Total Synthesis of Two Photoactivatable Analogues of the Growth-Factor-Like Mediator Sphingosine 1-Phosphate: Differential Interaction with Protein Targets
作者:Xuequan Lu、Sandor Cseh、Hoe-Sup Byun、Gabor Tigyi、Robert Bittman
DOI:10.1021/jo034828q
日期:2003.9.1
The first synthesis of two photoreactive analogues of the lipid mediator and second messenger sphingosine 1-phosphate (S1P), [P-32]-labeled (2S,3R)-14-O-(4'-benzoylphenyl)- and (2S,3R)-14-O-((4'-trifluoromethyldiazirinyl)phenyl)-(4E)-tetradecenyl-2-amino-3-hydroxy-1-phosphate, is described. The interactions of these probes with the SIP type-1 receptor (S1P(1)) transfected into membranes of rat hepatoma cells and with plasma proteins were analyzed. The S1P(1) receptor interacted in a specific manner with the benzophenone-containing ligand (K-D = 84 +/- 10 nM vs K-D for S1P = 36 +/- 2 nM); in contrast, no saturable specific binding was found with the diazirine-containing ligand. However, the same pattern was found for labeling of plasma proteins by both probes, indicating that different parts of the SIP pharmacophore underlie the interaction of S1P with its receptor and plasma carrier proteins.