Learn More
An oligodeoxyribonucleotide, d(GCTCACAAT-X-ATTGTGAGC), where X represents a hexaethylene glycol chain, was studied using circular dichroism spectroscopy. Its conformation and conformational stability were compared to those of compounds where X was replaced by four thymines and to the duplex of same sequence without loop. The compound with the hexaethylene(More)
The binding of the cyclic-AMP receptor protein (CRP) of Escherichia coli to a non-specific DNA fragment of 46 base pairs has been studied using fluorescence spectroscopy. The equilibrium binding constant was found to be several orders of magnitude lower than in the specific binding to a DNA fragment of the same size. The salt dependence of the equilibrium(More)
The secondary structure of guanine-rich oligodeoxynucleotides has been investigated with fluorescent probes. Intramolecular folding of a telomeric oligonucleotide into a quadruplex led to fluorescence resonance energy transfer (FRET) between a donor (fluorescein) and an acceptor (tetramethylrhodamine) covalently attached to the 5' and 3' ends of the DNA,(More)
We have used circular dichroism and UV absorption spectroscopy to characterize the formation and melting behaviour of an intramolecular DNA triple helix containing parallel T*A:T and G*G:C triplets. Our approach to induce and to stabilize a parallel triplex involves the oligonucleotide 5'-d(G4A4G4[T4]C4T4C4-[T4]G4T4G4) ([T4] represents a stretch of four(More)
Defensin A is an inducible antibacterial protein isolated from the larvae of Phormia terranovae. The conformation of defensin A has been previously determined by two-dimensional 1H-NMR for concentrations in the range of 4-8 mM in water (Bonmatin JM et al (1992) J Biomol NMR 2, 235-256). CD spectroscopic data of defensin A at lower concentrations (10(-5) to(More)
We have investigated the effect on the DNA structure of protein MC1, a basic and small polypeptide (Mr 10700) representing the major chromosomal protein in Methanosarcinaceae. The ability of protein MC1 to strongly favour cyclization upon polymerization of short DNA fragments by T4 DNA ligase indicates that protein MC1 mediates DNA bending. Several(More)
We designed a peptide, H5WYG (GLFHAIAHFIHGGWHGLIHGWYG), that permeabilizes cell membrane at a slightly acidic pH but not at neutral pH. Absorbance, fluorescence, and circular dichroism spectra showed that H5WYG undergoes a dramatic conformational change between pH 7.0 and 6.0 that correlates with the protonation of the histidyl residues. Cell(More)