E. James Petersson
Associate Professor of Chemistry


Protein motion underlies both proper function and disease in biological systems. Many signaling and transport proteins require complex rearrangements for function, and some proteins, such as amyloids, misfold into toxic conformations. Studying these protein motions not only aids our understanding of diverse biological phenomena, it also contributes to an important fundamental problem in biochemistry: understanding how motions propagate from one end of a protein to another. The Petersson laboratory is developing tools to address questions of how dynamic proteins mediate communication and how the cellular environment catalyzes protein misfolding, from detailed in vitro folding studies to modeling protein motion in living cells. These tools include novel chromophores, which we synthesize and incorporate into proteins through unnatural amino acid mutagenesis and synthetic protein ligation.


• A.B. Dartmouth College (1998)

• Ph.D. California Institute of Technology (2005)

• NIH Postdoctoral Fellow, Yale University (2005-2008)

• Searle Scholar (2010)

• Sloan Research Fellow (2012)

• NSF CAREER Award (2012)

• Award for Early Excellence in Physical Organic Chemistry      (2013)

Selected Publications

Inteins as Traceless Purification Tags for Unnatural Amino Acid Proteins

Batjargal, S.; Walters, C. R.; Petersson, E. J.

J. Am. Chem. Soc. 2015, 137, 1734-1737.


Specific Modulation of Protein Activity Through a Bioorthogonal Reaction

Warner, J. B.; Muthusamy, A. K.; Petersson, E. J.

ChemBioChem 2014, 24, 2508-2514.


Thioamide-Based Fluorescent Protease Sensors

Goldberg, J. M.; Chen, X. S.; Meinhardt, N.; Greenbaum, D. C.; Petersson, E. J. 

J. Am. Chem. Soc. 2014, 136, 2086-2093.


Efficient Synthesis and In Vivo Incorporation of Acridonylalanine, a Fluorescent Amino Acid for Lifetime and Förster Resonance Energy Transfer/Luminescence Resonance Energy Transfer Studies 

Speight, L. C.; Muthusamy, A. K.; Goldberg, J. M.; Warner, J. B.; Wissner, R. F.; Willi, T.; Woodman, B.; Mehl, R. A.; Petersson,     E. J. 

J. Am. Chem. Soc. 2013, 135, 18806-18814.


Expressed Protein Ligation at Methionine: N-terminal Attachment of Homocysteine, Ligation, and Masking

Tanaka, T.; Wagner, A. M.; Warner, J. B.; Wang, Y. J.; Petersson, E. J. 

Angew. Chem. Int. Ed. 2013, 52, 6210-6213.


Labeling Proteins with Fluorophore/Thioamide FRET Pairs by Combining Unnatural Amino Acid Mutagenesis and Native Chemical Ligation

Wissner, R. F.; Batjargal, S.; Fadzen, C. M.; Petersson, E. J. 

J. Am. Chem. Soc. 2013, 135, 6529-6540.


Thioamide Quenching of Fluorescent Probes Through Photoinduced Electron Transfer: Mechanistic Studies and Applications

Goldberg, J. M.; Batjargal, S.; Chen, B. S.; Petersson, E. J. 

J. Am. Chem. Soc. 2013, 135, 18651-18658.

Office Location

350 N



Admin Support

Department of Chemistry

231 S. 34 Street, Philadelphia, PA 19104-6323

215.898.8317 voice | 215.573.2112 fax | web@chem.upenn.edu