Abstract
Several yeast species are able to synthesize and accumulate UV-radiation-absorbing mycosporine metabolites that are of unclear physiological function. In this work we analyzed the relationship between mycosporine-glutaminol glucoside (MGG) production, cell survival after UVB irradiation, and formation of cyclobutane pyrimidine dimers (CPDs). We also assessed the photostability and singlet oxygen quenching activity of MGG. A set of nine isolates of the basidiomycetous yeast Cryptococcus steppossus cultured in both dark and light conditions was used for the studies. Survival of the UVB-irradiated isolates and MGG concentration had a linear relationship when the concentration was over 2.5 mg g(-1). CPD accumulation and MGG accumulation were inversely related. MGG in aqueous solution was photostable with a photodecomposition quantum yield of 1.16 × 10(-5). MGG quenching of singlet oxygen was also observed, and the rate constant for the process in D(2)O was 5.9 × 10(7) M(-1) s(-1). Our results support the idea that MGG plays an important role as a UVB photoprotective metabolite in yeasts by protecting against direct damage on DNA and probably against indirect damage by singlet oxygen quenching.
| Original language | English |
|---|---|
| Pages (from-to) | 44-50 |
| Number of pages | 7 |
| Journal | Radiation Research |
| Volume | 175 |
| Issue number | 1 |
| Publication status | Published - Jan 2011 |
Keywords
- Antioxidants
- Cryptococcus
- Cyclohexanols
- DNA Damage
- Glucosides
- Pyrimidine Dimers
- Singlet Oxygen
- Ultraviolet Rays
- Journal Article
- Research Support, Non-U.S. Gov't