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Theoretical and Computational Biophysics Seminar: Professor Wonpil Im

Event Type
Beckman 3269 - 3rd Floor Tower Room
Dec 9, 2019   3:00 pm  
Professor Wonpil Im, Departments of Biological Sciences and Bioengineering, Lehigh University
Donna Fackler
Originating Calendar
Beckman Insititute Calendar (only)

Bacterial Outer Membranes and Interactions with Membrane Proteins”


The outer membrane of gram-negative bacteria is a unique asymmetric membrane bilayer that is composed of phospholipids in the inner leaflet and lipopolysaccharides (LPS) in the outer leaflet. Its function as a selective barrier is crucial for the survival of bacteria in many distinct environments, and it also renders gram-negative bacteria more resistant to antibiotics than their gram-positive counterparts. LPS comprises three regions: lipid A, core oligosaccharide, and O-antigen polysaccharide. In this talk, I will present our ongoing efforts to understanding various bacterial outer membranes and their interactions with outer membrane proteins. In addition, I will also present other research projects in my lab, such as the CHARMM-GUI development, a local structure-centric bioinformatics for drug development, and structure-based computational glycobiology.


Gram-negative bacterial outer membrane molecular complexity. This image illustrates a typical E. coli outer membrane. The bilayer is composed of (from the top, external leaflet) glycosylated amphipathic molecules known as lipopolysaccharide (LPS) consisting of an O-antigen polysaccharide, a core oligosaccharide, and lipid A and (the bottom, periplasmic leaflet) consisting of various phospholipid molecules. The cyan atoms interspersed with the core oligosaccharides are calcium atoms, which immobilize the membrane by mediating the cross-linking electrostatic interaction network. K+ and Cl- ions are magenta and green spheres.


Research in our group is focused on the applications of theoretical/computational methods to chemical and physical problems in biology and material science.

  • Protein/peptide interactions with/in biological membranes
  • Transmembrane-induced signaling and regulation
  • NMR structure calculation & refinement
  • Modeling and simulation of glycoconjugates (GlycanStructure.ORG)
  • Bacterial outer membranes and interactions with proteins
  • Protein-ligand and protein-protein interactions (G-LoSA)
  • In addition, we are involved in developing the biomolecular simulation program CHARMM and its user interface CHARMM-GUI as well as ST-analyzer, a general graphical user interface toolset for simulation trajectory analysis.


2:30 pm: Coffee hour Theoretical and Computational Biophysics Group area, 3rd Floor Beckman

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