Cooperative long range protein-protein dynamics in Purple Membrane

Abstract

We present experimental evidence for a cooperative long range protein-protein interaction in the purple membrane (PM). Dynamics has been quantified by determining the spectrum of the acoustic phonons in the 2d Bacteriorhodopsin (BR) protein lattice. Data were compared to an analytical model. The effective spring constant for the collective interaction between protein trimers was determined to be k=53.49 N/m. The finding might be relevant for protein function in PM.