PMID: 7931851Jul 1, 1994Paper

Synergistic action of near-UV and phenylalanine, tyrosine or tryptophan on the inactivation of phage T7: role of superoxide radicals and hydrogen peroxide

Journal of Photochemistry and Photobiology. B, Biology
J CraggsS I Ahmad

Abstract

Near ultraviolet (NUV) light can cause a variety of damage to biological systems. The effects of NUV are significantly enhanced in the presence of sensitizers. One of the most important targets of such synergistic effects is DNA. Cellular DNA exposed to NUV plus sensitizers is damaged in a variety of ways, DNA strand breaks and interstrand cross-links being the most common effects. In this study, phenylalanine, tyrosine and tryptophan are shown to act as sensitizers for NUV action of phage T7; superoxide anions are produced. The reactive species probably interacts with phage DNA causing damage responsible for phage inactivation. Superoxide dismutase reverses the synergistic activities of phenylalanine and tyrosine on NUV-induced phage inactivation, but catalase is additionally required to reverse the effect of tryptophan. Therefore, it is probable that NUV photolysis of tryptophan causes the production of superoxide ions and hydrogen peroxide, both of which contribute to phage inactivation. The ubiquitous nature of NUV in our environment and the presence of amino acids in skin cells suggests that an important mechanism for the induction of skin cancer in humans by solar exposure is amino acid photolysis by NUV.

References

Nov 1, 1976·Photochemistry and Photobiology·H N Ananthaswamy, A Eisenstark
Jan 1, 1973·Photochemistry and Photobiology·R M Tyrrell
Oct 1, 1970·Photochemistry and Photobiology·R B Webb, J R Lorenz
Nov 1, 1971·Analytical Biochemistry·C Beauchamp, I Fridovich
Dec 1, 1983·Photochemistry and Photobiology·A W Girotti
Nov 30, 1967·Biochemical and Biophysical Research Communications·S Y Wang, A J Varghese

❮ Previous
Next ❯

Citations

Oct 1, 1996·Journal of Photochemistry and Photobiology. B, Biology·S I Ahmad
Nov 6, 2007·Journal of Photochemistry and Photobiology. B, Biology·A HargreavesS I Ahmad
Feb 9, 2006·Photochemical & Photobiological Sciences : Official Journal of the European Photochemistry Association and the European Society for Photobiology·Georg T WondrakElaine L Jacobson

❮ Previous
Next ❯

Related Concepts

Related Feeds

Bacteriophage: Phage Therapy

Phage therapy uses bacterial viruses (bacteriophages) to treat bacterial infections and is widely being recognized as an alternative to antibiotics. Here is the latest research.