Synthesis of characteristic lipopeptides of the human N-Ras protein and their evaluation as possible inhibitors of protein farnesyl transferase

• Published in: Bioorganic & medicinal chemistry Vol. 5; no. 1; pp. 75 - 83
• Main Authors: Stöber, Paul, Schelhaas, Michael, Nägele, Edgar, Hagenbuch, Patrizia, Rétey, János, Waldmann, Herbert
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.01.1997
• Subjects: Alkyl and Aryl Transferases; Enzyme Inhibitors - chemical synthesis; Enzyme Inhibitors - pharmacology; Farnesyltranstransferase; Humans; Magnetic Resonance Spectroscopy; Mass Spectrometry; Peptides - chemical synthesis; Peptides - pharmacology; ras Proteins - chemistry; Transferases - antagonists & inhibitors
• ISSN: 0968-0896; 1464-3391
• DOI: 10.1016/S0968-0896(96)00213-1

Lipopeptides carrying a farnesyl thioether or a palmitic acid thioester and a farnesyl thioether were prepared from S-farnesyl cysteine methyl ester by N-terminal extension of the peptide chain employing the base labile Fmoc blocking group or the palladium(0) sensitive Aloc urethane. By means of this technique a lipohexapeptide representing the completely functionalized, i.e. palmitoylated and farnesylated C-terminus of the human N-Ras protein, was prepared. If acid labile blocking functions like the Boc group were used, upon deprotection an undesired addition of the acid to the double bonds of the farnesyl residue occurred. Therefore, acid labile blocking groups should not be employed in the synthesis of farnesylated lipopeptides. The lipopeptide methyl esters which carry only a farnesyl group do not inhibit protein farnesyl transferase, whereas palmitoylated peptides are weak inhibitors of this enzyme. [Display omitted]