Twisted Cyanines: A Non-Planar Fluorogenic Dye with Superior Photostability and its Use in a Protein-Based Fluoromodule
摘要:
The cyanine dye thiazole orange (TO) is a well-known fluorogenic stain for DNA and RNA, but this property precludes its use as an intracellular fluorescent probe for non-nucleic acid biomolecules. Further, as is the case with many cyanines, the dye suffers from low photostability. Here, we report the synthesis of a bridge-substituted version of TO named alpha-CN-TO, where the central methine hydrogen of TO is replaced by an electron withdrawing cyano group, which was expected to decrease the susceptibility of the dye toward singlet oxygen-mediated degradation. An X-ray crystal structure shows that alpha-CN-TO is twisted drastically out of plane, in contrast to TO, which crystallizes in the planar conformation. alpha-CN-TO retains the fluorogenic behavior of the parent dye TO in viscous glycerol/water solvent, but direct irradiation and indirect bleaching studies showed that alpha-CN-TO is essentially inert to visible light and singlet oxygen. In addition, the twisted conformation of alpha-CN-TO mitigates nonspecific binding and fluorescence activation by DNA and a previously selected TO-binding protein and exhibits low background fluorescence in HeLa cell culture. alpha-CN-TO was then used to select a new protein that binds and activates fluorescence from the dye. The new alpha-CN-TO/protein fluoromodule exhibits superior photostability to an analogous TO/protein fluoromodule. These properties indicate that alpha-CN-TO will be a useful fluorogenic dye in combination with specific RNA and protein binding partners for both in vitro and cell-based applications. More broadly, structural features that promote nonplanar conformations can provide an effective method for reducing nonspecific binding of cationic dyes to nucleic acids and other biomolecules.
New Cyanine–Oligonucleotide Conjugates: Relationships between Chemical Structures and Properties
作者:Rémy Lartia、Ulysse Asseline
DOI:10.1002/chem.200500908
日期:2006.3.1
range of conjugates with various structural patterns. Different cyaninedyes such as thiocyanine, quinocyanine, and thiazole orange isomers were obtained. In the case of unsymmetrical cyanines, the linker was attached to either the quinoline or the benzothiazolenucleus. The influence of the ODN counterpart was evaluated by linking the cyanines to the 5'-end or to an internucleotidic phosphate. In the first
Quaternary heterocyclylamino .beta.-lactams: a generic alternative to the classical acylamino side chain
作者:John Hannah、Charles R. Johnson、Arthur F. Wagner、Edward Walton
DOI:10.1021/jm00346a024
日期:1982.4
beta-[(1-substituted-4-pyridinio)amino]ceph-3-em-4-carboxylates have been found to be interesting new classes of antibacterial beta-lactams, readily available by SN2 Ar coupling of fluoro-substituted quaternized pyridines and appropriate amino lactam carboxylic acids. Compared to penicillin G, the penam 12c exhibited a spectrum extended to Gram-negative species, such as Escherichia, Shigella, Klebsiella
active compounds with new mechanisms of action. Based on the molecular structures of the FtsZ inhibitors reported, a variety of thiazole-quinolinium derivatives with aliphatic amino and/or styrene substituents were synthesized from benzothiazolidine derivatives. In the present study, to further explore the antibacterial potential of thiazole-quinolinium derivatives, several Gram-positive and Gram-negative
迫切需要新的抗菌剂来解决多重耐药生物的出现,特别是那些具有新作用机制的活性化合物。根据报道的 FtsZ 抑制剂的分子结构,从苯并噻唑烷衍生物合成了多种具有脂肪族氨基和/或苯乙烯取代基的噻唑-喹啉衍生物。在本研究中,为了进一步探索噻唑喹啉衍生物的抗菌潜力,用新修饰的化合物处理了几种革兰氏阳性和革兰氏阴性细菌,并详细研究了其生物学效应,以了解其杀菌作用。化合物。我们的研究结果表明,其中一些衍生物具有良好的杀菌活性,因为它们可以抑制革兰氏阳性耐甲氧西林金黄色葡萄球菌、耐万古霉素肠球菌以及一些革兰氏阴性菌和 NDM-1大肠杆菌。此外,化合物4a1-4a4和4b1-4b4改变了细菌细胞的形态,并且与未经处理的细胞相比,这些细胞显示出更细长的形状。生化分析表明,4a4和4b4刺激细菌细胞中的 FtsZ 聚合,最终破坏其动态组装和 Z 环形成。对细菌细胞分裂中这一关键步骤的抑制可能代表了它们抗菌活性的主
DNA gated photochromism and fluorescent switch in a thiazole orange modified diarylethene
作者:Keyin Liu、Ying Wen、Ting Shi、Yi Li、Fuyou Li、Yi-lei Zhao、Chunhui Huang、Tao Yi
DOI:10.1039/c4cc02783c
日期:——
Thiazole orange-modified diarylethene (1) shows weak fluorescence but no photochromism in aqueous solution. When binding with DNA, the fluorescence of 1 is enhanced drastically and the photochromic reactivity is unlocked. This kind of DNA-responsive photoswitchable system can be used for imaging nucleic acids within cells.
噻唑橙修饰的二元蒽(1)在水溶液中会发出微弱的荧光,但没有光致变色作用。当与 DNA 结合时,1 的荧光急剧增强,光致变色反应活性被释放。这种 DNA 响应光开关系统可用于细胞内核酸的成像。
Single point mutation detection in living cancer cells by far-red emitting PNA–FIT probes
SNP detection of the mutated kRAS oncogene in living cells is shown to be achieved for the first time by cell-permeable and far-red emitting PNA–FIT probes.