Protein flexibility as revealed by fluorescence resonance energy transfer:an extension of the method for systems with multiple labels

The temperature profile of the normalized fluorescence resonance energy tra nsfer efficiency is capable of monitoring the relative change of flexibilit y and/or conformational state of macromolecules [Biochemistry 23 (1984) 340 3]. The method described earlier for one donor-one acceptor systems is exte nded to multiple fluorophore systems when the energy transfer occurs betwee n either one donor-m accepters, or n donors-one acceptor or rt donors-m acc epters (where n and m are integer values). It is shown that the normalized energy transfer efficiency obtained for systems containing multiple labels is a linear combination of the normalized transfer efficiency assigned to i ndividual donor-acceptor pairs of the system, thus its temperature profile is capable of monitoring the change of intramolecular flexibility and/or co nformational state. (C) 2000 Elsevier Science B.V. All rights reserved.