Structural and dynamic studies on Pore Forming Toxins by NMR

Seminar

Title: Structural and Dynamic studies on Pore Forming Toxins by NMR

Speaker: Marta Bruix

Affiliation: Instituto de Quimica Fisica "Rocasolano", Madrid, Spain

Host: Ricardo Louro, Inorganic Biochemistry and NMR Lab

Abstract

Pore forming toxins (PFTs) are a large and interesting group of proteins that show cytotoxic effects, as they create unregulated pores in the membrane of targeted cells. Actinoporins are small PFTs that are expressed in a soluble monomeric form but oligomerize and change conformation upon membrane interaction leading to the formation of a functional pore and finally cell lysis. We are interested in the special behaviour of these proteins in the water-membrane interface.
In aqueous solution, actinoporins remain stably folded but, upon interaction with lipid complexes with a specific composition, they become integral membrane structures. We have used NMR methods, combined with molecular biology and biochemistry approaches, to better understand the mechanism of pore formation by this interesting family of proteins. On the basis of all obtained results, i) we propose specific roles for some residues in the actinoporin?s cytotoxic actions, and ii) a revised model for protein interaction with membranes and molecular association has been proposed.

• L. García-Ortega, L., J. Alegre-Cebollada, S. García-Linares, M. Bruix, A. Martínez-del-Pozo, and J.G. Gavilanes, Biochim. Biophys. Acta, Biomembranes 2011, 1808, 2275-2288.
• M.A. Pardo-Cea, I. Castrillo, J. Alegre-Cebollada, A. Martínez-del-Pozo, J.G. Gavilanes, and M. Bruix, FEBS J. 2011, 278, 2080-2089.
• I. Castrillo, S. García-Linares, A. Martínez-del-Pozo, J.G. Gavilanes, and M. Bruix, submitted (2012)
• I. Castrillo, N.A. Araujo, J. Alegre-Cebollada, J.G. Gavilanes, A. Martínez-del-Pozo, and M. Bruix. Proteins, 2010, 78, 1959-1970.