Related Experiment Video
Updated: Aug 9, 2026

Transmembrane Domain Oligomerization Propensity determined by ToxR Assay
Published on: May 26, 2011
The stability of transmembrane helix interactions measured in a biological membrane
Carmen Finger1, Thomas Volkmer, Alexander Prodöhl
1Institut für Biochemie und Molekularbiologie, Albert-Ludwigs-Universität Freiburg, Stefan-Meier-Strasse 19, 79104 Freiburg, Germany.
Abstract:
Despite some promising progress in the understanding of membrane protein folding and assembly, there is little experimental information regarding the thermodynamic stability of transmembrane helix interactions and even less on the stability of transmembrane helix-helix interactions in a biological membrane. Here we describe an approach that allows quantitative measurement of transmembrane helix interactions in a biological membrane, and calculation of changes in the interaction free energy resulting from substitution of single amino acids. Dimerization of several variants of the glycophorin A transmembrane domain are characterized and compared to the wild-type (wt) glycophorin A transmembrane helix dimerization. The calculated DeltaDeltaG(app) values are further compared with values found in the literature. In addition, we compare interactions between the wt glycophorin A transmembrane domain and helices in which critical glycine residues are replaced by alanine or serine, respectively. The data demonstrate that replacement of the glycine residues by serine is less destabilizing than replacement by alanine with a DeltaDeltaG(app) value of about 0.4 kcal/mol. Our study comprises the first measurement of a transmembrane helix interaction in a biological membrane, and we are optimistic that it can be further developed and applied.
Related Concept Videos
Single-pass Transmembrane Proteins
Multi-pass Transmembrane Proteins and β-barrels
α-Helix containing multi-pass transmembrane proteins
Multi-pass transmembrane proteins such as G-protein-linked receptors (GPCRs) and...
Mechanisms of Membrane-bending
Membrane bending can happen due to intrinsic changes in lipid composition or extrinsic association with different proteins. The proteins involved...
Membrane Fluidity
Mosaic nature of the membrane
The mosaic characteristic of the membrane helps the plasma membrane remain fluid. The integral proteins and lipids exist as separate but loosely-attached molecules in the membrane. The membrane is a relatively...
Membrane Fluidity
Protein Diffusion in the Membrane

