RESUMO
Communicated by Ramaswamy H. Sarma.
Assuntos
Nanopartículas Metálicas/química , Prata/química , gama-Globulinas/química , Sítios de Ligação , Ácido Cítrico , Nanopartículas Metálicas/ultraestrutura , Espectrometria de Fluorescência , Termodinâmica , gama-Globulinas/metabolismoRESUMO
A new ion-pair complex, (C16H14N)2[Ni(C4N2S2)2] or (1-NaMePy)2[Ni(imnt)2], where 1-NaMePy is 1-(4-naphthyl-methyl-ene)pyridinium and imnt is 2,2-di-cyano-ethene-1,1-di-thiol-ate, was obtained by the direct reaction of NiCl2, K2imnt and (1-NaMePy)(+)Br(-) in H2O. The asymmetric unit contains a [1-NaMePy](+) cation and one half of an Ni(imnt)2 (2-) anion. The Ni(II) ion lies on an inversion centre and adopts a square-planar configuration with Ni-S bond lengths of 2.200â (1) and 2.216â (1)â Å. In the [1-NaMePy](+) cation, the naphthyl ringsystem and the pyridinium ring make a dihedral angle of 90.0â (2)°. In the crystal, C-Hâ¯N and C-Hâ¯Ni hydrogen bonds, as well as π-π inter-actions between the chelate ring and the pyridinium ring [centroid-centroid distance = 3.675â (2)â Å] link the ions into a three-dimensional network.
RESUMO
OBJECTIVE: At transcriptional level, the inhibitory effects of formic acid was investigated on Candida shehatae, a model yeast strain capable of fermenting xylose to ethanol. Thereby, the target genes were regulated by formic acid and the transcript profiles were discovered. METHODS: On the basis of the transcriptome data of C. shehatae metabolizing glucose and xylose, the genes responsible for ethanol fermentation were chosen as candidates by the combined method of yeast metabolic pathway analysis and manual gene BLAST search. These candidates were then quantitatively detected by RQ-PCR technique to find the regulating genes under gradient doses of formic acid. RESULTS: By quantitative analysis of 42 candidate genes, we finally identified 10 and 5 genes as markedly down-regulated and up-regulated targets by formic acid, respectively. CONCLUSION: With regard to gene transcripts regulated by formic acid in C. shehatae, the markedly down-regulated genes ranking declines as follows: xylitol dehydrogenase (XYL2), acetyl-CoA synthetase (ACS), ribose-5-phosphate isomerase (RKI), transaldolase (TAL), phosphogluconate dehydrogenase (GND1), transketolase (TKL), glucose-6-phosphate dehydrogenase (ZWF1), xylose reductase (XYL1), pyruvate dehydrogenase (PDH) and pyruvate decarboxylase (PDC); and a declining rank for up-regulated gens as follows: fructose-bisphosphate aldolase (ALD), glucokinase (GLK), malate dehydrogenase (MDH), 6-phosphofructokinase (PFK) and alcohol dehydrogenase (ADH).
Assuntos
Candida/efeitos dos fármacos , Candida/genética , Formiatos/farmacologia , Genes Fúngicos/genética , Candida/enzimologia , Candida/metabolismo , Fermentação/efeitos dos fármacos , Perfilação da Expressão Gênica , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Xilose/metabolismoRESUMO
OBJECTIVE: We detected and analyzed transcript profile differences between hexose and pentose fermentation by Candida shehatae, a typical xylose fermenting yeast strain. On this basis, the encoding genes of key enzymes and functional protein were screened for discovering candidates of metabolism and regulation. METHODS: To discover the key genes of xylose metabolism and ethanol fermentation in Candida shehatae, we performed a new high throughout de novo transcriptome sequencing technology on Roche 454 GS FLX Titanium platform. Two cDNA libraries were constructed and sequenced for xylose and glucose fermentation for comparison of its expressed sequence tags differences. RESULTS: Second sequencing run resulted in 600000 reads with the average length of 400bp for each cDNA library. We got 7250 and 7168 contigs by assembly, and annotated 2412 and 2456 unique genes by BLAST and Gene Ontology analysis for xylose and glucose respectively. By comparison, we identified 158 genes as different expression genes candidates at p < 0.05 for xylose metabolism and ethanol fermentation in Candida shehatae. CONCLUSIONS: The group genes for xylose metabolism and ethanol fermentation in Candida shehatae was discovered by using transcript profile sequencing and comparison. It will provide fundamental data for the relative research on molecular biology and metabolic regulation.
Assuntos
Candida/genética , Candida/metabolismo , Etanol/metabolismo , Glucose/genética , Glucose/metabolismo , Xilose/genética , Xilose/metabolismo , Candida/enzimologia , Fermentação/genética , Perfilação da Expressão Gênica/métodos , Hexoses/genética , Hexoses/metabolismo , TranscriptomaRESUMO
An MEKC method with LIF detection has been developed for the determination of seven neurotransmitter amino acids (NAAs) using 1,3,5,7-tetramethyl-8-(N-hydroxysuccinimidyl butyric ester)difluoroboradiaza-S-indacene as the labeling reagent. After derivatization at room temperature for 30 min, the seven target NAAs including glycine, alanine, γ-aminobutyric acid, taurine, glutamine, glutamic acid, and aspartic acid were separated in running buffer, which consisted of 70 mM pH 4.00 H3 PO4 /Na3 PO4 buffer, 5.5 mM cetyltrimethyl ammonium bromide and 20% v/v acetonitrile within 17 min. The LODs were 2 ~ 14 × 10(-10) M without interference from other coexisting amino acids. The proposed method has been applied to the analysis of NAAs in the central nervous systems of healthy mice and those with Alzheimer's disease with recoveries of 92-104%.
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Aminoácidos/análise , Sistema Nervoso Central/química , Eletroforese Capilar/métodos , Neurotransmissores/análise , Espectrometria de Fluorescência/métodos , Animais , Eletroforese Capilar/instrumentação , Corantes Fluorescentes/química , Concentração de Íons de Hidrogênio , Camundongos , Espectrometria de Fluorescência/instrumentaçãoRESUMO
1,3,5,7-Tetramethyl-8-butyrethylenediamine-difluoroboradiaza-s-indacene (TMBB-EDAN) has been designed and synthesized as a highly fluorescent labeling reagent for carboxylic acids. By using TMBB-EDAN, a sensitive and rapid method based on high performance liquid chromatography-fluorescence detection for the determination of twelve fatty acids (FAs) in bio-samples has been developed. Under optimized conditions, these FAs were tagged with TMBB-EDAN in the presence of 1-ethyl-3-(3-dimethyla-minopropyl) carbodiamide at 20°C for 30min and then the baseline separation was achieved on a C18 column with a linear gradient elution in 26min. With fluorescence detection at λex/λem=490nm/510nm, the linear ranges of FAs were from 3.0 to 300nM and the detection limits with a signal-to-noise ratio of 3 were in the 0.2-0.4nM range. The proposed method offers advantages of milder derivatization condition and much better sensitivity for the determination of FAs, when compared to the reported fluorescence derivatization-based methods.
Assuntos
Compostos de Boro/química , Cromatografia Líquida de Alta Pressão/métodos , Ácidos Graxos/análise , Corantes Fluorescentes/química , Indenos/química , Animais , Ácidos Graxos/sangue , Ácidos Graxos/química , Humanos , Modelos Lineares , Fígado/química , Camundongos , Óleos de Plantas/química , Reprodutibilidade dos Testes , Espectrometria de Fluorescência/métodosRESUMO
The HIV-1 viral infectivity factor (Vif), one of the six accessory proteins, is essential for viral replication and pathogenesis. Its main function is to form Vif-Cullin5-ElonginBC complex and then is able to ubiquitinate and degrade the human anti-viral factor APOBEC3G, which markedly enhances the virus infectivity. Delete Vif leads to the loss of the infectivity of HIV-1; therefore, Vif is a potentially new attractive target for therapeutic intervention in AIDS. This review describes the structure, function and especially inhibitors of HIV-1 Vif.
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Fármacos Anti-HIV/farmacologia , HIV-1/efeitos dos fármacos , HIV-1/crescimento & desenvolvimento , Replicação Viral/efeitos dos fármacos , Produtos do Gene vif do Vírus da Imunodeficiência Humana/antagonistas & inibidores , Fármacos Anti-HIV/química , HIV-1/metabolismo , Humanos , Produtos do Gene vif do Vírus da Imunodeficiência Humana/metabolismoRESUMO
An ultrasensitive and selective high-performance liquid chromatographic method for the volatile signaling hormone, jasmonic acid, has been developed based on precolumn derivatization with 1,3,5,7-tetramethyl-8-aminozide-difluoroboradiaza-s-indacene (BODIPY-aminozide). The derivatization reaction was carried out at 60 °C for 30 min in the presence of phosphoric acid. The formed jasmonic acid derivative was eluted using a mobile phase of methanol/pH 6.50 ammonium formate buffer/tetrahydrofuran (67:30:3, v/v/v) in 10 min on a C(18) column and detected with fluorescence detection at excitation and emission wavelengths of 495 and 505 nm, respectively. The detection limit (signal-to-noise ratio = 4) reached 1.14 × 10(-10) M or 2.29 fmol per injection (20 µL), which is the lowest of the existing methods. The proposed method has been successfully applied to the direct determination of trace jasmonic acid in the crude extracts of soybean leaves from soybean mosaic virus-infected and normal plants with recoveries of 95-104%.
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Cromatografia Líquida de Alta Pressão/métodos , Ciclopentanos/análise , Glycine max/química , Oxilipinas/análise , Folhas de Planta/química , Compostos de Boro , Fluorescência , Corantes Fluorescentes , Vírus do Mosaico , Doenças das Plantas/virologia , Extratos Vegetais/química , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Glycine max/virologiaRESUMO
Six phytohormones including indole butyric acid (IBA), naphthalene acetic acid (NAA), 2,4-dichloro-phenoxy acetic acid (2,4-D), indole-3-acetic acid (IAA), abscisic acid (ABA), and salicylic acid (SA) in crude plant extractions have been quantitated by means of high-performance liquid chromatography (HPLC) with fluorescence detection based on the precolumn derivatization using 1,3,5,7-tetramethyl-8-aminozide-difluoroboradiaza-s-indacene (BODIPY-aminozide), a fluorescent reagent synthesized in our lab recently. The optimization of derivatization conditions was carefully studied by an L(25) (5(6)) orthogonal array design (OAD) with five factors at five levels that are important influence parameters in the improvement of derivatization efficiency. The separation conditions were also studied in detail. Under the optimal conditions, the detection limits (S/N=3) of the six phytohormones were found from 0.12 to 0.75 nM. The proposed method was the first investigation of aminozide for the analysis of phytohormones and has been successfully applied to the determination of phytohormones in plant samples such as cucumber and tomato with recoveries of 94-105%.
Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Corantes Fluorescentes/química , Extratos Vegetais/análise , Reguladores de Crescimento de Plantas/análise , Cromatografia Líquida de Alta Pressão/instrumentação , Cucumis sativus/química , Corantes Fluorescentes/síntese química , Solanum lycopersicum/químicaRESUMO
A BODIPY-based fluorescent derivatization reagent with a hydrazine moiety, 1,3,5,7-tetramethyl-8-aminozide-difluoroboradiaza-s-indacene (BODIPY-aminozide), has been designed for aldehyde labeling. An increased fluorescence quantum yield was observed from 0.38 to 0.94 in acetonitrile when it reacted with aldehydes. Twelve aliphatic aldehydes from formaldehyde to lauraldehyde were used to evaluate the analytical potential of this reagent by high performance liquid chromatography (HPLC) on C(18) column with fluorescence detection. The derivatization reaction of BODIPY-aminozide with aldehydes proceeded at 60 degrees C for 30min to form stable corresponding BODIPY hydrazone derivatives in the presence of phosphoric acid as a catalyst. The maximum excitation (495nm) and emission (505nm) wavelengths were almost the same for all the aldehyde derivatives. A baseline separation of all the 12 aliphatic aldehydes (except formaldehyde and acetaldehyde) is achieved in 20min with acetonitrile-tetrahydrofuran (THF)-water as mobile phase. The detection limits were obtained in the range from 0.43 to 0.69nM (signal-to-noise=3), which are better than or comparable with those obtained by the existing methods based on aldehyde labeling. This reagent has been applied to the precolumn derivatization followed with HPLC determination of trace aliphatic aldehydes in human serum samples without complex pretreatment or enrichment method.