异草盲蝽属一新种及陕西昧盲蝽雌性的描述(半翅目,盲蝽科)

记述了盲蝽科盲蝽亚科异草盲蝽属Heterolygus Zheng et Yu 1新种,郑氏异草盲蝽Heterolygus zhengi sp.nov.,模式标本采于我国四川省炉霍。发现了盲蝽科合垫盲蝽亚科昧盲蝽属Mecomma Fieber陕西昧盲蝽Mecomma shaanxiensis Liuet Yamamoto的短翅型雌性,并进行了描述。标本均保存于内蒙古师范大学生命科学与技术学院昆虫标本馆。     

Two new antibacterial sesquiterpenoids from Centipeda minima

Two new guaiane-type sesquiterpene lactones, compounds 1 and 2, along with three known guaianolide- or pseudoguaianolides, were isolated from Centipeda minima (whole plant). Their structures were identified by spectroscopic and mass-spectrometric analyses. The configuration at C5 of the guaiane framework of 1 was rationalized by quantum-mechanical calculations (Table 2). All compounds were found to be active against eight different microbial pathogens (Table 3), with MIC values in the range of 6.25-100 microg/ml.     

Predicting disulfide connectivity patterns

Disulfide bonds play an important role in stabilizing protein structure and regulating protein function. Therefore, the ability to infer disulfide connectivity from protein sequences will be valuable in structural modeling and functional analysis. However, to predict disulfide connectivity directly from sequences presents a challenge to computational biologists due to the nonlocal nature of disulfide bonds, i.e., the close spatial proximity of the cysteine pair that forms the disulfide bond does not necessarily imply the short sequence separation of the cysteine residues. Recently, Chen and Hwang (Proteins 2005;61:507-512) treated this problem as a multiple class classification by defining each distinct disulfide pattern as a class. They used multiple support vector machines based on a variety of sequence features to predict the disulfide patterns. Their results compare favorably with those in the literature for a benchmark dataset sharing less than 30% sequence identity. However, since the number of disulfide patterns grows rapidly when the number of disulfide bonds increases, their method performs unsatisfactorily for the cases of large number of disulfide bonds. In this work, we propose a novel method to represent disulfide connectivity in terms of cysteine pairs, instead of disulfide patterns. Since the number of bonding states of the cysteine pairs is independent of that of disulfide bonds, the problem of class explosion is avoided. The bonding states of the cysteine pairs are predicted using the support vector machines together with the genetic algorithm optimization for feature selection. The complete disulfide patterns are then determined from the connectivity matrices that are constructed from the predicted bonding states of the cysteine pairs. Our approach outperforms the current approaches in the literature.     

Zero erucic acid trait of rapeseed (<Emphasis Type="Italic">Brassica napus</Emphasis> L.) results from a deletion of four base pairs in the <Emphasis Type="Italic">fatty acid elongase 1</Emphasis> gene

The fatty acid elongase 1 (FAE1) gene is a key gene in the erucic acid biosynthesis in rapeseed. The complete coding sequences of the FAE1 gene were isolated separately from eight high and zero erucic acid rapeseed cultivars (Brassica napus L.). A four base pair deletion between T1366 and G1369 in the FAE1 gene was found in a number of the cultivars, which leads to a frameshift mutation and a premature stop of the translation after the 466th amino acid residue. This deletion was predominantly found in the C-genome and rarely in the A-genome of B. napus. Expression of the gene isoforms with the four base pair deletion in a yeast system generated truncated proteins with no enzymatic activity and could not produce very long chain fatty acids as the control with an intact FAE1 gene did in yeast cells. In the developing rape seeds the FAE1 gene isoforms with the four base pair deletion were transcribed normally but failed to translate proteins to form a functional complex. The four base pair deletion proved to be a mutation responsible for the low erucic acid trait in rapeseed and independent from the point mutation reported by Han et al. (Plant Mol Biol 46:229–239, 2001). Gang Wu, Yuhua Wu contribute equally to this article.     

Involvement of glyceraldehyde-3-phosphate dehydrogenase in the X-Ray resistance of HeLa cells

We investigated changes in the sub-cellular distribution of glycelaldehyde-3-phosphate dehydrogenase (GAPDH) after X-ray irradiation in HeLa cells. Twenty-four h after irradiation at 5 Gy, nuclear GAPDH levels increased 2.6-fold, whereas total GAPDH levels increased only 1.2-fold. Knockdown of GAPDH using specific small interfering RNA (siRNA) led to sensitization to X-ray-induced cell death. These results suggest that GAPDH plays a role in the radioresponse.     

Involvement of aldolase A in X-ray resistance of human HeLa and UV(r)-1 cells

To find novel proteins involved in radio-resistance of human cells, we searched for nuclear proteins, whose expression levels alter after X-ray irradiation in HeLa cells, using agarose fluorescent two-dimensional differential gel electrophoresis following mass spectrometry. We identified 6 proteins, whose levels were increased in nuclei 24 h after irradiation at 5 Gy, including aldolase A. Nuclear aldolase A levels increased twofold after the irradiation, however, total aldolase A levels did not change. When the expression of aldolase A was suppressed by its specific siRNA, sensitization of the suppressed cells to X-ray-induced cell death was observed. In addition, UV^r-1 cells with higher aldolase A expression exhibited lower sensitivity to X-ray-induced cell death than the parental RSa cells with lower aldolase A expression. These results suggest that aldolase A may play a role in the radio-response of human cells, probably in nuclei, in addition to its glycolytic role in the cytosol.     

大黄酚和大黄素甲醚的制备性分离

经系统分离得到大黄酚和大黄素甲醚的混合物后,取该混合物约1g,用少量的氯仿溶解,加入少量的层析用硅胶（100～200目）拌匀,减压使氯仿蒸干。将吸附有大黄酚和大黄素甲醚的硅胶装在已装好的硅胶层析柱的上端,然后进行洗脱。通过实验,得到了最佳分离大黄酚和大黄素甲醚的条件：硅胶与混合物的质量比=150：1;层析柱长与直径的比=23：1;洗脱剂比例：石油醚（60～90℃）：乙酸乙酯（V/V）=17：1;减压淋洗。     

37份新疆粳稻品种(系)的IRAP遗传多样性分析

该研究基于4个稻属(Oryza)反转录转座子,包括活性、低拷贝[Tos17/Osr21(Ty1-copia)和RIRE7/Osr31(Ty3-gypsy)]和非活性、高拷贝[Osr34(Ty3-gypsy)和Houba/Tos5/Osr13(Ty1-copia)],在两侧翼长末端重复序列(LTR)区域分别设计引物,对37份新疆粳稻(Oryza sativa L.ssp.japonica)栽培品种(系)进行PCR扩增。评估鉴定适用于反转录转座子插入位点间扩增多态性(IRAP)标记方法,并分析37份供试品种(系)的遗传多样性。(1)PCR扩增结果显示,Tos17/Osr21、RIRE7/Osr31、Osr34和Houba/Tos5/Osr13依次获得73、63、107和560条谱带,其中多态性条带36、63、70和523个,多态性比率为49.3%、100.0%、65.4%和93.4%。(2)综合评估比较多态性、异质性、总谱带数和平均多态性谱带数发现,Houba/Tos5/Osr13适用于IRAP标记方法构建DNA指纹图谱数据库。(3)以Houba/Tos5/Osr13遗传相似系数为基础,对供试品种(系)采用非加权平均(UPGMA)法进行聚类分析显示,以0.55为阈值将37份新疆粳稻栽培品种(系)分为6大类群,绝大多数品种(系)得到了明确的区分,品种间的遗传相似性较高,多样化程度偏低;品系‘20-18’和‘96-16’分别各自聚为一类,表明品系与品种间遗传背景较远,多样化程度较高。综上所述,IRAP分子标记适用于新疆粳稻种质资源的亲缘关系分析、鉴别及育种遗传距离的判定和DNA指纹图谱数据库构建等相关研究,在实际育种中选取不同类群的水稻品种与品系进行杂交选育,成功率较高,可能会大大缩短优良品种的选育进程。     

Discovery of novel conformationally restricted diazocan peptidomimetics as inhibitors of interleukin-1beta synthesis

A novel diazocan containing dipeptide mimetic was synthesized via reductive N-N bond cleavage of a pyrazolidino-pyrazolidine using Raney-Ni and evaluated as an ICE inhibitor. This versatile 8-membered ring containing scaffold possesses an N-5 ring nitrogen that was used to explore structure-activity relationships in a cell-based assay measuring inhibition of interleukin-1beta.