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211.
Isotope-edited NMR of cyclosporin A bound to cyclophilin: evidence for a trans 9,10 amide bond 总被引:2,自引:0,他引:2
S W Fesik R T Gampe T F Holzman D A Egan R Edalji J R Luly R Simmer R Helfrich V Kishore D H Rich 《Science (New York, N.Y.)》1990,250(4986):1406-1409
The binding of a 13C-labeled cyclosporin A (CsA) analog to cyclophilin (peptidyl prolyl isomerase) was examined by means of isotope-edited nuclear magnetic resonance (NMR) techniques. A trans 9,10 peptide bond was adopted when CsA was bound to cyclophilin, in contrast to the cis 9,10 peptide bond found in the crystalline and solution conformations of CsA. Furthermore, nuclear Overhauser effects (NOEs) were observed between the zeta 3 and epsilon 3 protons of the methylleucine (MeLeu) residue at position 9 of CsA and tryptophan121 (Trp121) and phenylalanine (Phe) protons of cyclophilin, suggesting that the MeLeu9 residue of CsA interacts with cyclophilin. These results illustrate the power of isotope-edited NMR techniques for rapidly providing useful information about the conformations and active site environment of inhibitors bound to their target enzymes. 相似文献
212.
Background
A stable and systematic daily change in light levels at dawn and dusk provides the most reliable indicator of the phase of the day. It is likely that organisms have evolved mechanisms to use these twilight transitions as the primary zeitgeber to adjust their circadian phases. In this study, we investigated under natural illumination conditions the effects of daylight exposure restricted to twilights on the timing of testicular regression and locomotor activity of the house sparrow (Passer domesticus), which possesses a strongly self-sustaining circadian system. 相似文献213.
214.
The n-hexane and ethyl acetate extracts of whole plants of Dysophylla stellata significantly inhibited edema when applied topically at doses of 0.5 and 1 mg/ear in TPA-induced ear edema assay in mice. Further, both the extracts were evaluated for COX-1 and COX-2 inhibitory activities and showed 85.42 and 57.38%; and 71.79 and 89.27% inhibition at 50 µg/ml, respectively. Chromones (1 and 2) present in these extracts could be responsible for their COX-1 and COX-2 inhibitory and anti-inflammatory activities. The ethyl acetate extract showed antioxidant activity in DPPH and ABTS radical scavenging assay where as n-hexane extract found to be inactive. 相似文献
215.
BACKGROUND: Preplant fumigation with methyl bromide (MeBr) has been used for control of soilborne pests in high‐value annual, perennial and nursery crops, but is being phased out. In 2007 and 2008, research trials were conducted to evaluate the effects of surface treatments and two application shanks on pest control with 1,3‐dicloropropene (1,3‐D) in perennial crop nurseries. RESULTS: All 1,3‐D treatments controlled nematodes similarly to MeBr. Application of 1,3‐D with virtually impermeable film (VIF) reduced Fusarium oxysporum compared with unfumigated plots, but was not as effective as MeBr. Applications of 1,3‐D with VIF or 1,3‐D followed by metam sodium reduced Pythium spp., but 1,3‐D followed by intermittent water seals was comparable with the untreated plots. When sealed with high‐density polyethylene (HDPE) film or VIF, 1,3‐D generally was as effective as MeBr for reducing weed density and total weed biomass, but weed control was reduced by intermittent water seals and in unsealed plots subsequently re‐treated with additional 1,3‐D or metam sodium. CONCLUSION: Applications of 1,3‐D sealed with HDPE or VIF film or with intermittent water seals can control nematodes similarly to MeBr. However, additional management practices may be needed for effective pathogen and weed control if plastic film is not used. Copyright © 2011 Society of Chemical Industry 相似文献
216.
217.
G.?Krishna?Kishore S.?Pande J.?Narayana?Rao A.?R.?PodileEmail author 《European journal of plant pathology / European Foundation for Plant Pathology》2005,113(3):315-320
Three hundred and ninety-three groundnut-associated bacterial strains, applied both as seed treatment and soil amendment,
were evaluated for control of stem rot disease (caused by Sclerotium rolfsii) of groundnut in a controlled environment. Twelve strains significantly (P=0.01) reduced the incidence of stem, rot of which groundnut seed endophytes Pseudomonas aeruginosa GSE 18 and GSE 19 reduced the seedling mortality by 54% and 58%, compared to the control. In dual cultures, the 12 biocontrol
strains reduced the mycelial growth of S. rolfsii by 32%–74% as compared to the control. Cell- free culture filtrates of P. aeruginosa GSE 18 and GSE 19 inhibited the activity in vitro of the cell wall-degrading enzymes (CWDE) polygalacturonase and cellulase by S. rolfsii up to a maximum of 55% and 50%, respectively, when measured 6 days after inoculation. Pseudomonas aeruginosa GSE 18 and GSE 19 with a known tolerance to thiram, a commonly used seed dressing fungicide, suppressed the growth of S. rolfsii, inhibited the activity of CWDE, and reduced the incidence of stem rot, suggesting the usefulness of these biocontrol strains
as components in the integrated management of groundnut stem rot. 相似文献
218.
Sk. Z. Ali V. Sandhya Minakshi Grover N. Kishore L. Venkateswar Rao B. Venkateswarlu 《Biology and Fertility of Soils》2009,46(1):45-55
A thermotolerant strain AKM-P6 of Pseudomonas sp. possessing plant growth-promoting properties was isolated from rhizosphere of pigeon pea grown under semiarid conditions
in India. The effect of inoculation with AKM-P6 on survival and growth of sorghum seedlings at elevated temperatures (ET)
was investigated under sterile and nonsterile soil conditions. Inoculation with strain AKM-P6 helped sorghum (var CSV-15)
seedlings to survive and to grow at elevated temperatures (47–50°C day/30–33°C night) up to 15 days while uninoculated plants
died by the fifth day of exposure to elevated temperature. Under sterile and nonsterile conditions, significantly higher root
and shoot biomass were recorded in inoculated seedlings as compared to uninoculated control at ET, but this difference was
nonsignificant at ambient temperature. Inoculation induced the biosynthesis of high-molecular weight proteins in leaves under
elevated temperature, reduced membrane injury, and improved the levels of cellular metabolites like proline, chlorophyll,
sugars, amino acids, and proteins. Scanning electron microscopy studies confirmed the colonization and establishment of the
organism on the root surface. The 16SrDNA sequence of the strain AMK-P6 showed 97% homology with that of Pseudomonas aeruginosa in the existing database. The results indicate that Pseudomonas sp. strain AKM-P6 can enhance tolerance of sorghum seedlings to elevated temperatures by inducing physiological and biochemical
changes in the plant. 相似文献
219.
A study of the biochemical oxygen demand (BOD) of waters from ten channel catfish ponds at Auburn, Alabama, revealed that the 5-d BOD (BOD5 ) seldom exceeded 8 mg/L and that the ultimate BOD (BODu ) was usually less than 30 mg/L. Water samples from catfish ponds usually needed to be diluted only 2 or 3 times to permit BOD5 measurements, and nitrification occurred even during a 5-d incubation period. Catfish pond waters were not extremely high in ammonia nitrogen concentration, and ammonia nitrogen introduced in the ammonium chloride-enriched dilution water caused an appreciable increase in BOD of some samples. Plankton respiration is a major component of carbonaceous BOD (CBOD) in catfish pond waters. Thus, the BOD is not expressed as rapidly during 5-d incubations as in typical waste-water. The ultimate BOD (BODu ) would be a good measurement of oxygen demand for catfish pond effluents, but it is difficult to measure. Data from this study suggest that BODu can be estimated from BOD5 , but the correlation is not strong ( R 2 = 0.62). An alternative is to develop a short-term BOD measurement specifically for effluents from channel catfish and other aquaculture ponds. This study suggests that a 10-d BOD conducted without nitrification inhibition or addition of ammonia nitrogen in dilution water might be a better alternative to standard BOD5 or BODu measurements normally used in wastewater evaluation. 相似文献