University of Waterloo
200 University Avenue West
Waterloo, Ontario, Canada N2L 3G1
Phone: (519) 888-4567 ext 32215
Fax: (519) 746-8115
In Professor Ha's research group, they explore a few theoretical problems in soft matter and biophysics, namely, chromosomes in living cells and lipid bilayer membranes.
Office: PHY 372
Phone: 519 888-4567 ext. 47004
Chromosomes in living cells are strongly confined but show a high level of spatial organization. Recent experiments suggest that bacterial chromosomes behave as confined polymers and undergo abrupt compaction in a crowed medium. We have been exploring as model chromosomes confined polymers possibly with non-linear topology or cross-linking, and their compaction by crowding particles. For instance, we have shown how cylindrical confinement reshapes individual polymer chains and enhances their segregation, in the way seen in rod-shaped bacteria.
Lipid bilayer membranes, enclosing living cells, primarily serve as permeability barriers. As self-assembled structures, however, their permeability and stability can be altered by surrounding ions or molecules (e.g., Mg2+ and antimicrobial peptides). Along this line, lipopolysaccharide (LPS), which carries multiple negative charges, is the key surface component of Gram-negative bacteria, constituting the outer layer of their outer membrane or simply the LPS layer. If Mg2+ stabilizes the (negatively-charged) LPS layer, cationic antimicrobial peptides permeabilize it. Inspired by this long-standing observation, we have been interested in presenting a physical picture of how the LPS layer can be electrostatically modified.
Bae-Yeun Ha and Youngkyun Jung. "Polymers under confinement: single polymers, how they interact, and as model chromosomes". Soft Matter, 2015, 11, 2333-2352
Juin Kim, Chanil Jeon, Hawoong Jeong, Youngkyun Jung and Bae-Yeun Ha. "A polymer in a crowded and confined space: effects of crowder size and poly-dispersity". Soft Matter, 2015, 11, 1877-1888
Chanil Jeon, Juin Kim, Hawoong Jeong, Youngkyun Jung and Bae-Yeun Ha. "Chromosome-like organization of an asymmetrical ring polymer confined in a cylindrical space". Soft Matter, 2015, 11, 8179-8193
Azadeh Bagheri, Sattar Taheri-Araghi, and Bae-Yeun Ha. "How Cell Concentrations Are Implicated in Cell Selectivity of Antimicrobial Peptides". Langmuir, 2015, 31 (29), pp 8052–8062.
Please see Pubfacts for a complete list of Dr. Ha's publications.
1996 PhD Physics, University of Maryland, College Park, Maryland, U.S.A.
1986 MS Physics, Korea University, Seoul, Korea
1985 BS Physics, Korea University, Seoul, Korea
The University of Waterloo acknowledges that much of our work takes place on the traditional territory of the Neutral, Anishinaabeg and Haudenosaunee peoples. Our main campus is situated on the Haldimand Tract, the land granted to the Six Nations that includes six miles on each side of the Grand River. Our active work toward reconciliation takes place across our campuses through research, learning, teaching, and community building, and is centralized within our Office of Indigenous Relations.