Studying the effect of a charged surface on the interaction of bleomycin with DNA using an atomic force microscope.
The cleavage of DNA caused by the antitumoral drug bleomycin has been investigated using atomic force microscopy (AFM). This work deals with the effect that adsorbing DNA onto a positively- or negatively-charged surface has on the double-strand cleavage of DNA by Fe(III)/bleomycin. Quantitative analysis of the number of breaks per DNA molecule, in bulk and at the surface of the mica substrate, has been performed by analyzing AFM images. It turns out that the cleavage of DNA is strongly inhibited by a positively-charged surface. Our experiments can be interpreted using a simple electrostatic model. This paper is a first step in the study of DNA accessibility to ligand such as bleomycin, using AFM in liquids.
Piétrement
Olivier
O
Laboratoire de Microscopie Moléculaire et Cellulaire, UMR 8126 CNRS-IGR-UPS, Institut Gustave-Roussy, 39 rue Camille Desmoulins, 94805 Villejuif Cedex, France. Olivier.Pietrement@igr.fr
Pastré
David
D
Landousy
Fabrice
F
David
Marie-Odile
MO
Fusil
Stéphane
S
Hamon
Loïc
L
Zozime
Alain
A
Le Cam
Eric
E
D000327:Adsorption; D000538:Aluminum Silicates / Q000737:chemistry*; D001761:Bleomycin / Q000737:chemistry*; D020099:Coated Materials, Biocompatible / Q000032:analysis / Q000737:chemistry*; D004247:DNA / Q000737:chemistry* / Q000648:ultrastructure*; D004249:DNA Damage; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008422:Materials Testing; D018625:Microscopy, Atomic Force / Q000379:methods*; D055672:Static Electricity; D013499:Surface Properties
D000538:Aluminum Silicates; D020099:Coated Materials, Biocompatible; D001761:Bleomycin; D004247:DNA; C011934:mica