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951.
952.
Evaluation of biomolecular interactions of sulfated polysaccharide isolated from Grateloupia filicina on blood coagulation factors 总被引:2,自引:0,他引:2
Athukorala Y Jung WK Park PJ Lee YJ Kim SK Vasanthan T No HK Jeon YJ 《Journal of microbiology and biotechnology》2008,18(3):503-511
An edible marine red alga, Grateloupia filicina, collected from Jeju Island of Korea was hydrolyzed by cheap food-grade carbohydrases (Viscozyme, Celluclast, AMG, Termamyl, and Ultraflo) to investigate its anticoagulant activity. Among the tested enzymatic extracts of G. filicina, a Termamyl extract showed the highest anticoagulant activity. Anion-exchange chromatography on DEAE-cellulose and gelpermeation chromatography on Sepharose-4B were used to purify the active polysaccharide from the crude polysaccharide fraction of G. filicina. The purified sulfated polysaccharide (0.42 sulfate/total sugar) showed approximately 1,357 kDa molecular mass and was comprised mainly of galactose (98%) and 1-2% of glucose. The sample showed potential anticoagulant activity on activated partial thromboplastin time (APTT) and thrombin time (TT) assays. The purified G. filicina anticoagulant (GFA) inhibited the coagulation factor X (92%), factor II (82%), and factor VII (68%) of the coagulation cascade, and the molecular interaction (protein-polysaccharide) was highly enhanced in the presence of ATIII (antithrombin III). The dissociation constant of polysaccharide towards serine proteins decreased in the order of FXa (58.9 nM) >FIIa (74.6 nM) >FVII (109.3 nM). The low/less cytotoxicity of the polysaccharide benefits its use in the pharmaceutical industry; however, further studies that would help us to elucidate the mechanism of its activity are needed. 相似文献
953.
Chitosan microspheres containing Bordetella bronchiseptica antigens as novel vaccine against atrophic rhinitis in pigs 总被引:3,自引:0,他引:3
Kang ML Kang SG Jiang HL Guo DD Lee DY Rayamahji N Seo YS Cho CS Yoo HS 《Journal of microbiology and biotechnology》2008,18(6):1179-1185
The immune-stimulating activities of Bordetella bronchiseptica antigens containing dermonecrotoxin (BBD) loaded in chitosan microspheres (CMs) have already been reported in vitro and in vivo with a mouse alveolar macrophage cell line (RAW264.7) and mice. Therefore, this study attempted to demonstrate the successful induction of mucosal immune responses after the intranasal administration of BBD loaded in CMs (BBD-CMs) in colostrum-deprived pigs. The BBD was introduced to the CMs using an ionic gelation process involving tripolyphosphate (TPP). Colostrum-deprived pigs were then directly immunized through intranasal administration of the BBD-CMs. A challenge with a field isolate of B. bronchiseptica was performed ten days following the final immunization. The BBD-specific IgG and IgA titers, evident in the nasal wash and serum from the vaccinated pigs, increased with time (p<0.05). Following the challenge, the clinical signs of infection were about 6-fold lower in the vaccinated pigs compared with the nonvaccinated pigs. The grades for gross morphological changes in the turbinate bones from the vaccinated pigs were also significantly lower than the grades recorded for the nonvaccinated pigs (p<0.001). Therefore, the mucosal and systemic immune responses induced in the current study would seem to indicate that the intranasal administration of BBD-CMs may be an effective vaccine against atrophic rhinitis in pigs. 相似文献
954.
Both src-dependent and -independent mechanisms mediate phosphatidylinositol 3-kinase regulation of colony-stimulating factor 1-activated mitogen-activated protein kinases in myeloid progenitors 下载免费PDF全文
Colony-stimulating factor 1 (CSF-1) supports the proliferation, survival, and differentiation of bone marrow-derived cells of the monocytic lineage. In the myeloid progenitor 32D cell line expressing CSF-1 receptor (CSF-1R), CSF-1 activation of the extracellular signal-regulated kinase (ERK) pathway is both Ras and phosphatidylinositol 3-kinase (PI3-kinase) dependent. PI3-kinase inhibition did not influence events leading to Ras activation. Using the activity of the PI3-kinase effector, Akt, as readout, studies with dominant-negative and oncogenic Ras failed to place PI3-kinase downstream of Ras. Thus, PI3-kinase appears to act in parallel to Ras. PI3-kinase inhibitors enhanced CSF-1-stimulated A-Raf and c-Raf-1 activities, and dominant-negative A-Raf but not dominant-negative c-Raf-1 reduced CSF-1-provoked ERK activation, suggesting that A-Raf mediates a part of the stimulatory signal from Ras to MEK/ERK, acting in parallel to PI3-kinase. Unexpectedly, a CSF-1R lacking the PI3-kinase binding site (DeltaKI) remained capable of activating MEK/ERK in a PI3-kinase-dependent manner. To determine if Src family kinases (SFKs) are involved, we demonstrated that CSF-1 activated Fyn and Lyn in cells expressing wild-type (WT) or DeltaKI receptors. Moreover, CSF-1-induced Akt activity in cells expressing DeltaKI is SFK dependent since Akt activation was prevented by pharmacological or genetic inhibition of SFK activity. The docking protein Gab2 may link SFK to PI3-kinase. CSF-1 induced Gab2 tyrosyl phosphorylation and association with PI3-kinase in cells expressing WT or DeltaKI receptors. However, only in DeltaKI cells are these events prevented by PP1. Thus in myeloid progenitors, CSF-1 can activate the PI3-kinase/Akt pathway by at least two mechanisms, one involving direct receptor binding and one involving SFKs. 相似文献
955.
Assessing the generality of global leaf trait relationships 总被引:14,自引:0,他引:14
Wright IJ Reich PB Cornelissen JH Falster DS Garnier E Hikosaka K Lamont BB Lee W Oleksyn J Osada N Poorter H Villar R Warton DI Westoby M 《The New phytologist》2005,166(2):485-496
Global-scale quantification of relationships between plant traits gives insight into the evolution of the world's vegetation, and is crucial for parameterizing vegetation-climate models. A database was compiled, comprising data for hundreds to thousands of species for the core 'leaf economics' traits leaf lifespan, leaf mass per area, photosynthetic capacity, dark respiration, and leaf nitrogen and phosphorus concentrations, as well as leaf potassium, photosynthetic N-use efficiency (PNUE), and leaf N : P ratio. While mean trait values differed between plant functional types, the range found within groups was often larger than differences among them. Future vegetation-climate models could incorporate this knowledge. The core leaf traits were intercorrelated, both globally and within plant functional types, forming a 'leaf economics spectrum'. While these relationships are very general, they are not universal, as significant heterogeneity exists between relationships fitted to individual sites. Much, but not all, heterogeneity can be explained by variation in sample size alone. PNUE can also be considered as part of this trait spectrum, whereas leaf K and N : P ratios are only loosely related. 相似文献
956.
Kalthoum Tizaoui Jae Won Yang Keum Hwa Lee Ji Hong Kim Minseok Kim Sojung Yoon Yeonwoo Jung Joon Beom Park Kitae An Hyeok Choi Donggyu Song HyunTaek Jung Seongmin Ahn Taeho Yuh Hee Min Choi Jae Ha Ahn Younjuong Kim Sanghyun Jee Hyeongsun Lee Soohwa Jin Jun-Gu Kang Bohyun Koo Joo Yeop Lee Kyoung Min Min Wonseok Yoo Hyeong Jun Rhyu Yeonjung Yoon Min Ho Lee Sung Eun Kim Jimin Hwang Ai Koyanagi Louis Jacob Seoyeon Park Jae Il Shin Lee Smith 《International journal of biological sciences》2022,18(9):3731
YKL-40, a chitinase-3-like protein 1 (CHI3L1) or human cartilage glycoprotein 39 (HC gp-39), is expressed and secreted by various cell-types including macrophages, chondrocytes, fibroblast-like synovial cells and vascular smooth muscle cells. Its biological function is not well elucidated, but it is speculated to have some connection with inflammatory reactions and autoimmune diseases. Although having important biological roles in autoimmunity, there were only attempts to elucidate relationships of YKL-40 with a single or couple of diseases in the literature. Therefore, in order to analyze the relationship between YKL-40 and the overall diseases, we reviewed 51 articles that discussed the association of YKL-40 with rheumatoid arthritis, psoriasis, systemic lupus erythematosus, Behçet disease and inflammatory bowel disease. Several studies showed that YKL-40 could be assumed as a marker for disease diagnosis, prognosis, disease activity and severity. It is also shown to be involved in response to disease treatment. However, other studies showed controversial results particularly in the case of Behçet disease activity. Therefore, further studies are needed to elucidate the exact role of YKL-40 in autoimmunity and to investigate its potential in therapeutics. 相似文献
957.
Intracellular Mycobacterium tuberculosis Exploits Host-derived Fatty Acids to Limit Metabolic Stress
Wonsik Lee Brian C. VanderVen Ruth J. Fahey David G. Russell 《The Journal of biological chemistry》2013,288(10):6788-6800
Recent data indicate that the nutrients available to Mycobacterium tuberculosis (Mtb) inside its host cell are restricted in their diversity. Fatty acids and cholesterol appear more favored; however, their degradation can result in certain metabolic stresses. Their breakdown can generate propionyl-CoA, which gives rise to potentially toxic intermediates. Detoxification of propionyl-CoA relies on the activity of the methylcitrate cycle, the methylmalonyl pathway, or incorporation of the propionyl-CoA into methyl-branched lipids in the cell wall. The current work explores carbon flux through these pathways, focusing primarily on those pathways responsible for the incorporation of propionyl-CoA into virulence-associated cell wall lipids. Exploiting both genetic and biochemical rescue, we demonstrate that these metabolic pressures are experienced by Mtb inside its host macrophage and that the bacterium accesses host fatty acid stores. The metabolism of these host lipids expands the acetyl-CoA pool and alleviates the pressure from propionyl-CoA. These data have major implications for our appreciation of central metabolism of Mtb during the course of infection. 相似文献
958.
Seongjin Yoo Doo-Ahn Kwak Guishan Cui Woo-Kyun Lee Hanbin Kwak Akihiko Ito Yowhan Son Seongwoo Jeon 《Ecological Research》2013,28(6):1045-1059
A carbon flux model, the vegetation integrated simulator for trace gases, was employed to estimate the carbon budgets of vegetation ecosystems in South Korea. The geographic information system was used to prepare the input variables for the model, such as climate, soil, and land-cover data, from reliable national inventories. Model simulation results indicated that the annual average gross primary production, net primary production, and soil respiration (SR) for 10 years were 91.89, 40.16, and 62.91 Tg C year?1, respectively. The model also estimated a net ecosystem production with a value of 3.51 Tg C year?1 between 1999 and 2008. Such results indicate that the vegetation ecosystems of South Korea offset 3.3 % of anthropogenic emissions as a net carbon sink. Latitudinal and topographical gradients over the total simulation area were found for all estimates. In addition, the estimates varied between seasons and years, especially in estimates for biomass growth and carbon uptake, because of variations in the weather conditions. Finally, model validation was conducted using measured soil efflux and flux measurement data from the Gwangneung experimental forest (GEF). The estimated SR accounted for 81.6 % of the observed SR at the GEF site (P < 0.005). Further, the model accounted well for the observed phase and amplitude of changes in the summer and autumn seasons. 相似文献
959.
In eukaryotic cells, protein kinase CKII is required for progression through the cell division cycle. We recently reported that CKBBP1/SAG/ROC2/Rbx2 associates with the beta-subunit of CKII and is phosphorylated by purified CKII in the presence of ATP in vitro. In this report, we demonstrate that CKBBP1 is efficiently phosphorylated in vitro by purified CKII in the presence of GTP and by heparin-sensitive protein kinase in HeLa cell extract. Mutational analysis indicates that CKII phosphorylates threonine at residue 10 within CKBBP1. Furthermore, CKBBP1 is phosphorylated in vivo and threonine to alanine mutation at residue 10 abrogates the phosphorylation of CKBBP1 observed in vivo, indicating that CKII is a major kinase that is responsible for in vivo phosphorylation of CKBBP1. As compared with the wild-type CKBBP1 or CKBBP1T10E (in which threonine 10 is replaced by glutamate), overexpression of nonphosphorylatable CKBBP1 (CKBBP1T10A) results in accumulation of IkappaBalpha and p27Kip1. Experiments using proteasome inhibitor MG132 and CKII inhibitor 5,6-dichloro-1-beta-d-ribofuranosylbenzimidazole suggest that the accumulation of IkappaBalpha and p27Kip1 results primarily from the reduction of proteasomal degradation in cells expressing CKBBP1T10A, and that CKII-mediated CKBBP1 phosphorylation is required for efficient degradation of IkappaBalpha and p27Kip1. Overexpression of CKBBP1T10A in HeLa cells suppresses cell proliferation and causes accumulation of G1/G0 peak of the cell cycle. Taken together, our results indicate that CKII may control IkappaBalpha and p27Kip1 degradation and thereby G1/S phase transition through the phosphorylation of threonine 10 within CKBBP1. 相似文献
960.
Effects of C10‐ and C12‐chain length alkyl analogs of monochamol on attraction of longhorn pine sawyer Monochamus saltuarius (Coleoptera: Cerambycidae) 下载免费PDF全文
Sung‐Min Lee Do Kyung Hong Sei‐Heon Jang Kyeong‐Yeoll Lee ChangWoo Lee 《Entomological Research》2018,48(5):446-450
The aggregation pheromone of Monochamus (Coleoptera: Cerambycidae) beetles, 2‐(undecyloxy) ethanol (hereafter referred to as monochamol), has gained considerable attention because of its usefulness in monitoring and population control of pine sawyer beetles. The hydroxyether structural motif is conserved in pheromones of the subfamily Lamiinae of the Cerambycidae. In this study, we investigated the effects of C10‐ and C12‐chain length alkyl analogs of monochamol, 2‐(decyloxy) ethanol and 2‐(dodecyloxy) ethanol, on attracting M. saltuairus in Andong, Gyeongsangbuk‐do, Korea. The C10 and C12 analogs attracted M. saltuarius when used in combination with α‐pinene and ethanol, but the responses of these alkyl chain analogs were lower than those of monochamol. Furthermore, the addition of either C10 or C12 analog to the use of monochamol with α‐pinene and ethanol had no effect on attraction of M. saltuarius, indicating high sensitivity of M. saltuarius to monochanol. Taken together, the results of this study suggest that chemical communication within a Monochamus species depends not only on monochamol, but also on other semiochemicals. 相似文献