Annelise Barron

Annelise Barron aims to beat nature at its own game

Ask Annelise Barron, associate professor of chemical and biological engineering, about her research, and her first response is: “I am really excited about several projects ongoing in my lab, but in fact the most important products of my research are my graduate students. As professors, we develop the next generation of researchers. I'm a mentor first, and the recognition I get for research is shared with my graduate students.”

Her second response is: “Which research project?”

Barron has many irons in the fire. She has a joint appointment in the Weinberg College Department of Chemistry, and in five associated labs and three offices, she oversees some two dozen PhD candidates, four postdoctoral fellows, and a handful of master's students and undergraduates conducting research in three major areas: biomimetic oligomers, novel polymeric materials for genetic analyses by microchannel electrophoresis, and free-solution conjugate electrophoresis for microchannel DNA separations.

That first area — biomimetic oligomers, or nature-imitating compounds that consist of a finite number of monomer units (as opposed to polymers, which consist of many units) — includes three subgroups that focus on the use of peptoids for biomedical applications: lung-surfactant protein mimics, antibacterial peptide mimics, and novel “foldamers” that mimic folded proteins. Peptoids are chainlike molecules strung together in the laboratory to create new compounds designed to mimic naturally occurring peptides. In the case of the second subgroup, antibacterial peptide mimics, that means copying a model from nature — antibacterial peptides from frog skin — to create novel molecules that promise to wage a selective fight against bacteria in the human body without being rapidly degraded or harming mammalian cells.

Barron was working with peptoids and looking for molecules she could mimic in the laboratory when she came across an article about the antibacterial properties of magainin-2, a peptide found in the skin of the African clawed frog. Barron's hunch was that if she and her students could mimic the structure of magainin-2, they might be able to mimic its function, a supposition that has succeeded in her related research on lung surfactant. “Our goal is to copy the ability of magainin-2 to kill bacteria but create a molecule with greater stability, which is less likely to be rapidly proteolyzed or recognized by the immune system,” says Barron.

Because Barron and her team are trying to create mimics, they do not work with actual frog skin but with one of three peptide synthesizers in her labs. The process of creating an antibacterial peptoid takes two to three days and yields perhaps 100 milligrams of compound, sufficient for research purposes, Barron says, because “very tiny amounts can be used to kill bacteria.”

The project is highly innovative and interdisciplinary. “Students on the project are developing their skills in organic, analytical, and physical chemistry, as well as a bit of microbiology and biophysics when they characterize and test the peptoids,” says Barron. The promise of its applications has attracted funding from industry giants such as DuPont as well as from the U.S. government and, more recently, interest from 3M and Pfizer. The Department of Homeland Security awarded a fellowship to Nathaniel Chongsiriwatana, a graduate student of Barron's who is focusing on the antimicrobial peptoid research. Chongsiriwatana sees many possible applications for their research, from combating resistant bacteria to creating antibacterial surfaces.

Just as Barron is quick to credit her team members for their contributions, Chongsiriwatana praises the way Barron supports her students. “She's a strong believer in having students work independently,” says Chongsiriwatana. “She's always calling or e-mailing to share new ideas, which she allows us to analyze and develop. That's been an important learning experience for me.”

—Leanne Star

Northwestern University