From green to red--To more dead? Autofluorescent proteins as photosensitizers.
Inactive compounds like autofluorescent proteins can absorb visible daylight (around 500-700 nm) and can emit active electrons producing reactive oxygen species (ROS) leading to an increase in photokilling processes in bacteria. The endogenously originated ROS create single strand breaks in the cells DNA. These various types of breaks can be partially repaired by different cellular repair systems but a high number of breaks leads to cell death. A dramatic increase in cell killing can be observed from green, via yellow to red color emission. This was tested by colony forming ability. The generation of ROS and the bacterial protection mechanisms are discussed. We outline some possibilities for use the protein's properties for treatment of antibiotic multi-resistant and difficult to treat bacteria like the methicillin-resistant Staphylococcus aureus (MRSA).
Mueller
Gabriele
G
German Cancer Research Center, Division of Biophysics of Macromolecules, INF 580, D-69120 Heidelberg, Germany.
Waldeck
Waldemar
W
Braun
Klaus
K
D001426:Bacterial Proteins / Q000633:toxicity; D004249:DNA Damage; D005456:Fluorescent Dyes; D049452:Green Fluorescent Proteins / Q000633:toxicity; D008164:Luminescent Proteins / Q000633:toxicity*; D055624:Methicillin-Resistant Staphylococcus aureus / Q000187:drug effects / Q000528:radiation effects; D017319:Photosensitizing Agents / Q000633:toxicity*; D017382:Reactive Oxygen Species / Q000378:metabolism; D013472:Sunlight
D001426:Bacterial Proteins; D005456:Fluorescent Dyes; D008164:Luminescent Proteins; D017319:Photosensitizing Agents; D017382:Reactive Oxygen Species; C485184:enhanced green fluorescent protein; C508771:killer red protein, Anthomedusae; C054562:yellow fluorescent protein, Bacteria; D049452:Green Fluorescent Proteins