Effect of Adenine on the Riboflavin-Sensitized Photoreaction

• Published in: Journal of biochemistry (Tokyo) Vol. 71; no. 5; pp. 805 - 810
• Main Authors: UEHARA, Kihachiro, MIZOGUCHI, Tadashi, HOSOMI, Saburo
• Format: Journal Article
• Language: English
• Published: Oxford University Press 01.05.1972
• ISSN: 0021-924X; 1756-2651
• DOI: 10.1093/oxfordjournals.jbchem.a129829

Upon the addition of adenine, the marked enhancement of the riboflavin-sensitized photoinactivation of transforming deoxyribonucleic acid (DNA) of Bacillus subtilis was observed, and the inactivation of the DNA was found to be first-order reaction. The extent of the enhancement calculated from the apparent first-order rate constants was about seventy times. The effect of adenine was not found when methylene blue, thiopyronin, eosin yellowish or fluorescein was used as a sensitizer in place of riboflavin. Adenine was the most effective compound among purine and pyrimidine derivatives tested. The pH dependence of the riboflavin-sensitized photoinactivation of the DNA in the presence of adenine was different from that observed in the absence of adenine. The rate of the riboflavin-sensitized photoinactivation increased as the temperature increased, whereas in the presence of adenine, a slight decrease in the rate was observed with increase in temperature. It was assumed from the above facts that adenine caused the enhancement of the inactivation of the DNA through the formation of a specific complex with riboflavin.