| dc.contributor.author | Ban, Fuqiang. | en_US |
| dc.date.accessioned | 2014-10-21T12:36:24Z | |
| dc.date.available | 2001 | |
| dc.date.issued | 2001 | en_US |
| dc.identifier.other | AAINQ66646 | en_US |
| dc.identifier.uri | http://hdl.handle.net/10222/55774 | |
| dc.description | Numerous biological radical systems have been discovered that are fundamental to understanding the catalysis of enzymes, the oxidative damage to DNA and proteins, and the mechanisms of anticancer drugs. Spectroscopic techniques are powerful tools for monitoring radicals. However, highly reactive and short-lived radical species are extremely difficult to characterize in experiments. Fortunately, recent advancements in density functional theory offer a complementary approach to solving chemical problems for biological systems of reasonable sizes. | en_US |
| dc.description | This thesis describes the application of density functional theory to predicting properties and reaction mechanisms of several biological radical systems. In the first part of the thesis, the structures and hyperfine coupling constants of a number of amino acid-derived radicals generated upon irradiation are investigated systematically. A valid computational scheme for obtaining the zwitterionic form of amino acid radicals is provided. The second part of the thesis concentrates on selected reaction mechanisms for the radical systems of DNA. In particular, the cross-linking mechanisms of a DNA base and an amino acid residue in a nucleohistone and the actions of an antitumor drug that leads to cleavage of DNA strands are investigated. The preferred mechanisms are identified on the basis of computed potential energy surfaces for possible reaction pathways, providing great insight into the radical-mediated oxidative damage to DNA and into the chemistry of tumor-selective drugs. The observations from the amino acid-derived and DNA-based radicals provide a fundamental basis for future work on biological radical systems. | en_US |
| dc.description | Thesis (Ph.D.)--Dalhousie University (Canada), 2001. | en_US |
| dc.language | eng | en_US |
| dc.publisher | Dalhousie University | en_US |
| dc.publisher | | en_US |
| dc.subject | Chemistry, Radiation. | en_US |
| dc.title | Computational studies on the properties and reactions of biological radicals. | en_US |
| dc.type | text | en_US |
| dc.contributor.degree | Ph.D. | en_US |
