DNA: an extensible molecule.
The force-displacement response of a single duplex DNA molecule was measured. The force saturates at a plateau around 70 piconewtons, which ends when the DNA has been stretched about 1.7 times its contour length. This behavior reveals a highly cooperative transition to a state here termed S-DNA. Addition of an intercalator suppresses this transition. Molecular modeling of the process also yields a force plateau and suggests a structure for the extended form. These results may shed light on biological processes involving DNA extension and open the route for mechanical studies on individual molecules in a previously unexplored range.
Cluzel
P
P
Institut Curie URA Centre National de la Recherche Scientifique (CNRS), Paris, France.
Lebrun
A
A
Heller
C
C
Lavery
R
R
Viovy
J L
JL
Chatenay
D
D
Caron
F
F
D055598:Chemical Phenomena; D002627:Chemistry, Physical; D004247:DNA / Q000737:chemistry*; D008958:Models, Molecular; D009690:Nucleic Acid Conformation; D012984:Software
D004247:DNA