“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