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991.
It is well-known that there is a large amount of antimicrobial peptides in amphibian skins but few antimicrobial peptides are found in amphibian brains. Twenty-two and four antimicrobial peptides were purified and characterized from the brain homogenate of Bombina maxima and B. microdeladigitora, respectively. One hundred fifty-eight cDNA clones encoding 79 antimicrobial peptides were isolated from brain cDNA libraries of B. maxima and B. microdeladigitora. These antimicrobial peptides belong to two peptide groups (maximin and maximin-H). Twenty of them are identical to previously reported antimicrobial peptides (maximin 1-8, 10, 11, maximin H1, 3-5, 7, 9, 10, 12, 15, 16) from B. maxima skin secretions. Fifty-nine of them are novel antimicrobial peptides. Some of these antimicrobial peptides showed strong antimicrobial activities against tested microorganism strains including Gram-positive and -negative bacteria and fungi. The current diversity in peptide coding cDNA sequences is, to our knowledge, the most extreme yet described for any animal brains. The extreme diversity may give rise to interest to prospect the actual functions of antimicrobial peptides in amphibian brains. 相似文献
992.
虹鳟生长激素cDNA在酵母中的表达 总被引:10,自引:0,他引:10
采用聚合酶链式反应( P C R) 技术对虹鳟生长激素c D N A 进行改造。将改造后的基因克隆到含酵母 P G K 启动子的大肠杆菌酵母穿梭质粒p M A91 ,转化酿酒酵母 Y33 ,构建表达鱼生长激素的酵母工程菌 Y33(p M Ar G H16) ,并在酵母中获得表达,表达量约占细胞可溶性蛋白总量的3 % 。表达产物作为饲料添加剂投喂罗非鱼,具有明显的促进生长作用 相似文献
993.
几种木本植物的N2O释放与某些生理活动的关系 总被引:16,自引:4,他引:16
使用带有开放气路的气体交换测定系统,同步测定了几种针、阔叶树种的光合作用、呼吸作用及气孔导度.结果表明,低光下树木针叶或叶片释放N2O的速率与光合速率无显著相关.伴随根、茎、叶的呼吸,检测到有N2O吸收现象,其通量与温度及呼吸强度呈正相关.气孔导度明显影响N2O的通量,表明气孔可能是木本植物释放N2O的主要途径. 相似文献
994.
995.
996.
Xuemei Han Shauna P. Dendy Karen A. Garrett Liang Fang Melinda D. Smith 《Plant Ecology》2008,198(2):197-210
We surveyed the prevalence and amount of leaf damage related to herbivory and pathogens on 12 pairs of exotic (invasive and
noninvasive) and ecologically similar native plant species in tallgrass prairie to examine whether patterns of damage match
predictions from the enemy release hypothesis. We also assessed whether natural enemy impacts differed in response to key
environmental factors in tallgrass prairie by surveying the prevalence of rust on the dominant C4 grass, Andropogon gerardii, and its congeneric invasive exotic C4 grass, A. bladhii, in response to fire and nitrogen fertilization treatments. Overall, we found that the native species sustain 56.4% more
overall leaf damage and 83.6% more herbivore-related leaf damage when compared to the exotic species. Moreover, we found that
the invasive exotic species sustained less damage from enemies relative to their corresponding native species than the noninvasive
exotic species. Finally, we found that burning and nitrogen fertilization both significantly increased the prevalence of rust
fungi in the native grass, while rust fungi rarely occurred on the exotic grass. These results indicate that reduced damage
from enemies may in part explain the successful naturalization of exotic species and the spread of invasive exotic species
in tallgrass prairie. 相似文献
997.
Ho Nam Chang Nag-Jong Kim Jongwon Kang Chang Moon Jeong 《Biotechnology and Bioprocess Engineering》2010,15(1):1-10
The typical biorefinery platforms are sugar, thermochemical (syngas), carbon-rich chains, and biogas platforms, each offering
unique advantages and disadvantages. The sugar platform uses hexose and pentose sugars extracted or converted from plant body
mass. The thermochemical (syngas) platform entails a chemical or biological conversion process using pyrolysis or gasification
of plants to produce biofuels. The carbon-rich chains platform is used to produce biodiesel from long-chain fatty acids or
glycerides. In the present work, we suggest a new platform using volatile fatty acids (VFAs) for the production of biofuels
and biochemicals production. The VFAs are short-chain fatty acids composed mainly of acetate and butyrate in the anaerobic
digestion (AD) process, which does not need sterilization, additional hydrolysis enzymes (cellulose or xylanase), or a high
cost pretreatment step. VFAs are easily produced from almost all kinds of biomass with low lignin content (terrestrial, aquatic,
and marine biomass) by the AD process. Considering that raw material alone constitutes 40∼80% of biofuel production costs,
biofuels made from VFAs derived from waste organic biomass potentially offer significant economical advantage. 相似文献
998.
DNA vaccines consisted of tumor-associated antigen (TAA) are well suited for immunotherapy against tumor. The construct can
contain TAA fused to an appropriate molecule (biologic adjuvant) to improve the efficacy of anti-tumor immune response. Heat
shock protein 70 (HSP70) has been shown to be an excellent candidate, capable of cross-priming TAA by antigen presenting cells
leading to a robust T-cell response. However, the relationship between strong T-cell responses and tumor rejection is not
always mutually exclusive, for which TAA loss or activation of suppressive mechanisms may occur. HSP70 fused to downstream
of Her2/neu as DNA vaccine has been shown to be efficient against Her2-expressing tumors. In this study, we examined if N-terminally
fusion of Her2/neu to HSP70 could also improve efficiency of Her2/neu DNA vaccine. Therefore, mice with an established Her2/neu
expressing tumor were immunized with DNA vaccine consisting of extracellular and trans-membrane domain (EC+TM) of rat Her2/neu
alone or N-terminally fused to HSP70 and immune response was evaluated. Administration of rat Her2/neu led to partial control
of tumor progression. Surprisingly, fusion of HSP70 to N-terminal of rat Her2/neu led to tumor progression. Our result proposes
that fusion direction of biologic adjuvant is an important consideration when Her2/neu is used. 相似文献
999.
Ziyong Liu Yu Ying Fuli Li Cuiqing Ma Ping Xu 《Journal of industrial microbiology & biotechnology》2010,37(5):495-501
Wheat bran, a by-product of the wheat milling industry, consists mainly of hemicellulose, starch and protein. In this study,
the hydrolysate of wheat bran pretreated with dilute sulfuric acid was used as a substrate to produce ABE (acetone, butanol
and ethanol) using Clostridium beijerinckii ATCC 55025. The wheat bran hydrolysate contained 53.1 g/l total reducing sugars, including 21.3 g/l of glucose, 17.4 g/l
of xylose and 10.6 g/l of arabinose. C. beijerinckii ATCC 55025 can utilize hexose and pentose simultaneously in the hydrolysate to produce ABE. After 72 h of fermentation, the
total ABE in the system was 11.8 g/l, of which acetone, butanol and ethanol were 2.2, 8.8 and 0.8 g/l, respectively. The fermentation
resulted in an ABE yield of 0.32 and productivity of 0.16 g l−1 h−1. This study suggests that wheat bran can be a potential renewable resource for ABE fermentation. 相似文献
1000.
Xuelong Lu Yang Shi Quanlong Lu Yan Ma Jia Luo Qingsong Wang Jianguo Ji Qing Jiang Chuanmao Zhang 《The Journal of biological chemistry》2010,285(43):33281-33293
Lamin B receptor (LBR), a chromatin and lamin B-binding protein in the inner nuclear membrane, has been proposed to target the membrane precursor vesicles to chromatin mediated by importin β during the nuclear envelope (NE) assembly. However, the mechanisms for the binding of LBR with importin β and the membrane targeting by LBR in NE assembly remain largely unknown. In this report, we show that the amino acids (aa) 69–90 of LBR sequences are required to bind with importin β at aa 45–462, and the binding is essential for the NE membrane precursor vesicle targeting to the chromatin during the NE assembly at the end of mitosis. We also show that this binding is cell cycle-regulated and dependent on the phosphorylation of LBR Ser-71 by p34cdc2 kinase. RNAi knockdown of LBR causes the NE assembly failure and abnormal chromatin decondensation of the daughter cell nuclei, leading to the daughter cell death at early G1 phase by apoptosis. Perturbation of the interaction of LBR with importin β by deleting the LBR N-terminal spanning region or aa 69–73 also induces the NE assembly failure, the abnormal chromatin decondensation, and the daughter cell death. The first transmembrane domain of LBR promotes the NE production and expansion, because overexpressing this domain is sufficient to induce membrane overproduction of the NE. Thus, these results demonstrate that LBR targets the membrane precursor vesicles to chromatin by interacting with importin β in a LBR phosphorylation-dependent manner during the NE assembly at the end of mitosis and that the first transmembrane domain of LBR promotes the LBR-bearing membrane production and the NE expansion in interphase. 相似文献