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1.
Vacuolar sequestration of valuable secondary metabolites remains the major limitation to the use of immobilization technology for large scale plant-cell-based bioprocesses, which otherwise may be a more efficient culture system than suspension for this biomass. In this initial study, the release of indole alkaloids produced by immobilized Catharanthus roseus cells cultured in Zenk's Alkaloid Production Medium was evaluated. Unstimulated alkaloid release in immobilized cultures reached levels of 10 to 50% of total production or 3 to 100% of known alkaloid content (30 to 4700 micrograms l-1), which was higher than that found for suspension cultures of the cell line used (10 to 25% of total production) without apparent cell lysis. Modifications of the medium pH value of immobilized cultures were explored in order to improve this release. Periodical additions of acid (HCl 0.1 N) or base (KOH 0.1 N) solutions (2% v/v) to different cultures resulted in rapid (less than 3 h) and transient variations in extracellular pH value from 5.5 to 4.3, and 5.8 to 8.5, respectively. In both cases, these variations provoked significant increase in total alkaloid (from approximately 5-10 mg l-1 to 15 mg l-1), ajmalicine (from 0 to approximately 0.29 mg l-1) and serpentine (from 0 to approximately 0.20 mg l-1) release, without apparent cell lysis or decrease in the culture viability. This product release was estimated to represent 100% of alkaloids produced. 相似文献
2.
Association of adenovirus type 2 early proteins with a soluble complex that synthesizes adenovirus DNA in vitro 总被引:3,自引:0,他引:3
H M Rho Y H Jeng W S Wold M Green 《Biochemical and biophysical research communications》1977,79(2):422-428
A soluble Ad2 DNA synthesizing complex was prepared from Ad2-infected KB cell nuclei and purified by exclusion chromatography on a BioGel A-50m column. The purified complex was able to synthesize DNA from all regions of the virus genome, as indicated by RI restriction endonuclease analysis of labeled DNA. Experiments were performed to identify Ad2-induced early polypeptides present in the complex. Ad2-infected and mock-infected cells were labeled with [35S]methionine 7–10 h postinfection, then incubated for 8 h to allow the 35S-labeled early polypeptides to become associated with the complex. The polypeptides in the purified complex and each of the cell fractions were identified by sodium dodecyl sulfate polyacrylamide gel electrophoresis and autoradiography. The major components of the purified complex were the 73K DNA binding phosphoprotein and 11K, two adenovirus 2-induced early polypeptides. The 11K has a preferred nuclear location. Small quantities of other Ad2-induced early proteins, 21K, 15K, and possibly 8.3K were also associated with the complex. 相似文献
3.
Joon H. Rho 《Analytical biochemistry》1980,105(1):414-423
We have examined the metabolites produced by in vitro incubation of benzo(a)pyrene with 3-methylcholanthrene-induced mice liver microsomes. Our objective was to observe directly a possible difference in microsomal enzyme systems of animal models having different susceptibility to chemical carcinogens. The metabolites produced by the two animal models, and mice, were analyzed by a highly sensitive, “three-dimensional” fluorescence plotting technique. The fluorescence spectra of the total ethyl acetate-soluble metabolites clearly indicate that the metabolites produced by enzymes were predominantly monohydroxylated benzo(a)pyrene while those produced by the liver microsomes of were highly enriched with the 7,8-dihydrodihydroxybenzo(a)pyrene type. 相似文献
4.
Nakagami H Nishikawa T Tamura N Maeda A Hibino H Mochizuki M Shimosato T Moriya T Morishita R Tamai K Tomono K Kaneda Y 《Journal of cellular and molecular medicine》2012,16(7):1629-1639
We previously identified a novel angiogenic peptide, AG30, with antibacterial effects that could serve as a foundation molecule for the design of wound-healing drugs. Toward clinical application, in this study we have developed a modified version of the AG30 peptide characterized by improved antibacterial and angiogenic action, thus establishing a lead compound for a feasibility study. Because AG30 has an α-helix structure with a number of hydrophobic and cationic amino acids, we designed a modified AG30 peptide by replacing several of the amino acids. The replacement of cationic amino acids (yielding a new molecule, AG30/5C), but not hydrophobic amino acids, increased both the angiogenic and the antimicrobial properties of the peptide. AG30/5C was also effective against methicillin-resistant Staphylococcus aureus (MRSA) and antibiotic-resistant Pseudomonas aeruginosa. In a diabetic mouse wound-healing model, the topical application of AG30/5C accelerated wound healing with increased angiogenesis and attenuated MRSA infection. To facilitate the eventual clinical investigation/application of these compounds, we developed a large-scale procedure for the synthesis of AG30/5C that employed the conventional solution method and met Good Manufacturing Practice guidelines. In the evaluation of stability of this peptide in saline solution, RP-HPLC analysis revealed that AG30/5C was fairly stable under 5°C for 12 months. Therefore, we propose the use of AG30/5C as a wound-healing drug with antibacterial and angiogenic actions. 相似文献
5.
6.
The effects of changes in host plants on the mate-searching behavior and feeding preferences of the white-spotted longicorn beetle Anoplophora malasiaca (Thomson) (Coleoptera: Cerambycidae) were examined. All individuals were raised on the same artificial diet until they became pupae. Analysis of the mate-searching behavior of the males showed that many more newly emerged males were attracted to the odor of the artificial diet than to an unbaited control. We prepared three groups of beetles and fed each group on different host plants for one week. The host plants used included the following: an artificial diet (containing Morus alba Linné), Citrus unshiu Marc. branches, and Vaccinium spp. branches. The mate-searching behavior of the males changed in relation to the plant supplied for feeding. Simultaneously, the preference among the three host plants was tested. The newly emerged males preferred the artificial diet. After a week of feeding on one of the three plants, however, the adult males selected and consumed significantly more of the plant that they had just experienced than the other plants. These results suggest that the male mate-location cue can be acquired after adult eclosion. In addition, the male beetles are capable of changing their host-plant preference. If they do so, they use different odor cues for mate location. Newly emerged A. malasiaca females showed no preference for their first choice of food among the three host plants presented, whereas the consumption was significantly larger on C. unshiu branches. After one week of feeding on different host plants, females chose their host plant after the adult stage as well as C. unshiu, but consumed mostly C. unshiu. These results suggest that the food preferences of females are different from those of males. The behavior of females may not be affected by chemical signals from their original host-plant species (as pupae) or from the host-plant species acquired when they emerge as adults. 相似文献
7.
Yasuyo Sekiyama Akemi K. Horigane Nao Fujiwara-Tsujii Hiroe Yasui Hiroshi Ono 《Applied Entomology and Zoology》2013,48(4):423-429
The use of magnetic resonance imaging (MRI) as a tool for in vivo detection of eggs in living Dasylepida ishigakiensis Niijima et Kinoshita, a major pest of sugarcane, was explored using females with an ovary at different developmental stages. MRI measurements of beetles were performed at 13 °C to avoid motion artifacts on the MR images. Spin–lattice relaxation time-weighted images allowed the observation of eggs at short acquisition times (2 min, 8 s). By comparing MR images with dissection data, criteria for determining mature eggs in MR images were a clear circular or ellipsoidal shape surrounded by a relatively bright rim and a size typically larger than 1.3 mm in the minor axis. Although small oocytes could not be detected, females with a developed or undeveloped ovary could be clearly distinguished based on MR images. The possibility of confusing the digestive tract as eggs in a female with a less developed ovary can be eliminated using a proton density weighted image. 相似文献
8.
Nao Kusuhashi Yukiyasu Tsutsumi Haruo Saegusa Kenji Horie Tadahiro Ikeda Kazumi Yokoyama Kazuyuki Shiraishi 《Proceedings. Biological sciences / The Royal Society》2013,280(1759)
We here describe a new Early Cretaceous (early Albian) eutherian mammal, Sasayamamylos kawaii gen. et sp. nov., from the ‘Lower Formation’ of the Sasayama Group, Hyogo Prefecture, Japan. Sasayamamylos kawaii is characterized by a robust dentary, a distinct angle on the ventral margin of the dentary at the posterior end of the mandibular symphysis, a lower dental formula of 3–4 : 1 : 4 : 3, a robust lower canine, a non-molariform lower ultimate premolar, and a secondarily reduced entoconid on the molars. To date, S. kawaii is the earliest known eutherian mammal possessing only four premolars, which demonstrates that the reduction in the premolar count in eutherians started in the late Early Cretaceous. The occurrence of S. kawaii implies that the relatively rapid diversification of eutherians in the mid-Cretaceous had already started by the early Albian. 相似文献
9.
Hyung-Jun Kwon Young Bae Ryu Young-Min Kim Naaleum Song Cha Young Kim Mun-Chual Rho Jae-Ho Jeong Kyoung-Oh Cho Woo Song Lee Su-Jin Park 《Bioorganic & medicinal chemistry》2013,21(15):4706-4713
Despite the prepdominat agent causing severe entero-pathogenic diarrhea in swine, there are no effective therapeutical treatment of porcine epidemic diarrhea virus (PEDV). In this study, we evaluated the antiviral activity of five phlorotannins isolated from Ecklonia cava (E. cava) against PEDV. In vitro antiviral activity was tested using two different assay strategies: (1) blockage of the binding of virus to cells (simultaneous-treatment assay) and (2) inhibition of viral replication (post-treatment assay). In simultaneous-treatment assay, compounds 2–5 except compound 1 exhibited antiviral activities of a 50% inhibitory concentration (IC50) with the ranging from 10.8 ± 1.4 to 22.5 ± 2.2 μM against PEDV. Compounds 1–5 were completely blocked binding of viral spike protein to sialic acids at less than 36.6 μM concentrations by hemagglutination inhibition. Moreover, compounds 4 and 5 of five phlorotannins inhibited viral replication with IC50 values of 12.2 ± 2.8 and 14.6 ± 1.3 μM in the post-treatment assay, respectively. During virus replication steps, compounds 4 and 5 exhibited stronger inhibition of viral RNA and viral protein synthesis in late stages (18 and 24 h) than in early stages (6 and 12 h). Interestingly, compounds 4 and 5 inhibited both viral entry by hemagglutination inhibition and viral replication by inhibition of viral RNA and viral protein synthesis, but not viral protease. These results suggest that compounds isolated from E. cava have strong antiviral activity against PEDV, inhibiting viral entry and/or viral replication, and may be developed into natural therapeutic drugs against coronavirus infection. 相似文献
10.