特异性识别DNA的吡咯-咪唑多聚酰胺的研究进展

吡咯-咪唑多聚酰胺为一类人工合成的主要由五元杂环化合物N-甲基吡咯(Py)、N-甲基咪唑(Im)和N-甲基3-羟基吡咯(Hp)芳香氨基酸组成的,经酰胺键连接的人工小分子配体.它们具有与天然DNA结合蛋白相媲美的DNA特异性识别和结合能力.近20年来,对此类化合物的研究取得了重要进展,确定了简单的氨基酸对识别碱基对的规则,研究了多种方式连接的吡咯-咪唑多聚酰胺与DNA小沟结合模式,合成了多种双功能吡咯-咪唑多聚酰胺,且吡咯-咪唑多聚酰胺能穿过细胞膜,具有在体内外调节基因表达的作用。     

基于氧化石墨烯识别特定双螺旋DNA

依据三螺旋DNA的形成,以氧化石墨烯为基础建立了一种识别特定序列双螺旋DNA的方法。单链探针DNA能够通过静电引力作用吸附在氧化石墨烯表面,标记在单链DNA末端的荧光探针分子TAMRA由于荧光能量共振转移作用使得其荧光发生淬灭。加入目标双螺旋DNA后,单链探针DNA与目标DNA分子形成三螺旋DNA,探针DNA从氧化石墨烯表面脱附,标记在探针DNA上的荧光分子的荧光恢复。在最佳实验条件下,荧光恢复的强度与探针DNA的浓度在20.0～300.0 nmol/L具有良好的线性关系,检出限为16.9 nmol/L。该方法在DNA药物筛选及基因疾病的诊断方面具有一定的应用前景。     

N-硝基苯基吡咯酰胺对阴离子识别研究

合成了2个N-硝基苯基吡咯酰胺阴离子识别主体. 通过X射线单晶衍射确定了间位硝基取代物的结构, 氢键及π-π相互作用在该化合物的组装过程中起到了决定性的作用. 利用UV-Vis光谱研究了这两个主体对常见无机阴离子的识别, 结果表明， 它们不仅对F-和H2PO4-离子有比较强的识别能力, 而且在识别发生时还伴随着显著的颜色变化, 因此这两个化合物都可作为阴离子的比色传感器.     

序列特异性DNA断裂蛋白质

序列特异性DNA断裂蛋白质是在序列特异性DNA结合蛋白质及小分子DNA断裂试剂基础上设计合成的。其基本原理是在含有DN A结合域的蛋白质上引入一个金属鳌合剂并鳌合一个适当的金属离子,其中序列特异性DNA结合蛋白质具有与DNA特定序列结合的能力,从而可以起导向物的作用,而引入的金属鳌合齐J与金属离子复合物具有断裂DNA的功能,两者协同作用可以达到序列特异性断裂DNA的目的。     

DNA序列特征的统计分析

介绍了近年来在多种学科领域对DNA碱基序列的研究中发展起来的定量分析符号序列的方法,归纳了将碱基与数字对应起来的规则和进行统计分析的方法．并给予一定的评价。DNA分子包涵了丰富的化学信息和生物信息,对于DNA序列的统计分析显得非常重要。将DNA序列表达成数字信号通常有从一维到四维4种不同维数空间的映射方式,其相应的统计方法有均方根涨落、熵近似方法、傅立叶变换和小波变换等,各种方法从多个角度多个层次来分析揭示了DNA序列的结构规律。     

DNA芯片技术与脱氧核糖核酸序列分析

人类基因组计划的实施,有力地促进了ＤＮＡ序列分析技术的发展。ＤＮＡ芯片综合运用了固相合成化学、照相平版印制技术以及激光共聚焦扫描等技术,能够同时扫描分析多基因乃至基因组,可广泛应用于基因的多态性分析、基因定位、表达水平的监测以及遗传病的诊断等领域,是对传统的ＤＮＡ分析技术的一次重大突破。本文介绍了ＤＮＡ芯片技术的基本原理并对其应用作一简要综述。     

基于质谱的DNA序列测定进展

对质谱ＤＮＡ序列测定的各种技术的原理、进展，面临的困难以及发展的前景作了评述。     

DNA序列分析新技术——阵列毛细管凝胶电泳

“人的基因组项目”对ＤＮＡ序列分析的速度提出了极高的要求，阵列毛细管凝胶电泳主要为解决这一问题而发展起来。本文详细介绍了阵列毛细管凝胶电泳与毛细管凝胶电泳和板凝胶电泳的不同，它对电泳系统、检测系统的新要求及目前的研究及应用状况，并对其应用前景进行了展望。     

邻-二(吡咯-2-甲酰胺基)亚苯的合成、晶体结构及阴离子识别

设计合成了邻-二(吡咯-2-甲酰胺基)亚苯.用X射线单晶衍射研究了该化合物的固态构象,发现其可以通过氢键与DMSO发生络合.¹HNMR研究发现该化合物即使在强极性的DMSO溶液中也可对F^-,Cl^-和H₂PO₄^-常见阴离子产生一定的识别,其中对F-的识别为最优.     

DNA分子识别及传感技术

DNA杂交生物传感器为基因的识别及疾病的诊断提供了一种快速,简便,廉价的方法,此文从DNA的固定及检测技术两个方面,举例介绍了各不同方式的研究应用现状及对传感器灵敏度,杂交专一性,杂交速度及使用寿命的影响,对DNA识别技术的发展前景进行了展望。     

Interaction of Double-Helical Polynuclear Copper(I) complexes with double-stranded DNA

Double-helical metal complexes, the helicates H₂–H₅ , were found to bind to double-helical DNA by spectroscopic, DNA-melting, and electrophoretic-mobility measurements. The helicates also inhibited the cleavage of DNA by two restriction enzymes, Sspl and EcoRV, a property which agrees with the binding occurring in the major groove of the double helix. Visible-light irradiation of solutions containing a helicate and the pBR322 plasmid led to single-strand cleavage, indicating that these complexes could be of interest as potential probes for nucleic-acid structure.     

An Affinity Reagent for the Recognition of Pyrophosphorylated Peptides

A resin‐bound dinuclear zinc(II) complex for the selective capture of pyrophosphopeptides is reported. The metal complex binds diphosphate esters over other anionic groups, such as monophosphate esters, sulfate esters, and carboxylic acids, with high specificity. Immobilization of the compound provided a reagent capable of binding and retaining nanomolar quantities of pyrophosphopeptide in the presence of cell lysate. The high affinity and specificity of the reagent makes it an attractive tool for the study of in vivo pyrophosphorylation.     

366 - Polarographie Behaviour of Double-Helical DNA Containing Intramolecular Single Stranded Regions

Calf thymus DNA was digested processively and synchronously with exonuclease III of E. coli (an enzyme splitting off only nucleotides from 3′ ends) and samples of double-stranded (ds) DNA, containing single-stranded (ss) ends of varying length (100–1800 nucleotides), were obtained. Digestion of nicked circular DNA (plasmid Col E 1) with the same enzyme yielded circular DNA containing ss regions inside the molecule. These DNA samples were investigated by means of derivative (differential) pulse polarography (DPP) in connection with mercury dropping electrode in a neutral medium. It was found that the presence of intramolecular ss regions in ds DNA was manifested by DPP peak III, i.e. in the same manner as the presence of free denatured DNA. The height of this peak increases linearly with the content of ss ends in ds linear DNA and DPP peak II (characteristic for ds DNA) does not increase in consequence of the formation of ss ends. This finding supports our notion about local changes in the conformation of DNA caused by various factors including temperature changes in the premelting region, and contradicts the assumption of other authors that polarographic reduction of DNA is independent of its structure and that a sufficient prerequisite for reduction is the adsorption of the DNA molecule at the electrode.ds DNA containing ss ends of varying length was investigated by means of linear sweep voltammetry in connection with stationary mercury electrode at neutral pH. It was found that the presence of ss ends influences markedly the course of the dependence of the voltammetric peak on the initial potential. An assumption has been formulated that this effect is connected with the fixation of the molecule ends in the electrode surface, which inhibits the surface denaturation of DNA.     

Photoswitchable, DNA-Binding Helical Peptides Assembled with Two Independently Designed Sequences for Photoregulation and DNA Recognition

Diarylethene-bridged peptides were developed to photoregulate biomolecular interactions. The peptides are made up of diarylethene-bridged and DNA-binding regions at their N- and C?termini, respectively. The two regions could be independently designed and combined as desired. The α-helicities of the peptides were photoregulated in on/off or off/on manners, and the manner depended on the positions of two ornithine (Orn) residues for cross-linking reaction at the diarylethene-bridged region. In the case of the on/off manner, when the diarylethene structure adopted the open form on the peptides, the peptides folded into stable α-helices. Upon UV irradiation, the diarylethene moiety isomerized to its closed form to destabilize the helical structures. Quartz crystal microbalance (QCM) analysis showed that the open isomer strongly associated with a target DNA, as compared with the closed one. When the closed-form peptide existing in the DNA complex was irradiated with a fluorescent lamp in the middle of the QCM monitoring, the frequency change (ΔF) was enhanced by the diarylethene photoisomerization.     

基于Hoechst33258荧光染料检测单链DNA的方法研究

根据Hoechst与ssDNA作用时不产生荧光或荧光很弱,而与dsDNA作用时荧光增强的原理,将待测ssDNA与互补ssDNA杂交形成dsDNA,实现Hoechst染料对ssDNA的检测.文中研究了不同序列、不同长度、互补链及碱基错配链等杂交产物与Hoechst染料作用的荧光强度的变化规律.同时以H1N1禽流感病毒DN...     

Rational Design of Peptides Derived from Odorant-Binding Proteins for SARS-CoV-2-Related Volatile Organic Compounds Recognition

Peptides are promising molecular-binding elements and have attracted great interest in novel biosensor development. In this study, a series of peptides derived from odorant-binding proteins (OBPs) were rationally designed for recognition of SARS-CoV-2-related volatile organic compounds (VOCs). Ethanol, nonanal, benzaldehyde, acetic acid, and acetone were selected as representative VOCs in the exhaled breath during the COVID-19 infection. Computational docking and prediction tools were utilized for OBPs peptide characterization and analysis. Multiple parameters, including the docking model, binding affinity, sequence specification, and structural folding, were investigated. The results demonstrated a rational, rapid, and efficient approach for designing breath-borne VOC-recognition peptides, which could further improve the biosensor performance for pioneering COVID-19 screening and many other applications.     

A New Trace Analytic Method for the Determination of Sequence-Specific DNA with Fluorescent Probes

A new method of fluorescence spectrometry detection of single-strand DNA (ssDNA) was established by hybridizing the ssDNA with its complementary ssDNA to form double-stranded DNA (dsDNA). Our results show that the fluorescence intensity increased significantly when the nucleic acid molecular “light switch"(Ru(phen)₂dppx²⁺) or Hoechst 33258 dye interacted with dsDNA, and the fluorescence intensity also increased as the DNA concentration increased. The changing law was also studied about how the fluorescence intensity changed when the two kinds of fluorescent probes interacted with oligonucleotide of different lengths and different sequences, as well as DNA-DNA′ hybridization products. Then, the effect of the bases mismatch, varying length of DNA chain, and different DNA sequences on the fluorescence intensity were explored at the same time, by detecting the specific DNA sequence of avian influenza H1N1 virus, cauliflower mosaic virus, and hepatitis C virus. Additionally, the selectivity, linear range, and sensitivity of the two probes were compared.