Faculty

  • Chae Un Kim (김채운)

  • Assistant Professor
  • High pressure X-ray science and Biophysics
  • Current Research Interests

    X-ray Science, Biophysical Science, Biomedical Science: X-ray Diffraction, Protein Structures and Functions, X-ray Imaging of Biological Assemblies.

    Glassy water at cryogenic temperatures
    For decades, physicists, physical chemists, and biologists have been tremendously intrigued by the unusual thermodynamic and kinetic properties of supercooled water. Theories have been proposed to account for the properties but these theories remain contentious for lack of experimental evidence. We investigate phase behaviors of water at cryogenic temperatures, especially high-density amorphous (HDA) ice and its glass-to-cryogenic liquid transition. The results will contribute to developing delicate theoretical models of water.

    Biophysical study on protein function and dynamics
    Protein crystals used in X-ray protein crystallography have properties that distinguish them from typical inorganic crystals. An important difference is that protein crystals contain internal water, typically comprising 40 to 60 % of the volume of the crystal. This internal water forms solvent channels inside protein crystals and fills the significant void volume between the folded protein molecules that compose the crystal. We investigate the protein-water interactions inside protein crystals using X-ray diffraction. The results will be helpful to understand the physical origin of protein dynamics in relation to water-protein interactions.

  • Biographical Sketch

    Academic Career

    • Assistant Professor (2014 – present)
    • Department of Physics, Ulsan National Institute of Science and Technology Staff Scientist (2009-2014)
    • MacCHESS at the Cornell High Energy Synchrotron Source (CHESS), Cornell University Postdoctoral Associate (2008)
    • MacCHESS at the Cornell High Energy Synchrotron Source (CHESS), Cornell University Supervised by Dr. Sol M. Gruner and Dr. Richard A. Cerione

    Education

    • Ph.D. in Biophysics, Cornell University, Ithaca, NY (2002 – 2008)
    • High Pressure Cryocooling for Macromolecular Crystallography (Dr. Sol M. Gruner, advisor)
    • B.S in Physics, Seoul National University, South Korea (1995 – 1999)
    • Summa Cum Laude (Ranked No.1 in physics department)
  • Selected Publications
    1. Chae Un Kim, HyoJin Song, Balendu S. Avvaru, Sol M. Gruner, Sang Youn Park, and Robert McKenna. Tracking solvent and protein movement during CO2 release in carbonic anhydrase II crystals. Proc. Natl. Acad. Sci. USA113, 5257–5262 (2016).
    2. Chae Un Kim, Mark W. Tate, and Sol M. Gruner. Glass-to-cryogenic-liquid transitions in aqueous solutions suggested by crack healing. Proc. Natl. Acad. Sci. USA (2015) 112, 11765–11770.
    3. Chae Un Kim, Jennifer L. Wierman, Richard Gillilan, Enju Lima, Sol M. Gruner. A high pressure cryocooling method for protein crystals and biological samples with reduced background X-ray scatter, J. Appl. Cryst. (2013) 46, 234-241
    4. Chae Un Kim, Mark W. Tate and Sol M. Gruner. Protein dynamical transition at 110 K, Proc. Natl. Acad. Sci. USA (2011) 108, 20897-20901
    5. Chae Un Kim, Buz Barstow, Mark W. Tate and Sol M. Gruner. Evidence for liquid water during the high-density to low-density amorphous ice transition, Proc. Natl. Acad. Sci. USA (2009) 106, 4596-4600.
    6. Chae Un Kim, Yi-Fan Chen, Mark W. Tate and Sol M. Gruner. Pressure induced high-density amorphous ice in protein crystals, J. Appl. Cryst. (2008) 41, 1-7.
    7. Chae Un Kim, QuanHao and Sol M. Gruner. High pressure cryocooling for capillary sample cryoprotection and diffraction phasing at long wavelengths, ActaCryst. (2007) D63, 653-659.
    8. Chae Un Kim, QuanHao and Sol M. Gruner. Solution of protein crystallographic structures by high pressure cryocooling and noble gas phasing, ActaCryst. (2006) D62, 687-694.
    9. Chae Un Kim, Raphael Kapfer and Sol M. Gruner. High pressure cooling of protein crystals without cryoprotectants, ActaCryst. (2005) D61, 881-890.