Student research uncovers surprise in molecule’s shape

June 13, 2013

UW-L Assistant Professor of Chemistry Heather Schenck and her undergraduate research student Stefanie Sippl stand by the instrument used to uncover the molecule's structure.

UW-L Assistant Professor of Chemistry Heather Schenck and her undergraduate research student Stefanie Sippl stand by the instrument used to uncover the molecule’s structure.

In January, UW-L Assistant Professor of Chemistry Heather Schenck and her undergraduate research student Stefanie Sippl corrected an error in the literature that stood for 19 years.

The error was in the shape of one section of a tiny molecule. While a seemingly small inaccuracy, the information gives scientists new, foundational knowledge that could potentially have implications for future discoveries in the development of antibiotics or treatment of cancer.

“We repeated our experiment many times and continued to get the same results,” recalls Sippl. “It was exciting because it led to more questions and further investigation into the properties and behavior of our molecule.”

The little molecule, N-methylacetohydroxamic acid, is made up of carbon, nitrogen and oxygen connected in a somewhat unusual way. This molecule, and others of its type, have a major claim to fame for their ability to bond with ferric iron — found in such familiar places as rust.

While something people associate with old vehicles, different forms of oxidized iron are essential for organisms to live. Yet, for some organisms like bacteria, fungi and algae, it’s tricky to get ahold of iron at the atomic level. Unlike humans, they can’t simply swallow a medium-rare steak to get their intake. They need to be a bit more inventive.

Stefanie Sippl with the instrument.

This summer Stefanie Sippl is an intern at the University of Virginia Medical School in the Biomedical Sciences program and is working on cardiovascular research. She aspires to attend medical school and continue researching.

That’s where hydroxamic acids come in. Bacteria and other organisms create these molecules to catch iron. Even people with excess iron in their blood will get injections of a hydroxamic acid molecule to help them bind and get rid of the extra iron.

Because of the importance of hydroxamic acids, Schenk and Sippl were interested in learning more about them, using a tiny model that was easy to study. The molecule they are studying, like all hydroxamic acids, has two favored shapes. Using a large instrument in a Cowley Hall Science lab, Schenck and Sippl were able to get an inside look at the physical and chemical properties of the molecule through a technique called Nuclear Magnetic Resonance spectroscopy.

They found that what researchers thought was an alternate shape of hydroxamic acids was actually the more desirable and common shape. This means the molecule has to change its shape in order to bind with iron, which helps explain why hydroxamic acids have a slow rate of iron binding, says Schenck.

Understanding how this molecule behaves has implications for the world of medicine. Hydroxamic acids continue to be talked about as potential areas of exploration for antibiotics and treatment of cancer, says Schenck.

“If we are going to use hydroxamic acids for these tasks, we’d better understand what they’re doing,” she says.

With her name now tied to a significant research discovery, Sippl says undergraduate research has been one of the most rewarding experiences of her college career. Schenck, she says, has been an extraordinary mentor.

“I really enjoy working in lab and being involved in the investigation because I see concepts I have learned in biology, physics, and chemistry put into application,” says Sippl. “Research has helped me grow as a student and a scientist, especially in the way I perceive and process the world around me.”

Check it out

A UW-L student and her professor discovered an error in the shape of a molecule. The corrected molecular structure was published this year in Magnetic Resonance in Chemistry.

The instrument

UW-L researchers found this error using a highly technical process called Nuclear Magnetic Resonance, which employs the same technology as Magnetic Resonance Imaging (MRI). The instrument arrived in 2010 thanks to a $390,000 grant from the National Science Foundation. Schenck and Adrienne Loh, professor of chemistry, were co-principal authors of the grant proposal.