Formation of highly selective and efficient interstrand cross-linking to thymine without photo-irradiation.

Interstrand cross-linking (ICL) forming oligodeoxynucleotides (ODNs) have been expected to ensure the inhibition of gene expression. In this communication, we report a highly efficient and selective ICL reaction to thymine using a 4-amino-2-vinyl-6-oxopyrimidine derivative.

DNA-templated click chemistry for creation of novel DNA binding molecules.

We have developed a new methodology for producing new molecules that bind to dsDNA using DNA-templated click chemistry. The click reactions between the minor groove binding peptide and acridine intercalators were accelerated by the addition of dsDNA. Furthermore, the resulting peptide-acridine conjugate showed a slightly stronger binding to dsDNA.

Synthesis of the peptide nucleic acid (PNA) incorporating 2-amino-6-vinylpurine derivative and evaluation of the reactivity.

Previously, we established a new strategy of synchronous cross linking reaction activated by hybridization to target genes. In this strategy, the highly reactive cross-linking agent, 2-amino-6-vinylpurine nucleoside analog, is generated from its stable precursors by a hybridization-promoted activation process with selectivity to cytosine. In this paper, we wish to report the synthesis of the peptide nucleic acids (PNAs) incorporating 2-amino-6-vinylpurine derivatives and the evaluation of their reactivity to target DNA.

New methodology to search for DNA binding ligands based on duplex DNA-templated click chemistry.

We have developed a new methodology for searching new molecules that bind to dsDNA using DNA-templated click chemistry. The click reactions between the minor groove binding peptide and acridine intercalators were accelerated by addition of dsDNA. Furthermore, resulting peptide-acridine conjugate showed strong binding to dsDNA.

Copper(II) complexes of 1,10-phenanthroline-derived ligands: studies on DNA binding properties and nuclease activity.

A series of copper(II) complexes of the type [Cu(L)]2+, where L = N,N'-dialkyl-1,10-phenanthroline-2,9-dimethanamine and R = methyl (L1), n-propyl (L2), isopropyl (L3), sec-butyl (L4), or tert-butyl (L5) group, have been synthesized. The interaction of the complexes with DNA has been studied by DNA fiber electron paramagnetic resonance (EPR) spectroscopy, emission, viscosity and electrochemical measurements and agarose gel electrophoresis. In the X-ray crystal structure of [Cu(HL2)Cl2]NO3, copper(II) is coordinated to two ring nitrogens and one of the two secondary amine nitrogens of the side chains and two chloride ions as well and the coordination geometry is best described as trigonal bipyramidal distorted square based pyramidal (TBDSBP).

Effect of a conjugated acridine moiety on the binding and reactivity of Cu(II)[9-acridinylmethyl-1,4,7-triazacyclononane] with DNA.

The DNA binding orientation and dynamic behavior of Cu(II) complexes of 1,4,7-triazacyclononane ([9]aneN(3)), 1, and an acridine conjugate, 2, were investigated by DNA fiber EPR (EPR=electron paramagnetic resonance) spectroscopy. Crystal and molecular structure of 2 were determined by X-ray diffraction. It has been shown that 1 binds to DNA in two different modes at room temperature; one species is rapidly rotating and the other is immobilized randomly on the DNA.

EPR study of the dynamic behavior of cis,cis-1,3,5-triaminocyclohexane Cu(II) complex on B-form DNA-fibers.

The orientation and the dynamic behavior of [Cu(TACH)](2+)(TACH = cis,cis-1,3,5-triaminocyclohexane) on B-form DNA-fiber have been investigated by electron paramagnetic resonance (EPR) spectroscopy. The complex showed novel EPR spectra indicating that a rapidly moving species (X) is in equilibrium with a stereospecifically oriented species (Y) on the DNA-fiber in the range 20 and -20 degrees C. The thermodynamic parameters Delta H and Delta S of the equilibrium X right arrow over left arrow Y are respectively -51.

The effect of acridine moiety for binding and reaction of Cu(II)[1 ,4,7-triazacyclononane] with DNA.

The orientation and the dynamic behavior of Cu(II) complex of 1,4,7-triazacyclononane ([9]aneN3) and its acridine conjugate on B-form DNA fiber have been investigated by EPR spectroscopy. It has been shown that a Cu([9]aneN3)2+ binds to DNA with two different binding modes at room temperature; one species is rapidly moving and the other is immobilized randomly on the DNA. An introduction of acridine to 1,4,7-triazacyclononane fixed the orientation of all the Cu(II) complex with the g// axis perpendicular to DNA fiber axis, indicating that the tetragonal coordination plane is almost parallel to the DNA double helical axis.