Surface Properties of Insulin-DPPC/POPC mixed Langmuir monolayers

GRASSO, ERNESTO; RAFAEL GUSTAVO OLIVEIRA; MAGGIO, B.

Sierra de la Ventana

Congreso; 43º reunión Sociedad Argentina de Biofísica; 2014

Sociedad Argentina de Biofísica

The surface properties of the binary mixed Langmuir monolayers of Insulin and DPPC (dipalmitoylphosphatidylcholine) and POCP (palmitoyloleylphosphatidylcholine) spread at the air-water interface was studied. Pure and mixed monolayers were spread on Zn2+ containing solutions. Miscibility and interactions between the components were studied on the basis of the analysis of the surface pressure-mean molecular area isotherms, surface compressional modulus and plots of mean molecular area and surface potential versus mole fraction of Insulin. Our results indicate that the intermolecular interactions between Insulin and DPPC/POPC depend on both the monolayer state and the structural characteristics of Insulin at the interface, which is strongly influenced by the Zn2+ ions in the subphase (1). Brewster angle microscopy was applied to describe the surface topography of the monolayers. We concluded that Insulin forms mixed surfaces with DPPC/POPC at all the mole fraction studied.