Effects of trifluoperazine on the conformation and dynamics of membrane proteins in human erythrocytes.

The chemical modifications induced by trifluoperazine (TFP) in erythrocyte ghosts have been investigated by fluorescence quenching. The apparent distance separating the membrane protein tryptophans and bound 1-aniline-8-naphthalene sulfonate (ANS) molecules decreased after treating erythrocyte membranes with TFP. This effect was accompanied by a significant decrease in the maximum efficiency of energy transfer. We conclude that TFP-induced alterations in the structure of membrane proteins lead to a rearrangement of the surrounding lipids, and consequently to local conformational changes in membrane organization.