Mapping the phase diagram of single DNA molecule force-induced melting in the presence of ethidium.
When a single DNA molecule is stretched beyond its normal contour length, a force-induced melting transition is observed. Ethidium binding increases the DNA contour length, decreases the elongation upon melting, and increases the DNA melting force in a manner that is consistent with the ethidium-induced changes in duplex DNA stability known from thermal melting studies. The DNA stretching curves map out a phase diagram and critical point in the force-extension-ethidium concentration space. Intercalation occurs between alternate base pairs at low forces and between every base pair at high forces.
Vladescu
Ioana D
ID
Department of Physics, Northeastern University, 111 Dana Research Center, Boston, Massachusetts 02115, USA.
McCauley
Micah J
MJ
Rouzina
Ioulia
I
Williams
Mark C
MC
D001665:Binding Sites; D003198:Computer Simulation; D004247:DNA / Q000032:analysis / Q000737:chemistry*; D004548:Elasticity; D004996:Ethidium / Q000737:chemistry*; D008846:Micromanipulation / Q000379:methods*; D008956:Models, Chemical; D009690:Nucleic Acid Conformation; D009691:Nucleic Acid Denaturation; D044367:Phase Transition; D013314:Stress, Mechanical; D044366:Transition Temperature
D004247:DNA; D004996:Ethidium