title: Lanthanide-binding tags with unnatural amino acids: sensitizing Tb3+ and Eu3+ luminescence at longer wavelengths.
abstract: Lanthanide-binding tags (LBTs) are small, genetically encoded, versatile protein fusion partners that selectively bind lanthanide ions with high affinity. The LBT motif features a strategically positioned tryptophan residue that sensitizes Tb3+ luminescence upon excitation at 280 nm. Herein, we describe the preparation of new LBT peptides that incorporate unnatural amino acids in place of tryptophan, and which sensitize both Tb3+ and Eu3+ luminescence at lower energies. We also report the semisynthesis of proteins tagged with these new LBTs using native chemical ligation. This expands the scope of LBTs and will enable their wider use in luminescence applications.
authors.affiliation: Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139, USA.
authors.forename: Anne M
authors.initials: AM
authors.lastname: Reynolds
authors.forename: Bianca R
authors.initials: BR
authors.lastname: Sculimbrene
authors.forename: Barbara
authors.initials: B
authors.lastname: Imperiali
mesh_terms: D000596:Amino Acids / Q000737:chemistry* / Q000528:radiation effects; D004591:Electrophoresis, Polyacrylamide Gel; D005063:Europium / Q000737:chemistry* / Q000528:radiation effects; D007202:Indicators and Reagents; D028581:Lanthanoid Series Elements / Q000737:chemistry* / Q000528:radiation effects; D008027:Light; D049449:Luminescence; D050736:Oncogene Protein v-crk / Q000737:chemistry; D012394:Rosaniline Dyes; D013725:Terbium / Q000737:chemistry* / Q000528:radiation effects; D014364:Tryptophan / Q000737:chemistry / Q000528:radiation effects
chemical_list: D000596:Amino Acids; D007202:Indicators and Reagents; D028581:Lanthanoid Series Elements; D050736:Oncogene Protein v-crk; D012394:Rosaniline Dyes; D013725:Terbium; D005063:Europium; C048139:Coomassie blue; D014364:Tryptophan