Interactions of Night Blue with Nucleic Acids and Determination of Nucleic Acids Using Resonance Light Scattering Technique

The noncovalent interactions of night blue (NB) with several nucleic acids in buffer medium of Britton‐Robinson at pH 4.1 have been studied by spectroscopic methods. It is shown that the binding of NB with nucleic acids involves the J‐aggregation of NB molecules on the surface of nucleic acids. The aggregation was encouraged by polyanions nucleic acids, in which nucleic acids served for acting templates. In this connection, a new method of nucleic acids with sensitivity at nanogram level is proposed based on the measurement of enhanced resonance light scattering (RLS). The linear range of ctDNA, fsDNA and yRNA is 0.01—2.5, 0.03—2.5 and 0.04—1.0 μg/mL, respectively, and the corresponding detection limits (3s?) are 9.4, 7.3 and 5.7 ng/mL at 2.5 × 10–⁵mol/L of NB. Synthetic and real samples were analyzed with satisfactory results.     

稀土氨基酸配合物与核酸的相互作用*

很多抗癌金属药物是以核酸为靶标。阐明小分子与核酸之间的相互作用对筛选具有高效选择性和低毒副作用的抗癌药物有重要意义。近年来,开发新型的具有对核酸序列特异性识别能力的抗癌药物己成为本领域的研究热点。稀土离子具有良好的磁学、光学、电学特性和配位能力,使稀土配合物成为新型药物试剂。然而,稀土离子在中性条件下易水解的特性极大地阻碍了稀土配合物对核酸分子识别的研究。近年来在近生理条件下合成的一系列镧系氨基酸配合物具有结构稳定、溶解性好等优点,解决了镧系离子易水解的问题。本文总结了目前关于镧系氨基酸配合物与核酸的相互作用及其序列选择性等方面的研究进展。     

核酸与蛋白质相互作用研究的新技术与新方法

蛋白质和核酸是组成生命的主要生物大分子,两者的相互作用构成了诸如生长、繁殖、运动、遗传和代谢等生命现象的基础.因此,研究它们间的相互作用是人们解开生命奥秘的关键所在,在学术及应用上都具有极其重要的意义.探讨蛋白质和核酸相互作用涉及到众多学科的技术与方法,是多学科的前沿交叉领域.总体上该方面工作尚处于起步阶段,深入研究有待于研究手段的进步与创新.本文从研究手段与分析方法上对近年来该领域所采用的技术及其最新进展进行了评述.     

From Peptide Nucleic Acids to Supramolecular Structures of Nucleic Acid Derivatives

Nucleic acids play a pivotal role in life processes. The endeavours to shed light on the essential properties of these intriguing building blocks led us to the synthesis of different analogues and the investigation of their properties. First various peptide nucleic acid monomers and oligomers have been synthesized, using an Fmoc/acyl protecting group strategy, and their properties studied. The serendipitous discovery of a side reaction of coupling agents led us to the elaboration of a peptide sequencing method. The capricious behaviour of guanine derivatives spurred the determination of their substitution pattern using ¹³C, ¹⁵N NMR, and mass spectrometric methods. The properties of guanines initiated the logical transition to the study of supramolecular systems composed of purine analogues. Thus, xanthine and uracil derivatives have been obtained and their supramolecular self-assembly properties scrutinized in gas, solid, and liquid states and at solid-liquid interfaces.     

水溶性游离碱阳离子卟啉与核酸作用的光谱研究

研究了ｍｅｓｏ－四（对－三甲基氨基苯基）卟啉（ＴＡＰＰ）和ｍｅｓｏ－四（对－甲基吡啶基）卟啉（ＴＭｐｙＰ－４）与核酸作用的电子吸收光谱、荧光光谱和共振光散射光谱的特性，电子吸收和荧光光谱研究表明，这两个水溶性阳离子卟啉与核酸的摩尔比（Ｒ）大于０．２５时，核酸对卟啉的Ｓｏｒｅｔ带有减色效应和荧光猝灭效应；当Ｒ〈０．２５时，核酸与卟啉作用形成新的荧光复合物，共振光散射光谱研究表明，核酸使ＴＡＰＰ的共振     

Tellurium-Modified Nucleosides,Nucleotides, and Nucleic Acids with Potential Applications

Tellurium was successfully incorporated into proteins and applied to protein structure determination through X-ray crystallography. However, studies on tellurium modification of DNA and RNA are limited. This review highlights the recent development of Te-modified nucleosides, nucleotides, and nucleic acids, and summarizes the main synthetic approaches for the preparation of 5-PhTe, 2′-MeTe, and 2′-PhTe modifications. Those modifications are compatible with solid-phase synthesis and stable during Te-oligonucleotide purification. Moreover, the ideal electronic and atomic properties of tellurium for generating clear isomorphous signals give Te-modified DNA and RNA great potential applications in 3D crystal structure determination through X-ray diffraction. STM study also shows that Te-modified DNA has strong topographic and current peaks, which immediately suggests potential applications in nucleic acid direct imaging, nanomaterials, molecular electronics, and diagnostics. Theoretical studies indicate the potential application of Te-modified nucleosides in cancer therapy.     

卟啉化合物与核酸的相互作用研究

本文综述了卟啉化合物与核酸相互作用时的结合模式、光谱方法和重要的应用研究, 并对该领域的研究前景作了展望。     

小分子与核酸相互作用的研究进展

评述了小分子与核酸相互作用的结合模式和研究方法。引用文献59篇。     

Relative Orientation of Rigid Nitroxides by PELDOR: Beyond Distance Measurements in Nucleic Acids

Show me your angle : Incorporation of the rigid spin label Ç allows determination of both distance and orientation of two nitroxide spin labels in DNA by PELDOR experiments at common X‐band frequencies. The orientational information is obtained by varying the position of the detection pulses over the nitroxide spectrum. Simulation of the set of time traces yields very precise distances and angles.

     

多核配合物与核酸作用的研究

综述了近年来各种多核金属配合物与核酸作用的研究,作为抗肿瘤药物、核酸探针、核酸切割剂等的应用概况。计论了结构与作用机理之间的关系。     

Intercalating Nucleic Acids Containing Insertions of Naphthalimide

In a study of linker‐length dependence, we evaluated naphthalimide (= 1H‐benzo[de]isoquinoline‐1,3(2H)‐dione) and 4‐bromonaphthalimide as intercalating nucleic acids. We used a vicinal dihydroxy system when incorporating the six different naphthalimide monomers into DNA, and found the minimum linker‐length to be five C‐atoms. With this length of the linker, naphthalimide was discriminating between DNA and RNA – stabilizing DNA, while destabilizing RNA. Furthermore, naphthalimide showed universal base character by hybridizing to the four natural bases with a range as narrow as 1.4°. When compared to pyrene, naphthalimide with the same linker‐length gave significantly higher thermal meltings when hybridized to DNA.     

Orthogonal Synthesis of Xeno Nucleic Acids

Sequence‐defined peptide triazole nucleic acids (PTzNA) were synthesized by means of a solid‐phase orthogonal “AB+CD” iterative strategy. In this approach, AB and CD building blocks containing carboxylic acid (A), azide (B), alkyne (C), and primary amine (D) functions are assembled together by successive copper‐catalyzed azide–alkyne cycloaddition (CuAAC) and acid–amine coupling steps. Different PTzNA genetic sequences were prepared using a library of eight building blocks (i.e., four AB and four CD building blocks).     

Spectroscopic Study of the Interaction between New Fluorescent Dyes with Nucleic Acids

Considerableefforthasbeencofltinuingtofocusonthedevelopmentofnewfluorescentdyestorecognizenucleicacids'-'.Althoughdansylisawell-knownsensitivehydrophobicprobewhichhasbeenwidelyutilizedasafluorescentprobeforthestudyofproteins,yetlittleefforthasbeenfocusedontheexploringdansylamidederivativeswhichmayhavespecificeffectsonnucleicacids.Sincethebindingaffinityofsuchfluorophorestopolynucleotideswasgreatlyaffectedbytheirsidechainsubstitutions,inthisworkseveralnewdansylderivativeswithspecificbindingtonu…     

Resonance Double Light Scattering Method for the Determination of Nucleic Acids with Cetylpyridine Bromide

Cetylpyridine bromide (CPB) was used as a novel probe to determine nucleic acids by the resonance double light scattering technique in this paper. Under the optimum conditions, different nucleic acids have different binding properties with CPB. The sensitivity of this method decreases in the following order: ctDNA>yRNA>fsDNA. The detection limits are 8.9, 12.7 and 18.7ngmL^–1, respectively. Synthetic samples were analyzed satisfactorily.     

Studies on the Binding Mode of Pinacyanol Chloride to Nucleic Acids

The interaction of pinacyanol chloride(PC) with nucleic acids has been investigated by a series of experiments.Extensive hypochromism,appreciable peak shifts,isosbestic points and new peaks of the product of binding to nucleic acids in the spectra were observed.They showed that the interaction between PC and nucleic acids occurred.The results from absorption spectra of DNA,DNA melting,electrophoresis and fluorescence polarization studies have indicated that PC binds to DNA in nonintercalative way.Consistent with the nonintercalation,the studies of fluorescence titration and absorption titration specified that the binding of PC to nucleic acids occurred by an outside stacking binding,in which nucleic acids served for acting templates,The fact that the new absorption peaks of bound PC at ca,485nm are just close to the absorption bands of Haggregate of PC at high concentrations without DNA further supports the outside stacking binding mode,In addition,other evidence indicated that the interaction between PC and nucleic acids is not purely electrostatic.