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Potential involvement of both type I and type II mechanisms in M13 virus inactivation by methylene blue
H Abe1, K Ikebuchi, S J Wagner
1Hokkaido Red Cross Blood Center, Sapporo, Japan.
Abstract:
We have investigated the mechanism of virus photoinactivation with methylene blue (MB) by conducting deuterium oxide (D2O), azide ion (N3-) and oxygen-dependent studies. Inactivation of M13 bacteriophage and singlet oxygen (1O2) generation by MB photosensitization were irradiation dose dependent. Inactivation of M13 was enhanced by D2O and inhibited by N3-, suggesting that 1O2 participates in M13 inactivation by MB photosensitization. However, N3- did not inhibit M13 inactivation completely. On the other hand, deoxygenating the reaction solution still caused 52-67% of M13 inactivation observed in the presence of oxygen. These results suggest that 1O2-mediated (Type II) and sensitizer-mediated (Type I) reactions may both play roles in M13 inactivation by MB photosensitization.
Insights
Methylene blue (MB) photoinactivation of viruses involves both singlet oxygen (1O2) and sensitizer-mediated reactions. Studies using deuterium oxide (D2O) and azide ion (N3-) confirm 1O2 involvement, but other mechanisms also contribute to virus inactivation.
Area of Science:
- Photochemistry
- Virology
- Biophysics
Background:
- Methylene blue (MB) is a photosensitizer used for virus inactivation.
- The precise mechanisms of MB-mediated photoinactivation require further elucidation.
Purpose of the Study:
- To investigate the roles of singlet oxygen (1O2) and other reactive species in M13 bacteriophage photoinactivation by MB.
- To differentiate between Type I (sensitizer-mediated) and Type II (1O2-mediated) reaction pathways.
Main Methods:
- Deuterium oxide (D2O) and azide ion (N3-) dependent studies were performed.
- Oxygen-dependent inactivation experiments were conducted.
- Irradiation dose-dependent inactivation and 1O2 generation were monitored.
Main Results:
- M13 bacteriophage inactivation and 1O2 generation by MB photosensitization were dependent on irradiation dose.
- Inactivation was enhanced by D2O and partially inhibited by N3-, indicating 1O2 participation.
- Significant inactivation (52-67%) occurred even under deoxygenated conditions.
Conclusions:
- Both 1O2-mediated (Type II) and sensitizer-mediated (Type I) reactions contribute to M13 bacteriophage inactivation by MB.
- The findings provide a more comprehensive understanding of MB's antiviral photoinactivation mechanisms.