Arthur C. Cope Scholar Awards: Suzanne Walker

“Fearless.” This is how more than one colleague describes Suzanne Walker and her work in natural product antibiotics. Walker is receiving the Arthur C. Cope Scholar Award for her chemoenzymatic characterization of glycosyl transfer steps in bacterial cell wall biosynthesis as targets for antibiotics.

Walker, a microbiology and molecular genetics professor at Harvard Medical School, is honored to receive the award. “It is amazing to find myself in the company of scientists whose work has been highly influential,” she says.

In fact, the first person she told of her achievement was Christopher T. Walsh, Hamilton Kuhn Professor of Biological Chemistry & Molecular Pharmacology at Harvard Medical School and a previous Cope Scholar Award recipient. “I admire him as a scientist and a person. I knew he would be pleased for me,” Walker explains. “The second person I told was my husband, who wanted to know why he wasn’t the first person I told.”

Walker’s interest in bacterial cell wall biosynthesis was prompted by concern about antibiotic resistance. When she began to read about the pathway required to build cell walls, she was surprised to learn that some of the steps hadn’t been studied, let alone well characterized. “It seemed to me that the major impediment to studying the pathway steps was that suitable substrates were not available,” she says.

In order to solve that problem, Walker turned her attention to developing synthetic substrates to stand in for natural cell wall precursors. Her lab completed the first syntheses of lipid-linked substrates to study key steps in the peptidoglycan biosynthetic pathway. “Access to substrates has allowed us to do all kinds of mechanistic studies on peptidoglycan biosynthetic enzymes and the antibiotics that target them,” Walker says. She adds that her group has “established a tremendously successful collaboration” in this area with Daniel Kahne’s lab at Harvard Medical School. “And we have used a similar approach to enable the study of other important bacterial cell surface polymers,” she says.

Walsh says that Walker “embodies the best of modern chemical biology focused on the assembly of the bacterial cell wall layers, the mechanism of antibiotics, and the reprogramming of biosynthetic pathways to make optimized therapeutic agents.”

“Professor Walker is remarkable in her ability to move into new fields with conviction and fearlessness,” says Laura L. Kiessling, Hilldale Professor of Chemistry & Biochemistry at the University of Wisconsin, Madison. “It is not only her ability to acquire and apply methods and ideas from diverse fields that distinguishes her but also that she identifies key problems and offers new solutions.”

But Walker attributes her lab’s success to the students and postdocs who carried out the studies. “They are the ones who make things happen,” she says, “so my accomplishments are really theirs.”

After Walker received a B.A. in English literature from the University of Chicago in 1983, she followed “a meandering and bumpy road” to a chemistry Ph.D. from Princeton University in 1992. She is an active member of the ACS Division of Biological Chemistry. She received an Alfred P. Sloan Research Fellowship in 2002, a Camille Dreyfus Teacher-Scholar Award in 2003, and the Protein Society’s Emil Thomas Kaiser Award in 2010.