Induced Night Vision by Singlet-Oxygen-Mediated Activation of Rhodopsin
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Researchers have discovered how a cancer drug can lead to improved night vision.
Photodynamic therapy uses a laser beam to induce light-sensitive drugs such as chlorin e6 to produce a reactive form of oxygen called singlet oxygen, which kills nearby cancer cells. A surprising side effect of this treatment is that some patients can see better at night.
When a light-sensitive protein in retinal rods called rhodopsin is in contact with chlorin e6 it responds to infrared light in a similar way to visual light. But the mechanism for this was unclear.
An international team that included two researchers from Nankai University probed the interaction between chlorin e6 and rhodopsin by performing molecular dynamics simulations.
They found that the singlet oxygen produced by chlorin e6 when illuminated by infrared light indirectly isomerized the retinal active group in rhodopsin, which enabled night vision.
This knowledge could be used to intentionally enable night vision, the researchers say.
- The Journal of Physical Chemistry Letters 10, 7133–7140 (2019). doi: 10.1021/acs.jpclett.9b02911