RESUMO
Two novel FRET-pairs: Tb3+ -binding peptide-DsRed2 and Tb3+ -binding peptide-TagRFP have been produced based on the terbium-binding peptide and the red fluorescent proteins DsRed2 and TagRFP. Two induction-resonance energy transfer processes in both FRET-pairs have been registered, from tryptophan of the terbium-binding peptide to Tb3+ and from sensitized Tb3+ to the acceptor, the chromophore, DsRed2 or TagRFP. The lifetimes of terbium in the presence and absence of the acceptor have been determined. It has been shown that the lifetime of Tb3+ in the presence of 150 mM NaCl decreases in both FRET-pairs. The efficiency of fluorescent resonance transfer from Tb3+ to the acceptor proteins is 28 and 35% for Tb3+ -binding peptide-DsRed2 and Tb3+ -binding peptide-TagRFP, respectively.
