A series of oligodeoxynucleotides labeled by a pyrimidopyrimidoindole deoxynucleoside (1a: dC(PPI)) and its derivatives 2a and 3a substituted with electron-donating and -withdrawing groups, respectively, were synthesized according to the phosphoramidite approach. The photophysical properties and quenching efficiencies of oligonucleotides incorporating dC(PPI) derivatives were studied in detail. The thermal denaturation experiments and molecular dynamics simulation of DNA duplexes incorporating dC(PPI) suggested that a modified base of dC(PPI) could form base pairs with guanine and adenine in canonical Watson-Crick and reverse-wobble geometries, respectively. The fluorescence of oligonucleotides incorporating dC(PPI) derivatives increased upon binding to the counter strands, except when dC(PPI) and guanine formed a base pair. It was revealed that dGMP quenched the fluorescence of the cyano derivative 3a most effectively, whereas it affected that of the methoxy derivative 2a least effectively. The involvement of the electron transfer from guanine to the dC(PPI) derivatives in the fluorescence quenching was supported by energy considerations.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1021/jp807562c | DOI Listing |
J Phys Chem B
July 2009
Department of Life Science, Tokyo Institute of Technology, Nagatsuta, Midoriku, Yokohama 226-8501, Japan.
A series of oligodeoxynucleotides labeled by a pyrimidopyrimidoindole deoxynucleoside (1a: dC(PPI)) and its derivatives 2a and 3a substituted with electron-donating and -withdrawing groups, respectively, were synthesized according to the phosphoramidite approach. The photophysical properties and quenching efficiencies of oligonucleotides incorporating dC(PPI) derivatives were studied in detail. The thermal denaturation experiments and molecular dynamics simulation of DNA duplexes incorporating dC(PPI) suggested that a modified base of dC(PPI) could form base pairs with guanine and adenine in canonical Watson-Crick and reverse-wobble geometries, respectively.
View Article and Find Full Text PDFJ Am Chem Soc
July 2008
Department of Life Science, Tokyo Institute of Technology, Nagatsuta, Midoriku, Yokohama 226-8501, Japan.
New nucleotide pairs applicable to formation of DNA triplexes were developed. We designed oligonucleotides incorporating 5-aryl deoxycytidine derivatives (dC5Ars) and cyclic deoxycytidine derivatives, dCPPP and dCPPI, having an expanded aromatic area, as the second strand. As pairing partners, two types of abasic residues (C3: propylene linker, phi: abasic base) were chosen.
View Article and Find Full Text PDFJ Org Chem
July 2007
Department of Life Science, Frontier Collaborative Research Center, Tokyo Institute of Technology, and CREST of JST, 4259 Nagatsuta, Midori-ku Yokohama, Japan.
10-(2-Deoxy-beta-D-ribofuranosyl)pyrimido[4',5':4,5]pyrimido[1,6-a]indole-6,9(7H)-dione (dCPPI) and its derivatives were synthesized via the Suzuki-Miyaura coupling reaction of 5-iododeoxycytidine with 5-substituted N-Boc-indole-2-borates and characterized by UV-vis and fluorescence spectroscopy. The new fluorescent nucleosides showed rather large Stokes shifts (116-139 nm) in an aqueous buffer. The fluorescent intensities were dependent on the nature of the substituents on the indole rings.
View Article and Find Full Text PDFNucleic Acids Symp Ser (Oxf)
August 2007
Department of Life Science, Tokyo Institute of Technology, Nagatsuta, Midoriku, Yokohama 226-8501, Japan.
We report here the synthesis and spectroscopic characterization of a new fluorescent pyrimidopyrimidoindole nucleoside derivative (dC(PPI)) modified at the cytosine base. The photophysical properties of dC(PPI) were examined by fluorescent spectroscopy and quantum chemical calculations. It was found that dC(PPI)-labeled oligonucleotides gave almost the same thermal stability as that of the corresponding unmodified sequences.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!