Bioluminescence Resonance Energy Transfer (BRET) Allows Monitoring the Barnase-Barstar Complex In Vivo

Abstract

Bioluminescence resonance energy transfer (BRET) seems to be a promising biophysical technique to study protein–protein interactions within living cells due to a very specific reaction of bioluminescence that essentially decreases the background of other cellular components and light-induced destruction of biomacromolecules. An important direction of the development of this technique is the study of known strong protein–protein complexes in vivo and the estimation of an average distance between chromophores of the donor and acceptor. Here, we demonstrate an in vivo interaction between barnase fused with luciferase (from Renilla reniformis, RLuc) and barstar fused with EGFP (enhanced green fluorescent protein of Aequorea victoria) monitored by BRET. The distance between the luciferase and EGFP chromophores within the complex has been evaluated as equal to (56 ± 2) Å.