The protein farnesyltransferase from rat brain was previously shown to be inhibited competitively by tetrapeptides that conform to the consensus Cys-A1-A2-X, where A1 and A2 are aliphatic amino acids and X is methionine, serine, or phenylalanine. In the current studies we used a thin layer chromatography assay to show that most of these tetrapeptides are themselves farnesylated by the purified enzyme. Two classes of tetrapeptides are no farnesylated and therefore act as true inhibitors: 1) those that contain an aromatic residue at the A2 position and 2) those that contain penicillamine (β,β-dimethylcysteine) in place of cysteine. The most potent of these pure inhibitors was Cys-Val-Phe-Met, which inhibited farnesyltransferase activity by 50% at <0.1 μM. These data indicate that the inclusion of bulky aromatic or methyl residues in a tetrapeptide can abolish prenyl group transfer without blocking binding to the enzyme. This information should be useful in the design of peptides or peptidomimetics that inhibit farnesylation and thus block the action of p21(ras) proteins in animal cells.
|Original language||English (US)|
|Number of pages||4|
|Journal||Journal of Biological Chemistry|
|State||Published - Oct 29 1991|
ASJC Scopus subject areas
- Molecular Biology
- Cell Biology