共查询到19条相似文献,搜索用时 93 毫秒
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以琼胶糖为原料, 通过酸法与酶法降解以及凝胶过滤色谱分离, 获得了9种寡糖. 采用还原胺化法将其与1,2- 二-十六烷基-3-磷脂酰乙醇胺甘油(DHPE)偶联, 获得了相应拟糖脂. 采用糖芯片技术, 通过与标准寡糖(LNnT与LNT)比较, 评价了其与凝集素RCA120的相互作用. 首次发现, 酸法水解得到的琼胶寡糖与RCA120作用力明显高于LNnT, 表明具有Galβ1,4AnG-R结构类型的寡糖与RCA120亲和力强于Galβ1, 4GlcNAc-R, 且亲和力的大小与聚合度无关. 相似文献
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半乳糖凝集素是一类具有重要生理功能的蛋白质,杨树菇(Agrocybe aegerita)半乳糖凝集素(AAL)是被报道的第四种真菌半乳糖凝集素。本文用荧光光谱法研究了半乳糖、乳糖和X-gal两种含β-半乳糖残基的分子与AAL的相互作用。研究结果表明:半乳糖对AAL的荧光光谱无明显影响;乳糖的结合使AAL折叠为更紧密的结构而使其光谱蓝移;X-gal与AAL的结合强烈猝灭AAL的荧光,且X-gal的紫外吸收光谱与AAL的荧光发射光谱有一定程度的重叠,由此得出了其反应的结合常数(Kb=7.33×103L.mol-1),结合位点数(n=8.3)及作用距离(r=2.79 nm)。用同步荧光光谱法比较了乳糖和X-gal对AAL构象的影响,结果表明,乳糖和X-gal对AAL的结合方式有可能不同。此结果为深入研究AAL的生理功能提供了线索。 相似文献
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利用超高效液相色谱-轨道阱高分辨质谱(UHPLC-Orbitrap-MS)结合链霉亲和素包被的96孔板的方法筛选人参复杂体系中蓖麻凝集素120 (RCA 120)的寡糖结合剂。将RCA 120修饰的96孔板与溶菌酶修饰的96孔板分别与寡糖标准品孵育,对未结合的寡糖利用UHPLC-Orbitrap-MS进行分析,利用峰面积的变化表征寡糖是否与RCA 120发生相互作用。对影响亲和力的因素包括孵育时间、孵育温度和缓冲液等进行了优化。在优化条件下,对生晒参、红参和西洋参的寡糖提取物进行RCA 120结合剂的筛选,从生晒参中筛选出3种二糖化合物和2种三糖化合物,从西洋参中筛选出2种二糖化合物和2种三糖化合物,发现生晒参和西洋参中具有相同单糖残基的寡糖与RCA 120的结合强度均具有显著性差异。但是,从红参中未筛选到RCA 120结合剂,推测这是由红参炮制工艺导致的差异。本方法简单、快速、准确,可高通量地识别和筛选复杂体系中多个糖类组分与蛋白质的相互作用,为糖和蛋白质相互作用的研究提供了新方法。 相似文献
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将含糖基的简单两亲分子N-十八烷基麦芽糖酰胺(N-n-Octadecyl-D-maltonamide, NOMA)非共价修饰到单壁碳纳米管(SWNT)表面形成糖-碳纳米管复合体(NOMA-SWNT), 谱学和形态学结果表明, NOMA不仅能快速、高效地吸附到SWNT表面, 而且能有效地改善SWNT在水溶液中的分散性能. 以NOMA-SWNT管束为导通沟道构建了碳纳米管场效应管(CNTFET)器件, 检测了麦芽糖和伴刀豆凝集素蛋白(Con A)的特异性识别作用. 检测器件在每个修饰阶段的电学性能的变化证明了NOMA对SWNT的非共价糖基化修饰及用CNTFET来检测糖-凝集素特异性识别作用的可能性. 相似文献
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以D-甘露糖和伴刀豆球蛋白(ConA)的相互作用为研究对象,利用美拉德反应将D-甘露糖共价结合到负载蛋白牛血清蛋白(BSA)的表面形成拟糖蛋白,然后将拟糖蛋白固定到玻碳电极表面,以拟糖蛋白表面的D-甘露糖为分子识别物质,构建了检测伴刀豆球蛋白(ConA)的电化学阻抗传感器。拟糖蛋白制备过程简单,D-甘露糖负载量大,在空间中提供多个结合位点,因此能与ConA形成多价复合物,提高了传感器的灵敏度。该传感器的响应值与ConA浓度的对数在5.0×10-11~5.0×10-9mol/L之间呈良好的线性关系,检出限为1.7×10-11mol/L,D-甘露糖和ConA之间的结合常数为2.6×106L/mol。该方法简单,可适用于不同糖和蛋白质相互作用的研究,为构建高灵敏度的电化学阻抗传感器提供了新思路。 相似文献
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以含半乳糖的甲基丙烯酸羟乙酯和对苯乙烯磺酸钠为单体,通过可逆加成断裂链转移聚合设计合成了一系列具有不同结构的含糖高分子.采用核磁共振氢谱和凝胶渗透色谱对材料的结构进行了表征.分别通过比浊法和酶联免疫吸附实验,以花生凝集素(PNA)为模型,研究了磺酸基的数量及分布对材料与凝集素之间相互作用的影响.结果表明,磺酸基的引入能通过静电相互作用协同增强含半乳糖高分子与PNA之间的特异性结合作用,并且这一作用可通过磺酸基数量与排列方式进行调节,相对于嵌段共聚型材料,无规共聚型材料与PNA的结合作用更强,其中P(Gal21-r-SS41)与PNA的结合作用最强,较均聚半乳糖高分子(PGal)提高2.7倍.利用这种相互作用,材料能够通过阻断凝集素活性有效抑制肿瘤细胞的迁移,有望在临床抗肿瘤转移治疗中得以应用. 相似文献
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用合适的手段表征生物分子的相互作用对于深刻理解生命过程的本质以及进行医药开发都具有重要意义。将微流控芯片和毛细管电泳相结合的微流控芯片电泳技术具有快速、高效、高通量、样品用量少和易于整合等诸多优势。本文对近年来进行生物分子间相互作用结合常数测定以及结合动力学研究的微流控芯片电泳分离模式、分析方法和芯片检测方法分别做了介绍;简单对比了微流控芯片技术和微阵列生物芯片生物分子间相互作用研究技术;最后分析了微流控芯片技术目前的不足,并对其未来的发展进行了展望。 相似文献
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Schofield CL Mukhopadhyay B Hardy SM McDonnell MB Field RA Russell DA 《The Analyst》2008,133(5):626-634
Ricin is a toxic lectin which presents a potential security threat. Its rapid detection is highly desirable. Here we present a colorimetric bioassay based on the aggregation of carbohydrate-stabilised gold nanoparticles which has been used to detect Ricinus communis Agglutinin 120 (RCA(120)) - a ricin surrogate. To achieve a stable and robust sensing system the anchor chain length and the density of the assembled carbohydrates on the gold particle surface has been examined to determine the optimal coverage for maximal aggregation with both RCA(120) and Concanavalin A (Con A) lectins. Gold nanoparticles were stabilised with either a thiolated galactose derivative (9-mercapto-3,6-diaoxaoctyl-beta-d-galactoside) or a thiolated mannose derivative (9-merapto-3,6-dioxaoctyl-alpha-d-mannoside), for RCA(120) and Con A respectively, diluted in each instance with varying ratios of a thiolated triethylene glycol derivative. Aggregation was induced with the respective cognate lectin with the reaction monitored by UV-visible spectrophotometry. The results obtained show that a particle surface with at least 7.5% galactose is required for aggregation with RCA(120) and 6% mannose coverage is required for aggregation with Con A. For each lectin the sensitivity of the assay could be controlled by adjustment of the carbohydrate density on the gold nanoparticles, but with differing results. Maximal aggregation with Con A was achieved with a monolayer consisting of 100% mannose, whereas for RCA(120) maximal aggregation occurred with 70% coverage of galactose. The limit of detection for RCA(120) using the optimally presented galactose-stabilised nanoparticles was 9 nM. 相似文献
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Dr. Mehdi Almant Amira Mastouri Laura Gallego‐Yerga Prof. José Manuel García Fernandez Prof. Carmen Ortiz Mellet Prof. José Kovensky Dr. Sandrine Morandat Dr. Karim El Kirat Dr. Sébastien G. Gouin 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(2):729-738
We designed a set of multi‐galactosides with valencies ranging from one to seven and different spacer‐arm lengths. The compounds display a high structural homology for a strict assessment of multivalent phenomena. The multimers were first evaluated by an enzyme‐linked lectin assay (ELLA) toward the peanut agglutinin (PNA). The binding affinity was shown to be dependent on the spacer‐arm length, and cluster effects were observed for the galactosides bearing the shortest and the longest linkers. The latter compounds were shown to be much more potent PNA cross‐linkers in a “sandwich assay”. Dynamic light scattering (DLS) experiments also revealed the formation of soluble aggregates between heptavalent derivatives with medium or long linkers and the labeled PNA. ELLA experiments performed with valency‐controlled clusters and labeled lectins are therefore not always devoid from aggregative processes. The precise nature of the multivalent interaction observed by ELLA for the compounds bearing the shortest linkers, which are unable to form PNA aggregates, was further investigated by atomic force microscopy (AFM). The galactosides were grafted onto the tip of a cantilever and the PNA lectin onto a gold surface. Similar unbinding forces were registered when the valency of the ligands was increased, thus showing that the multimers cannot interact more strongly with PNA. Multiple binding events to the PNA were also never observed, thus confirming that a chelate binding mode does not operate with the multivalent galactosides, probably because the linkers are too short. Altogether, these results suggest that the cluster effect that operates in ELLA with the multimers is not related to additional PNA stabilizations and can be ascribed to local concentration effects that favor a dynamic turnover of the tethered galactosides in the PNA binding sites. 相似文献
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Gunjan Pandey Tasneem Fatma Sneha Sudha Komath 《Photochemistry and photobiology》2009,85(5):1126-1133
In a recent study, we found that jacalin, a T-antigen specific lectin could interact with phycocyanin (PC) in a carbohydrate-independent manner. We show here that concanavalin A and peanut agglutinin too can interact with PC, although the nature of the interaction is distinctly different from that for jacalin. The legume lectins bind PC weaker in the presence of their specific carbohydrate ligands. Like jacalin, the legume lectins too interact with PC via two distinct sites. Higher ionic strengths resulted in a weakening of the interaction at site 1 and did not affect the interaction at site 2 , clearly indicating that the interactions involve charged residues at the former and hydrophobic interactions at the latter site. The implications for the use of these lectin–PC complexes in photodynamic therapy and other clinical applications are discussed. 相似文献
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用荧光光谱法研究了生理酸度条件下,头孢噻肟对牛血清白蛋白,Cu(Ⅱ)对牛血清白蛋白以及Cu(Ⅱ)对头孢噻肟和牛血清白蛋白荧光光谱特性的影响。结果表明:Cu(Ⅱ)和头孢噻肟均可使牛血清白蛋白的荧光强度发生静态猝灭,并且在Cu(Ⅱ)存在下,头孢噻肟对牛血清白蛋白的荧光猝灭作用显著增强。根据荧光猝灭双倒数图计算头孢噻肟和牛血清白蛋白的结合常数为3.11×104L/mol,结合位点数为1.03;二元配合物Cu(Ⅱ)与牛血清白蛋白之间的结合常数为1.13×103L/mol,结合位点数为0.74。 相似文献
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采用电喷雾质谱法研究了防己诺林碱与双链核酸及G-四链体的相互作用. 结果表明, 防己诺林碱可选择性地与G-四链体结合. 利用串联质谱技术对防己诺林碱与核酸的结合模式进行了研究, 结果表明, 防己诺林碱可能通过末端堆积作用与G-四链体结合, 而通过插入作用与双链核酸结合. 结合模式的差异导致防己诺林碱选择性地与G-四链体结合. 相似文献
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盐酸阿霉素与人端粒DNA相互作用的电化学研究 总被引:1,自引:0,他引:1
建立了石墨烯修饰玻碳电极上研究盐酸阿霉素(DOX)与人端粒DNA相互作用的电化学方法。实验发现,在p H 6.0 PBS缓冲溶液中,DOX在-0.585 V和-0.638 V处有1对氧化还原峰,氧化峰电流与DOX的浓度在0.03~0.8μmol/L和0.8~10μmol/L范围内分段呈良好的线性关系,检出限(S/N=3)为0.01μmol/L。对0.5μmol/L的DOX进行11次平行测定,相对标准偏差为3.5%。将不同浓度的人端粒DNA加入DOX,DOX的氧化峰电流明显降低,且紫外光谱有蓝移增色效应,表明二者发生了相互作用,结合比为1∶1,结合常数为1.11×103L/mol。 相似文献
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Vanessa Moll Krzysztof B. Be Justyna Grabska Christian W. Huck 《Molecules (Basel, Switzerland)》2022,27(18)
The interaction of water with polymers is an intensively studied topic. Vibrational spectroscopy techniques, mid-infrared (MIR) and Raman, were often used to investigate the properties of water–polymer systems. On the other hand, relatively little attention has been given to the potential of using near-infrared (NIR) spectroscopy (12,500–4000 cm−1; 800–2500 nm) for exploring this problem. NIR spectroscopy delivers exclusive opportunities for the investigation of molecular structure and interactions. This technique derives information from overtones and combination bands, which provide unique insights into molecular interactions. It is also very well suited for the investigation of aqueous systems, as both the bands of water and the polymer can be reliably acquired in a range of concentrations in a more straightforward manner than it is possible with MIR spectroscopy. In this study, we applied NIR spectroscopy to investigate interactions of water with polymers of varying hydrophobicity: polytetrafluoroethylene (PTFE), polypropylene (PP), polystyrene (PS), polyvinylchloride (PVC), polyoxymethylene (POM), polyamide 6 (PA), lignin (Lig), chitin (Chi) and cellulose (Cell). Polymer–water mixtures in the concentration range of water between 1–10%(w/w) were investigated. Spectra analysis and interpretation were performed with the use of difference spectroscopy, Principal Component Analysis (PCA), Median Linkage Clustering (MLC), Partial Least Squares Regression (PLSR), Multivariate Curve Resolution Alternating Least Squares (MCR-ALS) and Two-Dimensional Correlation Spectroscopy (2D-COS). Additionally, from the obtained data, aquagrams were constructed and interpreted with aid of the conclusions drawn from the conventional approaches. We deepened insights into the problem of water bands obscuring compound-specific signals in the NIR spectrum, which is often a limiting factor in analytical applications. The study unveiled clearly visible trends in NIR spectra associated with the chemical nature of the polymer and its increasing hydrophilicity. We demonstrated that changes in the NIR spectrum of water are manifested even in the case of interaction with highly hydrophobic polymers (e.g., PTFE). Furthermore, the unveiled spectral patterns of water in the presence of different polymers were found to be dissimilar between the two major water bands in NIR spectrum (νs + νas and νas + δ). 相似文献