Record Details
Field | Value |
---|---|
Title | Hydroperoxide formation in the radiolysis of aqueous DNA and the pyrimidine bases |
Names |
Schwiebert, Maris Carol
(creator) Daniels, Malcolm (advisor) |
Date Issued | 1967-05-09 (iso8601) |
Note | Graduation date: 1967 |
Abstract | The formation of cytosine hydroperoxide was detected in aqueous cytosine solutions irradiated with Co-60 γ-rays at pH 2. The nucleotide of cytosine, cytidylic acid, forms a hydroperoxide which was detected in neutral solution. The stability of the hydroperoxides of cytosine, thymine, and their nucleotides was found to be a function of pH, with the decomposition rate increasing with increasing pH. Two hydroperoxides, differing in their thermal stabilities, were found in irradiated aqueous DNA. Through their decay kinetics and energetics, the fast-decaying hydroperoxide was identified with the cytosine component and the slower-decaying one with the thymine component of the DNA. The hydroperoxide formation in cytosine and DNA was studied as a function of dose, oxygen concentration, DNA structure, and initial cytosine and DNA concentration. The thermal decomposition of the thymine hydroperoxide in DNA was found to be influenced by the presence of added solutes. By studying the rate of decomposition at 80° C in the presence of added electrolytes, all having an ionic strength of 0.01, the change in rate constant was shown to be a specific effect of the solute rather than an ionic strength effect. Urea, a non-electrolyte, caused a similar change in the rate constant. |
Genre | Thesis/Dissertation |
Topic | Pyrimidines |
Identifier | http://hdl.handle.net/1957/47277 |