An efficient method for detecting membrane protein oligomerization and complex using 05SAR‐PAGE

Abstract

Oligomerization is an important feature of proteins, which gives a defined quaternary structure to complete the biological functions. Although frequently observed in membrane proteins, characterizing the oligomerization state remains complicated and time‐consuming. In this study, 0.05% (w/v) sarkosyl‐polyacrylamide gel electrophoresis (05SAR‐PAGE) was used to identify the oligomer states of the membrane proteins CpxA, EnvZ, and Ma‐Mscl with high sensitivity. Furthermore, two‐dimensional electrophoresis (05SAR/sodium dodecyl sulfate–PAGE) combined with western blotting and liquid chromatography–tandem mass spectrometry was successfully applied to study the complex of CpxA/OmpA in cell lysate. The results indicated that 05SAR‐PAGE is an efficient, economical, and practical gel method that can be widely used for the identification of membrane protein oligomerization and the analysis of weak protein interactions.