Christine P PiroAssociate Professor of Chemistry, Bonchek College House Don
Education
A.B. in Chemistry and Mathematics, Vassar College. PIs: Prof. Miriam Rossi and Prof. Joseph Tanski
PhD. in Biological Chemistry, Massachusetts Institute of Technology. PIs: Prof. Catherine L. Drennan and Prof. Collin M. Stultz.
Postdoctoral Research Assistant, University of California, Berkeley and The Scripps Research Institute. PI: Prof. Michael A. Marletta.
Research
Work in my lab uses a variety of biochemical techniques to understand protein function and X-ray crystallography to analyze protein structure. In general, I am interested in the utilization of non-canonical or unnatural amino acids to study protein structure and function, and more broadly how cells sense and respond to their environment.
Non-canonical amino acids to study protein structure and tune protein function
Amino acids can be thought of as the building blocks of life—they can be put together to form unique peptides or proteins with distinct structures and functions. There are 20 naturally occurring amino acids and a few additional amino acid variants that our cells are able to make by modifying the initial 20 amino acids. Scientists continue to expand the alphabet of amino acids by chemically synthesizing amino acids that are not made in nature—these are often called non-canonical amino acids (ncAAs) or unnatural amino acids (UAAs). This expanded alphabet provides biochemists with additional tools to both explore protein structure and tune protein function. A large portion of the work in my lab focuses on the development, characterization, and utilization of ncAAs to do exactly this – better understand protein structures (Area A) and alter protein functions (Area B). I also have an interest in small molecule and ion sensing proteins (Area C). Areas A and B are largely done in collaboration with my colleagues Prof. Scott Brewer and Prof. Edward Fenlon Central to all of this scholarship is the mentoring of and collaboration with undergraduate researchers.
Area A: Develop, characterize, and utilize ncAAs or other small molecules with vibrational reporters to study protein structure. Vibrational reporters in protein systems are functional groups made of a few atoms (e.g. nitriles CN or azides N3) whose infrared (IR) spectroscopic signals are outside the range of the normal functional groups present in a protein (e.g. carbonyls C=O, amides NH, and alcohols OH) (Figure 3). The exact location or frequency of the IR signals for these reporters will change according to local solvation, hydrogen bonding, and electrostatic environments. Using protein-binding small molecules or ncAAs with vibrational reporter functional groups attached, local environments in proteins can be explored site-specifically.
Area B: Using ncAAs to investigate and tune protein function. In addition to using ncAAs to study protein structure, we are utilizing them to tune the functionality of a number of protein systems. Using a variety of phenylalanine-derived ncAAs we have altered the photophysical properties of GFP. We are currently working to tune the oxygen binding affinity of the heme nitric oxide and/or oxygen binding (H-NOX) protein using a variety of tyrosine-derived ncAAs.
Area C: Sensing of small molecules and ions. All organisms have mechanisms to sense their environment and relay that signal to cause an appropriate response (e.g., altered metabolism or gene expression, movement away from a toxin or towards nutrients). The goals in these projects are to biochemically and structurally characterize proteins involved in sensing and signaling pathways.
Grants & Awards
Dreyfus Foundation Henry Dreyfus Teacher-Scholar Award TH-21-007, “Building Tools and Engineering Functionality: Utilizing Unnatural Amino Acids to Study Proteins”, 2022 – 2026, $75,000 (PI)
NSF CAREER Award 1847937, “CAREER: Probing Structure and Expanding Function with Genetically Encoded Non-Canonical Amino Acids”, September 2019 – August 2024, $515,000 (PI)
NIH R15 Academic Enhancement Award R15GM121984, “Monitoring and tuning a gas-binding heme protein with unnatural amino acids”, September 2016 – August 2019, $371,714 (PI)
Research Corporation Single-Investigator Cottrell College Science Award 23662, “Sensing of halogenated pollutants by Dehalococcoides mccartyi” July 2014 – June 2016, $35,000 (PI)
APS General User Award, provides access to free synchrotron time at APS at Argonne National Lab to collect X-ray diffraction data, five awards over 2014 – 2019 (PI)
Publications
F&M Undergraduate co-authors are in bold and corresponding authors are indicated with an asterisk.
Broughton, D. P.; Holod, C. G.; Camilo-Contreras, A.; Harris, D. R.;Brewer, S. H.; Phillips-Piro, C. M. Modulating the pH Dependent Photophysical Properties of Green Fluorescent Protein. RSC Advances,2024, 14, 32284-32291.
Lee, B. L.; Papoutsis, B. M.; Wong, N. Y.; Piacentini, J.; Kearney, C.; Huggins, N. A.; Cruz, N.; Ng, T. T.; Hao, K. H.; Kramer, J. S.; Fenlon, E. E.; Nerenberg, P. S.*; Phillips-Piro, C. M.*; Brewer, S. H.* Unraveling Complex Local Protein Environments with 4-Cyano-L-phenylalanine. Journal of Physical Chemistry B, 2022, 126, 8957-8969.
Olenginski, G.M., Piacentini, J., Harris, D., Runko, N., Papoutsis, B.M., Alter, J., Hess, K.R., Brewer, S.H.*, and Phillips-Piro, C.M.* Structural and spectrophotometric investigation of two unnatural amino acid altered chromophores in the superfolder green fluorescent protein. Acta Crystallographica D, 2021, D77, 1010-1018.
Luo, M., Eaton, C., Hess, K.R., Phillips-Piro, C.M.*, Brewer, S.H.*, and Fenlon, E.E.* Paired Spectroscopic and Crystallographic Studies of Protease Active Sites. Chemistry Select, 2019, 4, 9836-9843
Maurici, N., Savidge, N., Lee, B., Brewer, S.H., and Phillips-Piro, C.M.* Crystal structures of GFP with unnatural amino acid 4-nitro-L-phenylalanine. Acta Crystallographica F, 2018, F74, 650-655.
Kearney, C.; Olenginski, L. T., Hirn, T. D.; Fowler, G. D.; Tariq, D.; Brewer, S. H.*; Phillips-Piro, C. M.* Exploring Local Solvation Environments of a Heme Protein using the Spectroscopic Reporter 4-Cyano-L-phenylalanine. RSC Advances 2018, 8, 13503-13512.
Dippel, A.B.; Olenginski, G.M.; Maurici, N.; Liskov, M. T.; Brewer, S. H.*; and Phillips-Piro, C.M.* Probing the effectiveness of spectroscopic reporter unnatural amino acids: a structural study. Acta Cryst. D. 2016, D72, 121-130.
Tookmanian, E.M.; Phillips-Piro, C.M.*; Fenlon, E.E.*; and Brewer, S.H.* Azidoethoxyphenylalanine as a Vibrational Reporter and Click Chemistry Partner in Proteins. Chemistry–A European Journal 2015, 21, 19096-19103.
Student Collaborators
(listed by graduation year)
2026 - Gabe Butler, Liah Perez
2025 - Connor Brooks, Campbell Kelly, Kat Patitucci
2024 - David Broughton
2023 - Amelia McDowell, Jason Rienzo, James Georgetson, Aaron Bram
2022 - Nathan Wong, Muya Li, Sarah Schick, Pratiksha Mishra, Chloe Holod
2021 - Angelica Camilo, Brianna Papoutsis, Christian Bogardus, Lea Dungan
2020 - Darcy Harris, Nicolette Runko
2019 - ByungUk (Mike) Lee
2018 - Trexler Hirn, Maggie Luo
2017 - Caroline Kearney, Juliana Piacentini, Nicole Savidge
2016 - Nicole Maurici, Daniyal Tariq, Jordan Alter, Carolina Giraldo
2015 - Gregory Olenginski, Lukasz Olenginski, Elise Tookmanian
2014 - Andrew Dippel, Austin Zimmet
2013 - Brittany Sembler, Melanie Liskov
Courses Taught
CHM 111 - General Chemistry I: Picturing the Atomic World, Lecture & Lab
CHM 112 - General Chemistry II: Reactions in the Atomic World, Lecture & Lab
CHM 351 - Introductory Biochemistry: Chemistry of Life, Lecture & Lab
CHM 451 - Advanced Biochemistry: Biochemical and Biophysical Techniques
CNX 164 - #Science: Engaging the Public
In the News
Student Researcher Helps Develop Tool for Biochemists