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41.
Roselani I. Henry Simon A. Cobbold Richard J. W. Allen Asif Khan Rhys Hayward Adele M. Lehane Patrick G. Bray Susan M. Howitt Giancarlo A. Biagini Kevin J. Saliba Kiaran Kirk 《The Journal of biological chemistry》2010,285(24):18615-18626
The intraerythrocytic malaria parasite exerts tight control over its ionic composition. In this study, a combination of fluorescent ion indicators and 36Cl− flux measurements was used to investigate the transport of Cl− and the Cl−-dependent transport of “H+-equivalents” in mature (trophozoite stage) parasites, isolated from their host erythrocytes. Removal of extracellular Cl−, resulting in an outward [Cl−] gradient, gave rise to a cytosolic alkalinization (i.e. a net efflux of H+-equivalents). This was reversed on restoration of extracellular Cl−. The flux of H+-equivalents was inhibited by 4,4′-diisothiocyanostilbene-2,2′-disulfonic acid and, when measured in ATP-depleted parasites, showed a pronounced dependence on the pH of the parasite cytosol; the flux was low at cytosolic pH values < 7.2 but increased steeply with cytosolic pH at values > 7.2. 36Cl− influx measurements revealed the presence of a Cl− uptake mechanism with characteristics similar to those of the Cl−-dependent H+-equivalent flux. The intracellular concentration of Cl− in the parasite was estimated to be ∼48 mm in situ. The data are consistent with the intraerythrocytic parasite having in its plasma membrane a 4,4′-diisothiocyanostilbene-2,2′-disulfonic acid-sensitive transporter that, under physiological conditions, imports Cl− together with H+-equivalents, resulting in an intracellular Cl− concentration well above that which would occur if Cl− ions were distributed passively in accordance with the parasite''s large, inwardly negative membrane potential. 相似文献
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G protein-coupled receptors (GPCRs) are transmembrane proteins, which transduce signals from extracellular ligands to intracellular
G protein. Automatic classification of GPCRs can provide important information for the development of novel drugs in pharmaceutical
industry. In this paper, we propose an evolutionary approach, GPCR-MPredictor, which combines individual classifiers for predicting
GPCRs. GPCR-MPredictor is a web predictor that can efficiently predict GPCRs at five levels. The first level determines whether
a protein sequence is a GPCR or a non-GPCR. If the predicted sequence is a GPCR, then it is further classified into family,
subfamily, sub-subfamily, and subtype levels. In this work, our aim is to analyze the discriminative power of different feature
extraction and classification strategies in case of GPCRs prediction and then to use an evolutionary ensemble approach for
enhanced prediction performance. Features are extracted using amino acid composition, pseudo amino acid composition, and dipeptide
composition of protein sequences. Different classification approaches, such as k-nearest neighbor (KNN), support vector machine (SVM), probabilistic neural networks (PNN), J48, Adaboost, and Naives Bayes, have been used to classify GPCRs. The proposed hierarchical GA-based ensemble classifier exploits
the prediction results of SVM, KNN, PNN, and J48 at each level. The GA-based ensemble yields an accuracy of 99.75, 92.45, 87.80, 83.57, and 96.17% at the five levels, on
the first dataset. We further perform predictions on a dataset consisting of 8,000 GPCRs at the family, subfamily, and sub-subfamily
level, and on two other datasets of 365 and 167 GPCRs at the second and fourth levels, respectively. In comparison with the
existing methods, the results demonstrate the effectiveness of our proposed GPCR-MPredictor in classifying GPCRs families.
It is accessible at . 相似文献
45.
A Husain M Rashid R Mishra S Parveen DS Shin D Kumar 《Bioorganic & medicinal chemistry letters》2012,22(17):5438-5444
Two new series of benzimidazole bearing oxadiazole[1-(1H-benzo[d]imidazol-2-yl)-3-(5-substituted-1,3,4-oxadiazol-2-yl)propan-1-ones (4a-l)] and triazolo-thiadiazoles[1-(1H-benzo[d]imidazol-2-yl)-3-(6-(substituted)-[1,2,4]triazolo[3,4-b][1,3,4]thiadiazol-3-yl)propan-1-one (7a-e)] have been synthesized successfully from4-(1H-benzo[d]imidazol-2-yl)-4-oxobutanehydrazide (3) with an aim to produce promising anticancer agents. In vitro anticancer activities of synthesized compounds were screened at the National Cancer Institute (NCI), USA, according to their applied protocol against full NCI 60 human cell lines panel; results showed good to remarkable anticancer activity. Among them, compound (4j, NCS: 761980) exhibited significant growth inhibition and further screened at 10-fold dilutions of five different concentrations (0.01, 0.1, 1, 10 and 100μM) with GI(50) values ranging from 0.49 to 48.0μM and found superior for the non-small cell lung cancer cell lines like HOP-92 (GI(50) 0.49, TGI 19.9,LC(50) >100 and Log(10)GI(50) -6.30, Log(10)TGI -4.70, Log(10)LC(50) >-4.00). 相似文献
46.
A key feature of speech is its stereotypical 5 Hz rhythm. One theory posits that this rhythm evolved through the modification of rhythmic facial movements in ancestral primates. If the hypothesis has any validity, then a comparative approach may shed some light. We tested this idea by using cineradiography (X-ray movies) to characterize and quantify the internal dynamics of the macaque monkey vocal tract during lip-smacking (a rhythmic facial expression) versus chewing. Previous human studies showed that speech movements are faster than chewing movements, and the functional coordination between vocal tract structures is different between the two behaviors. If rhythmic speech evolved through a rhythmic ancestral facial movement, then one hypothesis is that monkey lip-smacking versus chewing should also exhibit these differences. We found that the lips, tongue, and hyoid move with a speech-like 5 Hz rhythm during lip-smacking, but not during chewing. Most importantly, the functional coordination between these structures was distinct for each behavior. These data provide empirical support for the idea that the human speech rhythm evolved from the rhythmic facial expressions of ancestral primates. 相似文献
47.
Xeroderma pigmentosum-Cockayne syndrome (XP-CS) includes facial freckling and early skin cancers typical of XP and some features typical of CS, such as mental retardation, spasticity, short stature, and hypogonadism. XP-CS does not include skeletal involvement, the facial phenotype of CS, or CNS demyelination and calcifications. We present a rare patient whose genome probably harbored a specific combination of mutations producing a rare double syndrome of XP-CS, with facial phenotype of CS, and CNS demyelination. 相似文献
48.
Ahmad Ali Muhammad Abdullah Masroor Ellahi Babar Khalid Javed Asif Nadeem 《Journal of genetics》2008,87(3):219-227
An investigation to understand the dynamics and biological significance of fragile site expression, and identification of
5-fluorodeoxyuridine (FUdR) induced chromosomal gaps/breaks, were carried out in an experimental flock of 45 Suffolk sheep.
The statistical comparison revealed, highly significant variation in the frequency of chromosomal fragile site expression
between control and FUdR cultures. Mean (± S.D.) values for cells with gaps and breaks, or aberrant cell count (AC), and the
number of aberrations (NoA) per animal were 2.02 ± 0.34, 2.42 ± 0.48, 13.26 ± 0.85 and 21.87 ± 1.88 (P < 0.01) in control and FUdR cultures, respectively. The comparison of age revealed nonsignificant variation between control
and FUdR cultures. The G-band analysis of fragile site data revealed gaps in 29 autosomal and two X-chromosomal bands in the
control cultures, whereas FUdR treated cultures scored 78 unstable bands in autosomes of which 56 were significantly fragile.
X-chromosomes expressed breaks and gaps in six G-negative bands and five of them (Xq13, Xq15, Xq17, Xq24 and Xq26) were significantly
fragile. The distribution comparison of autosomal fragile sites between sex groups did not reveal any significant variation.
Female X-chromosomes were significantly more fragile than the male X-chromosomes. The distribution comparison for age groups
(lambs versus adults) revealed significantly higher number of fragile bands in adults. Comparison of published data on reciprocal
translocations in sheep with the fragile-site data obtained in this study indicated that the break sites of both phenomena
were correlated. Similarities were also found between fragile sites and breakpoints of evolutionary significance in family
Bovidae. 相似文献
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Onion (Allium cepa L.) is protandrous in nature and requires cross‐pollination to avoid inbreeding. The pollination potential of native bees (Hymenoptera) and true flies (Diptera) was assessed in the perspective of finding the best pollinators for onion cross‐pollination and seed multiplication. The community of pollinators was composed of four bee species and twelve true fly species. Episyrphus balteatus, Eupeodes sp., Musca domestica and Eristalinus aeneus were the most abundant pollinators. The maximum pollinator activity was observed from 12 to 24 days after opening of the flowers. The pollination effectiveness of tested bees (Apis dorsata and Apis florea) was greater than true flies (E. balteatus, Eupeodes sp., M. domestica, E. aeneus and Callihoridae sp.) in terms of Spears values. 相似文献