报告题目：Role of Dynamics in Enzymatic Electrophilic Aromatic Substitution
报 告 人：Kenneth M. Merz Jr.（密歇根州立大学Joseph Zichis讲席教授，Journal of Chemical Information and Modeling主编）
邀 请 人：廖荣臻教授
Prof. Kenneth M. Merz Jr. did his undergraduate studies at Washington College and received his Ph.D. degree at The University of Texas at Austin in 1985 (with Michael J. S. Dewar). He was a postdoctoral fellow at Cornell University (with Roald Hoffmann), and at University of California, San Francisco (with Peter Kollman). In 1989, he joined the Pennsylvania State University as an assistant professor, promoted to associated professor in 1996 and full professor in 1998. In 2013, he moved to Michigan State University as a director of Institute for Cyber Enabled Research and a Joseph Zichis Chair in Chemistry. He has published over 300 papers in international journals, including Chem. Rev., Acc. Chem. Res., Proc. Natl. Acad. Sci. U.S.A., Angew. Chem. Int. Ed., and J. Am. Chem. Soc. Since the start of 2014, he has been the Editor-in-Chief of the Journal of Chemical Information and Modeling.
FtmPT1 is a fungal indole prenyltransferase that affords Tryprostatin B from Brevianamide F and dimethyl allyl pyrophosphate; however, when a single residue in the active site is mutated (Gly115Thr) a novel five-member ring compound is obtained as the major product with Brevianamide F as the minor product (see Scheme 1). We will discuss detailed studies of the catalysis of the Gly115Thr mutant of FtmPT1 with a focus on the observed regioselectivity of this enzymatically catalyzed electrophilic aromatic substitution reaction. We employ 1-D and 2-D potential of mean force (PMF) simulations to explore the catalytic mechanism, along with MD simulations exploring the reaction dynamics of the prenyl transfer reaction. Importantly, we observe that the two reaction pathways (native and mutant) have comparable activation parameters and propose that the origin for the formation of the novel product in the mutant protein is predicated on reaction dynamics.