Yuzhong Liu, Ph.D.
Assistant Professor
Department of Chemistry
The Scripps Research Institute
Website: https://www.liulabscripps.com/
Seminar Information
Many of the most effective vaccine adjuvants are derived from complex natural
products, yet their development and use are often limited by supply and structural
heterogeneity. QS-21, a saponin isolated from the bark of Quillaja saponaria, is a
prominent example: it is widely used in clinical vaccines but remains challenging to
access and modify.
In this work, we develop microbial platforms to produce QS-21 and related glycosylated
natural products in yeast. By reconstructing biosynthetic pathways and extending them
through enzyme discovery and engineering, we enable scalable production of these
molecules and create opportunities to access structural variants that are difficult to
obtain from natural sources. Using these systems, we begin to explore how changes in
glycosylation impact biological function. In particular, we generate and evaluate new
glycoside variants to probe how subtle differences in sugar composition and
connectivity influence immune activation. This work establishes microbial biosynthesis
as both a practical route to supply complex adjuvants such as QS-21 and a platform to
study and design glycosylated natural products with improved immunological properties.
Yuzhong Liu, Ph.D. is an Assistant Professor of Chemistry at Scripps Research. She
received her Ph.D. from UC Berkeley under the supervision of Omar Yaghi, where she
worked on molecular weaving and framework materials, and completed her postdoctoral
training with Jay Keasling, focusing on the complete biosynthesis of the vaccine
adjuvant QS-21 in yeast. Her research combines synthetic biology, chemistry, and
enzyme engineering to study and produce novel complex molecules, with an emphasis
on saponin-based adjuvants and other bioactive glycosides. Her group develops
microbial platforms to enable scalable access to these molecules and to explore how
glycosylation influences biological function, particularly in the context of immune
modulation.