循环伏安法研究天青A与dsDNA的相互作用

用循环伏安法研究了染料天青A(AA)与鲱鱼精DNA(dsDNA)在0.20 mol/L pH4.5的HAc-NaAc缓冲溶液中的相互作用。AA在玻碳电极上分别于-0.134 V和-0.082 V(vs.SCE)有一个还原峰和相应的氧化峰。加入dsDNA后,AA的还原峰和氧化峰电流均明显减小,但电子转移系数和电极反应标准速率常数基本不变。AA与dsDNA相互作用生成了一种非电活性的超分子复合物。求得AA与dsDNA复合物的结合比为n(AA)∶n(DNA)=3∶1,结合常数β=2.51×1015。紫外-可见吸收光谱法结果与循环伏安法结果一致。     

DNA与目标分子相互作用的预测性研究

以量化的分子结构参数和实验结果为依据, 运用模式识别技术、多元线性回归和人工神经网络研究了目标分子与DNA相互作用的主要影响因素, 建立了准确性较高的2个键合常数预测模型和1个作用模式预测模型. 初次量化的分子结构参数有21种, 经过筛选发现其中的10种参数对相互作用有显著影响. 研究结果可为抗癌药物的分子设计和筛选提供有价值的信息.     

基于硫化镉纳米团簇标记DNA电化学传感的研究

合成了表面具有自由羧基的硫化镉纳米团簇，以乙基-（3-二甲基丙基）碳二 亚胺盐酸盐为偶联活化剂，将其标记于人工合成的5'端氨基修饰的寡聚核苷酸片段 上，制备成CdS纳米团簇标记DNA探针，该寡聚核苷酸片段与大肠杆菌肠毒素基因相 关。在一定的条件下，使基与固定晨玻碳电极表面的待测DNA序列进行杂交反应， 利用阳极溶出示差脉冲伏安法（ASDPV）间接测定Cd的量，实现对互补、非互补 DNA片段的识别和电化学检测，从而对大肠杆菌肠毒素基因片段识别和检测。     

La-phen-邻苯二甲酸混配化合物与DNA作用的共振光散射光谱及分析应用

本文研究了镧的混配物LaL1L2·3H2O(L1为邻苯二甲酸,L2为邻菲咯啉)与DNA作用的共振光散射光谱。加入DNA后,在pH6.5～7.5的范围内,LaL1L2·3H2O在DNA分子表面发生长距离自组装,在470nm处产生了增强的共振光散射峰,其发光强度与DNA的浓度成线性关系。该方法的线性范围为23～1870ng·mL-1,检出限(3σ)为23ng·mL-1,可用于测定纳克级的DNA。     

四氢键二聚体和分子组装

介绍了最近几年新的四氢键有机二聚体研究的进展及其在分子自组装和分子聚 集体化学研究中的应用。     

Evanescent fluorobiosensor for the detection of polyaromatic hydrocarbon based on DNA intercalation

A flow-injection analysis (FIA) system coupled with an evanescent wave (EW) Biosensor employing total internal reflection of fluorescence radiation (TIRF) for the detection of polyaromatic hydrocarbon that intercalates into DNA is reported. A highly fluorescent intercalator, “ethidium bromide,” has been used as the reference compound for detection. The EW Biosensor was developed according to the procedure described earlier (1,2). Data on the analysis of Naphthalene, 3-methy cholanthrene, 7,12-dimethylbenz(a)anthracene, 1,2-benzanthracene, and some standard reference materials supplied by the National Institute of Standards and Technology are reported. The relative ability of the polyaromatic hydrocarbon to displace ethidium bromide, based on the relative binding ratio, is found to be on the order of 7,12-dimethylbenz[a]anthracene > 3-methylcholanthrene > 1,2-benzanthracene > napthalene.     

LIGHT-SCATTERING STUDY OF POLYELECTROLYTE HOLLOW CAPSULES

Silver halide (AgX) microcrystal was used as template to synthesize hollow polyelectrolyte capsules. These hollow capsules were characterized by laser light scattering (LLS) used to measure the size of the capsules in solution. The ratio of hydrodynamic radius (Rh) from dynamic LLS to the radius of gyration (Rg) from static LLS is almost unity, revealing that the entities are hollow in solution. The results suggest that the LLS method can be regarded as a good complement to the confocal laser scanning microscopy (CLSM) method for the characterization of small hollow capsules, and it possesses the advantage of not needing fluorescence labeling.     

TB-curve, a New 2-D Graphical Representation of DNA Sequences

Based on the classifications of the four nucleic acid bases, we introduce a new 2-D method of DNA representation: TB-curve, which avoids loss of information accompanying alternative 2-D representation in which the curve standing for DNA overlaps and intersects itself. The method is illustrated on the coding sequence of the first exon of human beta-globin gene.     

白菜DNA甲基化水平的反相离子对高效液相色谱法研究

建立了反相离子对液相色谱测定白菜的DNA甲基化水平的方法。采用的色谱柱为HypersilBDSC18柱(200mm×4.0mm,5μm),以pH4.0的甲醇-5mmol·L-1庚烷磺酸钠-三乙胺(10:90:0.2,体积比)的混合液为流动相,UV检测器波长为273nm。通过测定DNA水样所产生的胞嘧啶和甲基胞嘧啶的含量,即可得知DNA甲基化程度。胞嘧啶和甲基胞嘧啶回收率分别为99.6%及103.3%,RSD为3.7%(日内)及5.2%(日间)。