Application of an allosteric model to describe the interactions among retinol binding protein 4, transthyretin, and small molecule retinol binding protein 4 ligands |
| |
Authors: | Coward Peter Conn Marion Tang Jie Xiong Fei Menjares Anthony Reagan Jeff D |
| |
Institution: | a Department of Metabolic Disorders, Amgen, South San Francisco, CA 94080, USA b Department of Protein Sciences, Amgen, South San Francisco, CA 94080, USA |
| |
Abstract: | Retinol binding protein 4 (RBP4) is a serum protein that serves as the major transport protein for retinol (vitamin A). Recent reports suggest that elevated levels of RBP4 are associated with insulin resistance and that insulin sensitivity may be improved by reducing serum RBP4 levels. This can be accomplished by administration of small molecules, such as fenretinide, that compete with retinol for binding to RBP4 and disrupt the protein-protein interaction between RBP4 and transthyretin (TTR), another serum protein that protects RBP4 from renal clearance. We developed a fluorescence resonance energy transfer (FRET) assay that measures the interaction between RBP4 and TTR and can be used to determine the binding affinities of RBP4 ligands. We present an allosteric model that describes the pharmacology of interaction among RBP4, TTR, retinol, and fenretinide, and we show data that support the model. We show that retinol increases the affinity of RBP4 for TTR by a factor of 4 and determine the affinity constants of fenretinide and retinyl acetate. The assay may be useful for characterizing small molecule ligands that bind to RBP4 and disrupt its interaction with TTR. In addition, such a model could be used to describe other protein-protein interactions that are modulated by small molecules. |
| |
Keywords: | Retinol binding protein Transthyretin FRET Allosteric modulator Structure-activity relationship |
本文献已被 ScienceDirect PubMed 等数据库收录! |
|