A research group led by the Paul Scherrer Institute (PSI) has used X-ray laser technology to record one of the fastest processes in biology and capture it in a molecular movie.
The movie shows how the light sensor retinal is activated in a protein molecule. These reactions occur in numerous organisms, explained the PSI, enabling certain bacteria to produce energy through photosynthesis and initiating the process of vision in humans.
Occurring within 500 femtoseconds, the process is around a trillion times faster than the blink of an eye, according to Jörg Standfuss from the PSI.
Now, the process has been captured for the first time by the researchers – in 20 snapshots that show what happens on a molecular level. “No one has previously measured a retinal protein at such high speed and with such precision. It's a world record,” said Standfuss.
The PSI researchers conducted the work in California with colleagues from Japan, Germany, Israel and Sweden. In the future, however, they will be able to realize such films at the PSI with the newly commissioned X-ray laser facility SwissFEL.
There are already plans to use SwissFEL to investigate the retinal in rhodopsin in human eyes. Similar retinal proteins can also be artificially incorporated into nerve cells, according to the PSI, making it possible to selectively activate nerve cells with light and study their function.
“With these retinal proteins, one can activate any region in the brain with the help of light,” explained Jörg Standfuss of the goal of the new field called optogenetics.
