris KM71 as an extracellular enzyme. The purified enzyme had specific activity of 30.95 U/mg at 37°C and 38.62 U/mg at 42°C. Molecular weight of the deglycosylated recombinant phytase, determined by SDS-PAGE, was approximately 52 kDa. The optimum pH and temperature for activity were pH 5.5 and 50°C. The residual phytase activity remained over 80% of initial activity after the enzyme was stored in pH 3.0 to 7.0 for 1 h, and at 60% of initial activity after heating at 90°C for 20 min. The enzyme exhibited broad substrate specificity, with phytic acid as the most preferred substrate. Its K (m) and V (max) for sodium phytate were 1.39 mM and 434.78 U/mg, respectively. The enzyme was highly resistant to most metal ions tested, including Fe(2+), Fe(3+), and Al(3+). When incubated with pepsin at a pepsin/phytase ratio of 0.02 (U/U) at 37°C for 2 h, 92% of its initial activity was retained. However, the enzyme was very sensitive to trypsin, as 5% of its initial activity was recovered after treating with trypsin at a trypsin/phytase ratio of 0.01 (U/U).


Assuntos
6-Fitase/genética , 6-Fitase/metabolismo , Expressão Gênica , Neosartorya/enzimologia , Neosartorya/genética , Pichia/genética , 6-Fitase/química , 6-Fitase/isolamento & purificação , Motivos de Aminoácidos , Sequência de Aminoácidos , Sequência de Bases , Clonagem Molecular , Eletroforese em Gel de Poliacrilamida , Estabilidade Enzimática , Concentração de Íons de Hidrogênio , Cinética , Dados de Sequência Molecular , Peso Molecular , Ácido Fítico/metabolismo , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/isolamento & purificação , Proteínas Recombinantes/metabolismo , Especificidade por Substrato , Temperatura
20.
Org Biomol Chem ; 8(10): 2430-8, 2010 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-20448903

RESUMO

Six beta-configured reversely C3-prenylated pyrrolo[2,3-b]indoles were successfully prepared by using a recombinant prenyltransferase from Neosartorya fischeri. For this purpose, the putative prenyltransferase gene NFIA_074280 (termed herewith cdpC3PT) was cloned into pQE60 and overexpressed in Escherichia coli. The overproduced His(6)-CdpC3PT was purified to near homogeneity and incubated with five cyclic tryptophan-containing dipeptides in the presence of dimethylallyl diphosphate (DMAPP). All of the substrates were accepted by CdpC3PT and converted to reversely C3-prenylated pyrrolo[2,3-b]indoles. Using cyclo-l-Trp-l-Trp as substrate, both mono- and diprenylated derivatives were obtained. The structures of the enzymatic products were confirmed by HR-ESI-MS, (1)H- and (13)C-NMR analyses as well as by long-range (1)H-(13)C connectivities in heteronuclear multiple-bond correlation (HMBC) spectra after preparative isolation. (1)H-(1)H spatial correlations in nuclear overhauser effect spectroscopy (NOESY) were used for determination of absolute configuration. The K(M) values were determined at about 1.5 mM for DMAPP and in the range from 0.22 to 5.5 mM for cyclic dipeptides. The turnover number k(cat) were found in the range of 0.023 to 0.098 s(-1) and specificity constants k(cat)/K(M) from 14.2 to 122.7 M(-1) s(-1). In contrast to the products of AnaPT bearing alpha-configured C3-dimethylallyl residues, the C3-prenyl moieties in the products of CdpC3PT have a beta-configuration. Discovery and characterisation of CdpC3PT expand the usage of the chemoenzymatic approach for stereospecific synthesis of C3-prenylated derivatives.


Assuntos
Dimetilaliltranstransferase/biossíntese , Dimetilaliltranstransferase/metabolismo , Indóis/química , Indóis/síntese química , Proteínas Recombinantes/biossíntese , Proteínas Recombinantes/metabolismo , Clonagem Molecular , Dimetilaliltranstransferase/genética , Indóis/metabolismo , Espectroscopia de Ressonância Magnética , Neosartorya/enzimologia , Neosartorya/genética , Proteínas Recombinantes/genética
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