牛血清白蛋白介导合成的金纳米簇用于活细胞荧光成像

以牛血清白蛋白介导合成金纳米簇, 并利用荧光分光光度计、纳米粒度及zeta电位仪以及非变性聚丙烯酰胺蛋白质电泳对其进行了表征. 结果表明, 该金纳米簇不仅荧光信号较强, 而且在不同pH值溶液中荧光稳定性好. 在此基础上进一步考察了金纳米簇与宫颈癌细胞(HeLa)间的相互作用. 结果表明, 该金纳米簇可成功进入活细胞内, 在最佳的培育时间和金纳米簇浓度条件下可达到较好的活细胞荧光标记效果, 且在经过细胞固定化处理后仍保持其标记形态.     

免疫纳米金共振散射光谱探针检测痕量免疫球蛋白A

将纳米金的共振散射效应和纳米金标记免疫反应结合起来建立了一种测定免疫球蛋白A的新方法. 采用柠檬酸三钠改良法制备了粒径约为10 nm的纳米金, 用于标记羊抗人免疫球蛋白A获得了免疫球蛋白A (IgA)的免疫共振散射光谱探针. 在pH 5.6的Na₂HPO₄-C₆H₈O₇缓冲溶液和PEG 6000存在下, 金标羊抗人免疫球蛋白A与IgA产生特异性结合, 引起金纳米粒子聚集, 导致金纳米粒子580 nm处的共振散射峰增强. 对免疫分析的条件进行了优化, IgA浓度在0.0054～1.35 μg•mL^－1范围内与580 nm处的共振散射强度呈线性关系, 方法的检测限(3σ)为2.0 ng•mL^－1, 相关系数为0.9983. 用于定量分析人血清中的免疫球蛋白A, 结果满意.     

纳米金生物探针及其应用

纳米技术与生物技术的融合,使纳米生物技术获得了很多重要的进展.纳米金作为研究较早的一种纳米材料,其在纳米生物探针方面的应用是最近几年较为活跃的研究方向.本文评述了近年来纳米金探针在生物分析中的应用及进展,阐述了纳米金与生物大分子作用的机理,介绍了纳米金探针在核酸分析、免疫分析、单细胞分析和靶向药物载体4个方面应用的最新进展,并对其未来的发展方向进行了展望.     

用于质谱的稳定同位素化学标记技术

近年来,稳定同位素化学标记结合质谱技术在定量蛋白质组学、代谢组学及转化医学等领域得到了广泛的应用.从同位素标记的官能团的角度进行了分类,除了传统的、商品化的同位素标记技术,还综述了一些最新报道的针对巯基、氨基和羧基等基团的特异性和非特异性同位素标记的策略及应用等方面的研究进展,并对此方面的发展趋势和应用前景进行了展望.     

蛋白质标记荧光探针的研究及其进展

蛋白质标记荧光探针在生物分析及蛋白质组学中的应用日益广泛,被用于在分子水平上分析和识别蛋白质,检测蛋白质复杂的构象变化及各项生理活动过程如蛋白质之间的相互作用等.本文评述了近年来该类探针的研究及进展,展望了其应用前景,引用文献63篇.     

基于纳米金／壳聚糖掺杂碳纳米管修饰金电极非标记免疫传感器的研究

应用吸附法将羊抗人IgG抗体直接固定于纳米金(GNPs)/壳聚糖(Chit)掺杂碳纳米管(CNTs)修饰的金电极表面,制备了用于人IgG抗原检测的非标记电化学免疫传感器.利用循环伏安法和交流阻抗研究了修饰电极表面的电化学特性,用差分脉冲伏安法研究了测试底液的pH值对免疫传感器性能的影响.实验表明,在含不同浓度人IgG的...     

纳米标记技术在电化学免疫分析中的研究

纳米材料因其具有独特的性质,广泛应用于发展具有超高灵敏度、超高选择性的电化学免疫分析方法.纳米材料的免疫标记技术是免疫分析方面研究的一个重要领域,对于提高分析方法的灵敏度与准确性至关重要.本文总结了近年来国内外纳米标记物在电化学免疫分析技术中的应用和进展情况,并对该领域的发展前景做出了展望.     

邻近标记方法表征细胞-细胞相互作用

细胞-细胞相互作用在多种生理过程中有重要意义, 针对这些相互作用的研究是化学与生命科学交叉领域的前沿热点. 基于对酶的功能改造、 定向进化和精准的时空调控, 酶介导的邻近标记方法在分析细胞-细胞相互作用方面具有广泛的应用前景. 本文重点描述了现有邻近标记方法的原理、 效果、 优缺点及潜在应用.     

糖芯片的检测及应用

糖芯片技术具有样品少、通量高和特异性强等优点,是一种糖组学研究的新的技术平台和强大的分析工具,已经广泛用于糖和蛋白质的特异性作用、酶活性和抑制剂、病毒入侵机理、细菌检测和免疫反应等方面的研究.本文简要介绍了糖芯片的原理、制备和信号的检测技术(荧光标记法、质谱法、SPR法等),分析了糖芯片在各个领域的应用及其发展前景.     

微流控及纳米金应用于免疫检测的最新研究进展

免疫检测是一种十分重要的生物分析方法,许多新的技术和材料被引入免疫检测中以提高其效率.本文综述了近期微流控及纳米金应用于免疫检测的研究进展,微-纳尺度材料和技术的应用能够提高检测的灵敏度,并实现快速、高通量、便捷、低消耗的分析,使信号输出方法变得更简单易行.其中基于微流控技术的小型化和基于纳米金的可视化检测能较好地提高免疫分析的效率.     

Synthesis of Poly(methyl methacrylate) Labeled with Fluorescein Moieties via Atom Transfer Radical Polymerization

Fluorescein chromophore‐labeled poly(methyl methacrylate) (PMMA) was prepared via atom transfer radical polymerization (ATRP) with two novel bromine‐containing fluorescein derivatives, 3,6‐bi(2′‐bromo‐2′‐methyl‐propionic acid) fluorescein ester (Fla‐Br) and 3‐(2′‐bromo‐2′‐methyl‐propionic acid) fluorescein ester (Flb‐Br), as the functional initiators, and CuBr/PMDETA as the catalyst, respectively. The above mentioned fluorescein containing bromine were synthesized in our lab. The ATRP of PMMA was proved in a controlled fashion. The resultant PMMA with narrow molecular weight distribution was endowed with the fluorescein chromophore incorporated into the polymer backbone. The presence of the fluorescein labeling of the polymers was confirmed by ¹H‐NMR and GPC trace under UV detector. The UV spectroscopy and fluorescence measurements of the resultant polymer gave further evidence of the functionality of the fluorescein labeling.     

氘代阿戈美拉汀的合成

以苯酚为原料,氘代碘甲烷与氘代醋酸酐为氘代试剂.经过氘代甲基化、傅克酰基化、克脑文盖尔缩合、芳构化、还原及氘代乙酰化反应得到氘代标记的阿戈美拉汀(1).该合成路线简洁,原料易得、反应条件易于控制,总收率为15.2%,化学纯度为99.97%,氘代丰度大于98%.目标化合物结构经质谱、核磁共振等表征确定可用于其药代动力学研究.     

Synthesis of deuterium labeled compounds by KCN-assisted hydrolysis of phosphonium salts

We developed a facile deuterium labeling method for benzylic or allylic halides or acetates systems. Conversion of the halides or acetates to the corresponding phosphonium salts and the following mild hydrolysis with KCN afforded the deuterium labeled compounds in good yields.     

铕标记抗原、激光时间分辨荧光免疫分析尿中白蛋白

放射免疫分析法(RIA)将免疫反应的特效性与放射性测量的灵敏性相结合,是当今最广泛采用的方法之一。但RIA药盒使用寿命受放射性同位素半衰期的限制以及操作放射性对人体和环境可能导致某些危害,促使人们力图改善以非放射性物质标记的其它免疫分析法的灵敏度。1979年Soini和Hemmila提出的时间分辨荧光免疫分析(TR—FIA),以稀土螯合物作标记物连接到抗体或抗原上,免疫反应完成后,用时间分辨技术测荧光,很容易将稀土螯合物的荧光与背景荧光压分开。由于TR—FIA能达到甚至超过RIA灵敏度,标记物没有辐照分解之患,测定动态范围广,方法简便快速,     

Micellar electrokinetic chromatography of fluorescently labeled proteins on poly(dimethylsiloxane)-based microchips

MEKC of standard proteins was investigated on PDMS microfluidic devices. Standard proteins were labeled with AlexaFluor(R) 488 carboxylic acid tetrafluorophenyl ester and filtered through a size-exclusion column to remove any small peptides and unreacted label. High-efficiency MEKC separations of these standard proteins were performed using a buffer consisting of 10 mM sodium tetraborate, 25 mM SDS, and 20% v/v ACN. A separation of BSA using this buffer in a 3.0 cm long channel generated a peak with a plate height of 0.38 microm in <20 s. Additional fast separations of myoglobin, alpha-lactalbumin, lysozyme, and cytochrome c also yielded peaks with plate heights ranging from 0.54 to 0.72 microm. All proteins migrated with respect to their individual pIs. To improve the separations, we used a PDMS serpentine chip with tapered turns and a separation distance of 25 cm. The number of plates generated increased linearly with increasing separation distance on the extended separation channel chips; however, the resolution reached an asymptotic value after about 7 cm. This limited the peak capacity of the separation technique to 10-12.     

Synthesis of Novel Spin‐Labeled Derivatives of Podophyllotoxin as Potential Antineoplastic Agents

Five novel nitroxyl spin‐labeled ester derivatives of podophyllotoxin have been prepared by reacting the corresponding N‐(1‐oxyl‐2,2,6,6‐tetramethyl‐4‐piperidinyloxycarbonyl) amino acids with the hydroxy group of podophyllotoxin in the presence of dimethylaminopyridine and N,N‐dicyclohexylcarbodiimide and evaluated as potential antitumor agents. All of the target compounds showed more significant cytotoxicity against P‐388 murine leukemia and A‐549 human lung carcinoma in vitro than etoposide.     

Enzymatic cyclization of linear peptide to plant cyclopeptide heterophyllin B

Cyclopeptide is an important family of natural products.Over the past decade,about100cyclopep-tides have been isolated from higher plants by our group[1].The biosynthesis of cyclopeptides from mi-crobes such as tyrocidine A has been reported re-cently[2-4…     

A Facile Synthesis of Spin Labeled 4′-Epi-N-Trifuoroactyldaunomycin Derivatives

The anthracycline antibiotics, such as daunomycin 1 and doxorubicin 2, have attracted considerable interest because of their great therapeutic value in treating a number of human cancers. However, their use has been limited by a number of toxic and undesirable side effects and this stimulated the search for new anthracyclines with improved pharmacological profiles1,2,3. In our group, nitroxy radicals were first introduced to the sugar moieties of 1 and 2, and some exhibited significant antitum…     

Labeled brassinosteroids for biochemical studies

The present paper describes the results of our studies on the synthesis of brassinolide biosynthetic precursors as tools for investigations of new biosynthetic routes leading to brassinosteroids. The corresponding labeled compounds containing three or six deuterium atoms at terminal methyl group(s) of the side chain (in a position ensuring lack of isotopic exchange) were prepared starting from stigmasterol or bisnorcholenic acid. Two strategies for the construction of the carbon skeleton of the side chain were applied in this study: Claisen rearrangement of allylic alcohols and convergent synthesis based on the coupling of 22-aldehydes with appropriate chiral sulfone. More than 20 brassinolide precursors (actual or suspected) have been prepared for metabolic studies that enabled identification of new brassinosteroids and biosynthetic subpathways to brassinolide in Secale cereale and Arabidopsis thaliana.     

A quick,easy, cheap,effective, rugged,and safe sample pretreatment and liquid chromatography with tandem mass spectrometry method for the simultaneous quantification of 33 mycotoxins in Lentinula edodes

Lentinula edodes, one of the most cultivated edible fungi in the world, are usually neglected for mycotoxins contamination due to the initial thinking of its resistance to mycotoxingenic molds. In the present study, a sensitive and reliable liquid chromatography with tandem mass spectrometry method was developed for the simultaneous quantification of 33 mycotoxins in L. edodes. Targeted mycotoxins were extracted using a quick, easy, cheap, effective, rugged, and safe procedure without any further clean‐up step, and analyzed by liquid chromatography with tandem mass spectrometry on an Agilent Poroshell 120 EC‐C₁₈ column (100 × 3 mm, 2.7 μm) with a linear gradient elution program using water containing 5 mM ammonium acetate and methanol as the mobile phase. After validation by determining linearity (R² > 0.99), sensitivity (LOQ ≤ 20 ng/kg), recovery (73.6–117.9%), and precision (0.8–19.5%), the established method has been successfully applied to reveal the contamination states of various mycotoxins in L. edodes. Among the 30 tested samples, 22 were contaminated by various mycotoxins with the concentration levels ranging from 3.3–28 850.7 μg/kg, predicting that the edible fungus could be infected by the mycotoxins‐producing fungi. To the best of our knowledge, this is the first report about real mycotoxins contamination in L. edodes.