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1.
Kovalska VB Volkova KD Losytskyy MY Tolmachev OI Balanda AO Yarmoluk SM 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2006,65(2):271-277
The influence of methyl-, 2-hydroxyethyl-, dimethyl-, diethyl- and benzoyl-amino substituents in the 6,6'-positions of benzothiazole heterocycle of trimethine cyanines on their spectral-luminescent properties and behavior in presence of DNA, RNA and BSA was studied. It was shown that incorporation of 6,6'-substituents generally leads to the increase in dyes tendency to aggregation, resulting in the considerable decrease in the emission intensity of the disubstituted dyes as compared to the unsubstituted ones. Emission of the studied 6,6'-disubstited dyes in DNA presence is considerably more intensive than in presence of RNA, that points on the existing of DNA binding preference for the mentioned dyes. Insertion of benzoyl-amino groups into the 6,6'-positions permitted us to design the DNA-sensitive dyes on the basis of symmetric trimethine cyanines with unsubstituted polymethine chain, while typically such dyes slightly respond on the presence of biopolymers. 6,6'-Benzoyl-amino-disubstituted trimethine cyanines are proposed as efficient dyes for DNA detection. 相似文献
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T Y Ogulchansky M Y Losytskyy V B Kovalska S S Lukashov V M Yashchuk S M Yarmoluk 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2001,57(13):2705-2715
Spectral properties of carbocyanine dye 3-methyl-2-[3-methyl-2-(3-methyl-2,3-dihydro-1,3-benzothiazole-2-iliden)-1- butenyl]-1,3-benzothiazole-3-il iodide (Cyan betaiPr) in water solution, as well as in the presence of different types of double stranded DNA have been studied. While in water solution of 'free' dye Cyan betaiPr stays mainly in monomeric form, in the presence of DNA the dye molecules form J-aggregates. The molecular structure of these J-aggregates causes the Davydov splitting of their absorption band, corresponding to the first electronic transition. A study of site-specificity showed that in the presence of poly (dA/dT) the majority of Cyan betaiPr molecules form J-aggregates, while in the presence of poly (dGC/dGC) dye molecules stay mainly in monomeric form and in presence of chicken erythrocytes DNA both J-aggregate and monomeric forms of dye are present. We suppose that Cyan betaiPr molecules aggregate in DNA groove, which serves as a template for J-aggregate forming. An increase of ionic strength of solution leads to the release of dye molecules from DNA grooves and prevents J-aggregates formation. 相似文献
4.
We go back and forth between, on the one hand, presentations of arithmetic and Kac-Moody groups and, on the other hand, presentations of profinite groups, deducing along the way new results on both. 相似文献
5.
Xu C Losytskyy MY Kovalska VB Kryvorotenko DV Yarmoluk SM McClelland S Bianco PR 《Journal of fluorescence》2007,17(6):671-685
The dimeric cyanine dyes, YOYO-1 and TOTO-1, are widely used as DNA probes because of their excellent fluorescent properties.
They have a higher fluorescence quantum yield than ethidium homodimer, DAPI and Hoechst dyes and bind to double-stranded DNA
with high affinity. However, these dyes are limited by heterogeneous staining at high dye loading, photocleavage of DNA under
extended illumination, nicking of DNA, and inhibition of the activity of DNA binding enzymes. To overcome these limitations,
seven novel cyanine dyes (Cyan-2, DC-21, DM, DM-1, DMB-2OH, SH-0367, SH1015-OH) were synthesized and tested for fluorescence
emission, resistance to displacement by Mg2+, and the ability to function as reporters for DNA unwinding. Results show that Cyan-2, DM-1, SH-0367 and SH1015-OH formed
highly fluorescent complexes with dsDNA. Of these, only Cyan-2 and DM-1 exhibited a large fluorescence enhancement in buffers,
and were resistant to displacement by Mg2+. The potential of these two dyes to function as reporter molecules was evaluated using continuous fluorescence, DNA helicase
assays. The rate of DNA unwinding was not significantly affected by either of these two dyes. Therefore, Cyan-2 and DM-1 form
the basis for the synthesis of novel cyanine dyes with the potential to overcome the limitations of YOYO-1 and TOTO-1. 相似文献
6.
V. B. Kovalska M. Yu Losytskyy O. I. Tolmachev Yu L. Slominskii G. M. J. Segers-Nolten V. Subramaniam S. M. Yarmoluk 《Journal of fluorescence》2012,22(6):1441-1448
The pathogenesis of Parkinson’s disease that is the second most common neurodegenerative disease is associated with formation of different aggregates of α-synuclein (ASN), namely oligomers and amyloid fibrils. Current research is aimed on the design of fluorescent dyes for the detection of oligomeric aggregates, which are considered to be toxic and morbific spices. Fluorescent properties of series of benzothiazole trimethine and pentamethine cyanines were characterized in free state and in presence of monomeric, oligomeric and fibrilar ASN. The dyes with wide aromatic systems and bulky phenyl and alkyl substituents that are potentially able to interact with hydrophobic regions of oligomeric aggregates were selected for the studies. For majority of studied dyes noticeable changes in fluorescence characteristics were shown in the presence of fibrillar or oligomeric ASN, while the dyes slightly responded on the presence of monomeric protein. For pentamethine cyanine SL-631 and trimethine cyanine SH-299 certain specificity to oligomeric aggregates over fibrils was observed. Using these dyes at 10?6 M concentration permits the detection of oligomeric ASN in the concentrations range of at least 0.2–2 microM. Pentamethine cyanine SL-631 is proposed as dye for fluorescent detection of oligomeric aggregates of ASN, while trimethine cyanine SH-299 is shown to be a sensitive probe both on oligomeric and fibrillar ASN. It is proposed that wide aromatic system of SL-631 pentamethine dye molecule could better fix on the less dense and structured oligomeric formation, while less bulky and more “crescent-shape” molecule of trimethine dye SH-299 could easier enter into the groove of beta-pleated structure. 相似文献
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Yarmoluk SM Losytskyy MY Yashchuk VM 《Journal of photochemistry and photobiology. B, Biology》2002,67(1):57-63
The processes of nonradiative deactivation of electronic excitation energy in cyanine dyes determine their quantum yield. Because of that, the study of the influence of cyanines binding to DNA on these processes can provide information on the causes leading to the cyanines fluorescence intensity enhancement in the presence of DNA. In the presented paper, the activation energies of nonradiative degradation of electronic excitation, quantum yields and rate constants of nonradiative transitions of several cyanines in free state and in the presence of DNA were established and compared. The mechanisms of nonradiative deactivation of dye excitation energy were discussed. 相似文献
8.
Losytskyy MY Volkova KD Kovalska VB Makovenko IE Slominskii YL Tolmachev OI Yarmoluk SM 《Journal of fluorescence》2005,15(6):849-857
A series of pentamethine cyanine dyes with cyclohexene or cyclopentene group in polymethyne chain, assumed as DNA groove-binders,
were studied as fluorescent probes for nucleic acids as well as for native and denatured proteins. It was revealed that the
presence of methyl or dimethyl substituent in 5 position of the cyclohexene group hinders the formation of dye–DNA fluorescent
complex, while the methyl substituent in 2 position leads to the increasing of the dye–DNA complex fluorescence intensity.
The dyes SL-251, SL-1041, and SL-1046 containing methyl group in the 2 position of the cyclic group, are reported as bright
DNA-sensitive dyes. The study of the dyes DNA-binding specificity demonstrated significant AT-preference that points to the
groove-binding interaction mode. At the same time, the dyes SL-251, SL-377, and SL-957 with the 2-methyl substituted cyclohexene
group were shown to be sensitive fluorescent dyes both for nonspecific (in SDS presence) proteins detection and for native
BSA. 相似文献
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Kateryna D. Volkova Vladyslava B. Kovalska Mykhaylo Yu. Losytskyy Gertjan Veldhuis G. M. J. Segers-Nolten Olexiy I. Tolmachev Vinod Subramaniam Sergiy M. Yarmoluk 《Journal of fluorescence》2010,20(6):1267-1274
A key feature of Parkinson’s disease is the formation and accumulation of amyloid fibrils of the natively unfolded protein
α-synuclein (ASN) inside neurons. Recently we have proposed novel sensitive monomethinecyanine dye T-284 as fluorescent probe
for quantitative detection of ASN amyloid fibrils. In this study the T-284 dye complex with ASN fibril was characterized by
means of fluorescence anisotropy, atomic force microscopy and time-resolved fluorescence techniques to give further insights
into the mode of dye interaction with amyloid fibrils. The fluorescence anisotropy of T-284 was shown to noticeably increase
upon addition of aggregated proteins indicating on stable dye/amyloid fibril complex formation. AFM imaging of fibrillar wild-type
ASN revealed differences in heights between ASN fibrils alone and in presence of the T-284 dye (6.37 ± 1.0 nm and 8.0 ± 1.1 nm
respectively), that is believed to be caused by embedding of T-284 dye molecules in the “binding channel” running along the
fibril. Fluorescence decay analysis of the T-284 in complexes with fibrillar ASN variants revealed the fluorescence lifetime
values for T-284/fibril complexes to be an order of magnitude higher as compared to the free dye. Also, the fluorescence decay
of free T-284 was bi-exponential, while dye bound to protein yields tri-exponential decay. We suppose that in complexes with
fibrillar ASN variants T-284 dye might exist in different “populations” due to interaction with fibrils in different conformers
and ways. The exact binding mode of T-284 with ASN fibrils needs further studies. Studied parameters of dye/amyloid fibril
complexes are important for the characterization and screening of newly-developed amyloid-sensitive dyes. 相似文献