排序方式: 共有55条查询结果,搜索用时 32 毫秒
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《Bioscience, biotechnology, and biochemistry》2013,77(10):2002-2007
Hog1 of Saccharomyces cerevisiae is activated by hyperosmotic stress, and this leads to cell-cycle delay in G1, but the mechanism by which cells restart from G1 delay remains elusive. We found that Whi3, a negative regulator of G1 cyclin, counteracted Hog1 in the restart from G1 delay caused by osmotic stress. We have found that phosphorylation of Ser-568 in Whi3 by RAS/cAMP-dependent protein kinase (PKA) plays an inhibitory role in Whi3 function. In this study we found that the phosphomimetic Whi3 S568D mutant, like the Δwhi3 strain, slightly suppressed G1 delay of Δhog1 cells under osmotic stress conditions, whereas the non-phosphorylatable S568A mutation of Whi3 caused prolonged G1 arrest of Δhog1 cells. These results indicate that Hog1 activity is required for restart from G1 arrest under osmotic stress conditions, whereas Whi3 acts as a negative regulator for this restart mechanism. 相似文献
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本试验对表达猪瘟E2囊膜糖蛋白的原核表达载体pET—E2的表达条件进行了优化,在此基础上,对表达的蛋白质进行了纯化。在6mol/L盐酸胍存在的条件下,将包涵体溶解在Tris-HCl中,并直接用于His Band亲和层析。收集过柱产物并透析,在2%SDS条件下,对所得的重组蛋白质进行了定量。重组蛋白质被用来包被96孔ELISA板并应用于免疫猪瘟抗体水平的测定。 相似文献
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采用异硫氰酸胍一步法从480代猪瘟病毒兔化弱毒株(HCLV)脾毒中提取总RNA,以该RNA为模板,进行反转录,然后采用套式PCR扩增出HCLV的囊膜糖蛋白E0基因,琼脂糖凝胶电泳表明其大小与预计相符。将扩增出的E0基因克隆到pGEMT载体中,用自动序列分析仪对其进行序列测定。将测得的序列及推导的氨基酸序列与国外测得的C株相应序列进行比较,结果发现,它们之间核苷酸序列同源性为99.08%,氨基酸序列同源性为98.42%。 相似文献
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猪瘟病毒兔化弱毒株cDNA片段的克隆及序列分析 总被引:2,自引:0,他引:2
猪瘟是猪最重要的传染病之一,往往给养猪业造成重大经济损失,猪瘟的病原为猪瘟病毒(HCV),属黄病毒科,瘟病毒属成员,其基因组为单股正链RNA,长度为123kb,仅含有一个大的开放阅读框架,编码一个含3898个氨基酸残基(AA)的多聚前体蛋白[1,2]。目前已经定位的蛋白有5种,即Npro、C、E0、E1和E2,它们均由HCVRNA5′端所编码,除Npro外,其它4种均为HCV的结构蛋白[3]。Npro为具有自我催化功能的蛋白水解酶,也是多聚蛋白N端的第一个蛋白水解酶,分子量为23kD,C为构成… 相似文献
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González-Párraga P Sánchez-Fresneda R Martínez-Esparza M Argüelles JC 《Archives of microbiology》2008,189(4):293-296
Living organisms have evolved a complex network of mechanisms to face the unforeseen nutritional and environmental circumstances imposed on their natural habitats, commonly termed “stress”. To learn more about these mechanisms, several challenges are usually applied in the laboratory, namely nutrient starvation, heat shock, dehydration, oxidative exposures, etc. Yeasts are chosen as convenient models for studying stress phenomena because of their simple cellular organization and the amenability to genetic analysis. A vast scientific literature has recently appeared on the defensive cellular responses to stress. However, this plethora of studies covers quite different experimental conditions, making any conclusions open to dispute. In fact, the term “yeast stress” is rather confusing, since the same treatment may be very stressful or irrelevant, depending on the yeast. Customary expressions such as “gentle stress” (non-lethal) or “severe stress” (potentially lethal) should be precisely clarified. In turn, although prototypic yeasts share a common repertoire of signalling responsive pathways to stress, these are adapted to the specific ecological niche and biological activity of each particular species. What does “stress” really mean? Before we go any deeper, we have to define this uncertain meaning along with a proper explanation concerning the terms and conditions used in research on yeast stress. 相似文献
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本文报告了从猪肺中用改进后的碱性氯化钠盐解法萃取的粗肝素为原料,以新型分离材料DEAE-Sephacel分离纯化,并与SephadexG-50进行比较,前者使粗肝素比活由13.9USP/mg提高到203.64USP/mg(美国药典单位),纯化系数达到14.65,回收率达86.93%,而通过SephadexG-50分离纯化后的肺肝素其比活性提高到102.10USP/mg,纯化系数为7.35,回收率为72.22%,其比活性、总活性回收率及纯化系数等,DEAE-Sephacel均优于SephadexG-50。纯化相当量粗肝素所需时间、次数亦大大减少,并用醋酸纤维薄膜电泳,高效液相色谱进行性质和纯化鉴定,用红外光谱进行基团分析鉴定。 相似文献