An unfolding story of helical transmembrane proteins.
Reversible unfolding of helical transmembrane proteins could provide valuable information about the free energy of interaction between transmembrane helices. Thermal unfolding experiments suggest that this process for integral membrane proteins is irreversible. Chemical unfolding has been accomplished with organic acids, but the unfolding or refolding pathways involve irreversible steps. Sodium dodecyl sulfate (SDS) has been used as a perturbant to study reversible unfolding and refolding kinetics. However, the interpretation of these experiments is not straightforward. It is shown that the results could be explained by SDS binding without substantial unfolding. Furthermore, the SDS-perturbed state is unlikely to include all of the entropy terms involved in an unfolding process. Alternative directions for future research are suggested: fluorinated alcohols in homogeneous solvent systems, inverse micelles, and fragment association studies.
Renthal
Robert
R
Department of Biology, University of Texas, San Antonio, Texas 78249, USA. Robert.Renthal@UTSA.edu
D008565:Membrane Proteins / Q000737:chemistry* / Q000378:metabolism*; D008823:Micelles; D008958:Models, Molecular; D011487:Protein Conformation; D011489:Protein Denaturation; D017510:Protein Folding
D008565:Membrane Proteins; D008823:Micelles