Friday, 13 March 2009

Ep 101: Molecular Design

Dr. Luke Hunter is an organic chemist whose chemistry career has been based around molecular design - that is, designing organic molecules through experiment.

I grabbed Luke over a few cocktails and chatted organic chemistry, molecular synthesis and design, and the Hollywood lifestyle that organic chemists lead. This podcast also has our first Correlation of the Week. Listen to his podcast here.

Organic chemistry is a part of chemistry looking at compounds that contain carbon. The original definition of organic chemistry was "the chemistry of life" as it was thought all organic compounds had something to do with life - these days we know that there are many organic processes that have nothing to do with life, as well as many inorganic compounds that are essential for life.

One of Luke's research areas in the School of Chemistry at the University of NSW is to design molecules that can bind with DNA. By designing molecules in this way, it is hoped that drugs which can target particular genetic sequences in DNA can be developed. This could lead to advances in genetics research which could allow us to turn certain genes off and on, and could eventually lead to cures for genetic disorders such as infertility. To do this, Luke goes fishing! Luke dangles a strand of DNA into a soup of organic compounds to see which ones stick. Those that stick have the right shape to bind to DNA and so can then be further investigated. Different strands of DNA can be dangled into the soup - that is, different fishing lines can be used - and in this way, molecules that selectively bind to only one section of DNA can be found.

Luke's other area of interest is Fluorine Chemistry - he worked in this area whilst studying at the University of St Andrews. Again his work was in designing molecules with particular shapes. Knowing the shape of a molecule and how it behaves is very important for designing drugs to fit receptors in the body - when a receptor is bound by a molecule (for example, a drug), biological activity is generated (for example, nerve impulses send a message to your brain). Luke often works with Hydrofluroric acid, a strongly corrosive acid that is so dangerous you need to carry an antidote for it at all times when working with it - this antidote is calcium gluconate. HF burns may not initially be painful but as HF penetrates the skin, it can etch and weaken bones without damaging the skin. It can also be absorbed into blood and react with blood calcium, causing cardiac arrest. This is why calcium gluconate is used - it is a source of Ca2+ that sequesters the fluoride ions. If left untreated, amputation may be required.

Luke's PhD was in the total synthesis of a fungus that could be used to kill cancer cells. Total synthesis is the complete chemical synthesis of complex organic molecules from simpler pieces. Synthesising the molecule to selectively target cancerous cells is very difficult and one of the reasons why chemotherapy drugs have such terrible side-effects - they affect not only the cancer cells but other healthy cells.

Whilst it may seem that Luke leads the Hollywood lifestyle, carrying around antidotes to dangerous chemicals and all, Luke is perfectly happy with the relaxed lifestyle of an organic chemist in a white lab-coat:

"Day-to-day I'm wearing a white coat and safety glasses and I'm mixing together different compounds in round bottom flasks - it's not especially glamorous but I enjoy it anyway."

Luke is about to commence a post-doc at the University of Sydney.

The second part of this podcast is our new segment Correlation of the Week - dedicated to bad and funny correlations that make the news. You can read more about this week's correlation in our article from a few days back Correlation of the Week - Shark Attacks and the Global Financial Crisis

Listen to his podcast here:





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