Women in Science: Crystals leading to discovery of new medicines
I must admit that when was invited to speak at last week’s Soapbox Science event on the South Bank in London, I accepted with some trepidation as I have never done such a thing before. But I willingly agreed to participate as I appreciated that this was a very original and great idea.
We scientists get engrossed in our subject and its details, and having to deliver such a ‘speech’ focuses one’s own mind on the purpose and relevance of the research. My goal was to explain why crystals can lead to the design of new medicines.
I started by showing a poster with pictures of beautiful protein crystals looking like sparkling diamonds which I personally grew in my laboratory. My audience could not believe that these crystals were of biological materials that were photographed under a microscope.
I explained that when we get unwell this is often due to the malfunction of proteins. Proteins drive the machinery of our body and are responsible for many of its functions such as oxygen transport, food digestion, muscle movements and many more of our body’s tasks.
Each protein has a different role and its 3-dimensional shape (structure) determines this role – similar to giving the right task to the right person (for example, asking a tall person to take a book off a high shelf and not requesting this from a short person). In order for a medicine to be effective it needs to target the specific protein that is involved in the disease that is being tackled and to influence its activity, by either blocking or enhancing it. To achieve this we first need to know exactly what the protein looks like, in other words to determine its shape.
In their natural state, proteins are liquid (for example in the blood), unlike solids that have a definite shape and size due to orderly arrangement of their molecules. Hence in order to enable us to visualise their shapes clearly, we need to change the proteins’ liquid state to anordered solid (or semi-solid). In other words, a crystal which can then be x-rayed and its structure determined.
The expressions “crystal clear” and “to crystallise thoughts” stem from the science of crystals. It requires effort to organise thoughts and ideas, and so too, we need to ‘convince’ the proteins to depart from the liquid state in which they are comfortable and form crystals.Proteins being biological materials are sensitive to external conditions and cannot be made to form crystals by harsh means that are applied to producing crystals of diamonds and gems such as high pressures or temperatures.
Growing a crystal requires tender conditions, similar to the formation of a baby. First, two molecules are brought together and if they connect well you get a healthy embryo which then turns into a healthy baby. If however, too many molecules come together, which can happen duringin-vitro fertilisation (IVF), they may compete with each other and lead to difficulties. As with babies, the aim is to get one or two single large crystals, and one of the major problems in getting such crystals is too many molecules coming together,thereby leading to numerous small crystals. I described some ways in which we try to overcome thisincluding sending proteins to crystallise in outer space,and I gave examples of proteins that we work on that are connected to cancer therapy and other diseases.
I went on to show what the information obtained from x-raying crystals can give and had a picture with me showing a ribosome, the structure of which was recently awarded the Nobel prize.
The soapbox experience turned out to be a lively discussion in which the people around me were asking questions and voicing their take on crystals, medicine and science in general.I felt privileged to be asked to speak at this event and I congratulate the organisersand the sponsors who made it such fun to participate.
Professor Naomi Chayen is Professor of Biomedical Sciences at Imperial College London
She is working with the L’Oréal-UNESCO For Women in Science Programme and The Zoological Society of London to encourage more young women to pursue careers in science. www.womeninscience.co.ukTagged in: crystals, protein, science
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