Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 23
Filtrar
Mais filtros

Base de dados
Tipo de documento
Intervalo de ano de publicação
1.
J Food Sci Technol ; 60(1): 252-261, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36349282

RESUMO

Acute lung injury (ALI), is a severe inflammatory lung disease. We tested the prophylactic effect of a functional food mix comprising three anti-inflammatory plant products: turmeric, amla, and black pepper (TAB) against lipopolysaccharide (LPS)-induced ALI in rats. Two-month-old male Wistar rats were randomly divided into three groups: control (C), LPS (5 mg/kg), and LPS with TAB (TAB). After 6 h of LPS injection, the rats were sacrificed by cervical decapitation to collect the lung tissue. Results showed that TAB partially ameliorated LPS-induced increase in circulating inflammatory cytokines (TNFα and IL6) and significantly prevented lung histopathological changes. TAB also suppressed LPS-activated ER stress markers (GRP78, pIRE1, and CHOP) and apoptotic markers (caspase-3 and - 12) in the lung. The anti-inflammatory effects of the TAB support its potential use as an adjuvant to mitigate ALI. Importantly, TAB's ingredients have been used for centuries as part of the diet with limited or no toxic effects.

2.
Curr Genomics ; 22(2): 137-152, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34220300

RESUMO

BACKGROUND: Sorghum, the C4 dry-land cereal, important for food, fodder, feed and fuel, is a model crop for abiotic stress tolerance with smaller genome size, genetic diversity, and bio-energy traits. The heat shock proteins/chaperonin 60s (HSP60/Cpn60s) assist the plastid proteins, and participate in the folding and aggregation of proteins. However, the functions of HSP60s in abiotic stress tolerance in Sorghum remain unclear. METHODS: Genome-wide screening and in silico characterization of SbHSP60s were carried out along with tissue and stress-specific expression analysis. RESULTS: A total of 36 HSP60 genes were identified in Sorghum bicolor. They were subdivided into 2 groups, the HSP60 and HSP10 co-chaperonins encoded by 30 and 6 genes, respectively. The genes are distributed on all the chromosomes, chromosome 1 being the hot spot with 9 genes. All the HSP60s were found hydrophilic and highly unstable. The HSP60 genes showed a large number of introns, the majority of them with more than 10. Among the 12 paralogs, only 1 was tandem and the remaining 11 segmental, indicating their role in the expansion of SbHSP60s. Majority of the SbHSP60 genes expressed uniformly in leaf while a moderate expression was observed in the root tissues, with the highest expression displayed by SbHSP60-1. From expression analysis, SbHSP60-3 for drought, SbHSP60-9 for salt, SbHSP60-9 and 24 for heat and SbHSP60-3, 9 and SbHSP10-2 have been found implicated for cold stress tolerance and appeared as the key regulatory genes. CONCLUSION: This work paves the way for the utilization of chaperonin family genes for achieving abiotic stress tolerance in plants.

3.
Mol Biol Rep ; 47(10): 7379-7390, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32880065

RESUMO

The DnaJ/Hsp40s, are important components in the chaperone machine, and play pivotal roles in plant growth, development and stress tolerance. Sorghum, the semi-arid crop, is the drought resilient, model C4 crop. However, no reports of DnaJs have been available. Genome-wide analysis of Sorghum bicolor revealed 113 DnaJ/Hsp40 genes, classified into four groups; 8 genes in SbDnaJ-A class, 10 in SbDnaJ-B, 82 in SbDnaJ-C and 13 in SbDnaJ-D distributed unevenly on all the 10 chromosomes. Chromosomes 1 and 3 were found hot spots with 22 and 20 genes respectively. All genes displayed large number of introns, with an exception of 11 of the SbDnaJ-C which is devoid of introns. Out of 36 paralogous duplications, 7 tandem and 29 segmental duplications were noticed, indicating the major role of segmental duplications in the expansion. Analysis of digital data revealed tissue and stage-specific expressions. Transcriptional profiling of 12 selected genes representing all 4 classes revealed highly significant expression in leaf followed by root tissues. No expression was noticed in stems with an exception of SbDnaJ-C76. The SbDnaJ-A1, D1, and C subgroup genes displayed upregulation in roots, stems and leaves under cold, inferring the involvement of Hsp40s for cellular protection during cold stress. The results demonstrate that C76 and D1 are the candidate genes associated with multiple abiotic stresses. Present research furnishes valuable information about the role of sorghum DnaJs in abiotic stress response and establishes a foundation for understanding the molecular mechanisms associated with plant development and stress tolerance.


Assuntos
Regulação Viral da Expressão Gênica , Proteínas de Choque Térmico HSP40 , Proteínas de Choque Térmico HSP70 , Família Multigênica , Proteínas de Plantas , Sorghum , Estudo de Associação Genômica Ampla , Proteínas de Choque Térmico HSP40/biossíntese , Proteínas de Choque Térmico HSP40/genética , Proteínas de Choque Térmico HSP70/biossíntese , Proteínas de Choque Térmico HSP70/genética , Proteínas de Plantas/biossíntese , Proteínas de Plantas/genética , Sorghum/genética , Sorghum/metabolismo
4.
Curr Genomics ; 16(4): 279-91, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-27006630

RESUMO

A genome-wide scanning of Sorghum bicolor resulted in the identification of 25 SbHsf genes. Phylogenetic analysis shows the ortholog genes that are clustered with only rice, representing a common ancestor. Promoter analysis revealed the identification of different cis-acting elements that are responsible for abiotic as well as biotic stresses. Hsf domains like DBD, NLS, NES, and AHA have been analyzed for their sequence similarity and functional characterization. Tissue specific expression patterns of Hsfs in different tissues like mature embryo, seedling, root, and panicle were studied using real-time PCR. While Hsfs4 and 22 are highly expressed in panicle, 4 and 9 are expressed in seedlings. Sorghum plants were exposed to different abiotic stress treatments but no expression of any Hsf was observed when seedlings were treated with ABA. High level expression of Hsf1 was noticed during high temperature as well as cold stresses, 4 and 6 during salt and 5, 6, 10, 13, 19, 23 and 25 during drought stress. This comprehensive analysis of SbHsf genes will provide an insight on how these genes are regulated in different tissues and also under different abiotic stresses and help to determine the functions of Hsfs during drought and temperature stress tolerance.

5.
Indian J Crit Care Med ; 19(11): 690-2, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26730125

RESUMO

Cerebrospinal fluid (CSF) diversion procedure has been used for long to treat hydrocephalus in children. The principle of shunting is to establish a communication between the CSF and a drainage cavity (peritoneum, right atrium, and pleura). Ventriculoperitoneal shunt is used most commonly, followed secondly by ventriculopleural shunt (VPLS). Hydrothorax due to excessive CSF accumulation is a rare complication following both the type of shunts and is more frequently seen with VPLS. We report a case of a 6-year-old female child presenting with massive CSF hydrothorax with respiratory failure following VPLS. The aim of the article is to highlight early recognition of this rare and life-threatening condition, which could easily be missed if proper history is not available.

6.
Rejuvenation Res ; 2024 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-39162821

RESUMO

Aging-related muscle atrophy/sarcopenia is the most common type of muscle impairment that affects the quality of life. In the current study, we examined the effect of a functional food mixture of amla, turmeric, black pepper, cinnamon, and ginger on D-galactose-induced muscle alterations in rats. Wistar rats were randomly divided into three groups: Control (C), D-galactose (G), and D-galactose + functional food mixture intervention (G + I). Rats in group-G and -G + I were injected with D-galactose (300 mg/kg/day) for 90 days. After 3 months of the experimental period, the rats were sacrificed to collect gastrocnemius muscle. Group-G rats showed elevated levels of inflammatory cytokines (TNFα and NF-kB), atrogenes (atrogin-1 and MuRF1), decreased insulin/IGF1 signaling (decreased AKT phosphorylation), altered mitochondrial dynamics (increased fission and decreased fusion proteins), increased apoptotic mediators (Bax/Bcl-2, and caspase-3), and decreased muscle cell cross-sectional area when compared with group-C (p < 0.05). Interestingly, supplementation with the functional food mixture prevented galactose-induced alterations in the muscle. The observed anti-inflammatory, insulin-sensitizing, mitochondria-protective, and antiapoptotic effects of the functional food could be the underlying mechanisms in displaying positive effects against galactose-induced muscle atrophy and, hence, may be useful for the prevention of age-related muscle disorders.

7.
Bioorg Med Chem Lett ; 22(13): 4314-7, 2012 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-22668451

RESUMO

A new class of hybrid chalcones (17a-l &18a-l) was synthesized by Claisen-Schmidt condensation. All compounds were characterized by (1)H NMR, IR and mass spectral analysis and tested for their cytotoxic activity against PC-3 (prostate cancer), HT-29 (colon cancer), B-16 (mouse macrophages) and NCI-H460 (lung cancer) cell lines. Three compounds 18i, 18j and 18l (IC(50)=8.4, 7.9 & 5.9 µM) showed significant activity against PC-3 cell line.


Assuntos
Antineoplásicos/síntese química , Chalcona/análogos & derivados , Animais , Antineoplásicos/uso terapêutico , Antineoplásicos/toxicidade , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral , Chalcona/uso terapêutico , Chalcona/toxicidade , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Masculino , Camundongos , Neoplasias da Próstata/tratamento farmacológico , Relação Estrutura-Atividade
8.
Br J Cancer ; 105(9): 1313-21, 2011 Oct 25.
Artigo em Inglês | MEDLINE | ID: mdl-21952626

RESUMO

BACKGROUND: Phosphatase and tensin homologue deleted on chromosome 10 (PTEN) regulation of the Rho-like GTPase Cdc42 has a central role in epithelial polarised growth, but effects of this molecular network on apoptosis remain unclear. METHODS: To investigate the role of Cdc42 in PTEN-dependent cell death, we used flow cytometry, in vitro pull-down assays, poly(ADP ribose) polymerase (PARP) cleavage and other immunoblots in isogenic PTEN-expressing and -deficient colorectal cells (HCT116PTEN(+/+), HCT116PTEN(-/-), Caco2 and Caco2 ShPTEN cells) after transfection or treatment strategies. RESULTS: The PTEN knockout or suppression by short hairpin RNA or small interfering RNA (siRNA) inhibited Cdc42 activity, PARP cleavage and/or apoptosis in flow cytometry assays. Transfection of cells with wild-type or constitutively active Cdc42 enhanced PARP cleavage, whereas siRNA silencing of Cdc42 inhibited PARP cleavage and/or apoptosis. Pharmacological upregulation of PTEN by sodium butyrate (NaBt) treatment enhanced Cdc42 activity, PARP cleavage and apoptosis, whereas Cdc42 siRNA suppressed NaBt-induced PARP cleavage. Cdc42-dependent signals can suppress glycogen synthase kinase-ß (GSK3ß) activity. Pharmacological inhibition of GSK3ß by lithium chloride treatment mimicked effects of Cdc42 in promotion of PARP cleavage and/or apoptosis. CONCLUSION: Phosphatase and tensin homologue deleted on chromosome 10 may influence apoptosis in colorectal epithelium through Cdc42 signalling, thus providing a regulatory framework for both polarised growth and programmed cell death.


Assuntos
Proteínas de Ciclo Celular/metabolismo , PTEN Fosfo-Hidrolase/metabolismo , Proteínas de Ligação a RNA/metabolismo , Apoptose , Células CACO-2 , Técnicas de Inativação de Genes , Células HCT116 , Humanos , Poli(ADP-Ribose) Polimerases/metabolismo , Fatores de Processamento de RNA , RNA Interferente Pequeno/farmacologia , Transdução de Sinais
9.
Int J Biol Macromol ; 142: 822-834, 2020 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-31622710

RESUMO

The small heat shock proteins (sHsps/Hsp20s) are the molecular chaperones that maintain proper folding, trafficking and disaggregation of proteins under diverse abiotic stress conditions. In the present investigation, a genome-wide scan revealed the presence of a total of 47 sHsps in Sorghum bicolor (SbsHsps), distributed across 10 subfamilies, the major subfamily being P (plastid) group with 17 genes. Chromosomes 1 and 3 appear as the hot spot regions for SbsHsps, and majority of them were found acidic, hydrophilic, unstable and intron less. Interestingly, promoter analysis indicated that they are associated with both biotic and abiotic stresses, as well as plant development. Sorghum sHsps exhibited 15 paralogous and 20 orthologous duplications. Expression analysis of 15 genes selected from different subfamilies showed high transcript levels in roots and leaves implying that they are likely to participate in the developmental processes. SbsHsp genes were highly induced by diverse abiotic stresses inferring their critical role in mediating the environmental stress responses. Gene expression data revealed that SbsHsp-02 is a candidate gene expressed in all the tissues under varied stress conditions tested. Our results contribute to the understanding of the complexity of SbsHsp genes and help to analyse them further for functional validation.


Assuntos
Regulação da Expressão Gênica de Plantas/fisiologia , Proteínas de Choque Térmico Pequenas/genética , Proteínas de Plantas/genética , Sorghum/genética , Estresse Fisiológico/fisiologia , Sequência de Bases , Simulação por Computador , Perfilação da Expressão Gênica , Genoma de Planta , Proteínas de Choque Térmico Pequenas/metabolismo , Família Multigênica/genética , Filogenia , Folhas de Planta/genética , Proteínas de Plantas/metabolismo , Raízes de Plantas/genética , Transcriptoma
10.
J Phys Chem A ; 113(34): 9533-42, 2009 Aug 27.
Artigo em Inglês | MEDLINE | ID: mdl-19655710

RESUMO

Quantum chemical calculations and molecular dynamics simulations are carried out to study the host-guest inclusion complexes of cyclodextrins (alpha-, beta-, and gamma-CDs) with small guest molecules such as H(2)O, NH(3), NH(4)(+), C(6)H(6), and bisimidazolyl compounds. The uptake ability of the CDs to accommodate the small molecules inside the cavity is examined by the sequential addition of 10 molecules of water or ammonia using the semiempirical (PM3) method. In the case of benzene, this was done up to six molecules. PM3 calculations indicate that alpha-, beta-, and gamma-CD can accommodate three, seven, and nine water molecules, respectively. In the case of NH(3) as guest molecule, alpha-, beta-, and gamma-CDs can accommodate up to two, five, and six molecules, respectively. Semiempirical calculations indicate that two benzene molecules can be accommodated in the alpha-CD cavity, whereas beta- and gamma-CD cavities adopt three and four benzene molecules, respectively. Molecular dynamics simulations were carried out for 1.0 ns on benzene and bisimidazolyl complexes of CDs in explicit solvent (TIP3P water model). The interaction energies calculated by the MM/PBSA method reveal that ligand 1,6-bis(imidazol-l-lyl) hexane (B) and 1,4-bis(imidazol-l-lylmethyl) benzene (C) molecules prefer to form 1:1 complexes with alpha-, beta-, and gamma-CDs. However, C preferentially forms 1:2 complexes with alpha-CDs. Ligands 1,10-bis(imidazol-l-lyl) decane (A) and 4,4'-(bis(imidazol-l-ylmethylene))biphenyl (D) form 1:2 complexes with alpha-, beta-, and gamma-CDs in head-to-head (HH) orientation of CDs. The stability of inclusion compounds depends on the type of CD and the physicochemical properties of the involved guest. Both of these methods (semiempirical and MD simulations) reveal that beta-CDs form more stable complexes compared with alpha- and gamma-CDs with C, D, NH(4)(+), and C(6)H(6), whereas alpha-CD forms more stable complexes with A and B.


Assuntos
Ciclodextrinas/química , Simulação de Dinâmica Molecular , Teoria Quântica , Estrutura Molecular
11.
PLoS One ; 14(1): e0209980, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30650107

RESUMO

Late embryogenesis abundant (LEA) proteins, the space fillers or molecular shields, are the hydrophilic protective proteins which play an important role during plant development and abiotic stress. The systematic survey and characterization revealed a total of 68 LEA genes, belonging to 8 families in Sorghum bicolor. The LEA-2, a typical hydrophobic family is the most abundant family. All of them are evenly distributed on all 10 chromosomes and chromosomes 1, 2, and 3 appear to be the hot spots. Majority of the S. bicolor LEA (SbLEA) genes are intron less or have fewer introns. A total of 22 paralogous events were observed and majority of them appear to be segmental duplications. Segmental duplication played an important role in SbLEA-2 family expansion. A total of 12 orthologs were observed with Arabidopsis and 13 with Oryza sativa. Majority of them are basic in nature, and targeted by chloroplast subcellular localization. Fifteen miRNAs targeted to 25 SbLEAs appear to participate in development, as well as in abiotic stress tolerance. Promoter analysis revealed the presence of abiotic stress-responsive DRE, MYB, MYC, and GT1, biotic stress-responsive W-Box, hormone-responsive ABA, ERE, and TGA, and development-responsive SKn cis-elements. This reveals that LEA proteins play a vital role during stress tolerance and developmental processes. Using microarray data, 65 SbLEA genes were analyzed in different tissues (roots, pith, rind, internode, shoot, and leaf) which show clear tissue specific expression. qRT-PCR analysis of 23 SbLEA genes revealed their abundant expression in various tissues like roots, stems and leaves. Higher expression was noticed in stems compared to roots and leaves. Majority of the SbLEA family members were up-regulated at least in one tissue under different stress conditions. The SbLEA3-2 is the regulator, which showed abundant expression under diverse stress conditions. Present study provides new insights into the formation of LEAs in S. bicolor and to understand their role in developmental processes under stress conditions, which may be a valuable source for future research.


Assuntos
Regulação da Expressão Gênica de Plantas , Proteínas de Plantas/genética , Sorghum/genética , Estresse Fisiológico , Sequência de Aminoácidos , Mapeamento Cromossômico , Regulação da Expressão Gênica no Desenvolvimento , Genoma de Planta , MicroRNAs/genética , Filogenia , Proteínas de Plantas/análise , Sorghum/química , Sorghum/crescimento & desenvolvimento , Sorghum/fisiologia , Transcriptoma
12.
Int J Biol Macromol ; 140: 17-32, 2019 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-31419556

RESUMO

The SPX gene family, ubiquitous in all vascular plants, plays a critical role in plant development and growth as well as in response to phosphorus stress. Based on genomic census, 46 TaSPX genes were identified in the wheat genome. All of them are evenly distributed on 13 of the 21 wheat chromosomes and chromosome 7A contains the largest members. As many as 57 gene specific SSRs were discovered among genomic sequences of identified TaSPXs. MicroRNA target analysis revealed that TaSPX genes were targeted by 9 different miRNAs including tae-miR1120a, tae-miR1120b-3p, tae-miR1120c-5p, tae-miR1122b-3p, tae-miR1122c-3p, tae-miR1130a, tae-miR1130b-3p, tae-miR1137a, and tae-miR1137b-5p. Expression profiles derived from transcriptome data and real-time quantitative PCR revealed that TaSPX genes were significantly induced by Pi starvation. The modeled 3D structure of wheat SPX proteins shared high level of homology with template structures, providing information to understand their functions at proteomic level. We have also refined the modeled 3D structures on 10 ns using molecular dynamics simulations for conformational stability. The discovered members of SPX gene family and their targeting miRNAs may provide resource for genetic improvement and promote P use efficiency in cereals.


Assuntos
Cromossomos de Plantas , Regulação da Expressão Gênica de Plantas , Proteínas de Plantas , Transcriptoma , Triticum , Cromossomos de Plantas/genética , Cromossomos de Plantas/metabolismo , Perfilação da Expressão Gênica , Estudo de Associação Genômica Ampla , MicroRNAs/biossíntese , MicroRNAs/genética , Proteínas de Plantas/biossíntese , Proteínas de Plantas/genética , RNA de Plantas/biossíntese , RNA de Plantas/genética , Triticum/genética , Triticum/metabolismo
13.
PLoS One ; 14(9): e0222203, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31536532

RESUMO

Members of the plant Heme Activator Protein (HAP) or NUCLEAR FACTOR Y (NF-Y) are trimeric transcription factor complexes composed of the NF-YA, NF-YB and NF-YC subfamilies. They bind to the CCAAT box in the promoter regions of the target genes and regulate gene expressions. Plant NF-Ys were reported to be involved in adaptation to several abiotic stresses as well as in development. In silico analysis of Sorghum bicolor genome resulted in the identification of a total of 42 NF-Y genes, among which 8 code for the SbNF-YA, 19 for SbNF-YB and 15 for the SbNF-YC subunits. Analysis was also performed to characterize gene structures, chromosomal distribution, duplication status, protein subcellular localizations, conserved motifs, ancestral protein sequences, miRNAs and phylogenetic tree construction. Phylogenetic relationships and ortholog predictions displayed that sorghum has additional NF-YB genes with unknown functions in comparison with Arabidopsis. Analysis of promoters revealed that they harbour many stress-related cis-elements like ABRE and HSE, but surprisingly, DRE and MYB elements were not detected in any of the subfamilies. SbNF-YA1, 2, and 6 were found upregulated under 200 mM salt and 200 mM mannitol stresses. While NF-YA7 appeared associated with high temperature (40°C) stress, NF-YA8 was triggered by both cold (4°C) and high temperature stresses. Among NF-YB genes, 7, 12, 15, and 16 were induced under multiple stress conditions such as salt, mannitol, ABA, cold and high temperatures. Likewise, NF-YC 6, 11, 12, 14, and 15 were enhanced significantly in a tissue specific manner under multiple abiotic stress conditions. Majority of the mannitol (drought)-inducible genes were also induced by salt, high temperature stresses and ABA. Few of the high temperature stress-induced genes are also induced by cold stress (NF-YA2, 4, 6, 8, NF-YB2, 7, 10, 11, 12, 14, 16, 17, NF-YC4, 6, 12, and 13) thus suggesting a cross talk among them. This work paves the way for investigating the roles of diverse sorghum NF-Y proteins during abiotic stress responses and provides an insight into the evolution of diverse NF-Y members.


Assuntos
Fator de Ligação a CCAAT/genética , Genes de Plantas/genética , Proteínas de Plantas/genética , Sorghum/genética , Mapeamento Cromossômico , Regulação da Expressão Gênica de Plantas , Estudo de Associação Genômica Ampla , Filogenia , Reação em Cadeia da Polimerase em Tempo Real , Transcriptoma
14.
Genes (Basel) ; 9(5)2018 May 03.
Artigo em Inglês | MEDLINE | ID: mdl-29751546

RESUMO

Na⁺ transporters play an important role during salt stress and development. The present study is aimed at genome-wide identification, in silico analysis of sodium-proton antiporter (NHX) and sodium-proton exchanger (NHE)-type transporters in Sorghum bicolor and their expression patterns under varied abiotic stress conditions. In Sorghum, seven NHX and nine NHE homologs were identified. Amiloride (a known inhibitor of Na⁺/H⁺ exchanger activity) binding motif was noticed in both types of the transporters. Chromosome 2 was found to be a hotspot region with five sodium transporters. Phylogenetic analysis inferred six ortholog and three paralog groups. To gain an insight into functional divergence of SbNHX/NHE transporters, real-time gene expression was performed under salt, drought, heat, and cold stresses in embryo, root, stem, and leaf tissues. Expression patterns revealed that both SbNHXs and SbNHEs are responsive either to single or multiple abiotic stresses. The predicted protein⁻protein interaction networks revealed that only SbNHX7 is involved in the calcineurin B-like proteins (CBL)- CBL interacting protein kinases (CIPK) pathway. The study provides insights into the functional divergence of SbNHX/NHE transporter genes with tissue specific expressions in Sorghum under different abiotic stress conditions.

15.
Biotechnol Rep (Amst) ; 16: 18-20, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-29062722

RESUMO

Sclerospora graminicola pathogen is the most important biotic production constraints of pearl millet in India, Africa and other parts of the world. We report a de novo whole genome assembly and analysis of pathotype 1, one of the most virulent pathotypes of S. graminicola from India. The draft genome assembly contained 299,901,251 bp with 65,404 genes. This study may help understand the evolutionary pattern of pathogen and aid elucidation of effector evolution for devising effective durable resistance breeding strategies in pearl millet.

16.
Methods Enzymol ; 577: 185-212, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27498639

RESUMO

Adenosine triphosphate (ATP)-binding cassette (ABC) transporters are ubiquitous ATP-dependent membrane proteins involved in translocations of a wide variety of substrates across cellular membranes. To understand the chemomechanical coupling mechanism as well as functional asymmetry in these systems, a quantitative description of how ABC transporters hydrolyze ATP is needed. Complementary to experimental approaches, computer simulations based on combined quantum mechanical and molecular mechanical (QM/MM) potentials have provided new insights into the catalytic mechanism in ABC transporters. Quantitatively reliable determination of the free energy requirement for enzymatic ATP hydrolysis, however, requires substantial statistical sampling on QM/MM potential. A case study shows that brute force sampling of ab initio QM/MM (AI/MM) potential energy surfaces is computationally impractical for enzyme simulations of ABC transporters. On the other hand, existing semiempirical QM/MM (SE/MM) methods, although affordable for free energy sampling, are unreliable for studying ATP hydrolysis. To close this gap, a multiscale QM/MM approach named reaction path-force matching (RP-FM) has been developed. In RP-FM, specific reaction parameters for a selected SE method are optimized against AI reference data along reaction paths by employing the force matching technique. The feasibility of the method is demonstrated for a proton transfer reaction in the gas phase and in solution. The RP-FM method may offer a general tool for simulating complex enzyme systems such as ABC transporters.


Assuntos
Transportadores de Cassetes de Ligação de ATP/metabolismo , Trifosfato de Adenosina/metabolismo , Simulação de Dinâmica Molecular , Teoria Quântica , Termodinâmica , Transportadores de Cassetes de Ligação de ATP/química , Animais , Humanos , Hidrólise
17.
J Mol Model ; 17(7): 1801-16, 2011 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-21080017

RESUMO

The effect of alkyl substitution (CH3, C2H5, n-C3H7, i-C3H7, and t-C4H9) on the hydrogen bond strengths (H-bond) of substituted amide-alcohol complexes has been systematically explored. B3LYP/aug-cc-pVDZ method was applied to a total of 215 alkyl substituted amide-alcohol complexes to delineate the effect of substitution on the H-bond strength; formamide-water complex is taken as reference point. Complexes are classified into five types depending on the hydrogen donor, acceptor and the site of alkyl substitution (Type-IA, Type-IIA, Type-IB, Type-IIB and Type-III). The strength of H-bond was correlated with geometrical parameters such as proton-acceptor (H∙∙∙∙Y) distance, the length of proton donating bond (X-H). In all the complexes N-H and O-H stretching frequencies are red-shifted. The effect of alkyl substitution on N-H and O-H stretching frequencies were analyzed. Topological parameters like electron density at H∙∙∙∙Y and X-H bond critical points as derived from atom in molecules (AIM) theory was also evaluated. When C = O group is participating in H-bond, the strength of H-bond decreases with increasing size of alcohols except for methanol (Type-IA, Type-III and Type-IB complexes). But it increases with increasing size of alkyl groups on amide and decreases with bulky groups. In the case of N-H group as H-bond donor, the strength of H-bond increases with increasing size of alcohols (Type-IIA and Type-IIB complexes) whereas decreases with increasing size of alkyl groups on amide. Type-IA, IIA, IB and IIB complexes exhibit good correlations among IE, H-bond distance and electron density at bcp. In Type-III complexes, average H-bond distance and sum of electron densities shows better correlation with IEs than the corresponding individuals. The correlation of IE less with electron density at RCP compared to sum of electron densities.


Assuntos
Álcoois/química , Amidas/química , Ligação de Hidrogênio , Modelos Moleculares , Estrutura Molecular
18.
J Comput Aided Mol Des ; 19(12): 857-70, 2005 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-16741831

RESUMO

This study sheds new light on the role of acidic residues present in the active site cavity of human aromatase. Eight acidic residues (E129, D222, E245, E302, D309, E379, D380 and D476) lining the cavity are identified and studied using comparative modeling, docking, molecular dynamics as well as statistical techniques. The structural environment of these acidic residues is studied to assess the stability of the corresponding carboxylate anions. Results indicate that the environment of the residues E245, E302 and D222 is most suitable for carboxylate ion formation in the uncomplexed form. However, the stability of D309, D222 and D476 anions is seen to increase on complexation to steroidal substrates. In particular, the interaction between D309 and T310, which assists proton transfer, is found to be formed following androgen/nor-androgen complexation. The residue D309 is found to be clamped in the presence of substrate which is not observed in the case of the other residues although they exhibit changes in properties following substrate binding. Information entropic analysis indicates that the residues D309, D222 and D476 have more conformational flexibility compared to E302 and E245 prior to substrate binding. Interaction similar to that between D476 and D309, which is expected to assist androgen aromatization, is proposed between E302 and E245. The inhibition of aromatase activity by 4-hydroxy androstenedione (formestane) is attributed to a critical hydrogen bond formation between the hydroxy moiety and T310/D309 as well as the large distance from D476. The results corroborate well with earlier site directed mutagenesis studies.


Assuntos
Aminoácidos Acídicos/química , Aminoácidos Acídicos/metabolismo , Aromatase/química , Aromatase/metabolismo , Neoplasias da Mama/enzimologia , Modelos Moleculares , Aminoácidos Acídicos/genética , Aromatase/genética , Sítios de Ligação/genética , Neoplasias da Mama/tratamento farmacológico , Simulação por Computador , Estabilidade Enzimática/genética , Feminino , Humanos , Especificidade por Substrato/genética
19.
Inorg Chem ; 42(21): 6604-6, 2003 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-14552610

RESUMO

A novel chainlike coordination polymer [Cu(II)(2,2'-bipy)(H(2)O)(2)Al(OH)(6)Mo(6)O(18)](n)()(n)()(-), formed from a heteropolyanion [Al(OH)(6)Mo(6)O(18)](3)(-) as a building unit and a copper(II) complex fragment, [Cu(II)(2,2'-bipy)(H(2)O)(2)](2+), as a linker, provides the first example of an extended structure based on an Anderson type of polyanion and a transition metal complex with organic ligand. The intra- and interchain O-H.O hydrogen-bonding interactions are seemingly responsible for the spiral shape of this chain. Crystal data: triclinic space group Ponemacr;, a = 11.2253(18) A, b = 14.5194(17) A, c = 15.2672(10) A, alpha = 112.191(8) degrees, beta = 106.693(9) degrees, gamma = 93.916(13) degrees, and Z = 2.

20.
Am J Gastroenterol ; 90(10): 1881-3, 1995 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-7572915

RESUMO

Appendiceal endometriosis is a very uncommon clinical entity. We describe a 33-yr-old white female who presented with painless profuse rectal bleeding. Emergency colonoscopy revealed bleeding from the appendiceal opening. An emergency appendectomy was performed which controlled her bleeding. The histopathological examination demonstrated appendiceal endometriosis. Painless bleeding from appendiceal endometriosis is extremely rare; however, it should be considered when evaluating young women of reproductive age who present with rectal bleeding.


Assuntos
Apêndice , Endometriose/complicações , Hemorragia Gastrointestinal/etiologia , Adulto , Apendicectomia , Apêndice/patologia , Doenças do Ceco/complicações , Doenças do Ceco/patologia , Doenças do Ceco/cirurgia , Endometriose/patologia , Endometriose/cirurgia , Feminino , Humanos , Reto
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA