A mutational study of transmembrane helix–helix interactions

Diverse methods have been developed and applied in the recent years to study interaction of transmembrane α-helices and often interaction of single transmembrane helices is followed on SDS-gels. Here we compare two measurements of the stability of a transmembrane helix–helix interaction, and the stability of the PsbF transmembrane helix dimer was determined in a biological membrane as well as in SDS. The observations described in this study demonstrate that the environment, in which a transmembrane helix interaction is studied, can be very critical and detergent properties can significantly influence transmembrane helix interactions, especially, when the transmembrane domain contains strongly polar residues.