Bacterial protein complexes investigation using blue native PAGE

Abstract

Investigation of protein-protein interactions has arisen as a comprehensive approach for understanding bacterial physiology as well as pathogenesis. From this point of view, bacterial membrane as a place of contact with outer milieu seems to be crucial compartment and therefore, investigation of lipophilic proteins and their interactions is inevitable. Unfortunately, several methods developed for the analysis of protein interaction suffer from their labour intensiveness and underrepresent integral membrane proteins. Therefore, blue native polyacrylamide gel electrophoresis (BN-PAGE) with its simplicity and suitability for lipophilic entities has been widely employed in microbiological research. For investigation of membrane proteins interactions BN-PAGE became a method of choice. The efficacy in this area was proven by the elucidation not only of the stoichiometry, but also dynamic changes of several complexes involved in energetic metabolism, secretion and transport systems, localized both in inner as well as in outer membrane. Moreover, BN-PAGE was also successfully applied on peripheral membrane and cytoplasmic proteins and enabled complex analysis of interactomes of several microorganisms. This review shows BN-PAGE as a potent tool in microbiological fundamental research ranging from Archaea, through Gram-positive and Gram-negative bacteria to Chlamydia.