Interaction between FABP and a biological membrane. Computational Study of the Electrostatic contributions to the binding mechanism.

FERNANDO ZAMARREÑO; LISANDRO FALOMIR; BETINA CÓRSICO; MARCELO D. COSTABEL

Buzios

Congreso; VII Iberoamerican Congress of Biophysics; 2009

Federación Latinoamericana de Sociedades de Biofísica, Sociedad Portuguesa de Biofísica y Sociedad Española de Biofísica.

The study of several proteins implicated in processes of lipid solubilization is important in biomedicine because they are also examples of macromolecules interacting with membranes. An example of this kind of proteins is fatty acid binding protein (FABP). Particularly intestinal fatty acid binding protein (IFABP) is a protein that belongs to this family of intracellular lipid binding proteins of low molecular weight (14-15 kD) with the general function of lipid trafficking. However, the precise physiological functions of these proteins are yet unclear, but it is hypothesized that they are important in intracellular transport and targeting of FA to specific membranes and metabolic pathways. To get insight into the mechanism of the interaction between IFABP and membranes, we modeled the process by computer simulation with IFABP in different orientations and for different protein membrane distances By using the Finite Difference Poisson Boltzmann Equation (FDPB) implemented in the software APBS, we computed the energy involved in the interaction IFABP-membrane, and we show that binding of IFABP to membranes involves a significant electrostatic component that discriminates among possible membrane bound models and suggests, in each case, a favored orientation of IFABP in the interaction.