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951.
Ghosh A Datta R Majumdar A Bhattacharya M Datta B 《Experimental cell research》2006,312(16):3184-3203
Eukaryotic initiation factor 2 (eIF2)-associated glycoprotein, p67, plays an important role in protecting eIF2alpha from phosphorylation by eIF2alpha-specific kinases. To understand the molecular details of interaction between p67 and the subunits of eIF2, we applied several biochemical and mutational analyses to identify interacting domains within p67 and eIF2gamma. These studies were combined with functional in vivo and in vitro assays to address the importance of the interactions between p67 and eIF2gamma in eIF2alpha phosphorylation. Studies from yeast two-hybrid assays show that p67 interacts strongly with eIF2gamma, relatively weakly with eIF2alpha, and no interaction with eIF2beta. Further mutational analyses provided evidence that the N-terminal lysine-rich domain II and the 340-430 amino acid segment of p67 interact strongly with the C-terminal 409-472 amino acid segment of eIF2gamma. GST pull-down assays show that the interaction between p67 and eIF2gamma is direct. From co-immunoprecipitation studies, we find that the interaction between p67 and eIF2gamma could not only be detected in mammalian cells growing in growth medium, it could also be detected in transiently transfected cells with expression plasmids encoding p67 and eIF2gamma. However, this interaction could not be detected in p67 mutants lacking lysine-rich domain II and the 340-430 amino acid segment. We also find a very good correlation between p67 binding to eIF2gamma and the protection of eIF2alpha from phosphorylation. Altogether, our data provide genetic evidence for the interaction between p67 and eIF2gamma and that this interaction modulates the phosphorylation of eIF2alpha. 相似文献
952.
Seshadri R Joseph SW Chopra AK Sha J Shaw J Graf J Haft D Wu M Ren Q Rosovitz MJ Madupu R Tallon L Kim M Jin S Vuong H Stine OC Ali A Horneman AJ Heidelberg JF 《Journal of bacteriology》2006,188(23):8272-8282
The complete genome of Aeromonas hydrophila ATCC 7966(T) was sequenced. Aeromonas, a ubiquitous waterborne bacterium, has been placed by the Environmental Protection Agency on the Contaminant Candidate List because of its potential to cause human disease. The 4.7-Mb genome of this emerging pathogen shows a physiologically adroit organism with broad metabolic capabilities and considerable virulence potential. A large array of virulence genes, including some identified in clinical isolates of Aeromonas spp. or Vibrio spp., may confer upon this organism the ability to infect a wide range of hosts. However, two recognized virulence markers, a type III secretion system and a lateral flagellum, that are reported in other A. hydrophila strains are not identified in the sequenced isolate, ATCC 7966(T). Given the ubiquity and free-living lifestyle of this organism, there is relatively little evidence of fluidity in terms of mobile elements in the genome of this particular strain. Notable aspects of the metabolic repertoire of A. hydrophila include dissimilatory sulfate reduction and resistance mechanisms (such as thiopurine reductase, arsenate reductase, and phosphonate degradation enzymes) against toxic compounds encountered in polluted waters. These enzymes may have bioremediative as well as industrial potential. Thus, the A. hydrophila genome sequence provides valuable insights into its ability to flourish in both aquatic and host environments. 相似文献
953.
954.
The availability of hundreds of bacterial genome sequences has altered the study of bacterial pathogenesis, affecting both design of experiments and analysis of results. Comparative genomics and genomic tools have been used to identify virulence factors and genes involved in environmental persistence of pathogens. However, a major stumbling block in the genomics revolution has been the large number of genes with unknown function that have been identified in every organism sequenced to date. 相似文献
955.
956.
The present study evaluated whether neurotensin (NT) binding sites were altered in the aged rat brain and if these alterations were related to the cognitive status of the animal. Aged (24-25 months old) Long-Evans rats were behaviorally screened using the Morris water maze task and were classified as either aged, cognitively impaired (AI) or cognitively unimpaired (AU) based on their relative performances in the task compared to young control (Y) animals. Decreases in specific [125I]NT binding were observed in the hippocampal formation, namely the dentate gyrus (DG), as well as in the septum and hypothalamus. Both aged groups also showed significant reductions in specific [125I]NT binding levels compared to the Y animals in the hippocampal CA3 sub-field, with the AI animals exhibiting the lowest levels. In the Substantia Nigra Zona Compacta (SNc) and the ventral tegmental area (VTA), specific [125I]NT binding was decreased as a function of age while binding in the paraventricular nucleus of the hypothalamus (PVNh) was decreased as a function of age and cognitive status. These alterations in the level of specific [125I] NT binding in the aged animals suggest decreases in NT receptor signaling as a function of age and potential involvement of NT-ergic systems in the etiology of age-related cognitive deficits. 相似文献
957.
Jason R. Hillebrecht Jeremy F. Koscielecki Kevin J. Wise Duane L. Marcy William Tetley Rekha Rangarajan James Sullivan Michelle Brideau Mark P. Krebs Jeffrey A. Stuart Robert R. Birge 《NanoBioTechnology》2005,1(2):141-151
The potential use of proteins in device applications has advanced in large part due to significant advances in the methods
and procedures of protein engineering, most notably, directed evolution. Directed evolution has been used to tailor a broad
range of enzymatic proteins for pharmaceutical and industrial applications. Thermal stability, chemical stability, and substrate
specificity are among the most common phenotypes targeted for optimization. However, in vivo screening systems for photoactive
proteins have been slow in development. A high-throughput screening system for the photokinetic optimization of photoactive
proteins would promote the development of protein-based field-effect transistors, artificial retinas, spatial light modulators,
photovoltaic fuel cells, three-dimensional volumetric memories, and optical holographic processors. This investigation seeks
to optimize the photoactive protein bacteriorhodopsin (BR) for volumetric optical and holographic memories. Semi-random mutagenesis
and in vitro screening were used to create and analyze nearly 800 mutants spanning the entire length of the bacterio-opsin (bop) gene. To fully realize the potential of BR in optoelectronic environments, future investigations will utilize global mutagenesis
and in vivo screening systems. The architecture for a potential in vivo screening system is explored in this study. We demonstrate
the ability to measure the formation and decay of the red-shifted O-state within in vivo colonies of Halobacterium salinarum, and discuss the implications of this screening method to directed evolution.
These authors contributed equally to this work. 相似文献
958.
Seema Bag Sanjukta Ghosh Rekha Tulsan Abha Sood Weihong Zhou Christine Schifone Michelle Foster Harry LeVine Béla Török Marianna Török 《Bioorganic & medicinal chemistry letters》2013,23(9):2614-2618
A series of compounds containing an α,β-unsaturated carbonyl moiety, such as chalcones and coumarins were designed, synthesized and tested in a variety of assays to assess their potential as anti-Alzheimer’s disease (AD) agents. The investigations included the inhibition of cholinesterases (AChE, BuChE), the inhibition of amyloid beta (Aβ) self-assembly and the disassembly of preformed Aβ oligomers. Several compounds showed excellent potential as multifunctional compounds for AD. Docking studies for 16 that performed well in all the assays gave a clear interpretation of various interactions in the gorge of AChE. Based on the results, the long-chain coumarin scaffold appears to be a promising structural template for further AD drug development. 相似文献
959.
Štefan Karácsonyi Vladimír Kováčik Juraj Alföldi Marta Kubačková 《Carbohydrate research》1984,134(2):265-274
An arabinogalactan isolated from the wood of Larix sibirica L. was investigated by methylation analysis, partial hydrolysis, enzymic oxidation, and 13C-n.m.r. spectroscopy. The structural conclusions arrived at by 13C-n.m.r. spectroscopy were consistent with the data from methylation analysis. The polysaccharide is highly branched and similar in structure to those of arabino-3,6-galactans isolated from other Larix species. 相似文献
960.
Studies on the stability of the vanillin entrapped within the spherical aggregates obtained from amaranth (Amaranthus paniculatus L.), quinoa (Chenopodium quinoa L.), rice (Oryza sativa L.) and colocasia (Colocasia esculenta L.) in the presence of gum Arabic, carboxymethyl cellulose (CMC) and carrageenan at 0.1–1.0% as bonding agents, were obtained by spray drying a 20% (w/w) starch dispersion at 120 °C. Vanillin was used at 5% based on starch (bos). The loss of vanillin over a 6-week storage period followed a first order kinetics. The stability was evaluated in terms of t1/2 (weeks) from a semi-log plot of percentage retention of vanillin vs. storage time in weeks. The t1/2 for the total vanillin and entrapped vanillin within the spherical aggregates prepared from different starches decreased in the order, amaranth>colocasia>chenopodium>rice. The t1/2 decreased with an increase in the amylose content of the starches, although it was not linear. With respect to the bonding agent the stability decreased in the order, gum Arabic>CMC>carrageenan. While CMC and carrageenan gave an increasing value of t1/2 with an increase in concentration from 0.5 to 1.0%, gum Arabic surprisingly gave a higher t1/2 value at 0.5% as compared to 1.0%. 相似文献