Solvent spin-labelling for investigating the interaction of biological ligands with macromolecules. A 1H paramagnetic relaxation study.
The paramagnetic contributions to the spin-lattice relaxation rates of khellin protons, induced by the presence in an aqueous solution of TEMPO nitroxide, have been analyzed in the interaction of the furochromone with DNA. The relaxation data obtained at different temperatures, nitroxide and DNA concentrations indicate that the average solvent exposure of the furanic moiety of khellin is lower than that of the pyranic group. This feature suggests that the former is the main site of approach of khellin to DNA.
Niccolai
N
N
Dipartimento di Chimica, University of Siena, Italy.
Lampariello
R
R
Bovalini
L
L
Rustici
M
M
Mascagni
P
P
Martelli
P
P
D004247:DNA / Q000737:chemistry; D007666:Khellin / Q000737:chemistry*; D008024:Ligands; D009682:Magnetic Resonance Spectroscopy; D011522:Protons
D008024:Ligands; D011522:Protons; D007666:Khellin; D004247:DNA