Tsai, YL, Chang CC, Kang CC, Chang TC.
2007.
Effect of different electronic properties on 9-aryl-substituted BMVC derivatives for new fluorescence probes, Nov. Journal of Luminescence. 127:41-47., Number 1
AbstractWe have previously illustrated that the electron donor of carbazole moiety and the electron acceptor of methyl pyridinium cation in 3,6-bis(1-methyl-4-vinylpyridinium) carbazole diiodide (BMVC) molecule could form an intramolecular charge-transfer state. The intramolecular twist of the vinyl group in bridging the donor and acceptor plays an important role in the BMVC fluorescence. Here, we have synthesized three 9-aryl-substituted BMVC derivatives with different electronic properties for the design of the second generation of fluorescence probes. The steady-state solvatochromic studies show no appreciable change to the charge transfer of BMVC by substituting an anisole electron-donating group at 9-position of BMVC. However, substituting a 9-nitrobenzyl electron-withdrawing group in BMVC could restrict the charge transfer in the excited state. Moreover, the increase of the fluorescence yields of 9-anisole BMVC and 9-phenyl BMVC upon interaction with DNA is even higher than that in glycerol, while the fluorescence yield of 9-nitrobenzyl BMVC upon interaction with DNA is much lower than that in glycerol. Although 9-nitrobenzyl BMVC is a good G-quadruplex stabilizer, substituting an electron-withdrawing group at 9-position of BMVC is not recommended for the design of fluorescence probes. On the other hand, colocalization between 9-phenyl BMVC and MitoTracker Red in the merged image of cells indicates that the 9-phenyl BMVC is a potential fluorescent mitochondrial probe. (C) 2007 Elsevier B.V. All rights reserved.
Chang, CC, Chien CW, Lin YH, Kang CC, Chang TC.
2007.
Investigation of spectral conversion of d(TTAGGG)(4) and d(TTAGGG)(13) upon potassium titration by a G-quadruplex recognizer BMVC molecule, May. Nucleic Acids Research. 35:2846-2860., Number 9
AbstractWe have introduced a G- quadruplex- binding ligand, 3,6- bis( 1- methyl- 4- vinylpyridinium) carbazole diiodide ( BMVC), to verify the major structure of d( T(2)AG(3))(4) ( H24) in potassium solution and examine the structural conversion of H24 in sodium solution upon potassium titration. The studies of circular dichroism, induced circular dichroism, spectral titration and gel competition have allowed us to determine the binding mode and binding ratio of BMVC to the H24 in solution and eliminate the parallel form as the major G- quadruplex structure. Although the mixed- type form could not be eliminated as a main component, the basket and chair forms are more likely the main components of H24 in potassium solution. In addition, the circular dichroism spectra and the job plots reveal that a longer telomeric sequence d( T(2)AG(3))(13) ( H78) could form two units of G4 structure both in sodium or potassium solutions. Of particular interest is that no appreciable change on the induced circular dichroism spectra of BMVC is found during the change of the circular dichroism patterns of H24 upon potassium titration. Considering similar spectral conversion detected for H24 and a long sequence H78 together with the G4 structure stabilized by BMVC, it is therefore unlikely that the rapid spectral conversion of H24 and H78 is due to structural change between different types of the G4 structures. With reference to the circular dichroism spectra of d( GAA)(7) and d( GAAA)(5), we suggest that the spectral conversion of H24 upon potassium titration is attributed to fast ion exchange resulting in different loop base interaction and various hydrogen bonding effects.
Kang, CC, Chang CC, Chang TC, Liao LJ, Lou PJ, Xie W, Yeung ES.
2007.
A handheld device for potential point-of-care screening of cancer. Analyst. 132:745-749., Number 8
AbstractA simple handheld device based on the fluorescence analysis of 3,6-bis(1-methyl-4-vinylpyridinium) carbazole diiodide ( BMVC) stained cells was established for routine screening and potentially for early detection of cancer cells at extremely low cost. Flow cytometry assay further supported the utility of this simple device, where a preliminary study of tissue biopsy showed highly encouraging results.
Chang, CC, Chien CW, Lin YH, Kang CC, Chang TC.
2007.
Investigation of spectral conversion of d(TTAGGG)4 and d(TTAGGG)13 upon potassium titration by a G-quadruplex recognizer BMVC molecule. Nucleic Acids Res. 35:2846-60., Number 9
AbstractWe have introduced a G-quadruplex-binding ligand, 3,6-bis(1-methyl-4-vinylpyridinium)carbazole diiodide (BMVC), to verify the major structure of d(T2AG3)4 (H24) in potassium solution and examine the structural conversion of H24 in sodium solution upon potassium titration. The studies of circular dichroism, induced circular dichroism, spectral titration and gel competition have allowed us to determine the binding mode and binding ratio of BMVC to the H24 in solution and eliminate the parallel form as the major G-quadruplex structure. Although the mixed-type form could not be eliminated as a main component, the basket and chair forms are more likely the main components of H24 in potassium solution. In addition, the circular dichroism spectra and the job plots reveal that a longer telomeric sequence d(T2AG3)13 (H78) could form two units of G4 structure both in sodium or potassium solutions. Of particular interest is that no appreciable change on the induced circular dichroism spectra of BMVC is found during the change of the circular dichroism patterns of H24 upon potassium titration. Considering similar spectral conversion detected for H24 and a long sequence H78 together with the G4 structure stabilized by BMVC, it is therefore unlikely that the rapid spectral conversion of H24 and H78 is due to structural change between different types of the G4 structures. With reference to the circular dichroism spectra of d(GAA)7 and d(GAAA)5, we suggest that the spectral conversion of H24 upon potassium titration is attributed to fast ion exchange resulting in different loop base interaction and various hydrogen bonding effects.