Choon Kim

Choon Kim


Research Assistant Professor, University of Notre Dame
Research Scientist, University of Notre Dame
Research Associate, The Rockefeller University
Postdoctoral Associate, The Rockefeller University
Ph.D. in Biochemistry, University of Notre Dame
M.S. in Biology, Chonnam National University, Korea
B.S. in Genetic Engineering, Chonnam National University, Korea

Research Interests

Methicillin-resistant Staphylococcus aureus (MRSA) is a nefarious human pathogen. It causes both hospital-acquired (HA-MRSA) and community-acquired (CA-MRSA) infections. MRSA kills approximately 11,000 individuals annually in the United States alone. About 80% of MRSA bacteria harbor a bla operon that consists of two regulatory genes, blaR1 and blaI, and a structural gene blaZ encoding a class A β-lactamase (BlaZ), a resistant determinant for β-lactam antibiotics. Dr. Kim recently identified for the first time that the staphylococcal BlaZ exists in two forms, one phosphorylated and another not phosphorylated. A remarkable feature of this discovery is that when the protein is phosphorylated, it is sequestered exclusively to the bacterial membrane by lipidation, whereas the non-phosphorylated form is excreted to the milieu. An intriguing observation pointed to the potential involvement of BlaZ in staphylococcal virulence. When the blaZ was removed from MRSA, it exhibited an increase of opsonophagocytic killing by neutrophil cells as well as a decrease in deposition of the complementary protein C3b.

Dr. Kim’s research focuses on the elucidation of the pathways that inhibition of phosphorylation of BlaZ would target for release from the S. aureus surface, leading to its loss as a virulence factor for the bacterium. We expect that our identification of the kinase(s) phosphorylating BlaZ will make it a target for inhibition that converts virulent strains to avirulent ones.

Recent Publications

  • Ceballos, S., Kim, C., Qian, Y., Mobashery, S., Chang, M., Torres, C. "Susceptibility of Methicillin-Resistant Staphylococcus aureus to Five Quinazolinone Antibacterials" 2020 Antimicrobial Agents and Chemotherapy, 64 (1), e01344-19. DOI:10.1128/AAC.01344-19.
  • Dik, D. A., Kim, C., Madukoma, C. S., Fisher, J. F., Shrout, J. D., Mobashery, S. "Fluorescence assessment of the ampr-signaling network of pseudomonas aeruginosa to exposure to β-lactam antibiotics" 2020 ACS Chemical Biology, 15 (5), pp. 1184-1194. DOI:10.1021/acschembio.9b00875.
  • Mahasenan, K. V., Batuecas, M. T., De Benedetti, S., Kim, C., Rana, N., Lee, M., Hesek, D., Fisher, J. F., Sanz-Aparicio, J., Hermoso, J. A., Mobashery, S. "Catalytic Cycle of Glycoside Hydrolase BglX from Pseudomonas aeruginosa and Its Implications for Biofilm Formation" 2020 ACS Chemical Biology, 15 (1), pp. 189-196. DOI:10.1021/acschembio.9b00754.
  • Dik, D. A., Madukoma, C. S., Tomoshige, S., Kim, C., Lastochkin, E., Boggess, W. C., Fisher, J. F., Shrout, J. D., Mobashery, S. "Slt, MltD, and MltG of Pseudomonas aeruginosa as Targets of Bulgecin A in Potentiation of β-Lactam Antibiotics" 2019 ACS Chemical Biology, in press. DOI:10.1021/acschembio.8b01025.
  • Speri, E., Kim, C., De Benedetti, S., Qian, Y., Lastochkin, E., Fishovitz, J., Fisher, J. F., Mobashery, S. "Cinnamonitrile adjuvants restore susceptibility to β-lactams against methicillin-resistant staphylococcus aureus" 2019 ACS Medicinal Chemistry Letters, 10 (8), pp. 1148-1153. DOI:10.1021/acsmedchemlett.9b00169.
  • Ceballos, S., Kim, C., Ding, D., Mobashery, S., Chang, M., Torres, C. "Activities of oxadiazole antibacterials against staphylococcus aureus and other gram-positive bacteria" 2018 Antimicrobial Agents and Chemotherapy, 62 (8), e00453-18. DOI:10.1128/AAC.00453-18.

Contact Information

  • Research Assistant Professor
  • Office: 352C McCourtney Hall
  • Phone: 574-631-2955
  • Send an email

Primary Research Areas

Research Specialties