A mutational study of transmembrane helix-helix interactions

Diverse methods have been developed and applied in the recent years to study interaction of transmembrane a-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. (C) 2007 Elsevier Masson SAS. All rights reserved.