title: NMR studies of novel inhibitors bound to farnesyl-protein transferase.
abstract: 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.
authors.affiliation: Department of Cancer Research, Merck Research Laboratories, West Point, Pennsylvania 19486, USA.
authors.forename: K S
authors.initials: KS
authors.lastname: Koblan
authors.forename: J C
authors.initials: JC
authors.lastname: Culberson
authors.forename: S J
authors.initials: SJ
authors.lastname: Desolms
authors.forename: E A
authors.initials: EA
authors.lastname: Giuliani
authors.forename: S D
authors.initials: SD
authors.lastname: Mosser
authors.forename: C A
authors.initials: CA
authors.lastname: Omer
authors.forename: S M
authors.initials: SM
authors.lastname: Pitzenberger
authors.forename: M J
authors.initials: MJ
authors.lastname: Bogusky
mesh_terms: D019883:Alkyl and Aryl Transferases; D000577:Amides / Q000737:chemistry* / Q000378:metabolism / Q000494:pharmacology; D000595:Amino Acid Sequence; D003196:Computer Graphics; D006801:Humans; D009682:Magnetic Resonance Spectroscopy; D008958:Models, Molecular; D008969:Molecular Sequence Data; D015394:Molecular Structure; D009842:Oligopeptides / Q000737:chemistry* / Q000378:metabolism / Q000494:pharmacology; D011485:Protein Binding; D011487:Protein Conformation; D017368:Protein Prenylation; D011994:Recombinant Proteins / Q000737:chemistry; D014166:Transferases / Q000037:antagonists & inhibitors* / Q000737:chemistry / Q000378:metabolism
chemical_list: D000577:Amides; C089417:L 739750; C094720:L 739787; D009842:Oligopeptides; D011994:Recombinant Proteins; C094719:cysteinyl-valyl-tryptophyl-methionine; D014166:Transferases; D019883:Alkyl and Aryl Transferases; C064911:p21(ras) farnesyl-protein transferase