Penta-Coordinate Phosphorus Intermediates Analysis on Phospho-related Proteins

In this paper, based on known crystal structures of square pyramid （SP） and trigonal bipyramid （TBP） penta coordinated phosphorus compounds containing amino acid side chains, such as amino, carboxyl, hydroxyl or thiol, a software for survey the P（5）-structure of phosphorylated proteins was derived. By this software, it was found that 382 of 398 phosphorus related kinases （96%） from current PDB could go through the penta-coordinated phosphorus transition state or intermediate.     

Monitoring the Hydrolysis of p—Nitrophenyl Acetate Catalyzed by Seryl—histidine with Electrospray Ionization Mass Spectrometry

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Ligand Exchange Between Penta-Coordinated Phosphoryl Serine and Histidine Compounds

With the assistance of HPLC-ESI-MS/MS, the self-assembly products of serine and histidine penta-coordinated phosphorus compound were separated and identified. The expectative product was seryl-histidine dipeptide, but it was found that there was almost equimolar amount of histidyl-histidine dipeptide as well as seryl-histidine dipeptide. The mechanism was speculated that there was iigand exchange between penta-coordinated phosphoryl serine and histidine in the reaction process. As a result,two types of dipeptide were produced.     

Spontaneous Polymerization of An Amino Acid Based Amphiphile at Air/water Interface Investigated by ESI-MS and Transmission IR Spectrometry

Self-assemblies of amphiphilic molecules are proposed to play a ubiquitous role at the early stages of evolution in the formation of primitive biopolymers. [1] As regard to the significance of N-phosphoryl amino acids as a model for the co-evolution of protein and nucleic acids at the prebiotic stage, [2] amphiphilic N-phosphoryl amino acids with two hydrophobic tails were synthesized. [3]     

五氯化磷辅助下氨基酸的自组装成肽反应研究

L-α-氨基酸和D-α-氨基酸可与五氯化磷直接发生磷酰化反应，随后自组装成多肽，但β-氨基酸不能成肽，DL-α-氨基酸成肽困难；在SOCl2存在下，α-氨基酸也不能成肽，用电喷雾质谱研究了氨基酸的自组装反应，反应过程中有五元环状的氨基酸五配位磷中间体生成，使用硅烷基保护的氨基酸，在^31PNMR中可观察到五配位磷中间体。     

Optical measurement of the deformation of giant lipid vesicles driven by a micropipet electrode

We investigate the deformation of giant lipid vesicles driven by a micropipet electrode by use of differential confocal microscopy. This optical technique provides nanometer depth resolution without mechanical contact and hence prevents large tension or perforation of the soft membrane. For dipalmitoyl phosphatidylcholine (DPPC) membranes in the gel phase, we observed deformations of several hundreds of nanometers when the driving voltage was about 0.1 V. The voltage and frequency responses of the vesicle deformation can be explained by the balance between the electroosmotic force inside the micropipet and the membrane tension. We also used DPPC:cholesterol vesicles to check the validity of this model. In the fluid phase, however, the deformation is independent of the modulation signal because micrometer-scale thermal fluctuations dominate the membrane motion.     

气相[（SiO2）nX]^—团簇产生机理

利用ＸｅＣｌ准分子激光烧蚀多种硅氧多孔结构材料，在负离子通道测得丰富的「（ＳｉＯ２）ｎＸ」＾－负离子团簇，并讨论了多孔网结构和表面活性基团的分布对激光能量的吸收，传输及团簇产生的重要作用。     

Silica nanoparticles for separation of biologically active amines by capillary electrophoresis with laser-induced native fluorescence detection

This paper describes the analysis of biologically active amines by capillary electrophoresis (CE) in conjunction with laser-induced native fluorescence detection. In order to simultaneously analyze amines and acids as well as to achieve high sensitivity, 10 mM formic acid solutions (pH < 4.0) containing silica nanoparticles (SiNPs) were chosen as the background electrolytes. With increasing SiNP concentration, the migration times for seven analytes decrease as a result of increase in electroosmotic flow (EOF) and decrease in their electrophoretic mobilities against EOF. A small EOF generated at pH 3.0 reveals adsorption of SiNPs on the deactivated capillary wall. The decreases in electrophoretic mobilities with increasing SiNP concentration up to 0.3x indicate the interactions between the analytes and the SiNPs. Having a great sensitivity (the limits of detection at a signal-to-noise ratio (S/N) = 3 of 0.09 nM for tryptamine (TA)), high efficiency, and excellent reproducibility (less than 2.4% of the migration times), this developed method has been applied to the analysis of urinal samples with the concentrations of 0.50 +/- 0.02 microM, 0.49 +/- 0.04 microM, and 74 +/- 2 microM for TA, 5-hydroxytryptamine, and tryptophan, respectively. The successful examples demonstrated in this study open up a possibility of using functional nanoparticles for the separation of different analytes by CE.     

2′,3′-乙氧甲撑基腺苷5′-硫代磷酰氨基酸酯的合成和谱学分析

核苷磷酰氨基酸酯化合物是一类倍受重视的药物 ,特别是它可作为寡聚核苷酸的类似物用于反义药物 [1] .HIV逆转录酶是治疗艾滋病的有效靶点 ,目前普遍使用的抗 HIV核苷类似物中 ,2′,3′-双脱氧核苷 (dd Ns)具有良好的疗效 [2 ] .苯氧基取代的核苷 -磷酰氨基酸酯是 HIV逆转录酶的有效抑制剂[3 ] ,其药物毒性比 dd Ns低 ,但容易在体内被核酸酶水解 .由于硫代磷酸对核酸酶具有抵抗性 ,它可以抑制核酸酶对它的水解 [4 ] ,因此我们设计合成了核苷 5′-硫代磷酰氨基酸酯化合物 ,希望开发出一种全新的 HIV逆转录酶抑制剂 .由于分子中引入氨基…     

Hexa-Coordinate phosphorus Chemistry and Life Chemistry

The amino acids' side chains were acting as the relay device to regulate the chemical reactivi-ties of the N-phosphoryl amino acids. These modulation effects were performed through the partici-pation of the phosphoryl group.