Induced europium CPL for the selective signalling of phosphorylated amino-acids and O-phosphorylated hexapeptides.
Two bright, europium(iii) complexes based on an achiral heptadentate triazacyclononane ligand bearing two strongly absorbing chromophores have been evaluated for the selective emission and CPL signalling of various chiral O-phosphono-anions. Binding of O-phosphono-Ser and Thr gives rise to a strong induced CPL signature and a favoured Δ complex configuration is adopted. A similarly large induced CPL signal arises when [Eu·](2+) binds to lysophosphatidic acid (LPA), where the strong binding (log K 5.25 (295 K)) in methanol allowed its detection over the range 5 to 40 μM. Strong and chemoselective binding to the phosphorylated amino-acid residues was also observed with a set of four structurally related hexapeptides: in one case, the sign of the gem value in the ΔJ = 1 transition allowed differentiation between the binding to O-P-Ser and O-P-Tyr residues.
Department of Chemistry, Durham University, South Road, Durham, DH1 3LE, UK. david.parker@dur.ac.uk.
Emily R
ER
Neil
Department of Chemistry, Durham University, South Road, Durham, DH1 3LE, UK. david.parker@dur.ac.uk.
Mark A
MA
Fox
Department of Chemistry, Durham University, South Road, Durham, DH1 3LE, UK. david.parker@dur.ac.uk.
Robert
R
Pal
Department of Chemistry, Durham University, South Road, Durham, DH1 3LE, UK. david.parker@dur.ac.uk.
David
D
Parker
D000596:Amino Acids / Q000737:chemistry*; D056831:Coordination Complexes / Q000138:chemical synthesis / Q000737:chemistry* / Q000378:metabolism; D005063:Europium / Q000737:chemistry*; D008024:Ligands; D008246:Lysophospholipids / Q000737:chemistry; D008968:Molecular Conformation; D009842:Oligopeptides / Q000737:chemistry* / Q000378:metabolism; D010766:Phosphorylation; D011485:Protein Binding; D013237:Stereoisomerism; D013816:Thermodynamics
D000596:Amino Acids; D056831:Coordination Complexes; D008024:Ligands; D008246:Lysophospholipids; D009842:Oligopeptides; D005063:Europium; C032881:lysophosphatidic acid