IPiB Thesis Defense May 9, 2024: Anna Zmich

Anna ZmichAnna Zmich, an IPiB graduate student, will be defending her Ph.D. research on May 9, 2024. Through her research in the Buller Lab, Zmich identified and characterized enzymes that scientists can use to synthesize amino acids. Her work has been published in ACS Catalysis.

Proteins are made of chains of comprised of combinations of twenty amino acids, known as canonical amino acids. Beyond these twenty, there are additional, non-canonical amino acids (ncAAs). These molecules, which exist naturally, are found in many pharmaceuticals, agrochemicals, and natural products, and are involved in metabolism and other biological functions.

Zmich’s research focused on the development and engineering of enzymes which can be used to produce a variety of ncAAs.

Zmich was interested in exploring enzymes that scientists can use to synthesize gamma-substituted amino acids, a name which refers to the positioning of the amino acid’s sidechain. Using bioinformatics tools, Zmich identified forty proteins in the vinylglycine ketimine (VGK) subfamily which are well-adapted to synthesizing gamma-substituted amino acids. Zmich then characterized the form and function all forty proteins to identify which enzyme is most effective at biosynthesizing ncAAs. She then used directed protein evolution to further enhanced the enzyme’s biosynthesis activity.

Zmich also characterized and investigated the chemical mechanisms of action used by cystathionine gamma-lyase, an enzyme known to break down gamma-substituted amino acids. “We can use this enzyme as a model to answer mechanistic questions that can help aid future protein engineering projects,” explains Zmich.

During her time as an IPiB graduate student, Zmich learned how to talk about her research to audiences with diverse backgrounds and perspectives in the biochemical sciences. “When I give a presentation to chemists, they see immediately how much biology is involved in my work,” says Zmich. “When I give a seminar through IPiB, I get to explain more about things like how the electrons are flowing in an enzyme mechanism. It’s the same research, but the way I explain it depends on the expertise of my audience.”

Zmich also served on IPiB’s Graduate Leadership and Development Committee. After graduating, Zmich is planning to work in industry.

To learn more about Zmich’s research, attend her Ph.D. defense, “Exploration of the Dual Reactivities of the Vinylglycine Ketimine PLP-Dependent Enzyme Activity,” on Thursday, May 9 at 2:00 p.m. CT in Room 1211 of Hector F. DeLuca Biochemical Sciences Building.