NMR studies of novel inhibitors bound to farnesyl-protein transferase

Autor: J. Christopher Culberson, Steven M. Pitzenberger, Charles A. Omer, Michael J. Bogusky, Scott D. Mosser, Kenneth S. Koblan, S. Jane Desolms, E A Giuliani
Rok vydání: 2008
Předmět:
Zdroj: Protein Science. 4:681-688
ISSN: 1469-896X
0961-8368
DOI: 10.1002/pro.5560040408
Popis: Farnesyl-protein transferase (FPTase) catalyzes the posttranslational farnesylation of the cysteine residue located in the carboxyl-terminal tetrapeptide of the Ras oncoprotein. Prenylation of this residue is essential for the membrane association and cell-transforming activities of ras. Inhibitors of FPTase have been demonstrated to inhibit ras-dependent cell transformation and thus represent a potential therapeutic strategy for the treatment of human cancers. The FPTase-bound conformation of a tetrapeptide inhibitor, CVWM, and a novel pseudopeptide inhibitor, L-739,787, have been determined by NMR spectroscopy. Distance constraints were derived from two-dimensional transferred nuclear Overhauser effect experiments. Ligand competition experiments identified the NOEs that originate from the active-site conformation. Structures were calculated with the combination of distance geometry and restrained energy minimization. Both peptide backbones are shown to adopt nonideal reverse-turn conformations most closely approximating a type III beta-turn. These results provide a basis for understanding the spatial arrangements necessary for inhibitor binding and selectivity and may aid in the design of therapeutic agents.
Databáze: OpenAIRE