Electrostatic interaction between AcylCoA Binding Protein and Hepatocyte Nuclear Factor-4. Computational indications of the union mechanism.

FERNANDO ZAMARREÑO; MARÍA J. AMUNDARAIN; 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.

Acyl-CoA binding proteins (ACBPs) are highly conserved 10 kDa cytosolic proteins that bind medium- and long-chain acyl-CoA esters. They act as intracellular carriers of acyl-CoA and play a role in acyl-CoA metabolism, gene regulation, acyl-CoA-mediated cell signaling, transport-mediated lipid synthesis, membrane trafficking. ACBPs were also indicated as a possible inhibitor of diazepam binding to the GABA-A receptor. Moreover, acyl-CoA binding protein (ACBP) has been also detected in the nucleus, although the behavior of this protein here in is not completly known. However, it has been shown that ACBP in the nucleus interacts with hepatocyte nuclear factor-4 (HNF-4 ), a nuclear binding protein that regulates transcription of genes involved in both lipid and glucose metabolism. In this work we propose the initial mechanism of interaction between ACBP and HNF-4 . We modeled the mechanism by using the Finite Difference Poisson Boltzmann Equation (FDPB) implemented in the software APBS, and computed the electrostatic energy involved in the interaction between both proteins for different relative configurations.