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排序方式: 共有112条查询结果,搜索用时 24 毫秒
41.
Christeller JT Farley PC Marshall RK Anandan A Wright MM Newcomb RD Laing WA 《Journal of molecular evolution》2006,63(6):747-757
The squash (Cucurbita maxima) phloem exudate-expressed aspartic proteinase inhibitor (SQAPI) is a novel aspartic acid proteinase inhibitor, constituting
a fifth family of aspartic proteinase inhibitors. However, a comparison of the SQAPI sequence to the phytocystatin (a cysteine
proteinase inhibitor) family sequences showed ∼30% identity. Modeling SQAPI onto the structure of oryzacystatin gave an excellent
fit; regions identified as proteinase binding loops in cystatin coincided with regions of SQAPI identified as hypervariable,
and tryptophan fluorescence changes were also consistent with a cystatin structure. We show that SQAPI exists as a small gene
family. Characterization of mRNA and clone walking of genomic DNA (gDNA) produced 10 different but highly homologous SQAPI
genes from Cucurbita maxima and the small family size was confirmed by Southern blotting, where evidence for at least five loci was obtained. Using primers
designed from squash sequences, PCR of gDNA showed the presence of SQAPI genes in other members of the Cucurbitaceae and in
representative members of Coriariaceae, Corynocarpaceae, and Begoniaceae. Thus, at least four of seven families of the order
Cucurbitales possess member species with SQAPI genes, covering ∼99% of the species in this order. A phylogenetic analysis
of these Cucurbitales SQAPI genes indicated not only that SQAPI was present in the Cucurbitales ancestor but also that gene
duplication has occurred during evolution of the order. Phytocystatins are widespread throughout the plant kingdom, suggesting
that SQAPI has evolved recently from a phytocystatin ancestor. This appears to be the first instance of a cystatin being recruited
as a proteinase inhibitor of another proteinase family.
[Reviewing Editor: Dr. Antony Dean] 相似文献
42.
Parsons AB Lopez A Givoni IE Williams DE Gray CA Porter J Chua G Sopko R Brost RL Ho CH Wang J Ketela T Brenner C Brill JA Fernandez GE Lorenz TC Payne GS Ishihara S Ohya Y Andrews B Hughes TR Frey BJ Graham TR Andersen RJ Boone C 《Cell》2006,126(3):611-625
Discovering target and off-target effects of specific compounds is critical to drug discovery and development. We generated a compendium of "chemical-genetic interaction" profiles by testing the collection of viable yeast haploid deletion mutants for hypersensitivity to 82 compounds and natural product extracts. To cluster compounds with a similar mode-of-action and to reveal insights into the cellular pathways and proteins affected, we applied both a hierarchical clustering and a factorgram method, which allows a gene or compound to be associated with more than one group. In particular, tamoxifen, a breast cancer therapeutic, was found to disrupt calcium homeostasis and phosphatidylserine (PS) was recognized as a target for papuamide B, a cytotoxic lipopeptide with anti-HIV activity. Further, the profile of crude extracts resembled that of its constituent purified natural product, enabling detailed classification of extract activity prior to purification. This compendium should serve as a valuable key for interpreting cellular effects of novel compounds with similar activities. 相似文献
43.
Jan A. Pechenik Richelle Berard Dara Daniels Timothy R. Gleason Denise Champlin 《Invertebrate Biology》2001,120(2):142-148
Abstract. It is well known that the competent larvae of many marine invertebrate species can be stimulated to metamorphose by exposing them to elevated concentrations of certain ions, neuroactive substances, and pharmacological agents. In this study we report that larvae of the euryhaline polychaete Capitella sp. I are induced to metamorphose within 24–48 h by reducing salinity from 30%‰ to 12–15%‰. At 10%‰, however, fewer larvae metamorphosed and the normal metamorphic response to sediment was inhibited; competence was restored within 3 h of transferring the larvae back to full strength seawater (30%‰). Larvae also metamorphosed within 24 h in response to increased external cadmium concentrations of 1000–2000 μg 1–1 . Further understanding of how reduced salinity and elevated cadmium stimulate (or inhibit) metamorphosis may lead to a better understanding of signal perception and transduction in this and other species. 相似文献
44.
Hodek P Bortek-Dohalská L Sopko B Sulc M Smrcek S Hudecek J Janků J Stiborová M 《Journal of enzyme inhibition and medicinal chemistry》2005,20(1):25-33
The series of diamondoids: adamantane, diamantane, triamantane, 2-isopropenyl-2-methyladamantane and 3-isopropenyl-3-methyldiamantane (3-IPMDIA), were employed to elucidate the molecular basis of their interaction with the active site of cytochromes P450 (CYP) of a 2B subfamily. These potent inhibitors of CYP2B enzymes were docked into the homology model of CYP2B4. Apparent dissociation constants calculated for the complexes of CYP2B4 with docked diamandoids agreed closely with the experimental data showing inhibition potency of the compounds and their binding affinity to CYP2B4. Superimposed structures of docked diamondoids mapped binding site residues. As they are mainly non-polar residues, the hydrophobicity plays the major role in the binding of diamondoids. Overlapping structure of diamondoids defined an elliptical binding cavity (5.9A inner diameter, 7.9A length) forming an angle of approximately 43 degrees with the heme plane. CYP2B specific diamondoids, namely 3-IPMDIA, showing the highest binding affinity, should be considered for a potential clinical use. 相似文献
45.
Serum thyroid function tests (T4, T3, rT3 and TSH levels) and measures of peripheral thyroid hormone action (serum dopamine-beta-hydroxylase activity (DBH) and sex hormone binding globulin (SHBG] were determined in 6 women before and one month after initiating an aerobic physical conditioning program. The same measurements were made in a control group of 6 women who did not increase their activity during this time. In physically conditioned subjects, the resting heart rate decreased from 65.1 +/- 3.9 (mean +/- SE) at baseline to 58.0 +/- 2.9 beats per minute after one month (P less than 0.025), indicating an appreciable state of physical conditioning was achieved. However, there were no statistically significant changes in thyroid function test, serum DBH or SHBG levels in either the physically conditioned or the control group. These data indicate that being physically conditioned has a negligible effect on thyroid status. 相似文献
46.
Kamrul Islam Md. Abu Sayeed Emran Hossen Farhana Khanam Richelle C. Charles Jason Andrews Edward T. Ryan Firdausi Qadri 《PLoS neglected tropical diseases》2016,10(4)
Background
There is an urgent need for an improved diagnostic assay for typhoid fever. In this current study, we compared the recently developed TPTest (Typhoid and Paratyphoid Test) with the Widal test, blood culture, and two commonly used commercially available kits, Tubex and Typhidot.Methodology
For analysis, we categorized 92 Bangladeshi patients with suspected enteric fever into four groups: S. Typhi bacteremic patients (n = 28); patients with a fourfold change in Widal test from day 0 to convalescent period (n = 7); patients with Widal titer ≥1:320 (n = 13) at either acute or convalescent stage of disease; and patients suspected with enteric fever, but with a negative blood culture and Widal titer (n = 44). We also tested healthy endemic zone controls (n = 20) and Bangladeshi patients with other febrile illnesses (n = 15). Sample size was based on convenience to facilitate preliminary analysis.Principle findings
Of 28 S. Typhi bacteremic patients, 28 (100%), 21 (75%) and 18 (64%) patients were positive by TPTest, Tubex and Typhidot, respectively. In healthy endemic zone controls, the TPTest method was negative in all, whereas Tubex and Typhidot were positive in 3 (15%) and 5 (25%), respectively. We then estimated sensitivity and specificity of all diagnostic tests using Bayesian latent class modeling. The sensitivity of TPTest, Tubex and Typhidot were estimated at 96.0% (95% CI: 87.1%-99.8%), 60.2% (95% CI: 49.3%-71.2%), and 59.6% (95% CI: 50.1%-69.3%), respectively. Specificity was estimated at 96.6% (90.7%-99.2%) for TPTest, 89.9% (79.6%-96.8%) for Tubex, and 80.0% (67.7%-89.7%) for Typhidot.Conclusion
These results suggest that the TPTest is highly sensitive and specific in diagnosing individuals with typhoid fever in a typhoid endemic setting, outperforming currently available and commonly used alternatives. 相似文献47.
Alaullah Sheikh Farhana Khanam Md. Abu Sayeed Taibur Rahman Marcin Pacek Yanhui Hu Andrea Rollins Md. Saruar Bhuiyan Sean Rollins Anuj Kalsy Mohammad Arifuzzaman Daniel T. Leung David A. Sarracino Bryan Krastins Richelle C. Charles Regina C. LaRocque Alejandro Cravioto Stephen B. Calderwood W. Abdullah Brooks Jason B. Harris Joshua LaBaer Firdausi Qadri Edward T. Ryan 《PLoS neglected tropical diseases》2011,5(6)
48.
S. Richelle Monaghan Michael L. Kent Virginia G. Watral R. John Kaufman Lucy E. J. Lee Niels C. Bols 《In vitro cellular & developmental biology. Animal》2009,45(3-4):135-147
The use of animal cell cultures as tools for studying the microsporidia of insects and mammals is briefly reviewed, along with an in depth review of the literature on using fish cell cultures to study the microsporidia of fish. Fish cell cultures have been used less often but have had some success. Very short-term primary cultures have been used to show how microsporidia spores can modulate the activities of phagocytes. The most successful microsporidia/fish cell culture system has been relatively long-term primary cultures of salmonid leukocytes for culturing Nucleospora salmonis. Surprisingly, this system can also support the development of Enterocytozoon bienusi, which is of mammalian origin. Some modest success has been achieved in growing Pseudoloma neurophilia on several different fish cell lines. The eel cell line, EP-1, appears to be the only published example of any fish cell line being permanently infected with microsporidia, in this case Heterosporis anguillarum. These cell culture approaches promise to be valuable in understanding and treating microsporidia infections in fish, which are increasingly of economic importance. 相似文献
49.
50.
We present the prenatally identified case of mosaicism of chromosome 16 trisomy. A patient with the pregnancy complicated in the first trimester by the threat of breaking was refered to the high risk group according to the results of the screening program. The ultrasonic research revealed a number of phenotypical pathologies in 19-weeks-old fetus such as congenital heart disease (ventricular septal defect), hyperechoic bowel, single umbilical artery and some other ones. Cytogenetical and FISH analyses of the placental villi revealed karyotype with chromosome 16 trisomy. The further research of amniotic fluid cells revealed the karyotype of fetus as mos47,XX,+16 / 46,XX. The pathologoanatomic research of the abortus has verified the multiple congenital malformations. 相似文献