Reply to Comment on “Trehalose Interacts with Phospholipid Polar Heads in Langmuir Monolayers”

Trehalose interacts with phospholipid polar heads in Langmuir monolayers

Surface pressure−area isotherms, surface potential-area isotherms and fluorescence microscopy were employed to study the behavior of phospholipid monolayers at the air/water interface when trehalose was added to the aqueous subphase. In the presence of this sugar, the critical area corresponding to the onset of surface potential increases, indicating that trehalose is participating in the network of hydrogen bonds between the phospholipid polar heads. In addition, it causes an expansion of the isotherm, hindering the formation of the liquid-condensed phase. The collapse area is significantly increased, indicating that trehalose takes part in the monolayer structure without being expelled ev…

Amyloid fibrils formation and amorphous aggregation in Concanavalin A

We here report an experimental study on the thermal aggregation process of concanavalin A, a protein belonging to the legume lectins family. The aggregation process and the involved conformational changes of the protein molecules were followed by means of fluorescence techniques, light scattering, circular dichroism, zeta potential measurements and atomic force microscopy. Our results show that the aggregation process of concanavalin A may evolve through two distinct pathways leading, respectively, to the formation of amyloids or amorphous aggregates. The relative extent of the two pathways is determined by pH, as amyloid aggregation is favored at high pH values ( approximately 9), while th…