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11.
Sivaprasath Prabu Dapeng Jing Viswanathan Chandran Preethy Mathew 《Entomological Research》2020,50(8):402-413
The present study was focused on exploring the presence of active compounds in Origanum majorana essential oil (OmEO), and its various knock‐down effects against the rice moth, Corcyra cephalonica. GC–MS analysis detected the existence of major compounds such as monoterpenes, cis‐β‐terpineol and terpinen‐4‐ol with the total proportion of 52.16%. Fumigant toxicity against adult and larvae was calculated with an LC50 value of 11.31 and 49.83 μL/L air, respectively. The contact toxicity against adult, pupa, larvae and eggs was observed with LC50 value 2.54, 0.95, 2.78, and 0.49 μL/L, respectively. Furthermore, the influential repellent behavior against adults has been observed. Acetylesterase (AChE) inhibition activity of OmEO was observed against adult and larvae of C. cephalonica with an IC50 value of 35.89 and 118.54 μL/mL, respectively. Moreover, computational docking study revealed the binding affinity of Cis‐β‐terpineol and terpinen‐4‐ol towards the active binding sites of AChE. On the other hand, Fluorescence‐assisted cytometry and comet assay confirmed the cytotoxic and genotoxic effect of OmEO at various concentrations on C. cephalonica. Altogether, the results showed the knock‐down effect of OmEO against C. cephalonica, and it could be a potential biocontrol measure against the stored product pest. 相似文献
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Probing the role of a mobile loop in substrate binding and enzyme activity of human salivary amylase
Mammalian amylases harbor a flexible, glycine-rich loop 304GHGAGGA(310), which becomes ordered upon oligosaccharide binding and moves in toward the substrate. In order to probe the role of this loop in catalysis, a deletion mutant lacking residues 306-310 (Delta306) was generated. Kinetic studies showed that Delta306 exhibited: (1) a reduction (>200-fold) in the specific activity using starch as a substrate; (2) a reduction in k(cat) for maltopentaose and maltoheptaose as substrates; and (3) a twofold increase in K(m) (maltopentaose as substrate) compared to the wild-type (rHSAmy). More cleavage sites were observed for the mutant than for rHSAmy, suggesting that the mutant exhibits additional productive binding modes. Further insight into its role is obtained from the crystal structures of the two enzymes soaked with acarbose, a transition-state analog. Both enzymes modify acarbose upon binding through hydrolysis, condensation or transglycosylation reactions. Electron density corresponding to six and seven fully occupied subsites in the active site of rHSAmy and Delta306, respectively, were observed. Comparison of the crystal structures showed that: (1) the hydrophobic cover provided by the mobile loop for the subsites at the reducing end of the rHSAmy complex is notably absent in the mutant; (2) minimal changes in the protein-ligand interactions around subsites S1 and S1', where the cleavage would occur; (3) a well-positioned water molecule in the mutant provides a hydrogen bond interaction similar to that provided by the His305 in rHSAmy complex; (4) the active site-bound oligosaccharides exhibit minimal conformational differences between the two enzymes. Collectively, while the kinetic data suggest that the mobile loop may be involved in assisting the catalysis during the transition state, crystallographic data suggest that the loop may play a role in the release of the product(s) from the active site. 相似文献
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Dev Chandran Kolli Bhaktavatsala Reddy Shahana Pallichera Vijayan Parthasarthy Sugumar Gudavalli Sudha Rani Ponsekaran Santha Kumar Lingala Rajendra Villuppanoor Alwar Srinivasan 《Indian journal of microbiology》2010,50(3):266-274
Peste des Petits Ruminants (PPR) is a highly contagious animal disease caused by the Peste des Petits Ruminants virus (PPRV) belonging to the genus morbillivirus and family Paramyxoviridae. The disease results in high morbidity and mortality in goats, sheep and in some small wild ruminants. The presence of large number of small ruminants reared in endemic areas makes PPR a notorious disease threatening the livelihood of poor farmers. Conventional vaccination using a live, attenuated vaccine gives adequate protection but cannot be used in case of eradication of the disease due to difficulty in differentiation of infected animals from the vaccinated ones. 相似文献
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Reovirus outer capsid protein micro1 induces apoptosis and associates with lipid droplets, endoplasmic reticulum, and mitochondria 下载免费PDF全文
The mechanisms by which reoviruses induce apoptosis have not been fully elucidated. Earlier studies identified the mammalian reovirus S1 and M2 genes as determinants of apoptosis induction. However, no published results have demonstrated the capacities of the proteins encoded by these genes to induce apoptosis, either independently or in combination, in the absence of reovirus infection. Here we report that the mammalian reovirus micro1 protein, encoded by the M2 gene, was sufficient to induce apoptosis in transfected cells. We also found that micro1 localized to lipid droplets, endoplasmic reticulum, and mitochondria in both transfected cells and infected cells. Two small regions encompassing amphipathic alpha-helices within a carboxyl-terminal portion of micro1 were necessary for efficient induction of apoptosis and association with lipid droplets, endoplasmic reticulum, and mitochondria in transfected cells. Induction of apoptosis by micro1 and its association with lipid droplets and intracellular membranes in transfected cells were abrogated when micro1 was coexpressed with sigma3, with which it is known to coassemble. We propose that micro1 plays a direct role in the induction of apoptosis in infected cells and that this property may relate to the capacity of micro1 to associate with intracellular membranes. Moreover, during reovirus infection, association with sigma3 may regulate apoptosis induction by micro1. 相似文献
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We describe an approach to analyzing single- and multiunit (ensemble) discharge patterns based on information-theoretic distance measures and on empirical theories derived from work in universal signal processing. In this approach, we quantify the difference between response patterns, whether time-varying or not, using information-theoretic distance measures. We apply these techniques to single- and multiple-unit processing of sound amplitude and sound location. These examples illustrate that neurons can simultaneously represent at least two kinds of information with different levels of fidelity. The fidelity can persist through a transient and a subsequent steady-state response, indicating that it is possible for an evolving neural code to represent information with constant fidelity. 相似文献
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The Gorlin equation for the hemodynamic assessment of valve area is commonly used in cardiac catheterization laboratories. A study was performed to test the prediction capabilities of the Gorlin formula as well as the Aaslid and Gabbay formula for the effective orifice area of prosthetic heart valves. Pressure gradient, flow, and valve opening area measurements were performed on four 27 mm valve prostheses (two mechanical bileaflet designs, St. Jude and Edwards-Duromedics, an Edwards pericardial tissue valve, and a trileaflet polyurethane valve) each mounted in the aortic position of an in vitro pulse duplicator. With the known valve orifice area, a different discharge coefficient was computed for each of the four valves and three orifice area formulas. After some theoretical considerations, it was proposed that the discharge coefficient would be a function of the flow rate through the valve. All discharge coefficients were observed to increase with increasing systolic flow rate. An empirical relationship of discharge coefficient as a linear function of systolic flow rate was determined through a regression analysis, with a different relationship for each valve and each orifice area formula. Using this relationship in the orifice area formulas improved the accuracy of the prediction of the effective orifice area with all three formulas performing equally well. 相似文献
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Increasing autophagy and blocking Nrf2 suppress laminopathy‐induced age‐dependent cardiac dysfunction and shortened lifespan 下载免费PDF全文
Shruti Bhide Adriana S. Trujillo Maureen T. O'Connor Grant H. Young Diane E. Cryderman Sahaana Chandran Mastaneh Nikravesh Lori L. Wallrath Girish C. Melkani 《Aging cell》2018,17(3)
Mutations in the human LMNA gene cause a collection of diseases known as laminopathies. These include myocardial diseases that exhibit age‐dependent penetrance of dysrhythmias and heart failure. The LMNA gene encodes A‐type lamins, intermediate filaments that support nuclear structure and organize the genome. Mechanisms by which mutant lamins cause age‐dependent heart defects are not well understood. To address this issue, we modeled human disease‐causing mutations in the Drosophila melanogaster Lamin C gene and expressed mutant Lamin C exclusively in the heart. This resulted in progressive cardiac dysfunction, loss of adipose tissue homeostasis, and a shortened adult lifespan. Within cardiac cells, mutant Lamin C aggregated in the cytoplasm, the CncC(Nrf2)/Keap1 redox sensing pathway was activated, mitochondria exhibited abnormal morphology, and the autophagy cargo receptor Ref2(P)/p62 was upregulated. Genetic analyses demonstrated that simultaneous over‐expression of the autophagy kinase Atg1 gene and an RNAi against CncC eliminated the cytoplasmic protein aggregates, restored cardiac function, and lengthened lifespan. These data suggest that simultaneously increasing rates of autophagy and blocking the Nrf2/Keap1 pathway are a potential therapeutic strategy for cardiac laminopathies. 相似文献