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121.
122.
Cellular life requires the presence of a set of biochemical mechanisms in order to maintain a predictable process of growth and division. Several attempts have been made towards the building of minimal protocells from a top-down approach, i.e. by using available biomolecules. This type of synthetic approach has so far been only partially successful, and appropriate models of the synthetic protocell cycle might be needed to guide future experiments. In this paper, we present a simple biochemically and physically feasible model of cell replication involving a discrete semi-permeable vesicle with an internal minimal metabolism involving two reactive centers. It is shown that such a system can effectively undergo a whole cell replication cycle. The model can be used as a basic framework to model whole protocell dynamics including more complex sets of reactions. The possible implementation of our design in future synthetic protocells is outlined. 相似文献
123.
Frutos S Rodriguez-Mias RA Madurga S Collinet B Reboud-Ravaux M Ludevid D Giralt E 《Biopolymers》2007,88(2):164-173
HIV-1 protease (HIV-1 PR), which is encoded by retroviruses, is required for the processing of gag and pol polyprotein precursors, hence it is essential for the production of infectious viral particles. In vitro inhibition of the enzyme results in the production of progeny virions that are immature and noninfectious, suggesting its potential as a therapeutic target for AIDS. Although a number of potent protease inhibitor drugs are now available, the onset of resistance to these agents due to mutations in HIV-1 PR has created an urgent need for new means of HIV-1 PR inhibition. Whereas enzymes are usually inactivated by blocking of the active site, the structure of dimeric HIV-1 PR allows an alternative inhibitory mechanism. Since the active site is formed by two half-enzymes, which are connected by a four-stranded antiparallel beta-sheet involving the N- and C- termini of both monomers, enzyme activity can be abolished by reagents targeting the dimer interface in a region relatively free of mutations would interfere with formation or stability of the functional HIV-1 PR dimer. This strategy has been explored by several groups who targeted the four-stranded antiparallel beta-sheet that contributes close to 75% of the dimerization energy. Interface peptides corresponding to native monomer N- or C-termini of several of their mimetics demonstrated, mainly on the basis of kinetic analyses, to act as dimerization inhibitors. However, to the best of our knowledge, neither X-ray crystallography nor NMR structural studies of the enzyme-inhibitor complex have been performed to date. In this article we report a structural study of the dimerization inhibition of HIV-1 PR by NMR using selective Trp side chain labeling. 相似文献
124.
James S.V. Lally Sarani Ghoshal Danielle K. DePeralta Omeed Moaven Lan Wei Ricard Masia Derek J. Erstad Naoto Fujiwara Vivian Leong Vanessa P. Houde Alexander E. Anagnostopoulos Alice Wang Lindsay A. Broadfield Rebecca J. Ford Robert A. Foster Jamie Bates Hailing Sun Ting Wang Bryan C. Fuchs 《Cell metabolism》2019,29(1):174-182.e5
125.
126.
Water stress and recovery in the performance of two Eucalyptus globulus clones: physiological and biochemical profiles 总被引:1,自引:0,他引:1
Barbara Correia Marta Pintó‐Marijuan Lucinda Neves Ricard Brossa Maria Celeste Dias Armando Costa Bruno B. Castro Clara Araújo Conceição Santos Maria Manuela Chaves Glória Pinto 《Physiologia plantarum》2014,150(4):580-592
Eucalyptus plantations are among the most productive forest stands in Portugal and Spain, being mostly used for pulp production and, more recently, as an energy crop. However, the region's Mediterranean climate, with characteristic severe summer drought, negatively affects eucalypt growth and increases mortality. Although the physiological response to water shortage is well characterized for this species, evidence about the plants' recovery ability remains scarce. In order to assess the physiological and biochemical response of Eucalyptus globulus during the recovery phase, two genotypes (AL‐18 and AL‐10) were submitted to a 3‐week water stress period at two different intensities (18 and 25% of field capacity), followed by 1 week of rewatering. Recovery was assessed 1 day and 1 week after rehydration. Drought reduced height, biomass, water potential, NPQ and gas exchange in both genotypes. Contrarily, the levels of pigments, chlorophyll fluorescence parameters (Fv/Fm and φPSII), MDA and ABA increased. During recovery, the physiological and biochemical profile of stressed plants showed a similar trend: they experienced reversion of altered traits (MDA, ABA, E, gs, pigments), while other parameters did not recover (φPSII, NPQ). Furthermore, an overcompensation of CO2 assimilation was achieved 1 week after rehydration, which was accompanied by greater growth and re‐establishment of oxidative balance. Both genotypes were tolerant to the tested conditions, although clonal differences were found. AL‐10 was more productive and showed a more rapid and dynamic response to rehydration (namely in carotenoid content, φPSII and NPQ) compared to clone AL‐18. 相似文献
127.
Tim Vanuytsel Christophe Vanormelingen Hanne Vanheel Tatsuhiro Masaoka Shadea Salim Rasoel Joran Tóth Els Houben Kristin Verbeke Gert De Hertogh Pieter Vanden Berghe Jan Tack Ricard Farré 《PloS one》2014,9(10)
Background
Impaired intestinal barrier function, low-grade inflammation and altered neuronal control are reported in functional gastrointestinal disorders. However, the sequence of and causal relation between these events is unclear, necessitating a spontaneous animal model. The aim of this study was to describe the natural history of intestinal permeability, mucosal and neuromuscular inflammation and nitrergic motor neuron function during the lifetime of the BioBreeding (BB) rat.Methods
Normoglycemic BB-diabetes prone (DP) and control rats were sacrificed at different ages and jejunum was harvested to characterize intestinal permeability, inflammation and neuromuscular function.Results
Both structural and functional evidence of increased intestinal permeability was found in young BB-DP rats from the age of 50 days. In older animals, starting in the mucosa from 70 days and in half of the animals also in the muscularis propria from 110 days, an inflammatory reaction, characterized by an influx of polymorphonuclear cells and higher myeloperoxidase activity, was observed. Finally, in animals older than 110 days, coinciding with a myenteric ganglionitis, a loss of nitrergic neurons and motor function was demonstrated.Conclusion
In the BB-rat, mucosal inflammatory cell infiltration is preceded by intestinal barrier dysfunction and followed by myenteric ganglionitis and loss of nitrergic function. This sequence supports a primary role for impaired barrier function and provides an insightful model for the pathogenesis of functional gastrointestinal disorders. 相似文献128.
Inglés-Esteve J Morales M Dalmases A Garcia-Carbonell R Jené-Sanz A López-Bigas N Iglesias M Ruiz-Herguido C Rovira A Rojo F Albanell J Gomis RR Bigas A Espinosa L 《PloS one》2012,7(5):e38347
14-3-3σ is frequently lost in human breast cancers by genetic deletion or promoter methylation. We have now investigated the involvement of 14-3-3σ in the termination of NF-κB signal in mammary cells and its putative role in cancer relapse and metastasis. Our results show that 14-3-3σ regulates nuclear export of p65-NF-κB following chronic TNFα stimulation. Restoration of 14-3-3σ in breast cancer cells reduces migration capacity and metastatic abilities in vivo. By microarray analysis, we have identified a genetic signature that responds to TNFα in a 14-3-3σ-dependent manner and significantly associates with different breast and other types of cancer. By interrogating public databases, we have found that over-expression of this signature correlates with poor relapse-free survival in breast cancer patients. Finally, screening of 96 human breast tumors showed that NF-κB activation strictly correlates with the absence of 14-3-3σ and it is significantly associated with worse prognosis in the multivariate analysis. Our findings identify a genetic signature that is important for breast cancer prognosis and for future personalized treatments based on NF-κB targeting. 相似文献
129.
Benjamin Lallemand Marco Masi Lucia Maddau Manuela De Lorenzi Ricard Dam Alessio Cimmino Laetitia Moreno y Banuls Anna Andolfi Robert Kiss Véronique Mathieu Antonio Evidente 《Phytochemistry letters》2012,5(4):770-775
Sphaeropsidins A (1), B (7) and C (10), three fungal phytotoxins, unrearranged pimarane diterpenes produced by Diplodia cupressi and 10 semisynthetic derivatives were evaluated for their in vitro anticancer activities. Among these 13 compounds, sphaeropsidin A and two derivatives (2 and 6) thereof display 50% growth-inhibitory concentration in the low micromolar range for all cell lines analyzed. Structure activity relationship paralleled the phytopathogenic and antimicrobial ones except regarding the vinyl group at C-13 that does not seems to be required as it is for their antipathogenic activity. 相似文献
130.
Molin L Seraglia R Lapolla A Ragazzi E Gonzalez J Vlahou A Schanstra JP Albalat A Dakna M Siwy J Jankowski J Bitsika V Mischak H Zürbig P Traldi P 《Journal of Proteomics》2012,75(18):5888-5897
Non-invasive detection of diseases, based on urinary proteomics, is becoming an increasingly important area of research, especially in the area of chronic kidney disease (CKD). Different platforms have been used in independent studies, mostly capillary-electrophoresis coupled ESI-MS (CE-MS), liquid chromatography coupled mass spectrometry, and matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS). We have compared the performance of CE-MS with MALDI-MS in detecting CKD, based on a cohort of 137 urine samples (62 cases and 75 controls). Data cross-talk between the two platforms was established for the comparison of detected biomarkers. The results demonstrate superior performance of the CE-MS approach in terms of peptide resolution and obtained disease prediction accuracy rates. However, the data also demonstrate the ability of the MALDI-MS approach to separate CKD patients from controls, at slightly reduced accuracy, but expected reduced cost and time. As a consequence, a practical approach can be foreseen where MALDI-MS is employed as an inexpensive, fast, and robust screening tool to detect probable CKD. In a second step, high resolution CE-MS could be used in those patients only that scored negative for CKD in the MALDI-MS analysis, reducing costs and time of such a program. 相似文献