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51.
X-ray crystallographic studies performed on the product of the ketalization reaction of 13beta-ethyl-11alpha-hydroxy-gon-5-ene-3,17-dione have lead to the unequivocal assignment of the 10alpha stereochemistry to C10, showing that an inversion of configuration occurred during formation of the 3,17-diketal. From the Swern oxidation of this compound, 11alpha-(methylthio)methoxy-10alpha-gonene was obtained as the major product instead of the desired 11-ketone. Modeling studies showed that the configurational instability at C10 is determined by the presence of the 11alpha-hydroxyl group. 相似文献
52.
The full-length cDNA that encodes the hemolytic toxin Avt-I, with 226 amino acids, from the venomous sea anemone Actineria villosa has been cloned using the oligo-capping method. The cDNA contains 681bp open reading frame and its predicted amino acid sequences revealed that Avt-I was basic polypeptides without cysteine residues and Arg-Gly-Asp (RGD) motif sequence. The mature Avt-I has a predicted molecular weight of 19.6 kDa and its theoretical isoelectric point is 9.3. The Avt-I revealed 99, 61, 57, and 57% amino acid similarity with hemolytic toxins Pstx20, EqtII, StII, and HmT from Phyllodiscus semoni, Actinia Equina, Stichodactyla helianthus, and Heteractis magnifica, respectively. The characteristic amphiphilic alpha-helix structure was found at the N-terminal region of the mature Avt-I. Recombinant Avt-I (rAvt-I) was expressed in Escherichia coli BL21 (DE3) strain as a biologically active form and purified rAvt-I caused 50% hemolytic activity against 1% sheep erythrocytes at a concentration of 6.3 ng/ml (0.32 nM). M9Y medium led to more than 2-fold increase in rAvt-I yield than cultivation in Luria-Bertani medium. 相似文献
53.
Taira T Toma N Ichi M Takeuchi M Ishihara M 《Bioscience, biotechnology, and biochemistry》2005,69(4):852-854
We examined the tissue distribution, synthesis stage, and ethylene induction of three types of pineapple chitinase using chitinase activity gel and immunoblot analysis. Type A (acidic class III) exists in all tissues, while type B (weakly basic class I, which has strong antifungal activity) and type C (acidic class I) are localized mainly in the leaf and stem. In a pericarp, type A exists at all stages during fruit development, while type B and type C exist only at the early stage. Synthesis of type A is induced by ethylene, while that of types B and C is not affected by it. These results suggest that the physiological roles of these three types of chitinase in pineapple are different. 相似文献
54.
The conformational behavior of methyl(2-O-methyl-alpha-L-rhamnopyranosyl)phosphate, together with a group of potentially more stable analogues, was investigated through a DFT approach at the B3LYP/6-31G(d) level; the energy of all the optimized structures was recalculated using a continuum solvent model, C-PCM, choosing water as the solvent. The compounds exhibited several, sometimes tenths of populated conformations so that the overall properties of flexibility and mobility were evaluated. The analogue in which the pyranose oxygen atom is replaced by a methylene group emerges as the best candidate as a mimic of the reference 1-phosphate, in spite of the fact that it lacks the anomeric and exo-anomeric effects. The other analogues result poorer mimics because of a conformational equilibrium at the pyranose ring or of an excessive rigidity of the aglycone moiety. 相似文献
55.
The occurrence of the tachinid parasitoid Billaea rhynchophorae (Blanchard) on larvae of the palm weevil Rhynchophorus palmarum (L.) was evaluated in plantations of piassava palm (Attalea funifera Mart.) and African oil palm (Elaeis guineensis Jacquin), in southeastern Bahia, Brazil. The monthly percentages of parasitism were evaluated during 13 months, from November 2000 to November 2001, based on the comparison between the number of parasitized and non-parasitized cocoons of R. palmarum. Mean parasitism was 40% and ranged from 50% in November 2000 to 18% in July 2001. While there is no method of mass reproduction of the parasitoid, a simple management practice is recommended, in order to preserve its beneficial effects in palm plantations. 相似文献
56.
57.
Honda F Hane Y Toma T Yachie A Kim ES Lee SK Takagi M Mizutani S Morio T 《Biochemical and biophysical research communications》2012,417(1):162-168
Protein delivery to primary cells by protein transduction domain (PTD) serves as a novel measure for manipulation of the cells for biological study and for the treatment of various human conditions. Although the method has been employed to modulate cellular function in vitro, only limited reports are available on its application in the replacement of deficient signaling molecules into primary cells. We examined the potential of recombinant proteins to compensate for defective cytosolic components of the NADPH oxidase complex in chronic granulomatous disease (CGD) neutrophils in both p47(phox) and p67(phox) deficiency. The p47(phox) or p67(phox) protein linked to Hph-1 PTD was effectively expressed in soluble form and transduced into human neutrophils efficiently without eliciting unwanted signal transduction or apoptosis. The delivered protein was stable for more than 24h, expressed in the cytoplasm, translocated to the membrane fraction upon activation, and, most importantly able to restored reactive oxygen species (ROS) production. Although research on human primary neutrophils using the protein delivery system is still limited, our data show that the protein transduction approach for neutrophils may be applicable to the control of local infections in CGD patients by direct delivery of the protein product. 相似文献
58.
Yo Toma J. Ryan Stewart Aya Nishiwaki Fabián G. Fernández 《Global Change Biology Bioenergy》2012,4(5):566-575
Although Miscanthus sinensis grasslands (Misc‐GL) and Cryptomeria japonica forest plantations (Cryp‐FP) are proposed bioenergy feedstock systems, their relative capacity to sequester C may be an important factor in determining their potential for sustainable bioenergy production. Therefore, our objective was to quantify changes in soil C sequestration 47 years after a Misc‐GL was converted to a Cryp‐FP. The study was conducted on adjacent Misc‐GL and Cryp‐FP located on Mt. Aso, Kumamoto, Japan. After Cryp‐FP establishment, only the Misc‐GL continued to be managed by annual burning every March. Mass C and N, δ13C, and δ15N at 0–30 cm depth were measured in 5 cm increments. Carbon and N concentrations, C:N ratio, δ13C, and δ15N were measured in litter and/or ash, and rhizomes or roots. Although C input in Misc‐GL by M. sinensis was approximately 36% of that in Cryp‐FP by C. japonica, mean annual soil C sequestration in Misc‐GL (503 kg C ha?1 yr?1) was higher than that in Cryp‐FP (284 kg C ha?1 yr?1). This was likely the result of larger C input from aboveground litter to soil, C‐quality (C:N ratio and lignin concentration in aboveground litter) and possibly more recalcitrant C (charcoal) inputs by annual burning. The difference in soil δ15N between sites indicated that organic C with N had greater cycling between heterotrophic microbes and soil and produces more recalcitrant humus in Misc‐GL than in Cryp‐FP. Our data indicate that in terms of soil C sequestration, maintenance of Misc‐GL may be more advantageous than conversion to Cryp‐FP in Aso, Japan. 相似文献
59.
In sentence comprehension research, the case system, which is one of the subsystems of the language processing system, has been assumed to play a crucial role in signifying relationships in sentences between noun phrases (NPs) and other elements, such as verbs, prepositions, nouns, and tense. However, so far, less attention has been paid to the question of how cases are processed in our brain. To this end, the current study used fMRI and scanned the brain activity of 15 native English speakers during an English-case processing task. The results showed that, while the processing of all cases activates the left inferior frontal gyrus and posterior part of the middle temporal gyrus, genitive case processing activates these two regions more than nominative and accusative case processing. Since the effect of the difference in behavioral performance among these three cases is excluded from brain activation data, the observed different brain activations would be due to the different processing patterns among the cases, indicating that cases are processed differently in our brains. The different brain activations between genitive case processing and nominative/accusative case processing may be due to the difference in structural complexity between them. 相似文献
60.