Aggregation of sensitizing dyes in solution and their adsorption onto silver halides

Herz, Alexander

doi:10.1016/0001-8686(77)80011-0

Cited by 362 publications

(305 citation statements)

References 173 publications

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“…First, the linker that tethers cyanine moieties together could be optimized in terms of length, flexibility, and hydrophobicity so as to maximize presentation of binding surfaces, increase compound solubility, and minimize Haggregate formation. It may not be necessary to have two linkers as in 2, and bis-cyanines with a single linker have been described [14,27]. Second, the cyanine moiety could be optimized including the size and composition of the heterocyclic rings, and substituents connected to the rings.…”

Section: Discussionmentioning

confidence: 99%

Potent inhibition of tau fibrillization with a multivalent ligand

Honson

Jensen

Darby

et al. 2007

Biochemical and Biophysical Research Communications

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Small-molecule inhibitors of tau fibrillization are under investigation as tools for interrogating the tau aggregation pathway and as potential therapeutic agents for Alzheimer's disease. Established inhibitors include thiacarbocyanine dyes, which can inhibit recombinant tau fibrillization in the presence of anionic surfactant aggregation inducers. In an effort to increase inhibitory potency, a cyclic bis-thiacarbocyanine molecule containing two thiacarbocyanine moieties was synthesized and characterized with respect to tau fibrillization inhibitory activity by electron microscopy and ligand aggregation state by absorbance spectroscopy. Results showed that the inhibitory activity of the bisthiacarbocyanine was qualitatively similar to a monomeric cyanine dye, but was more potent with 50% inhibition achieved at ~80 nM concentration. At all concentrations tested in aqueous solution, the bis-thiacarbocyanine collapsed to form a closed clamshell structure. However, the presence of tau protein selectively stabilized the open conformation. These results suggest that the inhibitory activity of bis-thiacarbocyanine results from multivalency, and reveal a route to more potent tau aggregation inhibitors.

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Section: Discussionmentioning

confidence: 99%

Potent inhibition of tau fibrillization with a multivalent ligand

Honson

Jensen

Darby

et al. 2007

Biochemical and Biophysical Research Communications

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“…The case of weak dozy chaos (γ E) corresponds to a high degree of the dynamic self-organization of molecular quantum transitions 4,5,[11][12][13][14] and, consequently, to the large transition probabilities. The new theory of molecular quantum transitions explains a great variety of experimental results, [1][2][3][16][17][18][19] which previously could not be interpreted correctly. These data include the shape of optical bands in polymethine dyes and their aggregates, 1-5, 10-15, 17, 18 results in the well-known Brönsted relations for proton-transfer reactions, 16,20 and results for temperature-dependent electron 25 When the interaction of both the exciton transitions with the environment is absent, the optical absorption spectrum is given by two zero-width lines shifted relative to one another along the frequency axis (bottom right).…”

Section: Dozy Chaos and Dozy-chaos-exciton Couplingmentioning

confidence: 99%

Nature of the narrow optical band in H*-aggregates: Dozy-chaos–exciton coupling

Егоров

2014

AIP Advances

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Dozy chaos emerges as a combined effect of the collective chaotic motion of electrons and nuclei, and their chaotic electromagnetic interactions in the transient state of molecules experiencing quantum transitions. Following earlier discussions of the well-known Brönsted relations for proton-transfer reactions; the temperature-dependent electron transfer in Langmuir–Blodgett films; the shape of the optical bands of polymethine dye monomers, their dimers, and J-aggregates, this paper reports one more application of the dozy-chaos theory of molecular quantum transitions. The qualitative and quantitative explanations for shape of a narrow and blue-shifted optical absorption band in H*-aggregates is given on the basis of the dozy-chaos theory by taking into account the dozy-chaos–exciton coupling effect. It is emphasized that in the H*-aggregate chromophore (dimer of cyclic bis-thiacarbocyanines) there is a competition between two Frenkel exciton transitions through the chaotic reorganization motion of nuclear environment. As a result, the highly organized quantum transition to the upper exciton state becomes an exciton-induced source of dozy chaos for the low organized transition to the lower exciton state. This manifests itself in appearing the narrow peak and broad wing in the optical spectrum pattern of H*-aggregates. A similar enhancement in the H*-effect caused by the strengthening of the exciton coupling in H*-dimers, which could be achieved by synthesizing tertiary and quarternary thiacarbocyanine monomers, is predicted.

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“…So, it is necessary to study the spectral features between c-myc-core and MTC though both c-myc-core and c-myc-2345 have the same G-quadruplex core sequence. Due to the extended planar -electron conjugated system, MTC tends to self-assemble in PBS and exhibits only a predominant absorption band at 660 nm assigned to J-aggregates [54][55][56]. Figure 3(a) shows the absorption spectra of 10 mol L 1 MTC with different concentrations of c-myccore.…”

Section: The Binding Characterization and Stoichiometry Of Cyanine Dymentioning

confidence: 99%

Roles of flanking sequences in the binding between unimolecular parallel-stranded G-quadruplexes and ligands

et al. 2013

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G-quadruplexes attract more and more attention in recent years. Numerous small molecules which can induce or stabilize the formation of G-quadruplexes have been investigated on the purpose of anticancer drug development. As a motif existed in physiological condition, flanking sequences are an important part of G-quadruplexes but the study on the impact of flanking sequences on (G-quadruplex)-ligand binding is rarely reported. In this paper, the effects of flanking sequences on binding affinity between a series of unimolecular parallel-stranded G-quadruplex sequences derived from c-myc oncogene promoter (termed as c-myc G-quadruplexes) and their ligands are discussed in detail. The results showed that the flanking sequences on c-myc G-quadruplexes play key roles in (G-quadruplex)-ligand interaction. When a c-myc G-quadruplex is bound to its ligands, the flanking sequences might form a binding cavity above the terminal G-quartet, which could provide a suitable site for ligands to dock in. Moreover, the bases on flanking sequences could interact with ligand through - stacking, and finally form a sandwich-stacking mode (terminal G-quartet, ligand and bases on the flanking sequence). This mode could stabilize the (G-quadruplex)-ligand complex effectively and enhance the binding affinity dramatically. However, flanking sequences are also found to exhibit steric hindrance effect which could impede the (G-quadruplex)-ligand binding. G-quadruplex

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Aggregation of sensitizing dyes in solution and their adsorption onto silver halides

Cited by 362 publications

References 173 publications

Potent inhibition of tau fibrillization with a multivalent ligand

Potent inhibition of tau fibrillization with a multivalent ligand

Nature of the narrow optical band in H*-aggregates: Dozy-chaos–exciton coupling

Roles of flanking sequences in the binding between unimolecular parallel-stranded G-quadruplexes and ligands

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