Our group is interested in better defining the physiologic role for the iLBP that is specifically associated with binding bile acids, FABP6. This work has included a careful analysis of the ligand binding biophysics along with work implicating its interaction with the nuclear receptor FXR. This interest has migrated to understanding the detailed mechanism by which FABP5 can target ligands to the nuclear receptors PPARδ and RAR. In collaboration with Noa Noy, we have developed a novel class of lipids that target FABP5, and consequently modulate signaling of RAR. An additional area of iLBP physiology we are interested in is the detailed structure and energetics of how the iLBPs target ligands to nuclear receptors. Currently we have adopted a hypothesis that the helix-turn helix regions undergo an enthalpic rearrangement upon ligand binding that reveals a non-tradition nuclear localization sequence (NLS) that spans the two helices.

a. Badiee M, Tochtrop GP. Bile Acid Recognition by Mouse Ileal Bile Acid Binding Protein. ACS Chem Biol. 2017 12:3049-3056. PMID: 29058872

b. Horváth G, Bencsura Á, Simon Á, Tochtrop GP, DeKoster GT, Covey DF, Cistola DP, Toke O. Structural determinants of ligand binding in the ternary complex of human ileal bile acid binding protein   with glycocholate and glycochenodeoxycholate obtained from solution NMR. FEBS J. 2016 283:541-55. PMID: 26613247

c. Levi L, Lobo G, Doud MK, von Lintig J, Seachrist D, Tochtrop GP, Noy N. Genetic ablation of the fatty acid-binding protein FABP5 suppresses HER2-induced mammary tumorigenesis. Cancer       Res. 2013;73:477080. PMID: 4082958.

d. Tochtrop GP, DeKoster GT, Covey DF, Cistola DP. A single hydroxyl group governs ligand site selectivity in human ileal bile acid binding protein. J Am Chem Soc. 2004;126:11024-9. PMID: 15339188