Single-Molecule Mechanics of DNA - DNA Nanotechnology: From Structure to Function - page 84

Chapter 6
Single-Molecule Mechanics of DNA
Shuxun Cui
Abstract Mechanics is crucial for life. The single molecular mechanics of
biomacromolecules lays the base of mechanical movements of organism. Here
in this chapter, we will introduce the progress in single chain mechanics of DNA.
The related studies are very important not only to the understanding of phenomena
of life but also to the design and preparation of artificial nanomachines.
Keywords Single-molecule mechanics of DNA • Force spectroscopy • Binding
force • Entropic elasticity • Enthalpic elasticity • Torsional mechanical proper-
ties • Twist elasticity • Stretching elasticity • Force-induced melting
If we regard organism as a well-designed machine that works precisely, each
biomacromolecule will work as a component of the complex machine. Mechanical
activities, such as the generation of force and transportation of materials, are
involved in all of the metabolism processes of an organism. All the mechanical activ-
ities are mainly performed by biomacromolecules. The single molecular mechanics
of biomacromolecules lays the base of mechanical movements of organism. The
related studies are very important not only to the understanding of phenomena of
life but also to the design and preparation of artificial nanomachines.
DNA typically forms a double helix in the physiological environment. When
the gene code reading is required (in gene duplication, reparation, etc.), the helix
needs to be unwound. An interesting question would be that how strong is the
force needed to unwind the double helix? This problem is a typical one in the
single-molecule scope. Many traditional experimental methods, including NMR,
DSC, and UV-Vis-IR spectroscopy, have a common character: the obtained signals
S. Cui ( )
Key Laboratory of Advanced Technologies of Materials (Ministry of Education), Southwest
Jiaotong University, Chengdu 610031, China
e-mail: [e-mail]