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Carolyn Bertozzi

Baker Family Director of the ChEM-H Institute at Stanford University
Nobel Prize in Chemistry 2022

Glycans: the Sugars Coating Our Cells 

Human cells–like all cells on Earth–are covered with sugars: large carbohydrate molecules called glycans. Glycans have vastly more complex chemical structures than sucrose, the substance we know as table sugar. In humans, they are long, branching chains of complex carbohydrates formed from nine types of simple sugars called monosaccharides. (By contrast, sucrose is formed from two such monosaccharides, glucose and fructose.) 

In textbook drawings of cells, glycans are often depicted simply as halos around a cell. That’s because until recently, little was known about the structure and role of these sugars. As chemical biologist Carolyn Bertozzi often notes, when giving a lecture to a popular audience, she first learned about glycans in a college biochemistry course, where they were described as being like the coating on a peanut M&M: a smooth protective surface that guarded the cell’s inner workings. Period. Bertozzi has spent her career exploring glycans: working to understand their structure and identifying ways they can be manipulated to be used as the basis of diagnostics or therapeutics. It turns out they are almost nothing like that delicious candy coating. 

Glycans represent an important potential source of treatments for cancer and a range of genetic and autoimmune diseases. The glycans on cell surfaces protect healthy cells from the immune system…but they can also shield harmful cells like cancer cells in tumors. Researchers at , one of eight startup companies Bertozzi has co-founded, are developing ways to chemically alter glycans on specific cells so that the immune system can target and eliminate cancer cells. In December 2024, Palleon entered into a clinical collaboration with the biopharmaceutical company Henlius for a , using a Palleon glycan editing platform. 

 In addition to her innovative work at the interface of chemistry and biology, Bertozzi is well known for her support of underrepresented scientists. When Bertozzi won the 2024 Priestley Medal, the highest honor bestowed by the American Chemical Society (ACS), the Society lauded her both for her work in chemistry and for her efforts to shape the culture of the field of chemistry. A press releas announcing her prize notes that “when she began her career, Bertozzi’s field barely tolerated a person like her.” Bertozzi is a lesbian. The press release goes on to note that “Bertozzi epitomizes an ongoing cultural shift in chemistry: from professor as resident of the ivory tower to professor as entrepreneur, from scientific silos to interdisciplinary research and team science, and from an old boys’ club to an environment that values diversity of background in all its forms.” In remarks at Stanford in 2022, Bertozzi notes that her team’s diversity “created an environment where we felt we didn’t have to play by the same old rules as scientists. We could do things like organic chemistry in living animals—why not?”

After many years on the faculty of the University of California, Berkeley, Bertozzi left to join the newly-formed interdisciplinary institute ChEM-H (Chemistry, Engineering, and Medicine for Human Health) at Stanford University. Bertozzi’s many awards for her work in chemistry include a MacArthur Fellowship (1999) and the Nobel Prize in Chemistry (2022). Her efforts to create a new “culture of chemistry” were recognized with the LGBTQ Scientist of the Year award from the National Organization of Gay and Lesbian Scientists and Technical Professionals. 

Carolyn Bertozzi is the Baker Family Director of the ChEM-H Institute at Stanford University. She holds a PhD chemistry from the University of California at Berkeley. 

Her talk: All cells possess a sugar coating. Called the “glycocalyx”, this coating of complex carbohydrates serves numerous functions in human health and disease. For more than half a century, the structures of cell-surface carbohydrates have been known to undergo changes associated with cancer. Until recently, the significance of these changes was not understood. This presentation will summarize our work toward understanding why cancer cells have an altered glycocalyx and how we are using these findings in the design of new cancer therapies.