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Biophysics of Proteins at Surfaces: Assembly, Activation, Signaling
Poster Abstracts
37-POS
Board 37
Pore Forming of Fragaceatoxin C into Membrane Studied by Coarse-grained Molecular
Dynamics Simulations
Khuong Truong
1,2,3
, Myunggi Yi
1,2,3
.
2
Center of Marine-integrated Biomedical Technology (BK21+), Pukyong National Uni, Busan,
South Korea,
1
Interdisciplinary Program of Biomedical, Electrical & Mechanical Engineering,
Pukyong National Uni, Busan, South Korea,
3
Marine Integrated Bionics Research Center,
Pukyong National Uni, Busan, South Korea,
4
Department of Biomedical Engineering, Pukyong
National Uni, Busan, South Korea.
Pore-forming toxins (PFT) are water-soluble proteins. They have ability to self-assemble on the
membrane. They form oligomeric transmembrane pores and this causes cell damage. Many
studies have determined crystal structures of fragaceatoxin C, a PFT protein, at different states,
monomer in water, monomer with lipid-bound, dimer on membrane and transmembrane pore.
However, the mechanisms of lipid binding and conformational changes of fragaceatoxin C are
still unclear. We carried out 4 coarse-grained molecular dynamics simulations of fragaceatoxin C
in different states (monomer, dimer, oligomer (2 systems: pre-pore and pore)) with lipid bilayer.
The bilayer was composed of a mixture of Sphingomyeline (SM) and DOPC lipid at molar ratio
1:1. Long time simulations were performed to observe self assembly of fragaceatoxin C.
Including monomer binding to membrane, two monomers bound to membrane making dimer
then forming oligomer (pre-pore) and finally pore forming into membrane. We will present these
self assemblies and corresponding conformational changes. These simulations provide molecular
insight into pore forming of PFT into membrane.