Synthesis and Biological Activity of Photoactivatable N-Ras Peptides and Proteins
摘要:
A modular strategy for the assembly of farnesylated N-Ras heptapeptides carrying a photo-activatable benzophenone (BP) group within the lipid residue is described. This strategy is based on the fragment condensation of a N-terminal hexapeptide synthesized on the solid support with a cysteine methyl ester which is modified with different farnesyl analogues, incorporating the photophor. At the N-terminus of the peptides different functional groups can be attached, e.g., biotin for product enrichment and detection after photoactivation or a maleimido (MIC) linker, allowing for the coupling to proteins carrying a C-terminal free cysteine. Using this strategy, 24 peptides were synthesized, incorporating famesyl analogues with four different chain lengths. Two of these photoactivatable conjugates were ligated to oncogenic human N-RasG12VDelta181. A cellular transformation assay revealed that the semisynthetic proteins retain their biological activity despite the photolabel. The first photolabeling experiments with a geranyl-BP-labeled N-Ras construct and the farnesyl-sensitive guanine nucleotide exchange factor hSos1 indicate that this photoaffinity labeling system can be particularly useful for studying protein-protein interactions, e.g., the participation of the farnesyl group in Ras signaling, which is still discussed with controversy.
Benzoylphenoxy analogs of isoprenoid diphosphates as photoactivatable substrates for bacterial prenyltransferases
摘要:
Photoactivatable benzophenone-containing analogs of isoprenyl diphosphates have been synthesized and evaluated as substrates and inhibitors of three bacterial prenyltransferases: farnesyl diphosphate synthase (FPS), hexaprenyl diphosphate synthase (HexPS)and undecaprenyl diphosphate synthase (UPS). These analogs undergo chain extension and will allow identification of hydrophobic active site residues of these enzymes. (C) 1997 Elsevier Science Ltd.
A modular strategy for the assembly of farnesylated N-Ras heptapeptides carrying a photo-activatable benzophenone (BP) group within the lipid residue is described. This strategy is based on the fragment condensation of a N-terminal hexapeptide synthesized on the solid support with a cysteine methyl ester which is modified with different farnesyl analogues, incorporating the photophor. At the N-terminus of the peptides different functional groups can be attached, e.g., biotin for product enrichment and detection after photoactivation or a maleimido (MIC) linker, allowing for the coupling to proteins carrying a C-terminal free cysteine. Using this strategy, 24 peptides were synthesized, incorporating famesyl analogues with four different chain lengths. Two of these photoactivatable conjugates were ligated to oncogenic human N-RasG12VDelta181. A cellular transformation assay revealed that the semisynthetic proteins retain their biological activity despite the photolabel. The first photolabeling experiments with a geranyl-BP-labeled N-Ras construct and the farnesyl-sensitive guanine nucleotide exchange factor hSos1 indicate that this photoaffinity labeling system can be particularly useful for studying protein-protein interactions, e.g., the participation of the farnesyl group in Ras signaling, which is still discussed with controversy.
Benzoylphenoxy analogs of isoprenoid diphosphates as photoactivatable substrates for bacterial prenyltransferases
作者:Dale M. Marecak、Yutaka Horiuchi、Hiroyuki Arai、Masahiro Shimonaga、Yuji Maki、Tanetoshi Koyama、Kyozo Ogura、Glenn D. Prestwich
DOI:10.1016/s0960-894x(97)00342-9
日期:1997.8
Photoactivatable benzophenone-containing analogs of isoprenyl diphosphates have been synthesized and evaluated as substrates and inhibitors of three bacterial prenyltransferases: farnesyl diphosphate synthase (FPS), hexaprenyl diphosphate synthase (HexPS)and undecaprenyl diphosphate synthase (UPS). These analogs undergo chain extension and will allow identification of hydrophobic active site residues of these enzymes. (C) 1997 Elsevier Science Ltd.