20世纪生物科学前进的足迹(Ⅱ)

1951年　　△阿尔农(Ａｒｎｏｎ)确认叶绿体可以产生氧气,合成ＡＴＰ,固定ＣＯ2等。△英国桑格(ＦｒｅｄｅｒｉｃｋＳａｎｇｅｒ)确定胰岛素的分子结构及氨基酸排列顺序。1952年△布里吉斯(Ｂｌｅｃｇｉｓ)研究细胞分化中核与细胞质的关系。△派拉德(Ｐａｒｄｅｅ)发现线粒体的构造是梳子状的。△法国外科医生和生物学家亨利拉博里(Ｈｅｎｒｙ.Ｌａｒｂｅｌｙ)首次使用氯丙嗪,从此揭开了精神病药理学的新纪元。△美国的盖茨(Ｇａｔｅｓ)合成吗啡。△美国的赫尔希(Ａ.Ｄ.Ｈｅｒｓｈｙ)和蔡斯(Ｍ.Ｃｈａｓｅ)实验证明脱氧核糖核酸(ＤＮＡ)是遗…     

[反]-β-法尼烯与氟取代物分子结构叠合差异分析

利用计算机辅助分子叠合法对蚜虫报警信息素［反］-β-法尼烯(EBF)的氟取代系列物与EBF的结构进行比较,初步研究了EBF及其氟取代系列物的结构 活性之间的关系。发现对于1氟、2氟及3氟的取代物来说,在分子骨架共轭双键端进行氟取代修饰,所得取代物结构与EBF最为近似,可能具有生物报警活性。     

一种转录受病原物接种和机械创伤诱导的水稻WRKY基因的鉴定

WRKY基因编码一类植物特异性转录因子,该类基因目前在双子叶植物中得到了较好的研究.为了研究WRKY基因在单子叶植物中的生物学功能,从水稻(Oryza sativa L.)中分离了OsiWRKY基因的cDNA.该cDNA可编码一个含482个氨基酸残基的蛋白质,该蛋白质预测的一级结构中含有一个WRKY结构域,在该结构域中发现了一个典型的C2-H2锌指结构模块.OsiWRKY预测的一级结构中还可能含有一个细胞核定位因子;利用瞬时表达体系,发现OsiWRKY与GFP绿色荧光蛋白(GFP)的融合蛋白的确定位在水稻细胞核中.在凝胶阻滞实验中,体外表达的OsiWRKY蛋白可特异地结合W-box顺式因子.在水稻白叶枯病原细菌接种实验中,OsiWRKy基因的转录本在抗病品种(IR-26)中的诱导增加强度明显高于感病品种(Jingang 30).在模拟接种的水稻中,OsiWRKy基因的转录本也表现诱导增加,但其诱导增加的起始时间和幅度要显著低于水稻白叶枯病原细菌接种的水稻植株.这些结果表明,OsiWRKY基因可能编码了一个含有WRKY结构域的转录因子,该转录因子可能参与了水稻对病原物接种和机械创伤的反应,但OsiWRKY蛋白调节两种反应的机制可能有所不同.     

A vector whitefly endocytic receptor facilitates the entry of begomoviruses into its midgut cells via binding to virion capsid proteins

Many circulative plant viruses transmitted by insect vectors are devastating to agriculture worldwide. The midgut wall of vector insects represents a major barrier and at the same time the key gate a circulative plant virus must cross for productive transmission. However, how these viruses enter insect midgut cells remains poorly understood. Here, we identified an endocytic receptor complex for begomoviruses in the midgut cells of their whitefly vector. Our results show that two whitefly proteins, BtCUBN and BtAMN, compose a receptor complex BtCubam, for which BtCUBN contributes a viral-binding region and BtAMN contributes to membrane anchorage. Begomoviruses appear to be internalized together with BtCubam via its interaction with the 12–19 CUB domains of BtCUBN via clathrin-dependent endocytosis. Functional analysis indicates that interruption of BtCUBN and BtAMN lead to reduction of virus acquisition and transmission by whitefly. In contrast, CUBN-begomovirus interaction was not observed in two non-competent whitefly-begomovirus combinations. These observations suggest a major role of the specific endocytic receptor in facilitating viral entry into vector midgut cells.     

Phosphatase activity in relation to phytoplankton composition and pH in Swedish lakes

SUMMARY. 1. Potential phosphatase activity and phytoplankton from several lakes of different character were compared in order to evaluate the importance of lake water pH and phytoplankton composition for the activity and pH optimum of lake water phosphatases.
2. In oligotrophic lakes, in which phytoplankton biomass was most often dominated by Ochromonadaceae spp., optimum phosphate activity was found at pH values <6. In eutrophic lakes, where species of Cyanophyceae and Bacillariophyceae dominated the phytoplankton biomass, optimum phosphatase activity was found at pH 7.5 or 8.5.
3. The pH optimum of phosphatase activity often differed from the corresponding lake water pH.
4. Experimental variation in phosphorus availability resulted in predictable changes in phosphatase activity. However, specific phosphatase activity, calculated per biomass of phytoplankton, was dependent on plankton species composition.     

硫氧还蛋白还原酶：一种新型有效的胃癌化疗疗效监测标志物

胃癌是国际上发病率较高的肿瘤,寻找新型有效的肿瘤标志物用于胃癌的诊断和疗效评估,对于胃癌的临床治疗有较大的帮助。本研究选取经临床确诊的155例胃癌患者为研究对象,探究血浆硫氧还蛋白还原酶（thioredoxin reductase, TR）在胃癌化疗后临床获益人群与未获益人群中检测水平的差异,以及其与治疗效果的关系。结果显示,未获益组TR阳性率为82.67%,显著高于获益组TR阳性率（48.94%）。受试者操作特征曲线（receiver operating characteristic curve,ROC）分析显示,未获益组人群与获益组人群的TR活性诊断阈值为8.95 U/mL,ROC曲线下面积（area under the curve,AUC）为0.8423,明显优于常规胃癌标志物癌胚抗原（carcinoembryonic antigen,CEA）,肿瘤特异性抗原（cancer antigen,CA）19-9和CA72-4。同时,TR与常规胃癌标志物的联合检测提高阳性检出率至98.49%。TR被认为是一种新型的胃癌临床化疗疗效监测标志物,与临床疗效评价具有较高的一致性。     

Backbone and Ile-δ1, Leu,Val methyl <Superscript>1</Superscript>H, <Superscript>15</Superscript>N,and <Superscript>13</Superscript>C,chemical shift assignments for <Emphasis Type="Italic">Rhizopus chinensis</Emphasis> lipase

Lipase r27RCL is a 296-residue, 33 kDa monomeric enzyme with high ester hydrolysis activity, which has significant applications in the baking, paper and leather industries. The lipase gene proRCL from Rhizopus microsporus var. chinensis (also Rhizopus chinensis) CCTCC M201021 was cloned as a fusion construct C-terminal to a maltose-binding protein (MBP) tag, and expressed as MBP-proRCL in an Escherichia coli BL21 trxB (DE3) expression system with uniform ²H,¹³C,¹⁵N-enrichment and Ile-δ1, Leu, and Val ¹³CH₃ methyl labeling. The fusion protein was hydrolyzed by Kex2 protease at the recognition site Lys-Arg between residues ?29 and ?28 of the prosequence, producing the enzyme form called r27RCL. Here we report extensive backbone ¹H, ¹⁵N, and ¹³C, as well as Ile-δ1, Leu, and Val side chain methyl, NMR resonance assignments for r27RCL.     

近交系BALB/c小鼠及先天遗传性白内障突变型BALB/cBk-Cat小鼠的DNA指纹研究

采用人工合成的寡核苷酸探针(GATA)~4|分别与近交系小鼠BALB/c和经10年 30代培育而成的自发突变型近交系先天遗传性白内障BALB/cBk-Cat小鼠进行DNA分杂交,DNA指纹显示:(1)BALB/c小鼠个体之间以及BALB/cBk-C at小鼠个体之间没有差异;(2)BALB/c小鼠与BALB/cBk-Cat小鼠的DNA指纹在23-6kb之间的区域有差异。