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891.
892.
禾谷缢管蚜体内的病毒结合蛋白基因的克隆与原核表达 总被引:7,自引:0,他引:7
利用一对特异性引物,用PCR的方法从禾谷缢管蚜体内扩增出了病毒结合蛋白基因,序列测定结果表明其长度 为1647 bp,编码548个氨基酸,与GenBank中的禾谷缢管蚜美国生物型Buchnera groELNT核苷酸序列同源性为97%,氨基酸同源性为97.4%。构建了2个原核表达载体并进行表达得到了69kD融合蛋白和63kD的非融合蛋白。 相似文献
893.
人血管抑素(k1—3)在家蚕细胞和幼虫中的表达及活性测定 总被引:3,自引:1,他引:3
将人血管抑素 (angiostatin)基因重组于家蚕杆状病毒转移载体 pBacPAK8中 ,获得重组转移载体pBacPAK angiostatin ,并与被线性化的Bm BacPAK6病毒DNA共转染家蚕细胞 ,获得重组病毒BacPAK angiostatin。DNA点杂交结果表明重组病毒基因组中含有血管抑素基因。重组病毒以MOI=10感染家蚕细胞 (2×10 6个细胞 /瓶 )和家蚕 5龄幼虫 ,表达产物用体外培养的人脐静脉血管内皮细胞 (ECV30 4 )及体内鸡胚尿囊膜(CAM)新生血管实验检测其抑制活性 ,测得血管抑素可明显抑制体外培养的内皮细胞增殖 ,家蚕细胞的产物活性在表达 72h达到最高值 ,在 2× 10 6个细胞中的表达量约 2 2u ;在家蚕体内表达 14 4h生物活性达到最高值 ,表达量约 15 9u/ml。2 .5u/ml的血管抑素能使ECV30 4细胞在 2 4h发生明显凋亡 ;可使CAM新生血管化率明显下降。此外 ,用ELISA、Western印迹方法测定了表达产物的免疫反应性。 相似文献
894.
高山红景天(Rhodiola sachalinensis)遗传变异及其濒危机制的探讨 总被引:8,自引:3,他引:8
采用淀粉凝胶电泳手段,等位酶分析技术对分布于黑龙江大海林林业局高山红景天天然分布区内3个亚种群及吉林长白山1个亚种群的9种酶系统18个位点进行了遗传分析,结果表明种群内存在一定的遗传变异(从态位点百分比为30.55%,等位基因平均数为1.333)但不是很丰富,主要是该种类狭窄的分布区致使生境单一及人为破坏其本身的生物学特性长期的进化过程中相互适应相互选择的结果。在黑龙江的分布区内各亚种群之间一致度 相似文献
895.
大鼠骨骼肌多催化功能蛋白酶的提取、鉴定及其抗血清的制备 总被引:1,自引:0,他引:1
为了研究多催化功能蛋白酶(multicatalyticalproteinase,MCP)在负氮平衡形成中的作用,以大鼠骨骼肌为原料,提取此酶并制备其抗血清.将大鼠骨骼肌粗提物经45%~65%饱和度硫酸铵分级盐析、阴离子交换层析和凝胶过滤,最后从Sepharose4B层析柱上获得单一活性洗脱峰.酶活性用Carbobenzoxy-Val-Gly-Arg-4-nitrinilideacetate作底物检测.非变性PAGE银盐染色显示单一区带的骨骼肌多催化功能蛋白酶,SDS-PAGE银盐染色显示10条亚基电泳区带,分子量在25~32kD之间.纯化的酶免疫兔8周后,抗血清效价达132,用分级盐析和离子交换层析纯化抗血清,显示单一电泳区带的IgG.Western-blot分析显示只在25~32kD之间出现多条亚基区带.这些结果提示已获得电泳纯MCP及其较高特异性的多克隆抗体. 相似文献
896.
Zhen Hu Wenchao Guan Wei Wang Zhou Zhu Yanhong Wang 《Bioorganic & medicinal chemistry letters》2010,20(14):4159-4162
In the present study, we describe the synthesis and characterization of a novel folacin C60 derivative. The compound was analyzed by FT-IR, 1H NMR, 13C NMR, LC–MS and elemental analysis. This water soluble fullerene derivative was able to scavenge both superoxide and hydroxyl radical with biocompatibility. Rat pheochromocytoma (PC12) cells treated with hydrogen peroxide underwent cytotoxicity and apoptotic death determined by MTT assay and flow cytometry analysis. As a novel derivative of C60, the folacin C60 derivative self-assembled to form spherical aggregates in H2O. Because the compound was amphiphilic, it could penetrate the cell membrane and play its distinguished role in protecting PC12 cells against hydrogen peroxide-induced cytotoxicity. The results suggest that folacin C60 derivative has the potential to prevent oxidative stress-induced cell death without evident toxicity. 相似文献
897.
Z. J. Zhang W. J. Zhou H. Z. Li G. Q. Zhang K. Subrahmaniyan J. Q. Yu 《Biologia Plantarum》2006,50(3):453-456
The shoot fresh mass, root length and root numbers of two potato (Solanum tuberosum L.) cultivars Favorita and Helanwuhua were increased significantly by the application of 0.2 – 2 mg dm−3 jasmonic acid (JA) in the Murashige and Skoog medium. However, the growth of potato explants was inhibited by JA at high
concentrations (20 – 50 mg dm−3). Chlorophyll content in explant leaves decreased with an increase in the concentration of JA. In leaves treated with 0.2
mg dm−3 JA acid peroxidase activity increased, while in the leaves treated with more than 2 mg dm−3 JA peroxidase activity decreased. Under the dark, the microtuber numbers, fresh mass and percentage of big microtubers of
two potato cultivars were not promoted by the application of 0.2 – 50 mg dm−3 JA. 相似文献
898.
Correlation between initial chromatid damage and survival of various cell lines exposed to heavy charged particles 总被引:1,自引:0,他引:1
Jianshe Y Xigang J Wenjian L Zhuanzi W Guangming Z Jufang W Bingrong D Qingxiang G Linda W 《Radiation and environmental biophysics》2006,45(4):261-266
The biophysical characteristics of heavy ions make them a rational source of radiation for use in radiotherapy of malignant tumours. Prior to radiotherapy treatment, a therapeutic regimen must be precisely defined, and during this stage information on individual patient radiosensitivity would be of very great medical value. There are various methods to predict radiosensitivity, but some shortfalls are difficult to avoid. The present study investigated the induction of chromatid breaks in five different cell lines, including one normal liver cell line (L02), exposed to carbon ions accelerated by the heavy ion research facility in Lanzhou (HIRFL), using chemically induced premature chromosome condensation (PCC). Previous studies have reported the number of chromatid breaks to be linearly related to the radiation dose, but the relationship between cell survival and chromatid breaks is not clear. The major result of the present study is that cellular radiosensitivity, as measured by D0, is linearly correlated with the frequency of chromatid breaks per Gy in these five cell lines. We propose that PCC may be applied to predict radiosensitivity of tumour cells exposed to heavy ions. 相似文献
899.
Zhongli Peng Wei Qiao Zhisheng Wang Qiuzhong Dai Jianhua He Chunhua Guo Jun Xu Anguo Zhou 《Biological trace element research》2010,134(2):226-234
The aim of this study was to evaluate the impact of three different chromium forms—chromic chloride (CrCl3), chromium picolinate (CrPic), and a newly synthesized complex of chromium chelated with small peptides (CrSP)—on protein
metabolism in vitro. In cultured skeletal muscle cells, CrSP was able to increase the basal and insulin-stimulated levels
of protein deposition in skeletal muscles cells. CrCl3 and CrPic augmented insulin-stimulated protein synthesis. At the molecular level, insulin significantly increased the mRNA
levels of insulin-like growth factor 1 and insulin-like growth factor 1 receptor. These impacts could be enhanced by the addition
of chromium, especially CrSP. The mRNA levels of ubiquitin were significantly reduced when cells were cultured with chromium
or/and insulin. Assuming that the mRNA level increase or decrease results in increased or decreased levels of these proteins,
chromium would improve protein anabolism and reduce protein catabolism and then prove protein deposition in rat skeletal muscle
cells. 相似文献
900.
Construction of a Bacillus thuringiensis engineered strain with high toxicity and broad pesticidal spectrum against coleopteran insects 总被引:1,自引:0,他引:1
Jingjing Liu Guixin Yan Changlong Shu Can Zhao Chunqin Liu Fuping Song Lin Zhou Junlan Ma Jie Zhang Dafang Huang 《Applied microbiology and biotechnology》2010,87(1):243-249
A newly engineered strain, denominated BIOT185, was constructed through integrating the cry8Ca2 gene into the endogenous plasmid of BT185 (contains cry8Ea1) by homologous recombination. The thermosensitive plasmid vector was eliminated by the rising temperature of recombinant
cultures. No antibiotic gene or other unnecessary genes were introduced to the new strain. Sodium dodecyl sulfate–polyacrylamide
gel electrophoresis and Western blot analysis demonstrated that the cry8Ca2 gene was expressed normally and produced a 130-kDa protein in the BIOT185 strain. Bioassay results showed that the new strain
had high toxicity to the pests Anomala corpulenta and Holotrichia parallela, which often damage the same fields. 相似文献