NASA Logo, External Link
Facebook icon, External Link to NASA STI page on Facebook Twitter icon, External Link to NASA STI on Twitter YouTube icon, External Link to NASA STI Channel on YouTube RSS icon, External Link to New NASA STI RSS Feed AddThis share icon
 

Record Details

Record 1 of 4973
Detection of Strand Cleavage And Oxidation Damage Using Model DNA Molecules Captured in a Nanoscale Pore
Author and Affiliation:
Vercoutere, W.(NASA Ames Research Center, Moffett Field, CA, United States)
Solbrig, A.(California Univ., Chemistry Dept., Santa Cruz, CA, United States)
DeGuzman, V.(California Univ., Chemistry Dept., Santa Cruz, CA, United States)
Deamer, D.(California Univ., Chemistry Dept., Santa Cruz, CA, United States)
Akeson, M.(California Univ., Chemistry Dept., Santa Cruz, CA, United States)
Abstract: We use a biological nano-scale pore to distinguish among individual DNA hairpins that differ by a single site of oxidation or a nick in the sugar-phosphate backbone. In earlier work we showed that the protein ion channel alpha-hemolysin can be used as a detector to distinguish single-stranded from double-stranded DNA, single base pair and single nucleotide differences. This resolution is in part a result of sensitivity to structural changes that influence the molecular dynamics of nucleotides within DNA. The strand cleavage products we examined here included a 5-base-pair (5-bp) hairpin with a 5-prime five-nucleotide overhang, and a complementary five-nucleotide oligomer. These produced predictable shoulder-spike and rapid near-full blockade signatures, respectively. When combined, strand annealing was monitored in real time. The residual current level dropped to a lower discrete level in the shoulder-spike blockade signatures, and the duration lengthened. However, these blockade signatures had a shorter duration than the unmodified l0bp hairpin. To test the pore sensitivity to nucleotide oxidation, we examined a 9-bp hairpin with a terminal 8-oxo-deoxyguanosine (8-oxo-dG), or a penultimate 8-oxo-dG. Each produced blockade signatures that differed from the otherwise identical control 9bp hairpins. This study showed that DNA structure is modified sufficiently by strand cleavage or oxidation damage at a single site to alter in a predictable manner the ionic current blockade signatures produced. This technique improves the ability to assess damage to DNA, and can provide a simple means to help characterize the risks of radiation exposure. It may also provide a method to test radiation protection.
Publication Date: Jan 01, 2003
Document ID:
20040008882
(Acquired Feb 03, 2004)
Subject Category: INORGANIC, ORGANIC AND PHYSICAL CHEMISTRY
Document Type: Preprint
Meeting Information: Biophysical Society Meeting; 14-18 Feb. 2004; Baltimore, MD; United States
Meeting Sponsor: Biophysical Society; Bethesda, MD, United States
Financial Sponsor: NASA Ames Research Center; Moffett Field, CA, United States
Organization Source: NASA Ames Research Center; Moffett Field, CA, United States
Description: 1p; In English
Distribution Limits: Unclassified; Publicly available; Unlimited
Rights: No Copyright
NASA Terms: DEOXYRIBONUCLEIC ACID; DETECTION; OXIDATION; MOLECULES; NANOTECHNOLOGY; MOLECULAR BIOLOGY; RADIATION DOSAGE; RADIATION PROTECTION; STRANDS; REAL TIME OPERATION; SUGARS; PHOSPHATES; NUCLEOTIDES; ION CHANNELS (BIOLOGY)
Availability Source: Other Sources
Availability Notes: Abstract Only
› Back to Top
Find Similar Records
NASA Logo, External Link
NASA Official: Gerald Steeman
Site Curator: STI Program
Last Modified: August 23, 2011
Contact Us