Article
Molecular Targeting of Inhibitor of Apoptosis Proteins Based on Small Molecule Mimics of Natural Binding Partners†
This work was supported by the National Institutes of Health under Grants GM59348-02 and F32 GM20804.
Department of Chemistry, Frick Laboratory.
Department of Molecular Biology, Lewis Thomas Laboratory.
To whom correspondence should be addressed. Telephone: (609) 258-6808. Fax: (609) 258-6746. E-mail: glm@princeton.edu.
Abstract
An assay based on a solvent-sensitive fluorogenic dye molecule, badan, is used to test the binding affinity of a library of tetrapeptide molecules for the BIR3 (baculovirus IAP repeat) domain of XIAP (X-linked inhibitor of apoptosis protein). The fluorophore is attached to a tetrapeptide, Ala-Val-Pro-Cys-NH2, through a thiol linkage and, upon binding to XIAP, undergoes a solvatochromic shift in fluorescence emission. When a molecule (e.g., a natural protein known to bind to XIAP or a tetrapeptide mimic) displaces the dye, the emission shifts back to the spectrum observed in water. As emission intensity is related to the binding of the tetrapeptide, the intensity can be used to determine the equilibrium constant, K, for the displacement of the dye by the tetrapeptide. The results permit residue-specific analysis of the interaction. Furthermore, we show that hydrophobic effects in the fourth position are general and can effectively increase overall affinity.
View: Full Text HTML | Hi-Res PDF
Tools
-
Add to Favorites
-
Download Citation
-
Email a Colleague -
Permalink
Order Reprints
Rights & Permissions
Citation Alerts
History
- Published In Issue June 11, 2002
- Received December 11, 2001
Revised Manuscript Received March 28, 2002
Cart


