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1.
Phytother Res ; 38(3): 1695-1714, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38318763

RESUMO

Withania somnifera, the plant named Indian ginseng, Ashwagandha, or winter cherry, has been used since ancient times to cure various health ailments. Withania somnifera is rich in constituents belonging to chemical classes like alkaloids, saponins, flavonoids, phenolic acids, and withanolides. Several chemotypes were identified based on their phytochemical composition and credited for their multiple bioactivities. Besides, exhibiting neuroprotective, immunomodulatory, adaptogenic, anti-stress, bone health, plant has shown promising anti-cancer properties. Several withanolides have been reported to play a crucial role in cancer; they target cancer cells by different mechanisms such as modulating the expression of tumor suppressor genes, apoptosis, telomerase expression, and regulating cell signaling pathway. Though, many treatments are available for cancer; however, to date, no assured reliable cure for cancer is made available. Additionally, synthetic drugs may lead to development of resistance in time; therefore, focus on new and natural drugs for cancer therapeutics may prove a longtime effective alternative. This current report is a comprehensive combined analysis upto 2023 with articles focused on bio-activities of plant Withania somnifera from various sources, including national and international government sources. This review focuses on understanding of various mechanisms and pathways to inhibit uncontrolled cell growth by W. somnifera bioactives, as reported in literature. This review provides a recent updated status of the W. somnifera on pharmacological properties in general and anti-cancer in particular and may provide a guiding resource for researchers associated with natural product-based cancer research and healthcare management.


Assuntos
Withania , Vitanolídeos , Vitanolídeos/farmacologia , Withania/química , Extratos Vegetais/farmacologia , Compostos Fitoquímicos
2.
J Biomed Inform ; 151: 104602, 2024 03.
Artigo em Inglês | MEDLINE | ID: mdl-38346530

RESUMO

OBJECTIVE: An applied problem facing all areas of data science is harmonizing data sources. Joining data from multiple origins with unmapped and only partially overlapping features is a prerequisite to developing and testing robust, generalizable algorithms, especially in healthcare. This integrating is usually resolved using meta-data such as feature names, which may be unavailable or ambiguous. Our goal is to design methods that create a mapping between structured tabular datasets derived from electronic health records independent of meta-data. METHODS: We evaluate methods in the challenging case of numeric features without reliable and distinctive univariate summaries, such as nearly Gaussian and binary features. We assume that a small set of features are a priori mapped between two datasets, which share unknown identical features and possibly many unrelated features. Inter-feature relationships are the main source of identification which we expect. We compare the performance of contrastive learning methods for feature representations, novel partial auto-encoders, mutual-information graph optimizers, and simple statistical baselines on simulated data, public datasets, the MIMIC-III medical-record changeover, and perioperative records from before and after a medical-record system change. Performance was evaluated using both mapping of identical features and reconstruction accuracy of examples in the format of the other dataset. RESULTS: Contrastive learning-based methods overall performed the best, often substantially beating the literature baseline in matching and reconstruction, especially in the more challenging real data experiments. Partial auto-encoder methods showed on-par matching with contrastive methods in all synthetic and some real datasets, along with good reconstruction. However, the statistical method we created performed reasonably well in many cases, with much less dependence on hyperparameter tuning. When validating feature match output in the EHR dataset we found that some mistakes were actually a surrogate or related feature as reviewed by two subject matter experts. CONCLUSION: In simulation studies and real-world examples, we find that inter-feature relationships are effective at identifying matching or closely related features across tabular datasets when meta-data is not available. Decoder architectures are also reasonably effective at imputing features without an exact match.


Assuntos
Algoritmos , Registros Eletrônicos de Saúde , Simulação por Computador , Ciência de Dados , Motivação
3.
Plant Physiol Biochem ; 208: 108419, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38377888

RESUMO

Withania somnifera (Ashwagandha), is one of the most reputed Indian medicinal plants, having immense pharmacological activities due to the occurrence of withanolides. The withanolides are biosynthesized through triterpenoid biosynthetic pathway with the involvement of WsCAS leading to cyclization of 2, 3 oxidosqualene, which is a key metabolite to further diversify to a myriad of phytochemicals. In contrast to the available reports on the studies of WsCAS in withanolide biosynthesis, its involvement in phytosterol biosynthesis needs investigation. Present work deals with the understanding of role of WsCAS triterpenoid synthase gene in the regulation of biosynthesis of phytosterols & withanolides. Docking studies of WsCAS protein revealed Conserved amino acids, DCATE motif, and QW motif which are involved in efficient substrate binding, structure stabilization, and catalytic activity. Overexpression/silencing of WsCAS leading to increment/decline of phytosterols confers its stringent regulation in phytosterols biosynthesis. Differential regulation of WsCAS on the metabolic flux towards phytosterols and withanolide biosynthesis was observed under abiotic stress conditions. The preferential channelization of 2, 3 oxidosqualene towards withanolides and/or phytosterols occurred under heat/salt stress and cold/water stress, respectively. Stigmasterol and ß-sitosterol showed major contribution in high/low temperature and salt stress, and campesterol in water stress management. Overexpression of WsCAS in Arabidopsis thaliana led to the increment in phytosterols in general. Thus, the WsCAS plays important regulatory role in the biosynthetic pathway of phytosterols and withanolides under abiotic stress conditions.


Assuntos
Fitosteróis , Esqualeno/análogos & derivados , Triterpenos , Withania , Vitanolídeos , Vitanolídeos/metabolismo , Esteróis , Withania/genética , Withania/metabolismo , Triterpenos/metabolismo , Desidratação , Fitosteróis/metabolismo , Estresse Fisiológico/genética
4.
Res Sq ; 2023 Nov 28.
Artigo em Inglês | MEDLINE | ID: mdl-38077013

RESUMO

Background: Post-operative complications present a challenge to the healthcare system due to the high unpredictability of their incidence. However, the socioeconomic factors that relate to postoperative complications are still unclear as they can be heterogeneous based on communities, types of surgical services, and sex and gender. Methods: In this study, we conducted a large population cross-sectional analysis of social vulnerability and the odds of various post-surgical complications. We built statistical logistic regression models of postsurgical complications with social vulnerability index as the independent variable along with sex interaction. Results: We found that social vulnerability was associated with abnormal heart rhythm with socioeconomic status and housing status being the main association factors. We also found associations of the interaction of social vulnerability and female sex with an increase in odds of heart attack and surgical wound infection. Conclusions: Our results indicate that social vulnerability measures such as socioeconomic status and housing conditions could be related to health outcomes. This suggests that the domain of preventive medicine should place social vulnerability as a priority to achieve its goals.

5.
Bioinformation ; 19(12): 1197-1211, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38250539

RESUMO

The functional significance and evolutionary relationships of BURP domain-containing genes unique to plants is of interest. Network analysis reveals different associations of BURP proteins with other proteins and functional terms, throwing light on their involvement in various biological processes and pathways. The gene expression data reveals that BURP genes are affected by salinity stress, reflecting diverse expression patterns in roots and shoots.

6.
Planta ; 256(1): 4, 2022 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-35648276

RESUMO

MAIN CONCLUSION: Overexpression of a novel geranylgeranyl pyrophosphate synthase gene (WsGGPPS) in planta resulted in increased levels of gibberellic acid and decrease in withanolide content. Withania somnifera (L.) Dunal, the herb from family Solanaceae is one of the most treasured medicinal plant used in traditional medicinal systems owing to its unique stockpile of pharmaceutically active secondary metabolites. Phytochemical and pharmacological studies in this plant were well established, but the genes affecting the regulation of biosynthesis of major metabolites were not well elucidated. In this study cloning and functional characterization of a key enzyme in terpenoid biosynthetic pathway viz. geranylgeranyl pyrophosphate synthase (EC 2.5.1.29) gene from Withania somnifera was performed. The full length WsGGPPS gene contained 1,104 base pairs that encode a polypeptide of 365 amino acids. The quantitative expression analysis suggested that WsGGPPS transcripts were expressed maximally in flower tissues followed by berry tissues. The expression levels of WsGGPPS were found to be regulated by methyl jasmonate (MeJA) and salicylic acid (SA). Amino acid sequence alignment and phylogenetic studies suggested that WsGGPPS had close similarities with GGPPS of Solanum tuberosum and Solanum pennellii. The structural analysis provided basic information about three dimensional features and physicochemical parameters of WsGGPPS protein. Overexpression of WsGGPPS in planta for its functional characterization suggested that the WsGGPPS was involved in gibberellic acid biosynthesis.


Assuntos
Withania , Vitanolídeos , Clonagem Molecular , Regulação da Expressão Gênica de Plantas , Geranil-Geranildifosfato Geranil-Geraniltransferase/metabolismo , Giberelinas , Filogenia , Withania/genética , Vitanolídeos/metabolismo
7.
Theor Appl Genet ; 134(5): 1463-1474, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33554270

RESUMO

KEY MESSAGE: Analysis of autophagy-related genes in tomato shows the involvement of SlATG18f in leaf curl disease tolerance and a CAPS marker developed from this gene demonstrates its usefulness in marker-assisted selection. Autophagy is a highly conserved catabolic process regulating cellular homeostasis and adaptation to different biotic and abiotic stress. Several autophagy-related proteins (ATGs) are reported to be involved in autophagic processes, and considering their importance in regulating growth and stress adaptation, these proteins have been identified and characterized in several plant species. However, there is no information available on the role of autophagy-related proteins regulating the tolerance of tomato to tomato leaf curl disease (ToLCD). Given this, the present genome-wide study identified thirty ATG-encoding genes (SlATG) in tomato, followed by their functional characterization. Expression profiling of the SlATG genes in contrasting tomato cultivars subjected to virus infection showed a 4.5-fold upregulation of SlATG18f in the tolerant cultivar. Further, virus-induced gene silencing of SlATG18f in the tolerant cultivar conferred disease susceptibility, which suggested the role of this gene in Tomato leaf curl New Delhi virus tolerance. Comparison of the gene sequence of both tolerant and susceptible cultivars along with the 5' upstream regions identified an SNP (A/T) at -2916 upstream of the start codon. A cleaved amplified polymorphic sequence (CAPS) marker was developed targeting this region, which showed a significant association with the tolerance characteristics in the tomato germplasm (R2 = 0.1787). Altogether, the study identified a potential gene that could be used to develop ToLCNDV tolerant tomato cultivars using transgene-based or marker-assisted breeding-based approaches.


Assuntos
Begomovirus/fisiologia , Resistência à Doença/genética , Marcadores Genéticos , Genoma de Planta , Doenças das Plantas/genética , Proteínas de Plantas/genética , Solanum lycopersicum/genética , Resistência à Doença/imunologia , Regulação da Expressão Gênica de Plantas , Estudo de Associação Genômica Ampla , Solanum lycopersicum/crescimento & desenvolvimento , Solanum lycopersicum/virologia , Melhoramento Vegetal , Doenças das Plantas/virologia , Proteínas de Plantas/metabolismo , Polimorfismo de Nucleotídeo Único
9.
Sci Rep ; 10(1): 4877, 2020 03 17.
Artigo em Inglês | MEDLINE | ID: mdl-32184405

RESUMO

Withania somnifera owing to its strong and remarkable stress tolerance property is a reliable candidate for the determination of genes involved in mechanism of adaption/tolerance of various stress conditions. 187 AP2/ERF gene related transcripts (GRTs) were identified during comprehensive search in W. somnifera transcriptome repertoire. Major hits in homology search were observed from the model plant Arabidopsis and members of Solanaceae family. Cloning, expression analysis of the gene and genetic transient transformation with the gene (WsAP2) were performed to predict its functional role in planta. Enhanced expression of some of the pathway genes for terpenoid biosynthesis was observed in transformed tissues in comparison to the control tissues. It is speculated that WsAP2 gene crucially regulates the expression of GGPPS gene in addition to the regulation of other important genes of terpenoid pathway via induction of expression of other genes such as HMGR, CAS, DXS and DXR. To the best of our knowledge, this is the first report representing detailed study of AP2/ERF gene family in W. somnifera. It is also suggested from the study that gene might have role in eliciting responses to combat stress and attribute the strong stress tolerant property associated with the plant.


Assuntos
Mineração de Dados/métodos , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Withania/metabolismo , Vias Biossintéticas , Clonagem Molecular , Simulação por Computador , Regulação da Expressão Gênica de Plantas , Família Multigênica , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Análise de Sequência de RNA , Terpenos/metabolismo , Distribuição Tecidual , Withania/genética
10.
Physiol Plant ; 168(1): 148-173, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30767228

RESUMO

Withania somnifera (Ashwagandha) is considered as Rasayana in Indian systems of medicine. This study reports a novel transcriptome of W. somnifera berries, with high depth, quality and coverage. Assembled and annotated transcripts for nearly all genes related with the withanolide biosynthetic pathway were obtained. Tissue-wide gene expression analysis reflected almost similar definitions for the terpenoid pathway in leaf, root and berry tissues with relatively higher abundance of transcripts linked to steroid, phenylpropanoid metabolism as well as flavonoid metabolism in berries. The metabolome map generated from the data embodied transcripts from 143 metabolic pathways connected together and mediated collectively by about 1792 unique enzyme functions specific to berry, leaf and root tissues, respectively. Transcripts specific to cytochrome p450 (CYP450), methyltransferases and glycosyltransferases were distinctively located in a tissue specific manner and exhibited a complex network. Significant distribution of transcription factor genes such as MYB, early light inducible protein (ELI), minichromosome maintenance1, agamous, deficiens and serum response factor (MADS) and WRKY etc. was observed, as the major transcriptional regulators of secondary metabolism. Validation of the assembly was ascertained by cloning WsELI, which has a light dependent regulatory role in development. Quantitative expression of WsELI was observed to be considerably modulated upon exposure to abiotic stress and elicitors. Co-relation of over-expression of WsELI, may provide new aspects for the functional role of ELI proteins in plants linked to secondary metabolism. The study offers the first comprehensive and comparative evaluation of W. somnifera transcriptome data between the three tissues and across other members of Solanaceae (Nicotiana, Solanum and Capsicum) with respect to major pathways and their metabolome regulation.


Assuntos
Frutas/metabolismo , Metabolismo Secundário , Transcriptoma , Withania/metabolismo , Vitanolídeos/metabolismo , Frutas/genética , Genes de Plantas , Withania/genética
11.
Sci Rep ; 7(1): 16649, 2017 11 30.
Artigo em Inglês | MEDLINE | ID: mdl-29192149

RESUMO

Transcription factors (TFs) are important regulators of cellular and metabolic functions including secondary metabolism. Deep and intensive RNA-seq analysis of Withania somnifera using transcriptomic databases provided 3532 annotated transcripts of transcription factors in leaf and root tissues, belonging to 90 different families with major abundance for WD-repeat (174 and 165 transcripts) and WRKY (93 and 80 transcripts) in root and leaf tissues respectively, followed by that of MYB, BHLH and AP2-ERF. Their detailed comparative analysis with Arabidopsis thaliana, Capsicum annum, Nicotiana tabacum and Solanum lycopersicum counterparts together gave interesting patterns. However, no homologs for WsWDR representatives, LWD1 and WUSCHEL, were observed in other Solanaceae species. The data extracted from the sequence read archives (SRA) in public domain databases were subjected to re-annotation, re-mining, re-analysis and validation for dominant occurrence of WRKY and WD-repeat (WDR) gene families. Expression of recombinant LWD1 and WUSCHEL proteins in homologous system led to enhancements in withanolide content indicating their regulatory role in planta in the biosynthesis. Contrasting expression profiles of WsLWD1 and WsWUSCHEL provided tissue-specific insights for their participation in the regulation of developmental processes. The in-depth analysis provided first full-spectrum and comparative characteristics of TF-transcripts across plant species, in the perspective of integrated tissue-specific regulation of metabolic processes including specialized metabolism.


Assuntos
Perfilação da Expressão Gênica , Fatores de Transcrição/genética , Transcriptoma , Withania/genética , Withania/metabolismo , Vitanolídeos/metabolismo , Cromatografia Líquida de Alta Pressão , Regulação da Expressão Gênica de Plantas , Genes de Plantas , Metaboloma , Metabolômica/métodos , Filogenia , Fatores de Transcrição/metabolismo , Withania/classificação
12.
Protoplasma ; 254(1): 181-192, 2017 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26795344

RESUMO

Tryptophan decarboxylase (EC 4.1.1.28) catalyzes pyridoxal 5'-phosphate (PLP)-dependent decarboxylation of tryptophan to produce tryptamine for recruitment in a myriad of biosynthetic pathways of metabolites possessing indolyl moiety. A recent report of certain indolyl metabolites in Withania species calls for a possible predominant functional role of tryptophan decarboxylase (TDC) in the genome of Withania species to facilitate production of the indolyl progenitor molecule, tryptamine. Therefore, with this metabolic prospection, we have identified and cloned a full-length cDNA sequence of TDC from aerial tissues of Withania coagulans. The functional WcTDC gene comprises of 1506 bp open reading frame (ORF) encoding a 502 amino acid protein with calculated molecular mass and pI value of 56.38 kDa and 8.35, respectively. The gene was expressed in Escherichia coli, and the recombinant enzyme was affinity-purified to homogeneity to discern its kinetics of catalysis. The enzyme (WcTDC) exhibited much higher Km value for tryptophan than for pyridoxal 5'-phosphate and was dedicated to catalyze decarboxylation of only tryptophan or, to a limited extent, of its analogue (like 5-hydroxy tryptophan). The observed optimal catalytic functionality of the enzyme on the slightly basic side of the pH scale and at slightly higher temperatures reflected adaptability of the plant to hot and arid regions, the predominant natural habitat of the herb. This pertains to be the first report on cloning and characterization of heterologously expressed recombinant enzyme from W. coagulans and forms a starting point to further understanding of withanamide biosynthesis.


Assuntos
Descarboxilases de Aminoácido-L-Aromático/genética , Expressão Gênica , Proteínas Recombinantes/metabolismo , Withania/enzimologia , Withania/genética , Descarboxilases de Aminoácido-L-Aromático/metabolismo , Sequência de Bases , Biocatálise/efeitos dos fármacos , Clonagem Molecular , Biologia Computacional , Estabilidade Enzimática/efeitos dos fármacos , Concentração de Íons de Hidrogênio , Isopropiltiogalactosídeo/farmacologia , Cinética , Modelos Moleculares , Filogenia , Brotos de Planta/efeitos dos fármacos , Brotos de Planta/crescimento & desenvolvimento , Homologia Estrutural de Proteína , Especificidade por Substrato/efeitos dos fármacos , Temperatura , Withania/efeitos dos fármacos
13.
Protoplasma ; 252(6): 1421-37, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25687294

RESUMO

Cytochrome P450s (CYPs) catalyse a wide variety of oxygenation/hydroxylation reactions that facilitate diverse metabolic functions in plants. Specific CYP families are essential for the biosynthesis of species-specialized metabolites. Therefore, we investigated the role of different CYPs related to secondary metabolism in Withania somnifera, a medicinally important plant of the Indian subcontinent. In this study, complete complementary DNAs (cDNAs) of four different CYP genes were isolated and christened as WSCYP93Id, WSCYP93Sm, WSCYP734B and WSCYP734R. These cDNAs encoded polypeptides comprising of 498, 496, 522 and 550 amino acid residues with their deduced molecular mass of 56.7, 56.9, 59.4 and 62.2 kDa, respectively. Phylogenetic study and molecular modelling analysis of the four cloned WSCYPs revealed their categorization into two CYP families (CYP83B1 and CYP734A1) belonging to CYP71 and CYP72 clans, respectively. BLASTp searches showed similarity of 75 and 56 %, respectively, between the two CYP members of CYP83B1 and CYP734A1 with major variances exhibited in their N-terminal regions. The two pairs of homologues exhibited differential expression profiles in the leaf tissues of selected chemotypes of W. somnifera as well as in response to treatments such as methyl jasmonate, wounding, light and auxin. Light and auxin regulated two pairs of WSCYP homologues in a developing seedling in an interesting differential manner. Their lesser resemblance and homology with other CYP sequences suggested these genes to be more specialized and distinct ones. The results on chemotype-specific expression patterns of the four genes strongly suggested their key/specialized involvement of the CYPs in the biosynthesis of chemotype-specific metabolites, though their further biochemical characterization would reveal the specificity in more detail. It is revealed that WSCYP93Id and WSCYP93Sm may be broadly involved in the oxygenation reactions in the plant and, thereby, control various pathways involving such metabolic reactions in the plant. As a representative experimental validation of this notion, WSCYP93Id was heterologouly expressed in Escherichia coli and catalytic capabilities of the recombinant WSCYP93Id protein were evaluated using withanolides as substrates. Optimized assays with some major withanolides (withanone, withaferin A and withanolide A) involving spectrophotometric as well as high-pressure liquid chromatography (HPLC)-based evaluation (product detection) of the reactions showed conversion of withaferin A to a hydroxylated product. The genes belonging to other CYP group are possibly involved in some specialised synthesis such as that of brassinosteroids.


Assuntos
Clonagem Molecular , Sistema Enzimático do Citocromo P-450/metabolismo , Ácidos Indolacéticos/farmacologia , Luz , Modelos Moleculares , Proteínas de Plantas/metabolismo , Withania/enzimologia , Biotransformação , Biologia Computacional , Sistema Enzimático do Citocromo P-450/química , Sistema Enzimático do Citocromo P-450/genética , Bases de Dados Genéticas , Regulação Enzimológica da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Hidroxilação , Isoenzimas , Filogenia , Proteínas de Plantas/genética , Plantas Medicinais , Conformação Proteica , Proteínas Recombinantes/metabolismo , Análise de Sequência de DNA , Análise de Sequência de Proteína , Homologia de Sequência de Aminoácidos , Homologia de Sequência do Ácido Nucleico , Relação Estrutura-Atividade , Especificidade por Substrato , Withania/efeitos dos fármacos , Withania/genética , Withania/efeitos da radiação , Vitanolídeos/metabolismo
14.
Gene ; 525(1): 58-76, 2013 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-23644021

RESUMO

Centella asiatica (L.) Urban is an important medicinal plant and has been used since ancient times in traditional systems of medicine. C. asiatica mainly contains ursane skeleton based triterpenoid sapogenins and saponins predominantly in its leaves. This investigation employed Illumina next generation sequencing (NGS) strategy on a pool of three cDNAs from expanding leaf of C. asiatica and developed an assembled transcriptome sequence resource of the plant. The short transcript reads (STRs) generated and assembled into contigs and singletons, representing majority of the genes expressed in C. asiatica, were termed as 'tentative unique transcripts' (TUTs). The TUT dataset was analyzed with the objectives of (i) development of a transcriptome assembly of C. asiatica, and (ii) classification/characterization of the genes into categories like structural, functional, regulatory etc. based on their function. Overall, 68.49% of the 46,171,131 reads generated in the NGS process could be assembled into a total of 79,041 contigs. Gene ontology and functional annotation of sequences resulted into the identification of genes related to different sets of cellular functions including identification of genes related to primary and secondary metabolism. The wet lab validation of seventeen assembled gene sequences identified to be involved in secondary metabolic pathways and control of reactive oxygen species (ROS) was established by semi-quantitative and real time PCR (qRT-PCR). The validation also included sequencing/size matching of a set of semi-quantitative PCR amplicons with their in silico assembled contig/gene. This confirmed the appropriateness of assembling the reads and contigs. Thus, the present study constitutes the largest report to date on C. asiatica transcriptome based gene resource that may contribute substantially to the understanding of the basal biological functions and biochemical pathways of secondary metabolites as well as the transcriptional regulatory elements and genetic markers. This work sets the stage for multi-faceted future improvement of the plant, through discovery of new genes, marker-assisted breeding or genetic engineering, on this species as well as for other species of Apiaceae and triterpene producing medicinal plants.


Assuntos
Centella/genética , Genes de Plantas , Elementos Reguladores de Transcrição , Centella/metabolismo , DNA Complementar/genética , Deleção de Genes , Marcadores Genéticos/genética , Repetições de Microssatélites , Mutagênese Insercional , Folhas de Planta/genética , Folhas de Planta/metabolismo , Polimorfismo de Nucleotídeo Único , Estrutura Terciária de Proteína/genética , Espécies Reativas de Oxigênio/metabolismo , Análise de Sequência de DNA/métodos , Terpenos/metabolismo , Transcriptoma
15.
Gene ; 516(2): 238-47, 2013 Mar 10.
Artigo em Inglês | MEDLINE | ID: mdl-23266822

RESUMO

Tropinone reductases (TRs) are small proteins belonging to the SDR (short chain dehydrogenase/reductase) family of enzymes. TR-I and TR-II catalyze the conversion of tropinone into tropane alcohols (tropine and pseudotropine, respectively). The steps are intermediary enroute to biosynthesis of tropane esters of medicinal importance, hyoscyamine/scopolamine, and calystegins, respectively. Biosynthesis of tropane alkaloids has been proposed to occur in roots. However, in the present report, a tropine forming tropinone reductase (TR-I) cDNA was isolated from the aerial tissue (leaf) of a medicinal plant, Withania coagulans. The ORF was deduced to encode a polypeptide of 29.34 kDa. The complete cDNA (WcTRI) was expressed in E. coli and the recombinant His-tagged protein was purified for functional characterization. The enzyme had a narrow pH range of substantial activity with maxima at 6.6. Relatively superior thermostability of the enzyme (30% retention of activity at 60 °C) was catalytic novelty in consonance with the desert area restricted habitat of the plant. The in vitro reaction kinetics predominantly favoured the forward reaction. The enzyme had wide substrate specificity but did not cover the substrates of other well-known plant SDR related to menthol metabolism. To our knowledge, this pertains to be the first report on any gene and enzyme of secondary metabolism from the commercially and medicinally important vegetable rennet species.


Assuntos
Oxirredutases do Álcool/genética , Oxirredutases do Álcool/metabolismo , Tropanos/metabolismo , Withania/enzimologia , Withania/genética , Oxirredutases do Álcool/química , Oxirredutases do Álcool/isolamento & purificação , Sequência de Aminoácidos , Catálise , Clonagem Molecular , Concentração de Íons de Hidrogênio , Modelos Biológicos , Modelos Moleculares , Dados de Sequência Molecular , Filogenia , Folhas de Planta/química , Folhas de Planta/enzimologia , Folhas de Planta/genética , Folhas de Planta/metabolismo , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/isolamento & purificação , Proteínas Recombinantes/metabolismo , Homologia de Sequência de Aminoácidos , Especificidade por Substrato , Temperatura , Withania/química , Withania/metabolismo
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