Profiling of glycosidase activities using coumarin-conjugated glycoside cocktails

Glycosidases are a large subgroup of carbohydrate-processing enzymes that hydrolytically cleave the glycosidic bond. Glycans formed by the action of glycosidases are involved in various biological processes. Genetic abnormalities in glycosidases are associated with inherited diseases. Thus, characterization of the catalytic activities of glycosidases is of great importance. Herein, we describe a simple and rapid approach for determining glycosidase activity profiles using coumarin-conjugated glycoside cocktails. [reaction: see text].     

自组装膜

自动形成有序有机薄膜可通过自组装(SA)技术得到.SA成膜技术快速简便, SA膜对热, 时间, 化学环境及外压稳定, 有较高的二维或三维有序性, 是获得超晶格有序材料的一种有效方法, 在非线性光学, 分子器件, 分子生物学及表面材料工程中都有潜在的应用前景.     

Self-assembly of bipolar amphiphiles

Over the past 2 years, various symmetrical and unsymmetrical bipolar amphiphiles (bolaamphiphiles) have been synthesized to study their self-organizing and packing properties alone as well as in mixtures with conventional amphiphiles. This review focuses on the lyotropic properties of these bolaamphiphiles and describes their in some cases quite unusual supramolecular self-assembling properties in aqueous media and at the air–water and liquid–solid interface.     

Self-assembly of magnetic nanostructures

We use Monte Carlo and quaternion molecular dynamics simulations to study the self-assembly of intriguing structures which form in colloidal suspensions of small magnetite particles. We show that the only stable isomers with few particles, a ring and a chain, can be efficiently interconverted using a magnetizable tip. We propose to use the oscillating dipole field of the tip to locally anneal the aggregates to either a ring in zero field or a chain in nonzero applied field.     

Self-assembly of viral particles

Viruses, as typical bionanoparticles from nature, possess many superb properties, such as exquisite symmetry, uniformity of size and shape, well-characterized surface chemistry that governs the potential interparticle interactions. These features make viral particles ideal building blocks for self-assembly studies and novel materials development. This review outlines some of the recent research activities in the area of controlled self-assembly of viruses and its potential use as materials. One particular application of the assembled viruses, especially for biomaterials, is also briefly discussed.     

Self-assembly of an amphiphilic

The template-directed synthesis of a [2]rotaxane, in which a pi-electron deficient ring component-cyclobis(paraquat-p-phenylene)-is assembled around a pi-electron rich asymmetric monopyrrolotetrathiafulvalene unit on the rod section of an amphiphilic dumbbell component that is terminated by a hydrophilic dendritic stopper at one end and a hydrophobic tetraarylmethane stopper at the other end, is reported.     

Self-assembly of surfactant-like peptides

Inspired by recent work describing surfactant-like peptides, we have carried out a systematic study on peptides with the underlying composition of V6D2, altering the absolute sequence to determine the importance of the surfactant-like structure. All of the peptides examined here formed self-assembled structures in water. However, in contrast to other reports, we have found a surprising diversity of structures including fibers, tapes, and twisted ribbons but an absence of the vesicles and nanotubes described previously. Further investigations demonstrated that peptide purity plays a significant role in the outcome of the self-assembly. Different batches behave very differently, which can be linked to the compositions of these batches. This work shows that there is a need for not only rational design but also ease of synthesis of the building blocks for self-assembled structures.     

Self-assembly in glycolipids

The interest in the glyco-world is widespread and covers quite a number of different areas. We restrict ourselves to underline some features concerning interactions and organization in the hydrophilic region of glycolipid aggregates that, besides the biological or technological aspects, constitute an experimental and theoretical challenge, as they invest some aspects of colloidal self-assembly that keep on being not completely understood.     

Self-assembly sodalite-like framework

The dense packing of shape complementary N-donor molecules dominates the self-assembly of coordination polymers possessing sodalite-like topology and supports nanosize molecular cages.     

Self-assembly of inorganic nanorods

Generation of nanostructures containing from several to thousands of inorganic nanorods (NRs) organized in a highly ordered manner paves the way for applications that exploit directional properties of NR arrays. Self-assembly of NRs provides a simple and cost-efficient strategy for producing NR ensembles. This tutorial review highlights recent advances in the field of NR synthesis, summarizes the types of ligands used for NR synthesis and stabilization, reviews experimental and theoretical work on NR self-assembly that is driven by interactions between the ligands and describes current properties and applications of self-assembled NR structures.     

Self-assembly of block copolymers

Block copolymer (BCP) self-assembly has attracted considerable attention for many decades because it can yield ordered structures in a wide range of morphologies, including spheres, cylinders, bicontinuous structures, lamellae, vesicles, and many other complex or hierarchical assemblies. These aggregates provide potential or practical applications in many fields. The present tutorial review introduces the primary principles of BCP self-assembly in bulk and in solution, by describing experiments, theories, accessible morphologies and morphological transitions, factors affecting the morphology, thermodynamics and kinetics, among others. As one specific example at a more advanced level, BCP vesicles (polymersomes) and their potential applications are discussed in some detail.     

Self-assembly of pyrazine-containing tetrachloroacenes

In this paper, we report self-assembly of tetrachloroacenes containing pyrazine moieties. The title compounds, phenazine and bisphenazine substituted with four chlorine atoms for increased electron deficiency and alkyloxy side groups for solubility, demonstrated excellent gelation ability in select organic solvents. The assembled structure of these two series of compounds exhibited a morphological difference. Tetrachlorophenazine containing hexadecyloxy side groups induced rigid microbelts, while more extensive entanglement of thinner, more flexible fibers was observed from tetrachlorobisphenazine compounds, characterized by scanning electron microscopy. Tetrachlorophenazine and tetrachlorobisphenazine gels showed quite different emission behavior compared to their solution state. A strong, red-shifted emission compared to that of its diluted solution state was observed from the gel of tetrachlorophenazine. We have ascertained this is a result of J-aggregate formation. From the crystal structure of a model compound, it was found that tetrachlorophenazine cores adopt π-π stacking with a short stacking distance of 3.38 ?, enabling significant intermolecular π-orbital overlap. In addition, the π-cores were displaced longitudinally, indicative of J-aggregate formation. Surprisingly, the gel of tetrachlorobisphenazine showed fluorescence comparable to that of its dilute solution, suggesting that such a close packing of the π-cores may not be possible due to the bulky tert-butyl substituents.     

Self-assembly of dendritic structures

There have been some impressive achievements in the past 1–2 years in the area of self-assembled dendritic structures. The most notable include self-assembly by non-covalent interactions as reported by Zimmerman, Fréchet, and others, Percec's ground-breaking discovery of self-assembling liquid crystalline materials based on dendritic compounds, and the accomplishments of Crooks, among others, in the area of dendritic self-assembled monolayers. © 1999 Elsevier Science Ltd.     

有机铟化合物的自组装现象

结合作者近两年来有机铟化合物自组装研究的一系列工作，综述了有机铟化合 物的自组装现象。有机铟化合物可以通过分子间的配位键和次级键连接而形成自组 装的二聚体或多聚体结构。其中一些有机铟化合物可以作为InN，InP，InAs的前体。     

Self-assembly of cobalt nanoparticle rings

Weakly ferromagnetic cobalt nanoparticles can assemble spontaneously into nanosized "bracelets" when dispersed in organic solvents containing resorcinarenes as surfactants. Bracelet self-assembly occurs in solution and is directed by magnetic dipolar interactions, whereas nanoparticle rings with larger diameters are produced by evaporation-driven flow on wetted surfaces.     

超支化聚合物胶束自组装

超支化聚合物因其独特的拓扑结构和物理化学性质,引起了科学界和工业界的广泛关注,成为高分子学科一个新的研究热点之一。近年来,超支化聚合物在分子自组装研究领域展示出了独特的潜力,实现了多维多尺度自组装,制备了各种超分子结构。而胶束是超支化聚合物最容易自组装得到的超分子结构。本文我们将系统总结超支化聚合物包括聚醚、聚酯、聚磷酸酯、聚多糖等胶束自组装行为、组装机理及其在生物医药、纳米载体、金属纳米粒子制备等方面的最新应用。     

环境响应性多肽自组装研究进展

分子自组装广泛存在于自然界中,参与生物体的各项生命活动,从而确保生物体相关生理功能的实现和生化反应的有序进行.多肽自组装作为分子自组装的重要组成部分,其良好的生物相容性为构建具有重要应用价值的生物医用材料提供了新的思路.本文总结了多肽自组装过程中主要的驱动作用力;简述了多肽自组装形成的主要结构;详细介绍了自组装过程中环境变化,包括pH、温度、离子强度、特殊离子、氧化还原态以及光照等,对于环境响应性多肽自组装结构和性质的影响;并且阐述了多肽自组装生物材料的应用方向和前景,希望为该领域的进一步研究提供参考.