Invited Paper NT+BI-WeM5
Protein-induced Pores in Membranes Detected and Studied by Neutron Scattering

Wednesday, October 17, 2007, 9:20 am, Room 618

Gene encoded antimicrobial peptides kill bacteria by forming pores in the bacterial membranes. Apoptotic protein Bax forms pores in the outer mitochondrial membrane to release the apoptosis-inducing factor cytochrome c from mitochondria. The evidence of pore formation in membranes is usually ion conduction or leakage. The structure of a pore in a fluid membrane is difficult to detect or measure by conventional methods such as electron microscopy. Neutron scattering is uniquely suited for such structural studies. We will show neutron scattering from membrane pores made by antimicrobial peptides, alamethicin, magainin, protegrin as well as by bee venom toxin melittin. Surprisingly, these peptides form two different kinds of transmembrane pores first detected by neutron methods.