European researchers set sights on photoreceptor proteins

July 9, 2008--Capturing moving images of tiny protein molecules is the aim of a new research project at Imperial College London. The research will reveal the movements of proteins that help carry out important biological processes in people, animals, insects, and plants.

July 9, 2008--Capturing moving images of tiny protein molecules is the aim of a new research project at Imperial College London. The research will reveal the movements of proteins that help carry out important biological processes in people, animals, insects, and plants.

The 1 million euro study, funded by the European Research Council, will focus on light receptor proteins. Researchers will examine what happens when these proteins are hit with a pulse of bright laser light, and will record moving images of the results.

The photoreceptor proteins at the heart of the new study include those that enable plants to bend towards the sun

Photoreceptor proteins trigger important biological responses to light. The human photoreceptor proteins which the researchers will study are involved in maintaining the body's internal 24 hour clock which governs sleep cycles in relation to day and night, and have significant biomedical importance.

The researchers will also study plant light receptor proteins which help plants bend towards the sun, and are involved in photosynthesis - the process by which sunlight is converted into energy.

The new funding will allow scientists to bring together two different types of imaging technology to look at both vibrations and motions on extremely short timescales, for the first time in the UK. This will enable the scientists to record how the molecular structures of these types of proteins change when they are 'at work'.

Recipient of the new grant, Jasper van Thor from Imperial College London's Department of Life Sciences, explains why capturing dynamic images of these proteins is important:

"Although much is known about the structure of these types of proteins when they're in a static state, few experiments have been carried out to understand exactly what happens on a molecular level when they're 'activated' by light and start moving around doing their jobs.

"We hope that getting a dynamic, moving picture of how these proteins work will give us a greater understanding than ever before of how these important biological processes happen."

Dr. van Thor's grant will be used to fit out a new laser laboratory at Imperial for pump-probe experiments. In these experiments, the light receptor protein molecules will be stimulated into activity by a laser and their movements and structural changes recorded by an ultrafast spectroscopic probe.

The second type of technology that Dr van Thor and his colleagues will use to capture images of the proteins in action is extremely powerful x-rays produced in synchrotron facilities. In these experiments, the scientists will again use a laser pump to activate the proteins, but here they will use a very fast pulsed x-ray probe to record to the moving images. The combination of these two techniques will give van Thor and his colleagues a comprehensive set of moving images of the light receptor proteins at work.

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