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An AFM/Rotaxane Molecular Reading Head for Sequence‐Dependent DNA Structures
Author(s) -
Ashcroft Brian A.,
Spadola Quinn,
Qamar Shahid,
Zhang Peiming,
Kada Gerald,
Bension Rouvain,
Lindsay Stuart
Publication year - 2008
Publication title -
small
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.785
H-Index - 236
eISSN - 1613-6829
pISSN - 1613-6810
DOI - 10.1002/smll.200800233
Subject(s) - nanopore , threading (protein sequence) , dna , atomic force microscopy , helix (gastropod) , molecular dynamics , dna origami , nanotechnology , materials science , crystallography , biophysics , chemistry , nanostructure , protein structure , computational chemistry , biology , biochemistry , ecology , snail
DNA secondary structure may prove to be a significant obstacle both for enzymes that process DNA through an orifice and for the passage of DNA through nanopores proposed for some novel sequencing schemes. A nanomechanical molecular “tape reader” is assembled by threading a nanopore over DNA and pulling it using an atomic force microscope. Its formation is confirmed by studying the force required to open hairpins under that geometry. Unfolding induced by this 0.7‐nm‐diameter aperture requires 40 times more force than that reported for pulling on the ends of the DNA. Kinetic analysis shows that much less strain is required to destabilize the double helix in this geometry. Consequently, much more force is required to provide the free energy needed for opening.