Diamond News Update

Meera - Let's join Sarah Boundy from Diamond’s Communications Team for the latest news from the Light Source, starting with some eye-opening research...

Sarah – Yes, a group has been studying the microstructure of the peripheral cornea. The cornea is the external lens of the eye, it is responsible for refracting incoming light onto the crystalline lens behind it, which in turn focuses it on to the retina. To function, the cornea needs to be transparent to visible light, it also has to possess high mechanical strength and have precisely defined curvature to focus. The research was carried out by a team from Cardiff University and they were using Diamond’s non-crystalline diffraction beamline I22, and also the ESRF in Grenoble in France. There results were recently published in the Biophysical Journal.

Meera - What were the scientists looking into about it?

Sarah – Well they know that 90% of the thickness of the cornea is made from something called the stroma, which is a thick transparent layer primarily composed of collagen fibrils. So the shape of the cornea is thought to be strongly influenced by the arrangement of collagen fibrils in the stroma and surrounding tissues, and it’s this knowledge that is key to understanding how corneal disease and surgery can affect vision

Meera - So I guess by having a good understanding of the structure, you can see how disease can perhaps damage it and also when reconstructing it with surgery, you can have a better idea of what you’re doing.

Sarah – Well that’s right. The results show the fibril diameter is constant in the centre of the cornea, but increases rapidly when moving out towards the periphery. So this may be an important fact in understanding how the cornea responds to surgery involving peripheral incision, for example cataract surgery. So one of the side effects and complications is astigmatism, and this research will help to explain observations by clinicians that the extent of astigmatic changes depends on the location in which the cut is made.

Meera - So very useful in the post-surgical time as well I guess after corneal surgery. As well as the eye, scientists here have also been looking at viruses.

Sarah – Yes a group has used one of macromolecular crystallography beamlines I03 to look at the ancestry of viruses. So this is research carried out by Oxford University’s Welcome Centre for Human Genetics and it was published recently in Structure. Just as humans have an ancestry, so to do viruses. So the group are currently working at piecing together a complete history of viruses, by solving the 3D structure of the virus proteins.

Meera - So is much not currently known about virus structures?

Sarah – Well viruses are really large, complex structures, so it takes a lot of time and effort to solve the structure of the proteins involved in them.

Meera - Which viruses have they been looking into so far?

Sarah – Well the group have successfully solved the 3D structure of protein D13 from Vaccinia virus which is a member of the poxvirus family. So this protein is a scaffolding protein and its particles, or Virons, take the shape of a sphere as the virus starts to form before D13 is lost and the virus takes on a more brick-like shape. And this is the first time they have been able to determine the structure of the protein D13.

Meera - Why is it useful to know this particular virus structure?

Sarah – Well they found that it has a very distinctive shape, a shape that is also found in large DNA viruses such as human Adenovirus which is a cause of respiratory and eye infections. So by comparing the structural similarities of the different virus’ scaffolding proteins they can determine the lineage of Vaccinia Virus and place it within their virus family tree.

Meera - I guess an application of knowing the structures is to possibly come up with better treatments or antivirals?

Sarah – Exactly. Knowing who or what a particular organism is descended from, can tell us a great deal about how it may function. So in the case of viruses, this kind of knowledge could help us to define new ways to treat them. We could be looking at drugs for patients who are suffering from one of a number of viruses, just in the way we use antibiotic to treat a number of bacterial infections.

Meera - So treating a family of them rather than very specific viruses at a time?

Sarah – That’s right.

Meera - And what about more in-house news for Diamond?

Sarah – Well we now have our summer 2011 Issue of Diamond News, that’s our bi-annual newsletter. This one looks at research using altruistic bacteria, metal-organic frameworks for sustainable storage solutions, and tuneable polymers which are enabling scientists to produce colours without using pigments. There’s also a round-up of some of our PhD students’ in there and some updates on the facility as well, so there’s lots going on. Copies are available from the Diamond website.

Meera - And as well as news updates, you’ve got more multi-media content online as well?

Sarah – Yes, we’ve been working on some new video content. You can see the first instalment which we’ve call ‘We are all scientists’ and that’s on our website education pages. It features clips of scientists and engineers talking about what fascinates them about science and what they think about the Diamond synchrotron and why it’s important to them.