title: Total synthesis of two photoactivatable analogues of the growth-factor-like mediator sphingosine 1-phosphate: differential interaction with protein targets.
abstract: The first synthesis of two photoreactive analogues of the lipid mediator and second messenger sphingosine 1-phosphate (S1P), [(32)P]-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 S1P 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 S1P pharmacophore underlie the interaction of S1P with its receptor and plasma carrier proteins.
authors.affiliation: Department of Chemistry and Biochemistry, Queens College of The City University of New York, Flushing, New York 11367-1597, USA.
authors.forename: Xuequan
authors.initials: X
authors.lastname: Lu
authors.forename: Sandor
authors.initials: S
authors.lastname: Cseh
authors.forename: Hoe-Sup
authors.initials: HS
authors.lastname: Byun
authors.forename: Gabor
authors.initials: G
authors.lastname: Tigyi
authors.forename: Robert
authors.initials: R
authors.lastname: Bittman
mesh_terms: D000818:Animals; D045744:Cell Line, Tumor; D007202:Indicators and Reagents; D008114:Liver Neoplasms, Experimental; D008246:Lysophospholipids; D019920:Photoaffinity Labels; D010777:Photochemistry; D011506:Proteins / Q000187:drug effects; D011869:Radioligand Assay; D051381:Rats; D017207:Rats, Sprague-Dawley; D043562:Receptors, G-Protein-Coupled / Q000187:drug effects; D013110:Sphingosine / Q000031:analogs & derivatives* / Q000138:chemical synthesis* / Q000494:pharmacology*
chemical_list: D007202:Indicators and Reagents; D008246:Lysophospholipids; D019920:Photoaffinity Labels; D011506:Proteins; D043562:Receptors, G-Protein-Coupled; C060506:sphingosine 1-phosphate; D013110:Sphingosine