Different lethal effects by enzyme-generated triplet indole-3-aldehyde in different Escherichia coli strains

• Published in: Journal of photochemistry and photobiology. B, Biology Biology, 1990-03, Vol.4 (4), p.371-378
• Main Authors: Duran, Nelson, Marcucci, Maria C., Gatti, Maria S.V., Leite, Luciana C.C.
• Format: Article
• Language: English
• Subjects: 4-thiouridine; Biological and medical sciences; DNA; DNA Damage; DNA, Bacterial - radiation effects; Energy Metabolism - radiation effects; Escherichia Coli; Escherichia coli - genetics; Escherichia coli - metabolism; Escherichia coli - radiation effects; Fundamental and applied biological sciences. Psychology; indole-3-acetic acid; indole-3-aldehyde; Indoles - metabolism; Molecular and cellular biology; Molecular genetics; Mutagenesis. Repair; Mutation; Oxygen - metabolism; Oxygen - radiation effects; peroxidase; Photochemistry; Thiouridine - metabolism; Thiouridine - radiation effects; triplet state
• ISSN: 1011-1344; 1873-2682
• DOI: 10.1016/1011-1344(90)85016-P

Strains of Escherichia coli which lack 4-thiouridine (S 4U) exhibit a higher survival rate than their wild-type parents which contain S 4U after treatment with enzyme-generated triplet indole-3-aldehyde. In a similar manner to results obtained with monochromatic 334 nm UV light, the survival is related to single-strand breakage of DNA in E. coli containing the pBR 322 plasmid. The effects of the excited states generated by an enzymatic system suggest that S 4U is an important chromophore in the lethal effects observed. The results also suggest that the energy transferred from triplet indole-3-aldehyde to S 4U may also be passed from S 4U of T-RNA to DNA, possibly through a singlet oxygen intermediate generated by excited S 4U, resulting in a decrease in the survival rate of E. coli containing S 4U. These results emphasize the importance of excited states in biological systems.