Single nucleobase sensitivity of α-Hemolysin (α-HL) transmembrane protein pore: Toward single DNA sequencing

ORGN 74

Nurit Ashkenasy, nurita@bgu.ac.il, Department of Materials Engineering, Ben Gurion University of the Negev, P.O.B. 653, Beer-Sheva, 84105, Israel, Jorge Sánchez-Quesada, Department of Chemistry, The Scripps Research Institute, Hagan Bayley, bayley@medicine.tamu.edu, University of Oxford, Oxford, OX1 3TA, United Kingdom, and M. Reza Ghadiri, ghadiri@scripps.edu, Departments of Chemistry and Molecular Biology and The Skaggs Institute for Chemical Biology, Scripps Research Institute, 10550 N. Torrey Pines Rd, La Jolla, CA 92037.
The use of the Staphylococcus aureus α-hemolysin (α-HL) transmembrane protein pore as the sensor element in a rapid pore-mediated single-molecule DNA sequencing process has been the focus of intense work in the past few years. One of the un-assessed requirements for such process is the pore's nucleobase resolution. In this work, using the characteristic residual pore current of α-HL•DNA pseudorotaxanes, in which ss-DNA is held stably inside the pore, we show that α-HL can recognize ss-DNA with an apparent single nucleobase resolution. The work describes the use of series of adenine and cytosine DNA block copolymers, and cytosine homopolymeric strands with position-specific single adenine substitutions to locate the specific nucleotide position responsible for the measured current, and to identify the pore location at which detection occurs.
 

Materials, Devices, and Switches
1:00 PM-5:00 PM, Sunday, 13 March 2005 Convention Center -- Room 9, Oral

Division of Organic Chemistry

The 229th ACS National Meeting, in San Diego, CA, March 13-17, 2005