Sticholysin I - membrane interaction: an interplay between the presence of sphingomyelin and membrane fluidity

LOHANS PEDRERA PUENTES; MARIA L. FANANI; URIS ROS QUINCOCES; MARÍA E. LANIO; BRUNO MAGGIO; CARLOS ÁLVAREZ VALCÁRCEL

ELSEVIER SCIENCE BV

Lugar: Amsterdam; Año: 2014 vol. 1838 p. 1752 - 1752

ticholysin I (St I) is a pore-forming toxin (PFT) produced by the Caribbean Sea anemone Stichodactyla helianthus belonging to the actinoporin protein family, a unique class of eukaryotic PFT exclusively found in sea anemones. As for actinoporins, it has been proposed that the presence of sphingomyelin (SM) and the coexistence of lipid phases increases binding to the target membrane. However, little is known about the role of membrane structure and dynamics (phase state, fluidity, presence of lipid domains) on actinoporins? activity or which regions of the membrane are the most favourable platforms for protein insertion. To gain insight into the role of SM on the interaction of St I to lipid membranes we studied their binding to monolayers of phosphatidylcholine (PC) and SM in different proportions. Additionally, the effect of acyl chain length and unsaturation, two features related to membrane fluidity, was evaluated on St I binding to monolayers. This study revealed that St I binds a