Cloning, Expression and Purification of Wheat Acetyl-CoA Carboxylases CT Domain in E.coil

The entire gene of carboxyltransferase(CT) domain of acetyl-CoA carboxylase(ACCase) from Chinese Spring wheat(CSW) plastid was cloned firstly,and the 2.3 kb gene was inserted into PET28a+ vector and expressed in E.coil in a soluble state.The (His)6 fusion protein was identified by SDS-PAGE and Western blot.The recombinant protein was purified by affinity chromatography,and the calculated molecular mass(Mr) was 88000.The results of the sequence analysis indicate that the cloned gene(GeneBank accession No.EU124675) was a supplement and revision of the reported ACCase CT partial cDNA from Chinese Spring wheat plastid.The recombinant protein will be significant for us to investigate the recognizing mechanism between ACCase and herbicides,and further to screen new herbicides.     

Tracing the evolution of the mitochondrial protein import machinery

Mitochondria are eukaryotic organelles originated from a single bacterial endosymbiosis about 2 billion years ago. One of the earliest events in the evolution of mitochondria was the acquisition of a mechanism that facilitated the import of proteins from cytosol. The mitochondrial protein import machinery consists of dozens of subunits, and they are of modular design. However, to date, it is not clear when certain component was added to the machinery. Using extensive homology searches, the evolutionary history of the mitochondrial protein import machinery was reconstructed. The results indicated that 6 of the 35 subunits have homologs in prokaryote, suggesting that they were prokaryotic origin; the major subunit gains were occurred in the earliest stage of eukaryotic evolution; subsequent to the gain of these conserved set of subunits, the mitochondrial protein import machinery components diversified along the eukaryotic lineages and a number of lineage-specific subunits can be observed. Furthermore, protein import systems of mitochondria-like organelles (hydrogenosomes and mitosomes) have dramatically reduced their subunit contents, however, they share most of the prokaryotic origin components with mitochondrion.     

A structurally ordered thiophene-thiazole copolymer for organic thin-film transistors

This paper reports a new donor-acceptor copolymer semiconductor, PTBTh, comprising bithiophene and bithiazole where the regular coplanar structure and the intramolecular charge transfer are expected to increase the opportunity for --- stacking and charge transport. The AFM image shows lamellar stacking of the polymer on the surface. The field-effect transistor (FET) properties of PTBTh have been evaluated by a bottom-contact/bottom-gate TFT configuration. The device showed a high hole mobility of 1.14×10-2 cm2 V-1 s-1 and a current on/off ratio of 3×105 with the polymer thin film annealed at a mild temperature of 120 ℃ when measured under ambient conditions.     

以四氟对苯二甲酸为配体构建的两个铅的配位聚合物：合成、晶体结构和荧光性质

在4-甲基咪唑/三氮唑存在下,利用四氟对苯二甲酸为配体、与Pb(NO3)2作用,得到了2种配位聚合物{[Pb(tfbdc)(H2tfbdc)0.5]·(4-MI)·(H2O)}n(1)和{[Pb(tfbdc)(H2O)2]}n(2)(H2tfbdc=四氟对苯二甲酸,4-MI=4-甲基咪唑),并用红外光谱、元素分析和X-单晶衍射对其进行了表征。化合物1属于单斜晶系,空间群为P21/n,化合物2属于三斜晶系,空间群为P1。配合物1中,铅离子依靠正常的Pb-O键和次级键Pb…O,与7个氧原子配位;tfbdc2-阴离子和H2tfbdc分别采用不同的配位方式桥联铅离子,导致1个具有孔道的三维结构的形成。而4-甲基咪唑和游离水分子通过氢键作用嵌在这三维结构的孔道中。π-π堆积作用的存在增强了1的稳定性。配合物2中,铅离子是位于8个氧原子的配位环境中,tfbdc2-阴离子以螯合和桥联的方式与铅离子作用,导致1个二维层状结构的形成。此外还考察了1和2的热稳定性和固体荧光性质。     

化学基元组学与药物创新

化学基元组学（chemomics）是与化学信息学、生物信息学、合成化学等学科相关的交叉学科．生物系统从内源性小分子（天然砌块）出发,通过酶催化的化学反应序列制造天然产物．生物系统通过化学反应和天然砌块向目标天然产物“砌入”一组原子,这样的一组原子称为化学基元（chemoyl）．化学基元组（chemome）是生物组织中所含有的化学基元的全体．化学基元组学研究各种化学基元的结构、组装与演化的基本规律．在生存压力和繁衍需求的驱动下,生物系统已经进化出有效手段来合成天然产物以应付环境的变化,并产生了丰富多彩的生物和化学多样性．近年来,人们意识到药物创新的瓶颈之一是药物筛选资源的日益枯竭．化学基元组学可以解决这个瓶颈问题,它通过揭示生物系统制备化学多样性的规律,发展仿生合成方法制备类天然化合物库（quasi natural product libraries）以供药物筛选．本文综述了化学基元组学的主要研究内容及其在药物创新各领域中的潜在应用．     

Synthesis of water-soluble C_(60) derivatives and their scavenging free radical activity

Four piperazine-appended [60] fuilerenes (1a-1d) were synthesized and characterized. Their activities of scavenging radical were studied via UV-Vis and EPR. The results indicate that light irradiation is of advantage to increase the activity of scavenging radical.     

N-(2-甲基-6-乙基苯基)丙氨酸对映体的毛细管电泳分离

采用高效毛细管区带电泳法,以β-环糊精及其衍生物作为手性选择剂,对外消旋N-(2-甲基-6-乙基苯基)丙氨酸(EMPA)的两个对映体进行了手性分离,比较了环糊精种类、环糊精浓度、电解质溶液pH值、温度和电场强度对分离的影响.实验结果表明,采用2,6-O-二甲基-β-环糊精为手性选择试剂,环糊精浓度为40mmol/L、电解质溶液pH=5.5及温度为20℃时分离效果最佳,对映体基本达基线分离,线性范围为20～200mg/L,最低检测限为10mg/L.     

沉淀法制备CeO_2纳米晶与表征

采用乙醇为分散剂和保护剂 ,用反向沉淀法制备了不同粒径的CeO2 纳米晶。XRD分析表明 ,当焙烧温度为 2 5 0～ 80 0℃时 ,所合成的CeO2 纳米粒子属于立方晶系 ,空间群为O5 H FM 3M。TEM分析表明 ,CeO2 纳米粒子呈球形 ,粒度随焙烧温度的增加而增大。热失重分析表明 ,样品的热失重主要受温度的影响 ,而焙烧时间的影响不大。相对密度分析表明 ,随CeO2 纳米晶粒度的增大 ,粉末的密度增加。     

氢化硝基苯合成对氨基酚中活性炭负载铂催化剂的新制备方法研究

采用不同还原剂（甲醛、甲酸、硼氢化钾和氢气）,或于还原Pt(IV)过程中引入少量Pt/AC(AC：活性炭)催化剂“催化”氢气分子,制备了Pt/AC催化剂。其催化氢化硝基苯制对氢基酚的反应结果表明,制备催化剂时所用的还原剂对催化剂的活性影响很大,但对反应选择性影响较小。用甲醛、甲酸和硼氢化钾还原制成的催化剂的活性皆较高;以氢气还原制得的催化剂活性较差;采用“催化”氢气还原法,可大大提高Pt/AC催化剂的活性,与传统甲醛还原法相比,甲酸和“催化”氢气还原制备Pt/AC催化剂的方法较简便、有效。     

双金属洋葱结构纳米Mo0.9W0.1S2的合成

0 引言 继碳富勒烯和碳纳米管的发现,1992年R.Tenne等首次在Nature上发表了具有类富勒烯和纳米管结构的WS_2,开创了非碳无机类富勒烯(Inorganic Fullerene-like,简称IF)纳米化合物研究的新领域。由于具有与富勒烯碳或碳纳米管相类似