Sharon Hammes-Schiffer

Sharon Hammes-Schiffer (born May 27, 1966) is a physical chemist who has contributed to theoretical and computational chemistry. She is currently the John Gamble Kirkwood Professor of Chemistry at Yale University.[1] She has served as senior editor and deputy editor of the Journal of Physical Chemistry[2] and advisory editor for Theoretical Chemistry Accounts.[3] Since As of 1 January 2015 she is editor-in-chief of Chemical Reviews.[2]

Sharon Hammes-Schiffer
Born
Sharon Hammes-Schiffer

May 27, 1966 (1966-05-27) (age 54)
Ithaca, New York, United States
NationalityAmerican
Alma materPrinceton University
Stanford
Known forComputational chemistry
AwardsNational Academy of Sciences (2013)
Scientific career
FieldsChemistry
InstitutionsYale University
Websitehttp://www.hammes-schiffer-group.org/

Hammes-Schiffer studies "chemical reactions in solution, in proteins and at electrochemical interfaces, particularly the transfer of charged particles driving many chemical and biological processes."[4] Her research draws upon the areas of chemistry, physics, biology, and computer science and is significant for the fields of biochemistry, inorganic chemistry, physical chemistry and physical organic chemistry. A theoretician who works with computational models, Hammes-Schiffer blends classical molecular dynamics and quantum mechanics into theories that have direct relevance to a variety of experimental areas. In studying proton, electron and proton coupled electron transfer, Hammes-Schiffer has formulated a general theory of proton-coupled electron transfer reactions that explains the behavior of protons in energy conversion processes.[2][5][6] Her research has enhanced the understanding of hydrogen tunneling and protein motion in enzyme catalysis.[3][7] Her research group has also developed a nuclear-electronic orbital approach that allows scientists to incorporate nuclear quantum effects into electronic structure calculations.[7] Her work has application to a variety of experimental results and has implications for areas such as protein engineering, drug design,[8] catalyst of solar cells, and enzymatic reactions.[4]

Early life and education

Hammes-Schiffer completed her B.A. in chemistry at Princeton University in 1988. She completed her Ph.D. in chemistry at Stanford University in 1993 after working with Hans C. Andersen.[1][2][3] She then worked with John C. Tully at AT&T Bell Laboratories as a postdoctoral research scientist.[3]

Career

Hammes-Schiffer held positions on the faculty at the University of Notre Dame as Clare Boothe Luce Assistant Professor of Chemistry and Biochemistry (1995-2000) and at Pennsylvania State University (2000-2012).[3][9] As of 2012 she joined the University of Illinois at Urbana-Champaign as Swanlund Professor of Chemistry[8] where she leads the Hammes-Schiffer Research Group.[10] Hammes-Schiffer is an author or co-author on nearly 200 papers, and has given more than 200 invited talks.[11]

Research

Hammes-Schiffer's work delves primarily into three separate areas of chemistry: Proton-coupled electron transfer (PCET), Enzymatic Processes, and the Nuclear-Electronic Orbital method.[12] A sect of this research engages in the study of the Kinetic isotope effect, a difference in the reaction rate of a chemical based on what isotope is present.

Proton-coupled electron transfer (PCET)

The application of her work in PCET has elucidated the nature of various chemical mechanisms and led to her temperature dependence model of PCET rates.[13][14] One such process, Quinol Oxidation, studied the Kinetic isotope effect on Ubiquinol and Plastoquinol with regards to temperature, finding that the free energy of activation is greater for hydrogen than for deuterium, meaning the reaction is slower for hydrogen and therefore irreversible, if specific conditions are satisfied.[15] This finding has since been used by other investigators to reinforce the notion that reactions may or may not be unidirectional by influencing reaction rates with the kinetic isotope effect.[16] Additionally, her study of PCET in Iron Bi-imidazoline complexes has refined common comprehension of PCET, having proven her theory that electron transfer rate increases under the kinetic isotope effect as "the proton transfer distance increases and the electron transfer distance decreases."[17] These mechanisms have helped support the research of other PCET studies, with her main PCET paper, "Theoretical Studies of Proton-Coupled Electron Transfer Reactions",[13] having been cited over 90 times by papers ranging from studying protein motion to enzyme dynamics.[18]

Enzymatic processes

Hammes-Schiffer studies the effects of quantum tunnelling and hydrogen bonding on enzymatic reactions. Her work on Soybean Lipoxygenase-1 changed common perception of a previously proposed tunneling region diagram,[19] finding that the temperature dependence of KIEs are inversely proportional to each other and that active environmental dynamics leads to less of the KIE and promotes catalysis.[20] This finding should be applicable to any other enzymes which can transfer a proton due to the fact that there aren't as many enzymatic options for non-ionic transfer of a proton and therefore tunneling must be used throughout the process.[20]

Nuclear-electronic orbital method (NEO)

Hammes-Schiffer has also pioneered work in what she calls the Nuclear-electronic orbital method (NEO) which allows for a more accurate estimate of nuclear properties such as density, geometry, frequencies, electronic coupling, and nuclear motions.[21] As described in her paper, "Incorporation of Nuclear Quantum effects in electronic structure," Radial basis function kernel, a gaussian algorithm used to support vector machines, is applied to determine electronic and molecular orbitals. The NEO approach is specifically applicable in determining the exact mechanisms of hydrogen transfer reactions while accounting for other variables such as quantum tunneling and zero point energy. Hammes-Schiffer claims that the NEO approach is significantly advantageous over other methods that incorporate nuclear quantum effects because of the method's ability to calculate vibrational states, its avoidance of Born–Oppenheimer approximation and its apparent and inherent incorporation of quantum effects.[22]

In her study, published in September 2016, Hammes-Schiffer contributed towards discovering the effects of the active site of the magnesium ion in the Scissile Phosphate cofactor complex. She discovered that rather than the magnesium ion lying in the center of the complex, the ion lies in a separate site, termed the Hoogsteen Face, where it lowers the pKa of the complex in order to facilitate a deprotonation reaction necessary for a self-cleavage reaction.[23]

Honors and awards

Hammes-Schiffer is a Fellow of the American Physical Society (2010), the American Chemical Society (2011), the American Academy of Arts and Sciences (2012), the American Association for the Advancement of Science (2013), the National Academy of Sciences (2013), and the Biophysical Society (2015).[1] She was elected as a member of the International Academy of Quantum Molecular Science in 2014.[4][6][7]

Hammes-Schiffer has received a number of awards, including the following:

References
  1. "Sharon Hammes-Schiffer named the inaugural Kirkwood Professor of Chemistry". Hammes-Schiffer Research Group. Yale University. Retrieved 15 February 2018.
  2. "Sharon Hammes-Schiffer joins Chemical Reviews as new editor-in-chief". ACS Chemistry for Life. American Chemical Society. December 2, 2014.
  3. "2005 Iota Sigma Pi Agnes Fay Morgan Research Award" (PDF). Iota Sigma Pi: National Honor Society for Women in Chemistry. Retrieved 15 June 2015.
  4. "Sharon Hammes-Schiffer and So Hirata Elected Members of IAQMS". Chemistry at Illinois. University of Illinois at Urbana-Champaign. Retrieved 15 June 2015.
  5. Hammes-Schiffer, Sharon (21 December 2009). "Theory of Proton-Coupled Electron Transfer in Energy Conversion Processes". Accounts of Chemical Research. 42 (12): 1881–1889. doi:10.1021/ar9001284. PMC 2841513. PMID 19807148.
  6. "Sharon Hammes-Schiffer Elected International Academy of Quantum Molecular Science Member". PNNL. Pacific Northwest National Laboratory. 2014. Retrieved 15 June 2015.
  7. "Sharon Hammes-Schiffer". IAMQS. Retrieved 15 June 2015.
  8. "Sharon Hammes-Schiffer Joins Chemistry at Illinois". Chemistry at Illinois. University of Illinois at Urbana-Champaign. 2011. Retrieved 15 June 2015.
  9. "Sharon Hammes-Schiffer". Chemistry at Illinois. University of Illinois at Urbana-Champaign. Retrieved 15 June 2015.
  10. "The Hammes-Schiffer Research Group". University of Illinois at Urbana-Champaign. Retrieved 15 June 2015.
  11. Hammes-Schiffer, Sharon. "Curriculum Vitae" (PDF). University of Illinois at Urbana-Champaign. Retrieved 15 June 2015.
  12. "Research Overview – Hammes-Schiffer Research Group". hammes-schiffer-group.org. Retrieved 2016-11-05.
  13. "Proton-Coupled Electron Transfer – Hammes-Schiffer Research Group". hammes-schiffer-group.org. Retrieved 2016-11-06.
  14. Knapp, Michael J.; Rickert, Keith; Klinman, Judith P. (2002-04-17). "Temperature-dependent isotope effects in soybean lipoxygenase-1: correlating hydrogen tunneling with protein dynamics". Journal of the American Chemical Society. 124 (15): 3865–3874. doi:10.1021/ja012205t. ISSN 0002-7863. PMID 11942823.
  15. Ludlow, Michelle K.; Soudackov, Alexander V.; Hammes-Schiffer, Sharon (2009-05-27). "Theoretical Analysis of the Unusual Temperature Dependence of the Kinetic Isotope Effect in Quinol Oxidation". Journal of the American Chemical Society. 131 (20): 7094–7102. doi:10.1021/ja9001184. ISSN 0002-7863. PMC 2710000. PMID 19351186.
  16. Liu, Yi; Roth, Justine P. (2016-01-08). "A Revised Mechanism for Human Cyclooxygenase-2". Journal of Biological Chemistry. 291 (2): 948–958. doi:10.1074/jbc.M115.668038. ISSN 0021-9258. PMC 4705412. PMID 26565028.
  17. Iordanova, Nedialka; Decornez, Hélène; Hammes-Schiffer, Sharon (2001-04-01). "Theoretical Study of Electron, Proton, and Proton-Coupled Electron Transfer in Iron Bi-imidazoline Complexes". Journal of the American Chemical Society. 123 (16): 3723–3733. doi:10.1021/ja0100524. ISSN 0002-7863. PMID 11457104.
  18. pubmeddev. "Cited In for PubMed (Select 11942823) - PubMed - NCBI". www.ncbi.nlm.nih.gov. Retrieved 2016-11-07.
  19. Jonsson, Thorlakur; Glickman, Michael H.; Sun, Shujun; Klinman, Judith P. (1996-01-01). "Experimental Evidence for Extensive Tunneling of Hydrogen in the Lipoxygenase Reaction: Implications for Enzyme Catalysis". Journal of the American Chemical Society. 118 (42): 10319–10320. doi:10.1021/ja961827p. ISSN 0002-7863.
  20. Knapp, Michael J.; Rickert, Keith; Klinman, Judith P. (2002-04-01). "Temperature-Dependent Isotope Effects in Soybean Lipoxygenase-1: Correlating Hydrogen Tunneling with Protein Dynamics". Journal of the American Chemical Society. 124 (15): 3865–3874. doi:10.1021/ja012205t. ISSN 0002-7863. PMID 11942823.
  21. "Nuclear Electronic Orbital Method – Hammes-Schiffer Research Group". hammes-schiffer-group.org. Retrieved 2016-11-08.
  22. Webb, Simon P.; Iordanov, Tzvetelin; Hammes-Schiffer, Sharon (2002-09-01). "Multiconfigurational nuclear-electronic orbital approach: Incorporation of nuclear quantum effects in electronic structure calculations". The Journal of Chemical Physics. 117 (9): 4106–4118. Bibcode:2002JChPh.117.4106W. doi:10.1063/1.1494980. ISSN 0021-9606.
  23. Zhang, Sixue; Stevens, David R.; Goyal, Puja; Bingaman, Jamie L.; Bevilacqua, Philip C.; Hammes-Schiffer, Sharon (6 October 2016). "Assessing the Potential Effects of Active Site Mg Ions in the Ribozyme–Cofactor Complex". The Journal of Physical Chemistry Letters. 7 (19): 3984–3988. doi:10.1021/acs.jpclett.6b01854. PMC 5117136. PMID 27677922.
  24. "NSF logoFaculty Early Career Development (CAREER) Awards". National Science Foundation. Retrieved 15 June 2015.
  25. Wang, Linda (November 24, 2008). "Akron Section Award Goes To Sharon Hammes-Schiffer". Chemical & Engineering News. 86 (47).

Further reading
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