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Updated: Jun 1, 2026

Luminescence Resonance Energy Transfer to Study Conformational Changes in Membrane Proteins Expressed in Mammalian Cells
Published on: September 16, 2014
Luminescent trimethoprim-polyaminocarboxylate lanthanide complex conjugates for selective protein labeling and
D Rajasekhar Reddy1, Laura E Pedró Rosa, Lawrence W Miller
1University of Illinois at Chicago, Department of Chemistry, 845 W. Taylor Street, MC 111, Chicago, Illinois 60607, United States.
Abstract:
Labeling proteins with long-lifetime emitting lanthanide (III) chelate reporters enables sensitive, time-resolved luminescence bioaffinity assays. Heterodimers of trimethoprim (TMP) covalently linked to various cs124-sensitized, polyaminocarboxylate chelates stably retain lanthanide ions and exhibit quantum yields of europium emission up to 20% in water. A time-resolved, luminescence resonance energy transfer (LRET) assay showed that TMP-polyaminocarboxylates bind to Escherichia coli dihydrofolate reductase (eDHFR) fusion proteins with nanomolar affinity in purified solutions and in bacterial lysates. The ability to selectively impart terbium or europium luminescence to fusion proteins in complex physiological mixtures bypasses the need for specific antibodies and simplifies sample preparation.

