142923-97-5Relevant articles and documents
Synthesis of high specific activity 35S-labelled N-methanesulfonyl farnesylcysteine and a photoactive analog
Kale, Tamara A.,Raab, Conrad,Yu, Nathan,Aquino, Evelyn,Dean, Dennis C.,Distefano, Mark D.
, p. 29 - 54 (2003)
Prenylated cysteine analogs, which mimic the prenylated cysteine residue of prenylated GTP-binding proteins (G-proteins), have been used in a variety of contexts for the study of prenylated G-protein behavior. In earlier work in this area, we prepared the photoactive analog [35S]4 and showed that it labelled RhoGDI upon photolysis; those results were consistent with the idea that GDI contains an isoprenoid binding site. Here, we describe the preparation of [35S]N-methanesulfonyl labelled analogs (1a and 2a) of N-acetyl farnesylcysteine and its methyl ester together with an improved synthetic procedure for photoactive analogs 3 and 4; specific activities of ～1100 Ci/mmol were achieved. Compounds 1a and 2a in unlabelled form were used as competitors in photolysis reactions to show that the methanesulfonamido group is a reasonable acetamide substitution. Additional experiments show that the photoactive ester [35S]3 can cross-link GDI in both purified form and crude bacterial extract. However, the extent of cross-linking obtained with the ester ([35S]3) is significantly less than that observed with the free acid ([35S]4) despite the fact that the esterified form probably more closely reflects the structure of the C-terminus of a prenylated protein; using the GDI·Cdc42 co-crystal structure, the structural basis for these results is discussed. Copyright
A photoactivatable prenylated cysteine designed to study isoprenoid recognition
Kale,Raab,Yu,Dean,Distefano
, p. 4373 - 4381 (2007/10/03)
Protein prenylation, involving the alkylation of a specific C-terminal cysteine with a C15 or C20 isoprenoid unit, is an essential posttranslational modification required by most GTP-binding proteins for normal biological activity. Despite the ubiquitous nature of this modification and numerous efforts aimed at inhibiting prenylating enzymes for therapeutic purposes, the function of prenylation remains unclear. To explore the role the isoprenoid plays in mediating protein-protein recognition, we have synthesized a photoactivatable, isoprenoid-containing cysteine analogue (2) designed to act as a mimic of the C-terminus of prenylated proteins. Photolysis experiments with 2 and RhoGDI (GDI), a protein which interacts with prenylated Rho proteins, suggest that the GDI is in direct contact with the isoprenoid moiety. These results, obtained using purified GDI as well as Escherichia coli (E. coli) crude extract containing GDI, suggest that this analogue will be an effective and versatile tool for the investigation of putative isoprenoid binding sites in a variety of systems. Incorporation of this analogue into peptides or proteins should allow for even more specific interactions between the photoactivatable isoprenoid and any number of isoprenoid binding proteins.
