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161.
162.
Abhijit Dandapat Jagannath Bhattacharyya Srimonta Gayen Anirban Chakraborty Anannya Banga Rajeswari Mukherjee Chandi Charan Mandal Munshi Azad Hossain Samarjit Roy Asitava Basu Soumitra Kumar Sen 《Journal of plant biochemistry and biotechnology.》2014,23(1):81-92
The primary technical constraint plant scientists face in generating insect resistant transgenic crops with insecticidal Bacillus thuringiensis (Bt) crystal protein (Cry) genes remains failing to generate sufficiently large numbers of effective resistant transgenic plant lines. One possible means to overcome this challenge is through deployment of a Cry toxin gene that contains high levels of insecticidal specific activity for target insect pests. In the present study, we tested this hypothesis using a natural variant of the Cry1Ab toxin under laboratory conditions that possessed increased insecticidal potency against the yellow stem borer (YSB, Scirpophaga incertulus), one of the most damaging rice insect pests. Following adoption of a stringent selection strategy for YSB resistant transgenic rice lines under field conditions, results showed recovery of a significantly higher number of YSB resistant independent transgenic plant lines with the variant cry1Ab gene relative to transgenic plant lines harbouring cry1Ab berliner gene. Structural homology modelling of the variant toxin peptide with the Cry1Aa toxin molecule, circular dichroism spectral analysis, and hydropathy plot analysis indicated that serine substitution by phenylalanine at amino acid position 223 of the Cry1Ab toxin molecule resulted in a changed role for α-helix 7 in domain I of Cry1Ab for enhanced toxicity. 相似文献
163.
Li Xu Xihui Shen Andrew Bryan Simran Banga Michele S. Swanson Zhao-Qing Luo 《PLoS pathogens》2010,6(3)
Legionella pneumophila is an intracellular pathogen responsible for Legionnaires'' disease. This bacterium uses the Dot/Icm type IV secretion system to inject a large number of bacterial proteins into host cells to facilitate the biogenesis of a phagosome permissive for its intracellular growth. Like many highly adapted intravacuolar pathogens, L. pneumophila is able to maintain a neutral pH in the lumen of its phagosome, particularly in the early phase of infection. However, in all cases, the molecular mechanisms underlying this observation remain unknown. In this report, we describe the identification and characterization of a Legionella protein termed SidK that specifically targets host v-ATPase, the multi-subunit machinery primarily responsible for organelle acidification in eukaryotic cells. Our results indicate that after being injected into infected cells by the Dot/Icm secretion system, SidK interacts with VatA, a key component of the proton pump. Such binding leads to the inhibition of ATP hydrolysis and proton translocation. When delivered into macrophages, SidK inhibits vacuole acidification and impairs the ability of the cells to digest non-pathogenic E. coli. We also show that a domain located in the N-terminal portion of SidK is responsible for its interactions with VatA. Furthermore, expression of sidK is highly induced when bacteria begin to enter new growth cycle, correlating well with the potential temporal requirement of its activity during infection. Our results indicate that direct targeting of v-ATPase by secreted proteins constitutes a virulence strategy for L. pneumophila, a vacuolar pathogen of macrophages and amoebae. 相似文献
164.
Aims: Aim of the study was to develop a medium for optimal heparinase production with a strain of Aspergillus flavus (MTCC‐8654) by using a multidimensional statistical approach. Methods and Results: Statistical optimization of intracellular heparinase production by A. flavus, a new isolate, was investigated. Plackett–Burman design was used to evaluate the affect of medium constituents on heparinase yield. The experimental results showed that the production of heparinase was dependent upon heparin, the inducer; chitin, structurally similar to heparin and NH4NO3, the nitrogen source. A central composite design was applied to derive a statistical model for optimizing the composition of the fermentation medium for the production of heparinase enzyme. The optimum fermentation medium consisted of (g l?1) Mannitol, 8·0; NH4NO3, 2·5; K2HPO4, 2·5; Na2HPO4, 2·5; MgSO4.7H2O, 0·5; Chitin, 17·1; Heparin, 0·6; trace salt solution (NaMoO4.2H2O, CoCl2.6H2O, CuSO4.5H2O, FeSO4.7H2O, CaCl2), 10?4 mol l?1. Conclusions: A 2·37‐fold increase in heparinase production was achieved in economic and effective manner by the application of statistical designs in medium optimization. Significance and Impact of the Study: Heparinase production was doubled by statistical optimization in a cost‐effective manner. This heparinase can find application in pharmaceutical industry and for the generation of low‐molecular‐weight heparins, active as antithrombotic and antitumour agents. 相似文献
165.
166.
Alok Banga Tsewang Gyurmey David Matuskey Daniel F. Connor Richard F. Kaplan David C. Steffens 《The Yale journal of biology and medicine》2013,86(2):235-244
Depression and comorbid cognitive impairment in the elderly can be difficult to
distinguish from dementia. Adding to the complex differential is that depression
may be part of a bipolar illness rather than a unipolar mood disorder. A
diligent workup and close monitoring of patients can inform appropriate
treatment and can make the difference between recovery and persistence of
symptoms. The present case will illustrate how a comprehensive workup utilizing
extensive data gathering, laboratory workup, use of neuropsychological testing,
neuroimaging, and timely treatment can lead to successful clinical outcomes that
can be sustained for many years. 相似文献
167.
168.
Iron-histidine resonance raman band of deoxyheme proteins: effects of anharmonic coupling and glass-liquid phase transition
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Weak anharmonic coupling of two soft molecular vibrations is shown to cause pronounced temperature dependence of the corresponding resonance Raman bands. The developed theory is used to interpret the temperature dependence of the iron-histidine band of deoxyheme proteins and model compounds. It is shown that anharmonic coupling of the iron-histidine and heme doming vibrations must cause pronounced broadening of the band, its asymmetry, and shift of its maximum to the red upon heating. It also can lead to a structured shape of this band at room temperature. Proper consideration of the anharmonic coupling allows simulation of the temperature dependence of the iron-histidine band shape of horse heart myoglobin in the temperature interval of 10-300 K, using the minimum number of necessary parameters. Analysis of this temperature dependence clearly shows that the iron-histidine band of deoxyheme proteins is sensitive to the glass-liquid phase transition in the protein hydration shell, which takes place at 160-190 K. 相似文献
169.
170.
ITS sequences determined for 53 Erysiphe specimens on Syringa and Ligustrum collected in Europe, East Asia, and North and South America were divided into two ITS groups, S and K types. Phylogenetic
analysis showed that these two ITS types do not share a common ancestor and form separate clades. The K type on Ligustrum was identified as Erysiphe ligustri based on the three-dimensional branching pattern of appendages. Morphological observations showed that there are some morphological
differences—pigmentation of appendages and number of ascospores per ascus—between the S and K types on Syringa. Based on these morphological observations, the S and K types on Syringa were identified as E. syringae and E. syringae-japonicae, respectively. The recent abundant production of chasmothecia by lilac powdery mildew in Europe was caused by E. syringae-japonicae introduced from East Asia. DNA sequence analyses of the rDNA ITS region and the 28S rDNA, tub2, CYP51, and Chs1 genes did not support an interspecific hybrid origin for E. syringae-japonicae. Haplotype analysis suggested that E. syringae originated in North America and independently migrated to East Asia and Europe/South America. 相似文献