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Direct observation of radical intermediates in protein-dependent DNA charge transport.
J Am Chem Soc. 2001 May 16; 123(19):4400-7.JA

Abstract

Charge migration through the DNA base stack has been probed both spectroscopically, to observe the formation of radical intermediates, and biochemically, to assess irreversible oxidative DNA damage. Charge transport and radical trapping were examined in DNA assemblies in the presence of a site-specifically bound methyltransferase HhaI mutant and an intercalating ruthenium photooxidant using the flash-quench technique. The methyltransferase mutant, which can flip out a base and insert a tryptophan side chain within the DNA cavity, is found to activate long-range hole transfer through the base pair stack. Protein-dependent DNA charge transport is observed over 50 A with guanine radicals formed >10(6) s(-1); hole transport through DNA over this distance is not rate-limiting. Given the time scale and distance regime, such protein-dependent DNA charge transport chemistry requires consideration physiologically.

Authors+Show Affiliations

Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125, USA.No affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't
Research Support, U.S. Gov't, P.H.S.

Language

eng

PubMed ID

11457224

Citation

Wagenknecht, H A., et al. "Direct Observation of Radical Intermediates in Protein-dependent DNA Charge Transport." Journal of the American Chemical Society, vol. 123, no. 19, 2001, pp. 4400-7.
Wagenknecht HA, Rajski SR, Pascaly M, et al. Direct observation of radical intermediates in protein-dependent DNA charge transport. J Am Chem Soc. 2001;123(19):4400-7.
Wagenknecht, H. A., Rajski, S. R., Pascaly, M., Stemp, E. D., & Barton, J. K. (2001). Direct observation of radical intermediates in protein-dependent DNA charge transport. Journal of the American Chemical Society, 123(19), 4400-7.
Wagenknecht HA, et al. Direct Observation of Radical Intermediates in Protein-dependent DNA Charge Transport. J Am Chem Soc. 2001 May 16;123(19):4400-7. PubMed PMID: 11457224.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Direct observation of radical intermediates in protein-dependent DNA charge transport. AU - Wagenknecht,H A, AU - Rajski,S R, AU - Pascaly,M, AU - Stemp,E D, AU - Barton,J K, PY - 2001/7/18/pubmed PY - 2001/9/8/medline PY - 2001/7/18/entrez SP - 4400 EP - 7 JF - Journal of the American Chemical Society JO - J. Am. Chem. Soc. VL - 123 IS - 19 N2 - Charge migration through the DNA base stack has been probed both spectroscopically, to observe the formation of radical intermediates, and biochemically, to assess irreversible oxidative DNA damage. Charge transport and radical trapping were examined in DNA assemblies in the presence of a site-specifically bound methyltransferase HhaI mutant and an intercalating ruthenium photooxidant using the flash-quench technique. The methyltransferase mutant, which can flip out a base and insert a tryptophan side chain within the DNA cavity, is found to activate long-range hole transfer through the base pair stack. Protein-dependent DNA charge transport is observed over 50 A with guanine radicals formed >10(6) s(-1); hole transport through DNA over this distance is not rate-limiting. Given the time scale and distance regime, such protein-dependent DNA charge transport chemistry requires consideration physiologically. SN - 0002-7863 UR - https://www.unboundmedicine.com/medline/citation/11457224/Direct_observation_of_radical_intermediates_in_protein_dependent_DNA_charge_transport_ L2 - https://dx.doi.org/10.1021/ja003986l DB - PRIME DP - Unbound Medicine ER -