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. 37004
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