NJIT
Physics Department Seminar
October 13th, 2014, Monday
Modeling Protein-Membrane
Interactions and Pore Formation
Prof. Themis Lazaridis
The City College of New York
(Biophysics,
Host: Dias)
Time: 11:45am-12:45pm with 11:30am tea time
Room: ECE 202
Abstract:
Biological membranes consist of a lipid bilayer
forming a hydrophobic barrier to uncontrolled ion movement. Protein-membrane
interactions are involved in numerous biological processes. Over the past
decade we developed a simplified approach for modeling such interactions in
which lipid molecules and water are taken into account implicitly, via a
solvation free energy term in the energy function. The membrane surface charge
is modeled by use of the Gouy-Chapman theory. The transmembrane voltage, the dipole potential, and
lateral pressure effects have also been incorporated into the model. An
overview of the applications of this approach to biological problems such as transmembrane
helix association or protein adsorption will be given. Of particular interest
to us is the process of pore formation, which is involved in protein
translocation, antibacterial action, cytotoxicity, and apoptosis. We developed
an implicit model for aqueous membrane pores and used it to obtain insights
into the mechanism of action of antimicrobial peptides. At the same time, all-atom
explicit molecular dynamics simulations of peptides in lipid bilayers have
provided an atomically detailed view of peptide-stabilized pores.