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471.
A Lipidomic Study of the Effects of N-methyl-N′-nitro-N-nitrosoguanidine on Sphingomyelin Metabolism 总被引:1,自引:0,他引:1
Systems biology is a new and rapidly developing research area in which,by quantitativelydescribing the interaction among all the individual components of a cell,a systems-level understanding of abiological response can be achieved.Therefore,it requires high-throughput measurement technologies forbiological molecules,such as genomic and proteomic approaches for DNA/RNA and protein,respectively.Recently,a new concept,lipidomics,which utilizes the mass spectrometry(MS)method for lipid analysis,has been proposed.Using this lipidomic approach,the effects of N-methyl-N'-nitro-N-nitrosoguanidine(MNNG)on sphingomyelin metabolism,a major class of sphingolipids,were evaluated.Sphingomyelin moleculeswere extracted from cells and analyzed by matrix-assisted laser desorption ionization-time of flight MS.Itwas found that MNNG induced profound changes in sphingomyelin metabolism,including the appearance ofsome new sphingomyelin species and the disappearance of some others,and the concentrations of severalsphmgomyelin species also changed.This was accompanied by the redistribution of acid sphingomyelinase(ASM),a key player in sphingomyelin metabolism.On the other hand,imipramine,an inhibitor of ASM,caused the accumulation of sphingomyelin.It also prevented some of the effects of MNNG,as well as theredistribution of ASM.Taken together,these data suggested that the lipidomic approach is highly effectivefor the systematic analysis of cellular lipids metabolism. 相似文献
472.
High risk populations and HIV-1 infection in China 总被引:1,自引:0,他引:1
Tuo Fu ZHU- * Chun Hui WANG Peng LIN Na HE Departments of Laboratory Medicine Departments of Microbiology University of Washington School of Medicine Seattle WA USA Programs in Infectious Diseases Fred Hutchinson Cancer Research Center Seattle WA - USA Guangdong Center for Disease Control Prevention Guangzhou China School of Public Health Fudan University Shanghai China 《Cell research》2005,(Z1)
INTRODUCTION HIV has spread to all of China’s 31 provinces, autono- mous regions and municipalities, creating one of the fast- est-growing HIV/AIDS epidemics in the world [1,2]. The HIV/AIDS epidemic in China has gone through three phases: the Entry Phase (1985 -1988), the Spreading Phase (1989-1994) and the Expansion Phase (1995- present). The striking increase of HIV-1 infections over the past few years may herald entry into a new fourth phase that will include much larger nu… 相似文献
473.
LI Su Ql Xianglin HU Hong & WANG Yunjiu Laboratory for Visual Information Processing Institute of Biophysics Chinese Academy of Sciences Beijing China Institute of Computing Technology Chinese Academy of Sciences Beijing China 《中国科学:生命科学英文版》2005,48(1):6-17
The columnar organization is a ubiquitous feature in the cerebral cortex. In this study, a neural network model simulating the cortical columns has been constructed. When fed with random pulse input with constant rate, a column generates synchronized oscillations, with a frequency varying from 3 to 43 Hz depending on parameter values. The behavior of the model under periodic stimulation was studied and the input-output relationship was non-linear. When identical columns were sparsely interconnected, the column oscillator could be locked in synchrony. In a network composed of heterogeneous columns, the columns were organized by intrinsic properties and formed partially synchronized assemblies. 相似文献
474.
LI Feng LI Ying JIANG Wei WANG Zhenfang & LI Jilun . State Key Laboratory for Agro-biotechnology Department of Microbiology China Agricultural University Beijing China . Department of Biology Huaibei Coal Industry Teachers’ College Huaibei China 《中国科学:生命科学英文版》2005,48(6):574-584
The general property of the Magnetospirillum spp is capable of forming magnetosomes in their cells, which are nanometer-sized, membrane-bound and chain- linked particles of magnetite (Fe3O4)[1,2]. The magne-tosomes may be useful for some aspects; for example, as carriers of antibodies for highly sensitive immuno-assay[3,4] and as carriers of drugs for targeting therapy of tumors[5]. The findings of magnetic particles in the presence of bees[6] and human brain[7], aroused interest in studying … 相似文献
475.
DONG Qiwen WANG Xiaolong LIN Lei & GUAN Yi School of Computer Science Technology Harbin Institute of Technology Harbin China 《中国科学:生命科学英文版》2005,48(4):394-405
1 Introduction The prediction of protein structure and function from amino acid sequences is one of the most impor-tant problems in molecular biology. This problem is becoming more pressing as the number of known pro-tein sequences is explored as a result of genome and other sequencing projects, and the protein sequence- structure gap is widening rapidly[1]. Therefore, com-putational tools to predict protein structures are needed to narrow the widening gap. Although the prediction of three dim… 相似文献
476.
Deoxyribozymes inhibit the expression ofperiod1 genein vitro 总被引:1,自引:0,他引:1
ZHOU Wei WANG Yueqi LIU Yanyou PENG Wenzhen XIAO Jing ZHU Bin & WANG Zhengrong . Biomedical Engineering Department School of West China Basic Forensic Science Sichuan University Chengdu Chin . Molecular Biology Biology Chemistry Department School of West China Basic Forensic Science Sichuan Univers Chengdu China 《中国科学:生命科学英文版》2005,48(3):195-201
Throughout biology, a broad range of biochemical and physiological processes oscillate with approxi-mately 24-h rhythms or circadian rhythms as synchro-nizing with the rhythmic environment (day/night cy-cles, seasons, etc.). The circadian rhythms are under the control of an endogenous oscillator, the circadian clock[1]. Period (per), the first genetically identified circadian mutant[2], is assumed to be a key molecule in the regulation and functioning of the mammalian cir-cadian clock which is… 相似文献
477.
Insulin-like growth factor 2 as a candidate gene influencing growth and carcass traits and its bialleleic expression in chicken 总被引:4,自引:0,他引:4
WANG Genyu YAN Bingxue DENG Xuemei LI Changlü HU Xiaoxiang & Li Ning .State Key Laboratory for Agrobiotechnology China Agricultural University Beijing China .Department of Animal Genetics Breeding College of Animal Science Technology China Agricultural University Beijing China 《中国科学:生命科学英文版》2005,48(2):187-194
478.
DGP1, a drought-induced guard cell-specific promoter and its function analysis in tobacco plants 总被引:2,自引:0,他引:2
LI Jun GONG Ximing LIN Huiqiong SONG Quanbo CHEN Jia & WANG Xuechen State Key Laboratory of Plant Physiology Biochemistry China Agricultural University Beijing China 《中国科学:生命科学英文版》2005,48(2):181-186
Stomatal pores on the surface of leaf are gate-ways of gas exchange between plants and environment. For example, plants can take in CO2 via photosynthe-sis and lose water by transpiration. It was estimated that plants account for around 65% fresh water use every year, which was mainly lost through stomata[1]. So they attracted much more attention to increase the ability of drought resistance by regulating stomatal movement. Then a tentative plan came to our brains, is it possible for us to as… 相似文献
479.
Structural basis of interaction between protein tyrosine phosphatase PCP-2 and β-catenin 总被引:1,自引:0,他引:1
480.
朱智慧 曾宪春 王三霞 李文鑫 朱顺义ZHU Zhi-hui ZENG Xian-chun WANG San-xia LI Wen-xin ZHU Sun-yi 《遗传》2001,23(5):431-607
构建了东亚钳蝎毒腺cDNA文库,根据东亚钳蝎中性哺乳动物神经毒素BmKM4的氨基酸序列设计并合成引物,用PCR方法从文库中筛选到BmKM4全长cDNA序列.它由5′UTR、可读框和3′UTR组成.与其他东亚钳蝎哺乳动物神经毒素cDNA的相应区域相比,BmKM4cDNA的5′UTR高度保守,而其3′UTR则变异较大.AUG的旁侧序列为AAAATGAA,与绝大多数蝎毒素基因一致.在BmKM4mRNApoly(A)尾上游17nt处,有一典型的腺苷化信号(AATAAA).可读框编码84个氨基酸的毒素前体,包括N端19个氨基酸残基组成的信号肽,中间64个氨基酸残基组成的成熟毒素,以及C末端的额外碱性氨基酸Arg.椐据一般规律,尾端Arg在毒素前体的成熟过程中会被切除。
Abstract:A full-length cDNA sequence encoding the precursor of a neutral mammalian neurotoxin,BmKM4,was first isolated from a cDNA library made from thc venom gland of Chinese scorpion Buthus martensii Karsch.ABmKM4-specific primer and a primer corresponding to the partial sequence of pSPORT1 vector were used as forward primer and reverse primer,respectively,to screen the cDNA library by PCR reaction.Sequence analysis of positive clones showed that the BmKM4 cDNA is composed of three parts:5'UTR,open reading frame and 3'UTR.Compared with the corresponding regions of other scorpion mammalian neurotoxin cDNAs,the 5'UTR of BmKM4 cDNA is highly conservative versus highly variable for 3'UTR.The lateral sequence of initiation codon (AUG) is AAATGAA which is in consistent with that of most scorpion toxin genes.On the 3'-end,a putative polyadenylation signal (AATAAA) was 1Tnt upstream of Poly (A) tail.The open reading frame encodes a precursor of 84 amino acid residues,including a signal peptide of 19 residues,a mature toxin(BmKM4) of 64 residues,and a basic residue (Arg) tailwhich would be removed in the processing step. 相似文献